Study Library

Animal · 2026

Effects of BPC-157 and TB-500 on Achilles tendon healing in rats: A histopathological and biomechanical study

Biçer O et al. · Joint Diseases and Related Surgery

TB-500 significantly improved load to failure and histology scores; BPC-157 showed only non-significant numerical improvement; the combination added nothing over monotherapy.

RCT · 2026 · n=61

Effects of pentosan polysulfate sodium on synovial fluid biomarkers in moderate to severe knee osteoarthritis: an exploratory, phase 2, randomized, double-blind, placebo-controlled trial

Skerrett DL et al. · Arthritis Research & Therapy

Synovial-fluid cartilage-degradation marker ARGS-aggrecan fell ~57% vs placebo (p=0.028) with favorable shifts in other cartilage biomarkers; a biomarker trial, not a symptom-efficacy trial.

Animal · 2026

Effects of pentosan polysulfate sodium on joint structure and function out to six months in naturally-occurring canine osteoarthritis

Stapledon CJM et al. · PLoS One

Sustained owner-scored pain reduction, gait-symmetry normalization, and increased total cartilage volume on imaging at 26 weeks in the PPS group.

RCT · 2026 · n=251

Five-Year Follow-up of a Multicenter Randomized Controlled Trial Comparing an Aragonite-Based Scaffold With Microfracture and Debridement for Chondral and Osteochondral Knee Lesions

Altschuler N et al. · The American Journal of Sports Medicine

At 60 months the implant group maintained superiority: KOOS 81.0 vs 59.1 (22.6-point difference), responder rate 74.7% vs 29.6%, treatment failure 15.0% vs 35.7% (P < .001). Note implant failures roughly doubled between years 2 and 5 (7.2% to 15.0%).

Systematic review · 2025 · n=1652

A Greater Platelet Dose May Yield Better Clinical Outcomes for Platelet-Rich Plasma in the Treatment of Knee Osteoarthritis: A Systematic Review

Berrigan WA et al. · Arthroscopy

PRP arms with positive trials averaged ~5.5 billion platelets vs ~2.3 billion in non-positive trials (P<.01); the same pattern held at 12 months. Study-level (ecological) association, not a randomized dose comparison.

Meta-analysis · 2025 · n=1616

Efficacy of intra-articular platelet-rich plasma compared with placebo in knee osteoarthritis: A systematic review and meta-analysis

Auroux M et al. · Joint Bone Spine

Small pain benefit over placebo at 3 months (VAS MD -1.1) and 6 months (MD -2.0) that disappears by 12 months; WOMAC favored PRP only at 3 months. Authors call the clinical relevance debatable.

RCT · 2025 · n=75

Microfragmented Adipose Tissue Injection Reduced Pain Compared With a Saline Control Among Patients With Symptomatic Osteoarthritis of the Knee During 1-Year Follow-Up: A Randomized Controlled Trial

Richter DL et al. · Arthroscopy

MFAT showed statistically significant improvements over saline across primary pain/function outcomes at 1 year; corticosteroid benefit was significant only at 2-6 weeks.

Meta-analysis · 2025

Microfragmented Adipose Tissue as an Alternative to Platelet-Rich Plasma for Intra-articular Injection in Knee Osteoarthritis: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Park YB et al. · The American Journal of Sports Medicine

MFAT and PRP produced comparable pain and function improvements through 12-24 months, both typically reaching MCID; MFAT held a small statistical edge at 6 months only.

Cohort · 2025

Limited effects of non-steroidal anti-inflammatory drugs (NSAIDs) on imaging outcomes in osteoarthritis: observational data from the osteoarthritis initiative (OAI)

Kreutzinger V et al. · BMC Musculoskeletal Disorders

NSAID use showed limited association with MRI structural progression overall; cartilage-lesion progression was, if anything, slightly slower in some NSAID-user subgroups.

Case series · 2025 · n=2

Safety of Intravenous Infusion of BPC157 in Humans: A Pilot Study

Lee E et al. · Alternative Therapies in Health and Medicine

No biomarker changes or adverse effects in two people over two days — the entire published human safety dataset for systemic BPC-157.

Registry · 2025

A Study to Investigate the Treatment Effect of Subcutaneous Injections of Pentosan Polysulfate Sodium Compared With Placebo in Adult Participants With Knee Osteoarthritis Pain (PARA_OA_012)

Paradigm Biopharmaceuticals · ClinicalTrials.gov registration

The pivotal phase 3 readout to watch: interim DSMB review targeted late 2026, primary top-line results expected first quarter of 2027.

Animal · 2025

Betaine enhances SCAPs chondrogenic differentiation and promotes cartilage repair in TMJOA through WDR81

Wang M et al. · Stem Cell Research & Therapy

Betaine enhanced chondrogenic differentiation (via WDR81, lower ROS, improved mitochondrial membrane potential) and betaine-treated stem cells improved cartilage repair in the rat TMJ-OA model.

Animal · 2025

Altered nicotinamide adenine dinucleotide metabolism drives cartilage degeneration and osteoarthritis

Wu X et al. · Clinical and Translational Medicine

NAD+ was depleted in OA cartilage; restoring it with NAD+ precursors (including NMN) or NMNAT1 overexpression suppressed cartilage disruption and matrix-degrading changes in rodent OA models.

RCT · 2025 · n=40

Additional Benefits of Creatine Supplementation with Physical Therapy and Resistance Exercise in Knee Osteoarthritis: A Randomized Controlled Trial

Osama M et al. · Journal of Clinical Medicine

Creatine added to physical therapy improved pain (VAS, P=0.001), KOOS scores, isometric strength and fall-risk measures more than physical therapy alone over 4 weeks.

Case series · 2025 · n=48

Intermediate-Term Clinical Outcomes of High-Density Autologous Chondrocyte Implantation in Patients with Concomitant Anterior Cruciate Ligament Reconstruction and Focal Chondral Lesions

Guillén-Vicente I et al. · Cartilage

At 24 months both groups improved substantially (VAS about 8 to about 2; IKDC about 37 to about 75) with 71-90% returning to pre-injury activity; concurrent ACL reconstruction did not worsen results.

Meta-analysis · 2025 · n=5162

Conversion to Total Knee Arthroplasty After High Tibial Osteotomy: A Systematic Review and Meta-analysis

Loke RWK et al. · Orthopaedic Journal of Sports Medicine

Conversion to total knee replacement: 4.5% before 5 years, 8.3% at 5-10 years, 11.2% beyond 10 years; overall complications 12.1%. Adding cartilage repair procedures showed no significant survival benefit in pooled data.

RCT · 2024 · n=262

Krill Oil for Knee Osteoarthritis: A Randomized Clinical Trial

Laslett LL et al. · JAMA

Krill oil did not improve knee pain versus placebo (VAS change -19.9 vs -20.2; difference -0.3, 95% CI -6.9 to 6.4). A well-designed, adequately powered null in the population most expected to benefit (inflammatory phenotype).

Meta-analysis · 2024

The Effect of Platelet Dose on Outcomes after Platelet Rich Plasma Injections for Musculoskeletal Conditions: A Systematic Review and Meta-Analysis

Berrigan W et al. · Current Reviews in Musculoskeletal Medicine

In knee OA, doses above roughly 10 billion platelets were associated with more favorable outcomes, more pronounced for function than pain. Supports a dose-response hypothesis but not derived from randomized dose-ranging trials.

Cohort · 2024 · n=4197

Association of long-term use of non-steroidal anti-inflammatory drugs with knee osteoarthritis: a prospective multi-cohort study over 4-to-5 years

Salis Z et al. · Scientific Reports

Long-term NSAID users had higher odds of pain worsening (OR 2.04), disability (OR 2.21), and total knee replacement (OR 3.13), but no statistically significant difference in radiographic structural deterioration (OR 1.25, 95% CI 0.94–1.65).

Systematic review · 2024 · n=495

Autologous Osteochondral Transfer of the Knee Demonstrates Continued High Rates of Return to Sport and Low Rates of Conversion to Arthroplasty at Long-Term Follow-Up: A Systematic Review

Oeding JF et al. · Arthroscopy

Return-to-sport rates of 86-100% and conversion to arthroplasty of 0-16% at mean 15 years, with sustained IKDC/Lysholm improvement.

RCT · 2023 · n=45

Collagen Protein Ingestion during Recovery from Exercise Does Not Increase Muscle Connective Protein Synthesis Rates

Aussieker T et al. · Medicine and Science in Sports and Exercise

Neither collagen nor whey significantly increased muscle connective-tissue protein synthesis over 5 h (collagen 0.068 vs placebo 0.058 %/h, p = .09). A direct null against the idea that ingested collagen acutely drives connective-tissue synthesis, at least in muscle.

RCT · 2023 · n=480

Cell-based versus corticosteroid injections for knee pain in osteoarthritis: a randomized phase 3 trial

Mautner K et al. · Nature Medicine

At 12 months, none of the three cell-based injections was superior to a corticosteroid injection (or to each other) for pain or function. No serious adverse events.

Cohort · 2023 · n=38

The effect of pentosan polysulfate sodium for improving dyslipidaemia and knee pain in people with knee osteoarthritis: A pilot study

Liu X et al. · Osteoarthritis and Cartilage Open

Knee pain NRS fell from 6.4 to ~4.2–4.4 and LDL modestly decreased, but with no placebo arm the pain result is uninterpretable given OA's large placebo response.

Review · 2023

Chondrocytes secretory phenotype associated with aging: role in the pathogenesis of osteoarthritis and prospects for peptide bioregulation

Myakisheva SN et al. · Advances in Gerontology (Uspekhi Gerontologii)

Asserts efficacy of Sigumir and the AED tripeptide (Cartalax) in OA animal models and elderly patients, but cites institute-affiliated primary sources rather than independent trials.

Meta-analysis · 2023 · n=3077

Relationship between 25-hydroxy vitamin D and knee osteoarthritis: a systematic review and meta-analysis of randomized controlled trials

Wang R et al. · Frontiers in Medicine

Pooled improvements in WOMAC pain and function and reduced synovial-fluid/effusion measures, with authors reporting greater benefit above 2000 IU/day; structural (cartilage-volume) findings remain driven by secondary endpoints of individually null trials.

Cohort · 2023

Associations of Homocysteine, Folate, and Vitamin B12 with Osteoarthritis: A Mendelian Randomization Study

Hong H et al. · Nutrients

Genetically higher homocysteine modestly increased overall OA risk (OR ~1.10, 95% CI 1.044-1.155) and folate appeared protective (OR 95% CI 0.783-0.961) — indirect support for the methylation pathway betaine acts on, not evidence for betaine itself.

RCT · 2023 · n=80

The efficacy and safety of β-nicotinamide mononucleotide (NMN) supplementation in healthy middle-aged adults: a randomized, multicenter, double-blind, placebo-controlled, parallel-group, dose-dependent clinical trial

Yi L et al. · GeroScience

Blood NAD+ rose dose-dependently in all NMN arms (P<=0.001), six-minute walking distance improved modestly vs placebo, and no safety concerns emerged up to 900 mg/day; no joint outcomes were assessed.

RCT · 2023 · n=251

Aragonite-Based Scaffold Versus Microfracture and Debridement for the Treatment of Knee Chondral and Osteochondral Lesions: Results of a Multicenter Randomized Controlled Trial

Altschuler N et al. · The American Journal of Sports Medicine

At 24 months the implant group had roughly twice the mean KOOS improvement, a 77.8% responder rate vs 33.6% for control, 88.5% vs 30.9% defect fill on MRI, and 7.2% vs 21.4% failure. Basis of the 2022 FDA approval.

Meta-analysis · 2022 · n=46819

Knee extensor muscle weakness is a risk factor for the development of knee osteoarthritis: an updated systematic review and meta-analysis including 46 819 men and women

Øiestad BE et al. · British Journal of Sports Medicine

Knee extensor weakness increased the odds of developing knee OA (pooled OR ~1.7 in women and ~1.4-1.9 overall depending on outcome definition). Weak quads precede OA, supporting strengthening as prevention-plausible.

Cohort · 2022 · n=1212

Association Between Walking for Exercise and Symptomatic and Structural Progression in Individuals With Knee Osteoarthritis: Data From the Osteoarthritis Initiative Cohort

Lo GH et al. · Arthritis & Rheumatology

Walkers had LESS new frequent knee pain (OR 0.6, 95% CI 0.4-0.8) and less medial joint-space-narrowing progression (OR 0.8, 95% CI 0.6-1.0) over 4 years. Walking looked protective, not destructive, in established knee OA.

RCT · 2022 · n=50

Collagen and Vitamin C Supplementation Increases Lower Limb Rate of Force Development

Lis DM et al. · International Journal of Sport Nutrition and Exercise Metabolism

The collagen+C group recovered rate of force development to baseline while placebo remained depressed (p = .036), with better countermovement-jump measures (p = .008-.04). A neuromuscular/tendon-stiffness outcome, not cartilage.

Review · 2022

The impact of collagen protein ingestion on musculoskeletal connective tissue remodeling: a narrative review

Holwerda AM et al. · Nutrition Reviews

Concludes collagen's glycine/proline content plausibly supplies precursors for connective-tissue synthesis, but that direct evidence collagen ingestion increases connective-tissue protein synthesis in humans remains unclear and largely biomarker-based.

RCT · 2022 · n=90

Bone Marrow Aspirate Concentrate Is Equivalent to Platelet-Rich Plasma for the Treatment of Knee Osteoarthritis at 2 Years: A Prospective Randomized Trial

Anz AW et al. · The American Journal of Sports Medicine

Both groups improved significantly and remained improved at 24 months with no difference between BMAC and PRP at any time point — BMAC's extra cost and morbidity bought nothing over PRP.

Systematic review · 2022 · n=299

Bone Marrow Aspirate Concentrate for the Treatment of Knee Osteoarthritis: A Systematic Review

Keeling LE et al. · The American Journal of Sports Medicine

94% of reported outcome measures improved from baseline, but BMAC demonstrated no clinical superiority over PRP, microfragmented adipose tissue, or placebo in any comparative study.

RCT · 2022 · n=118

Microfragmented Adipose Tissue Versus Platelet-Rich Plasma for the Treatment of Knee Osteoarthritis: A Prospective Randomized Controlled Trial at 2-Year Follow-up

Zaffagnini S et al. · The American Journal of Sports Medicine

Both arms improved significantly and durably to 24 months with no between-group differences; imaging showed no structural change after either injection.

Meta-analysis · 2022 · n=21163

Viscosupplementation for knee osteoarthritis: systematic review and meta-analysis

Pereira TV et al. · BMJ

Pain reduction vs placebo of SMD -0.08 (~2 mm on a 100 mm VAS) — far below the minimal clinically important difference — with a 49% higher risk of serious adverse events (RR 1.49). Since 2009 there has been strong evidence of no clinically relevant benefit.

Review · 2022

AAOS Clinical Practice Guideline Summary: Management of Osteoarthritis of the Knee (Nonarthroplasty), Third Edition

Brophy RH et al. · The Journal of the American Academy of Orthopaedic Surgeons

AAOS third edition: hyaluronic acid injection is NOT recommended for routine use (moderate-strength recommendation); PRP receives only a limited recommendation citing inconsistent evidence; corticosteroids get a moderate recommendation for short-term relief.

Meta-analysis · 2022 · n=978

Effectiveness, Compliance, and Safety of Dextrose Prolotherapy for Knee Osteoarthritis: A Meta-Analysis and Metaregression of Randomized Controlled Trials

Chen YW et al. · Clinical Rehabilitation

Favorable effects on pain, global function, and quality of life vs placebo, with signals of dose-dependent pain reduction; comparable to other invasive therapies. Trial pool remains small and heterogeneous.

Case series · 2022 · n=125

10-Year Survival Rates After High Tibial Osteotomy Using Angular Stable Internal Plate Fixation: Case Series With Subgroup Analysis of Outcomes After Combined Autologous Chondrocyte Implantation and High Tibial Osteotomy

Bode L et al. · Orthopaedic Journal of Sports Medicine

10-year survival 87.2% overall and 94.3% in the HTO+ACI subgroup; pain fell and Lysholm rose. BMI of 35 or higher and female sex predicted conversion to arthroplasty.

Systematic review · 2021 · n=37

Management of patellar tendinopathy: a systematic review and network meta-analysis of randomised studies

Challoumas D et al. · BMJ Open Sport & Exercise Medicine

Progressive loading (eccentric-based) with or without adjuncts should remain first-line; isometrics did not emerge as a superior standalone therapy. Positions isometrics as adjunct pain-modulation, not the core program.

Meta-analysis · 2021 · n=724

Stationary cycling exercise for knee osteoarthritis: A systematic review and meta-analysis

Luan L et al. · Clinical Rehabilitation

Cycling reduced pain (WMD 12.86/100, 95% CI 6.90-18.81) and improved sport ability, but gains in stiffness, daily function and quality of life did not clear minimal clinically important differences. Honest read: helps pain, modest elsewhere.

Animal · 2021

Analysis of the Anti-Inflammatory Capacity of Bone Broth in a Murine Model of Ulcerative Colitis

Mar-Solís LM et al. · Medicina (Kaunas)

Bone broth reduced colonic pro-inflammatory cytokine expression (IL-6 down ~95%, IL-1beta down ~61%, TNF-alpha down ~69%) and raised anti-inflammatory IL-10 and IL-4. A gut-inflammation model — not a joint or cartilage outcome.

RCT · 2021 · n=288

Effect of Intra-articular Platelet-Rich Plasma vs Placebo Injection on Pain and Medial Tibial Cartilage Volume in Patients With Knee Osteoarthritis: The RESTORE Randomized Clinical Trial

Bennell KL et al. · JAMA

Null on both co-primary endpoints at 12 months: pain change -2.1 vs -1.8 (P=.17) and medial tibial cartilage volume change -1.4% vs -1.2% (P=.81); 29 of 31 secondary outcomes also showed no between-group difference.

Meta-analysis · 2021 · n=1608

Platelet-Rich Plasma Versus Hyaluronic Acid for Knee Osteoarthritis: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Belk JW et al. · The American Journal of Sports Medicine

PRP produced greater WOMAC improvement than HA (44.7% vs 12.6%, P<.01); 6 of 11 VAS studies favored PRP. Leukocyte-poor PRP was associated with better IKDC scores than leukocyte-rich.

RCT · 2021 · n=150

Platelet-rich plasma (PRP) in osteoarthritis (OA) knee: Correct dose critical for long term clinical efficacy

Bansal H et al. · Scientific Reports

WOMAC, IKDC and 6-minute walk improvements persisted in the PRP group at 12 months while the HA group's gains faded; authors argue ~10 billion platelets is the threshold for sustained effect.

RCT · 2021 · n=175

Bone Marrow Aspirate Concentrate versus Platelet Rich Plasma or Hyaluronic Acid for the Treatment of Knee Osteoarthritis

Dulic O et al. · Medicina (Kaunas)

All groups improved at 12 months; BMAC trended better than PRP and HA but differences vs PRP were not statistically significant.

Case series · 2021 · n=16

Intra-Articular Injection of BPC 157 for Multiple Types of Knee Pain

Lee E et al. · Alternative Therapies in Health and Medicine

Authors report subjective improvement in 11/12 patients given BPC 157 alone; no controls, no blinding, no validated outcome instruments.

Registry · 2021 · n=602

Treatment Effects of Subcutaneous Injections of Pentosan Polysulfate Sodium vs Placebo in Participants With Knee OA Pain (PARA_OA_002)

Paradigm Biopharmaceuticals · ClinicalTrials.gov registration

Phase 2/3 adaptive trial (primary endpoint WOMAC pain at day 56); listed active-not-recruiting with no peer-reviewed symptom results published as of August 2026.

Animal · 2021

Betaine Attenuates Osteoarthritis by Inhibiting Osteoclastogenesis and Angiogenesis in Subchondral Bone

Yajun W et al. · Frontiers in Pharmacology

Betaine reduced cartilage proteoglycan loss, lowered OARSI histology scores, decreased MMP-13/collagen-X-positive cells and normalised subchondral bone remodelling and aberrant angiogenesis, apparently via ROS/MAPK-dependent inhibition of osteoclastogenesis.

RCT · 2021 · n=25

Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women

Yoshino M et al. · Science

NMN increased skeletal-muscle insulin sensitivity and insulin signalling; no joint or cartilage outcomes were measured — cited here as the benchmark human-efficacy NMN trial, not as joint evidence.

Case series · 2021 · n=87

Long-term Prospective Clinical and Magnetic Resonance Imaging-Based Evaluation of Matrix-Induced Autologous Chondrocyte Implantation

Ebert JR et al. · The American Journal of Sports Medicine

Patient-reported outcomes remained significantly improved at 10-16 years; 9.1% of grafts failed; 88.5% of patients satisfied. MRI tissue infill showed a nonsignificant decline from 2 years to final review.

RCT · 2021 · n=35

An accelerated 6-week return to full weight bearing after matrix-induced autologous chondrocyte implantation results in good clinical outcomes to 5 years post-surgery

Ebert JR et al. · Knee Surgery, Sports Traumatology, Arthroscopy

No differences between rehab arms to a minimum 5 years; both improved significantly with 8.1% graft failure overall — faster loading did not harm the graft.

Case series · 2021 · n=24

High-Density Autologous Chondrocyte Implantation as Treatment for Ankle Osteochondral Defects

López-Alcorocho JM et al. · Cartilage

At 24 months median VAS pain fell from 8 to 2 and AOFAS score rose from 39.5 to 90; biopsy showed hyaline-like matrix. Uncontrolled, so placebo/rehab effects cannot be excluded.

Cohort · 2021 · n=86

Aragonite-Based Scaffold for the Treatment of Joint Surface Lesions in Mild to Moderate Osteoarthritic Knees: Results of a 2-Year Multicenter Prospective Study

Kon E et al. · The American Journal of Sports Medicine

All KOOS subscales improved significantly at 24 months (pain 49.6 to 79.5); MRI showed 78.7% defect surface coverage; 9.3% treatment failure needing revision — the study extending the indication toward OA knees.

Systematic review · 2020 · n=10

Effectiveness of isometric exercise in the management of tendinopathy: a systematic review and meta-analysis of randomised trials

Clifford C et al. · BMJ Open Sport & Exercise Medicine

Isometric exercise was NOT superior to isotonic exercise for tendinopathy overall; analgesic response varies within and across populations. Cools the early hype: isometrics are an option, not a proven superior therapy.

In vitro · 2020

Valorization of Chicken Feet By-Product of the Poultry Industry: High Qualities of Gelatin and Biofilm from Extraction of Collagen

Santana JCC et al. · Polymers

Chicken feet yielded >8% collagen; the extracted gelatin was ~71% collagen versus ~30% in a commercial gelatin, confirming chicken feet are genuinely collagen-dense raw material.

In vitro · 2020

Extraction and characterization of gelatin from black-bone chicken by-products

Saenmuang S et al. · Food Science and Biotechnology

Chicken-foot gelatin had higher extraction yield than skin gelatin and higher gel strength — but lower hydroxyproline content — than commercial bovine gelatin. Composition data only.

RCT · 2020 · n=76

Efficacy of Intra-Articular Hypertonic Dextrose (Prolotherapy) for Knee Osteoarthritis: A Randomized Controlled Trial

Sit RWS et al. · Annals of Family Medicine

WOMAC pain improved by an additional -10.34 points (95% CI -19.20 to -1.49, P=.022) vs saline at 52 weeks, with favorable effects on function and quality of life. No adverse events reported.

In vitro · 2020

Gene expression in human mesenchymal stem cell aging cultures: modulation by short peptides

Ashapkin V et al. · Molecular Biology Reports

AED increased IGF1 expression several-fold and shifted aging-related gene expression in MSCs — gene-expression changes only, no functional cartilage endpoint.

Review · 2020

Acute:Chronic Workload Ratio: Conceptual Issues and Fundamental Pitfalls

Impellizzeri FM et al. · International Journal of Sports Physiology and Performance

Concludes there is no solid evidence supporting ACWR thresholds in training-load management or for injury-risk reduction; the metric has statistical and conceptual flaws.

Meta-analysis · 2020 · n=545

Effectiveness of Boswellia and Boswellia extract for osteoarthritis patients: a systematic review and meta-analysis

Yu G et al. · BMC Complementary Medicine and Therapies

Pooled analysis found boswellia significantly reduced pain and stiffness and improved function versus control (e.g., VAS pain WMD about -8 on a 100 scale), with authors recommending at least 4 weeks of use.

RCT · 2020 · n=70

Effectiveness of Curcuma longa Extract for the Treatment of Symptoms and Effusion-Synovitis of Knee Osteoarthritis: A Randomized Trial

Wang Z et al. · Annals of Internal Medicine

Curcumin modestly reduced knee pain versus placebo (VAS difference -9.1 mm on a 100 mm scale, 95% CI -17.5 to -0.7) but had no effect on MRI-measured effusion-synovitis volume or cartilage composition.

Review · 2020

The Relationship between Vitamin K and Osteoarthritis: A Review of Current Evidence

Chin KY · Nutrients

Concludes sufficient vitamin K status is consistently associated with lower risk of OA and pathological joint features via activation of calcification inhibitors (MGP), but that interventional trial evidence remains limited and largely null on primary endpoints.

RCT · 2020 · n=1398

The Effects of Vitamin D and Marine Omega-3 Fatty Acid Supplementation on Chronic Knee Pain in Older US Adults: Results From a Randomized Trial

MacFarlane LA et al. · Arthritis & Rheumatology

NULL: WOMAC knee pain did not differ between vitamin D and placebo at any point over ~5 years (treatment-by-time P=0.41); omega-3 was also null.

RCT · 2019 · n=20

Oral Supplementation of Specific Collagen Peptides Combined with Calf-Strengthening Exercises Enhances Function and Reduces Pain in Achilles Tendinopathy Patients

Praet SFE et al. · Nutrients

VISA-A improved by 12.6 points with collagen vs 5.3 with placebo over the first 3 months.

Systematic review · 2019 · n=9

Impact of exercise on articular cartilage in people at risk of, or with established, knee osteoarthritis: a systematic review of randomised controlled trials

Bricca A et al. · British Journal of Sports Medicine

No evidence that exercise harms articular cartilage; most comparisons showed no effect on cartilage morphology, and one trial showed improved GAG content in at-risk participants. Authors conclude knee-loading exercise 'seems to not be harmful for articular cartilage'.

Systematic review · 2019 · n=12

Impact of Exercise Therapy on Molecular Biomarkers Related to Cartilage and Inflammation in Individuals at Risk of, or With Established, Knee Osteoarthritis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Bricca A et al. · Arthritis Care & Research

Exercise decreased cartilage-degradation/inflammation biomarkers in 30% of comparisons, had no effect in 63%, and increased them in 7%. Reassuring molecular signal that sensible exercise does not drive cartilage breakdown.

RCT · 2019 · n=28

Comparing the Effectiveness of Blood Flow Restriction and Traditional Heavy Load Resistance Training in the Post-Surgery Rehabilitation of Anterior Cruciate Ligament Reconstruction Patients: A UK National Health Service Randomised Controlled Trial

Hughes L et al. · Sports Medicine

Both groups roughly doubled injured-limb strength (~104-106% gains) with similar hypertrophy; BFR produced greater improvements in function, range of motion (78% vs 48%) and larger reductions in knee pain and effusion. Low joint load did not mean inferior recovery.

In vitro · 2019

Bone Broth Unlikely to Provide Reliable Concentrations of Collagen Precursors Compared With Supplemental Sources of Collagen Used in Collagen Research

Alcock RD et al. · International Journal of Sport Nutrition and Exercise Metabolism

Bone broth contained significantly lower and highly variable concentrations of the key collagen-precursor amino acids compared with a 20 g collagen supplement dose (p = .003-.004); the authors conclude broth cannot reliably deliver the doses used in collagen research.

RCT · 2019 · n=10

Effects of Different Vitamin C-Enriched Collagen Derivatives on Collagen Synthesis

Lis DM et al. · International Journal of Sport Nutrition and Exercise Metabolism

Serum PINP (collagen-synthesis marker) tended to rise ~20% after gelatin and hydrolyzed collagen but not after placebo or the gummy; large inter-individual variability kept the result short of statistical significance.

Case series · 2019

Plasma Amino Acid Concentrations After the Ingestion of Dairy and Collagen Proteins, in Healthy Active Males

Alcock RD et al. · Frontiers in Nutrition

Collagen proteins produced far higher plasma glycine peaks than dairy (683 vs 260 umol/L, p < .0001); dairy gave higher leucine. Bone broth was the weakest tested source. Shows bioavailability of collagen amino acids, not any joint benefit.

Cohort · 2019 · n=4330

Mediterranean diet and knee osteoarthritis outcomes: A longitudinal cohort study

Veronese N et al. · Clinical Nutrition

Highest versus lowest Mediterranean-diet adherence was associated with a 9% lower risk of incident symptomatic knee OA (RR 0.91, 95% CI 0.82-0.998) and marginally less pain worsening (RR 0.96) over 4 years — statistically fragile margins in both cases.

RCT · 2019 · n=192

Platelet-Rich Plasma Versus Hyaluronic Acid Injections for the Treatment of Knee Osteoarthritis: Results at 5 Years of a Double-Blind, Randomized Controlled Trial

Di Martino A et al. · The American Journal of Sports Medicine

No significant intergroup difference in any clinical score at any follow-up through ~5 years; median duration of benefit ~12 months in both. Reintervention rate at 24 months was lower with PRP (22.6% vs 37.1%, P=.036).

RCT · 2019 · n=16

Intra-articular injection of autologous adipose-derived stromal vascular fractions for knee osteoarthritis: a double-blind randomized self-controlled trial

Hong Z et al. · International Orthopaedics

SVF knees improved significantly on VAS, WOMAC and ROM at 12 months while HA knees did not; MRI (WORMS/MOCART) suggested cartilage improvement in SVF knees.

RCT · 2019 · n=24

Intra-Articular Injection of Autologous Adipose Tissue-Derived Mesenchymal Stem Cells for the Treatment of Knee Osteoarthritis: A Phase IIb, Randomized, Placebo-Controlled Clinical Trial

Lee WS et al. · Stem Cells Translational Medicine

AD-MSC group improved significantly on WOMAC at 6 months while placebo did not; MRI showed no cartilage-defect worsening in the MSC group vs progression in controls.

RCT · 2019 · n=30

Adipose-derived mesenchymal stem cell therapy in the treatment of knee osteoarthritis: a randomized controlled trial

Freitag J et al. · Regenerative Medicine

Both cell groups reported clinically significant pain and functional improvement at 12 months; MRI suggested modification of disease progression in the two-injection group.

RCT · 2019 · n=26

Umbilical Cord-Derived Mesenchymal Stromal Cells (MSCs) for Knee Osteoarthritis: Repeated MSC Dosing Is Superior to a Single MSC Dose and to Hyaluronic Acid in a Controlled Randomized Phase I/II Trial

Matas J et al. · Stem Cells Translational Medicine

Repeated UC-MSC dosing produced significantly lower WOMAC pain at 12 months than HA (1.1 vs 4.3, P=.04); single dosing was intermediate. No serious adverse events.

Case series · 2019 · n=12

Bone Marrow Mesenchymal Stromal Cell Treatment in Patients with Osteoarthritis Results in Overall Improvement in Pain and Symptoms and Reduces Synovial Inflammation

Chahal J et al. · Stem Cells Translational Medicine

Safe at all doses; KOOS pain and quality of life improved at 12 months with the 50-million dose performing best, alongside dose-dependent reductions in synovitis and cartilage catabolic biomarkers.

Cohort · 2019 · n=684

Intra-articular corticosteroids and the risk of knee osteoarthritis progression: results from the Osteoarthritis Initiative

Zeng C et al. · Osteoarthritis and Cartilage

Corticosteroid initiation was associated with a 3-fold hazard of radiographic KL-grade worsening (HR 3.02) and continuous use with 4.7-fold (HR 4.67); joint-space-narrowing hazards were similarly elevated.

Review · 2019

Intra-articular Corticosteroid Injections in the Hip and Knee: Perhaps Not as Safe as We Thought?

Kompel AJ et al. · Radiology

Describes four structural adverse outcomes — accelerated OA progression, subchondral insufficiency fracture, osteonecrosis, and rapid joint destruction with bone loss — observed in roughly 8% of injected patients in the authors' single-center experience.

Review · 2019

Gastric pentadecapeptide body protection compound BPC 157 and its role in accelerating musculoskeletal soft tissue healing

Gwyer D et al. · Cell and Tissue Research

All reviewed preclinical studies reported positive healing effects; authors note the complete absence of human trials and call for clinical research that has still not materialized.

Meta-analysis · 2019

Fluoroquinolones and the risk of tendon injury: a systematic review and meta-analysis

Alves C et al. · European Journal of Clinical Pharmacology

Pooled odds: any tendon disorder OR 1.98 (95% CI 1.62–2.43), Achilles tendinitis OR 3.95 (3.11–5.01), Achilles rupture OR 2.52 (1.81–3.52) — a consistent class-wide tendon-harm signal.

Review · 2019

OARSI guidelines for the non-surgical management of knee, hip, and polyarticular osteoarthritis

Bannuru RR et al. · Osteoarthritis and Cartilage

The OARSI expert panel did not recommend glucosamine or chondroitin for disease modification and gave them negative recommendations for symptom management in knee OA, citing low-quality and conflicting evidence.

RCT · 2019 · n=150

Bio-optimized Curcuma longa extract is efficient on knee osteoarthritis pain: a double-blind multicenter randomized placebo controlled three-arm study

Henrotin Y et al. · Arthritis Research & Therapy

Both curcumin doses improved patient global assessment of disease activity versus placebo and reduced knee pain VAS faster than placebo; the serum cartilage-degradation biomarker Coll2-1 trended down without a clear dose-response.

RCT · 2019 · n=139

Safety and efficacy of curcumin versus diclofenac in knee osteoarthritis: a randomized open-label parallel-arm study

Shep D et al. · Trials

Pain severity improved similarly in both arms at day 28, with curcumin causing fewer adverse events (13% vs 38%) and no need for H2-blocker rescue.

RCT · 2018 · n=48

Benefits of Resistance Training with Blood Flow Restriction in Knee Osteoarthritis

Ferraz RB et al. · Medicine and Science in Sports and Exercise

BFR matched heavy training: 26-33% leg-press strength gains and 7-8% quadriceps hypertrophy in both (p<0.0001), beating plain low-load; WOMAC pain improved 39-45%. Notably, 4 participants dropped from the heavy-load arm due to exercise-induced knee pain, versus none from BFR.

Animal · 2018

Dose-Related Antihypertensive Properties and the Corresponding Mechanisms of a Chicken Foot Hydrolysate in Hypertensive Rats

Mas-Capdevila A et al. · Nutrients

The hydrolysate lowered systolic blood pressure at 55 and 85 mg/kg via ACE inhibition. Included only to show the kind of evidence that exists for chicken-feet peptides — blood pressure in rats, not cartilage in anyone.

In vitro · 2018

High glycine concentration increases collagen synthesis by articular chondrocytes in vitro: acute glycine deficiency could be an important cause of osteoarthritis

de Paz-Lugo P et al. · Amino Acids

Glycine at or above 1.0 mM increased chondrocyte collagen synthesis by roughly 60-75%, more than proline or lysine enrichment, supporting the glycine-limitation hypothesis at the cell level.

Cohort · 2018 · n=783

The association between the Mediterranean diet and magnetic resonance parameters for knee osteoarthritis: data from the Osteoarthritis Initiative

Veronese N et al. · Clinical Rheumatology

Each SD higher Mediterranean-diet adherence was associated with slightly greater medial femoral cartilage volume (beta = 0.12) and thickness (beta = 0.13) on MRI — the only cartilage-specific human data for this diet, and it is associational.

RCT · 2018 · n=30

Intra-articular injection of two different doses of autologous bone marrow mesenchymal stem cells versus hyaluronic acid in the treatment of knee osteoarthritis: long-term follow up of a multicenter randomized controlled clinical trial (phase I/II)

Lamo-Espinosa JM et al. · Journal of Translational Medicine

At 4 years both cell-dose groups maintained pain and WOMAC improvements vs control (median VAS 2-3 vs 7; P=.043 and .004) — one of the few durability signals for a cell injection.

RCT · 2018 · n=128

Matrix-Applied Characterized Autologous Cultured Chondrocytes Versus Microfracture: Five-Year Follow-up of a Prospective Randomized Trial

Brittberg M et al. · The American Journal of Sports Medicine

The clinically and statistically significant advantage of MACI over microfracture in KOOS pain and function was maintained at 5 years.

Case series · 2018 · n=6

Pigmentary Maculopathy Associated with Chronic Exposure to Pentosan Polysulfate Sodium

Pearce WA et al. · Ophthalmology

Described a novel pigmentary maculopathy in chronic oral PPS users — the safety signal that led to US label warnings for long-term Elmiron use.

RCT · 2018 · n=60

Beneficial effects of natural eggshell membrane versus placebo in exercise-induced joint pain, stiffness, and cartilage turnover in healthy, postmenopausal women

Ruff KJ et al. · Clinical Interventions in Aging

NEM reduced exercise-induced stiffness versus placebo and lowered the urinary cartilage-degradation biomarker CTX-II both at rest and after exercise; effects on exercise-induced pain were smaller and inconsistent across days.

Case series · 2018 · n=50

Cartilage Defect Treatment Using High-Density Autologous Chondrocyte Implantation: Two-Year Follow-up

López-Alcorocho JM et al. · Cartilage

At 24 months, IKDC improved by a mean 31 points with significant reductions in pain and swelling; no comparator arm, so no evidence of superiority over standard MACI.

Systematic review · 2018 · n=1036

Clinical Outcomes and Failure Rates of Osteochondral Allograft Transplantation in the Knee: A Systematic Review

Familiari F et al. · The American Journal of Sports Medicine

Weighted survivorship 78.7% at 10 years, 72.8% at 15, 67.5% at 20; reoperation 30.2%, failure 18.2%. Revisions, patellar, and bipolar lesions did worse.

RCT · 2017 · n=139

Improvement of activity-related knee joint discomfort following supplementation of specific collagen peptides

Zdzieblik D et al. · Applied Physiology, Nutrition, and Metabolism

Activity-related knee pain decreased significantly more with collagen peptides than placebo; pain at rest did not differ.

RCT · 2017 · n=8

Vitamin C-enriched gelatin supplementation before intermittent activity augments collagen synthesis

Shaw G et al. · The American Journal of Clinical Nutrition

15 g gelatin before exercise doubled serum PINP (a collagen-synthesis marker) and improved engineered-ligament mechanics ex vivo.

Meta-analysis · 2017 · n=29

Impact of a daily exercise dose on knee joint cartilage - a systematic review and meta-analysis of randomized controlled trials in healthy animals

Bricca A et al. · Osteoarthritis and Cartilage

Dose-response is an inverted U: moderate doses had positive effects on cartilage in 12/12 comparisons, while low dose (21/25) and high dose (19/27) comparisons showed no effect or worse cartilage. Supports a 'sweet spot' of loading.

Meta-analysis · 2017 · n=4699

The role of muscle strengthening in exercise therapy for knee osteoarthritis: A systematic review and meta-regression analysis of randomized trials

Bartholdy C et al. · Seminars in Arthritis and Rheumatism

ACSM-compliant strength training produced greater knee-extensor strength gains (SMD 0.448, 95% CI 0.091-0.805); analysis suggests a 30-40% strength increase may be needed for clinically meaningful pain/disability improvement. Strengthening per se was not required for symptom relief.

RCT · 2017 · n=20

Isometric Contractions Are More Analgesic Than Isotonic Contractions for Patellar Tendon Pain: An In-Season Randomized Clinical Trial

Rio E et al. · Clinical Journal of Sport Medicine

Both groups improved, but isometrics produced significantly greater immediate analgesia over 4 weeks (p<0.002); week-1 pain response predicted 4-week VISA-P improvement (r=0.64). Supports isometrics as an in-season pain-modulation tool.

Systematic review · 2017 · n=20

Blood flow restriction training in clinical musculoskeletal rehabilitation: a systematic review and meta-analysis

Hughes L et al. · British Journal of Sports Medicine

Low-load BFR was more effective for strength than low-load alone (moderate effect) and less painful/better tolerated than heavy-load training, though heavy load remained somewhat stronger for maximal strength. Supports BFR when joints can't tolerate heavy load.

Meta-analysis · 2017 · n=114829

Running and Knee Osteoarthritis: A Systematic Review and Meta-analysis

Timmins KA et al. · The American Journal of Sports Medicine

No overall increase in knee OA among runners; runners had LOWER odds of knee surgery for OA (OR 0.46, 95% CI 0.30-0.71). Elite/competitive exposure showed higher prevalence (13.3% vs 10.2%), suggesting dose matters at the extreme.

In vitro · 2017

Essential and toxic metals in animal bone broths

Hsu DJ et al. · Food & Nutrition Research

Calcium and magnesium content was under 5% of daily recommended levels per serving even after long acidified cooking; lead and cadmium were a few micrograms per serving, judged a minimal ingestion risk. Contradicts the Monro lead alarm and the 'mineral-rich' marketing claim simultaneously.

Meta-analysis · 2017

Marine Oil Supplements for Arthritis Pain: A Systematic Review and Meta-Analysis of Randomized Trials

Senftleber NK et al. · Nutrients

Small overall pain reduction (SMD -0.24, 95% CI -0.42 to -0.07) driven by rheumatoid arthritis trials; in the 5 osteoarthritis trials the effect was not significant (SMD -0.17, 95% CI -0.57 to 0.24). Evidence quality rated low.

RCT · 2017 · n=99

Effect of a Mediterranean Type Diet on Inflammatory and Cartilage Degradation Biomarkers in Patients with Osteoarthritis

Dyer J et al. · The Journal of Nutrition, Health & Aging

The diet group had a ~47% fall in IL-1alpha (p = .010) and an 8% fall in serum COMP, a cartilage-degradation marker (p = .014), plus improved knee flexion; pain scores did not clearly differ. Biomarker, not clinical, endpoints.

Cohort · 2017 · n=640

Is Weight Loss Associated with Less Progression of Changes in Knee Articular Cartilage among Obese and Overweight Patients as Assessed with MR Imaging over 48 Months? Data from the Osteoarthritis Initiative

Gersing AS et al. · Radiology

Cartilage degeneration (WORMS) progressed less with weight loss and in dose-response fashion: score change 1.0 with >10% loss and 1.6 with 5-10% loss versus 2.3 with stable weight (p <= .002).

RCT · 2017 · n=162

Multiple PRP injections are more effective than single injections and hyaluronic acid in knees with early osteoarthritis: a randomized, double-blind, placebo-controlled trial

Görmeli G et al. · Knee Surgery, Sports Traumatology, Arthroscopy

All active groups beat saline on IKDC/EQ-VAS at 6 months; three PRP injections outperformed single PRP and HA in early OA. No between-treatment differences in advanced OA.

RCT · 2017 · n=25

A Prospective, Single-Blind, Placebo-Controlled Trial of Bone Marrow Aspirate Concentrate for Knee Osteoarthritis

Shapiro SA et al. · The American Journal of Sports Medicine

Pain decreased markedly in BOTH knees at 1 week, 3 and 6 months with no significant difference between BMAC and saline knees (P>.09) — consistent with a large placebo/natural-history effect, not a BMAC-specific one.

RCT · 2017 · n=140

Effect of Intra-articular Triamcinolone vs Saline on Knee Cartilage Volume and Pain in Patients With Knee Osteoarthritis: A Randomized Clinical Trial

McAlindon TE et al. · JAMA

Repeated triamcinolone caused significantly GREATER cartilage volume loss than saline (-0.21 vs -0.10 mm index-compartment thickness) with NO difference in knee pain over 2 years. The authors conclude the findings do not support this treatment.

Case report · 2017 · n=1

Improved clinical outcome measures of knee pain and function with concurrent resolution of subchondral Bone Marrow Edema Lesion and joint effusion in an osteoarthritic patient following Pentosan Polysulphate Sodium treatment

Sampson MJ et al. · BMC Musculoskeletal Disorders

MRI resolution of bone marrow edema with pain falling from 8/10 to 0 — hypothesis-generating only.

Meta-analysis · 2017 · n=125810

The Association of Recreational and Competitive Running With Hip and Knee Osteoarthritis: A Systematic Review and Meta-analysis

Alentorn-Geli E et al. · Journal of Orthopaedic and Sports Physical Therapy

Hip/knee OA prevalence: 3.5% in recreational runners vs 10.2% in sedentary controls vs 13.3% in competitive runners — a U-shaped dose-response where moderate load looks protective and extreme load harmful.

Meta-analysis · 2017 · n=1625

Subgroup analyses of the effectiveness of oral glucosamine for knee and hip osteoarthritis: a systematic review and individual patient data meta-analysis from the OA trial bank

Runhaar J et al. · Annals of the Rheumatic Diseases

No clinically relevant effect of glucosamine on pain or function versus placebo overall, and no subgroup (by pain severity, BMI, inflammation, radiographic grade) could be identified that did benefit.

RCT · 2017 · n=164

Combined Treatment With Chondroitin Sulfate and Glucosamine Sulfate Shows No Superiority Over Placebo for Reduction of Joint Pain and Functional Impairment in Patients With Knee Osteoarthritis: A Six-Month Multicenter, Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Roman-Blas JA et al. · Arthritis & Rheumatology

The combination was not superior to placebo; placebo patients actually reported a larger mean reduction in global pain VAS (about -20 mm vs -12 mm), and the trial was stopped for futility.

Review · 2017

Methylsulfonylmethane: Applications and Safety of a Novel Dietary Supplement

Butawan M et al. · Nutrients

Summarizes evidence that MSM dampens NF-kB signalling and oxidative stress in preclinical models and is well tolerated in humans (GRAS status; trials up to ~6 g/day report adverse events comparable to placebo).

Cohort · 2017 · n=340

Maintaining Vitamin D Sufficiency Is Associated with Improved Structural and Symptomatic Outcomes in Knee Osteoarthritis

Zheng S et al. · The American Journal of Medicine

Participants who stayed vitamin-D sufficient lost less tibial cartilage (~2.1% less loss), had less increase in effusion-synovitis volume (-2.5 mL difference) and better preserved physical function than the consistently insufficient group.

Meta-analysis · 2017 · n=1136

The effect of vitamin D supplementation on knee osteoarthritis: A meta-analysis of randomized controlled trials

Gao XR et al. · International Journal of Surgery

Small improvements in WOMAC pain and function, larger with >2000 IU/day, but NO effect on tibial cartilage volume loss — symptomatic signal without structural protection.

Meta-analysis · 2017 · n=721

Effect of creatine supplementation during resistance training on lean tissue mass and muscular strength in older adults: a meta-analysis

Chilibeck PD et al. · Open Access Journal of Sports Medicine

Creatine added ~1.37 kg lean tissue mass (95% CI 0.97-1.76) and modestly greater upper- and lower-body strength (leg-press SMD 0.24, P=0.01) vs training alone — the indirect 'stronger muscle protects the joint' foundation.

Review · 2017

International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine

Kreider RB et al. · Journal of the International Society of Sports Nutrition

Position stand concluding creatine monohydrate at recommended doses is safe long-term in healthy populations (including older adults) and effective for strength and lean mass; kidney-damage claims in healthy users are not supported by controlled data.

Case series · 2017 · n=31

A Prospective Clinical and Radiological Evaluation at 5 Years After Arthroscopic Matrix-Induced Autologous Chondrocyte Implantation

Ebert JR et al. · The American Journal of Sports Medicine

At 5 years all KOOS subscales improved significantly; 93% satisfied with pain relief, 90% good-to-excellent MRI tissue infill, 2 graft failures.

Systematic review · 2017 · n=578

Matrix-Assisted Autologous Chondrocyte Transplantation in the Knee: A Systematic Review of Mid- to Long-Term Clinical Outcomes

Schuette HB et al. · Orthopaedic Journal of Sports Medicine

At 5+ years outcomes remained improved; overall treatment failure 9.7% (12.4% tibiofemoral, 4.7% patellofemoral).

RCT · 2016 · n=48

Improved Function and Reduced Pain after Swimming and Cycling Training in Patients with Osteoarthritis

Alkatan M et al. · The Journal of Rheumatology

Both swimming and cycling significantly reduced joint pain, stiffness and physical limitation, with 15-30% gains in knee-extensor strength; no difference between modes. Either low-impact mode works; pick the one you'll keep doing.

Systematic review · 2016 · n=13

Aquatic exercise for the treatment of knee and hip osteoarthritis

Bartels EM et al. · Cochrane Database of Systematic Reviews

Moderate-quality evidence of small short-term benefits: pain SMD -0.31 (~5 points/100) and disability SMD -0.32 immediately post-treatment. Real but modest — value is enabling movement when land exercise hurts.

Systematic review · 2016 · n=1117

Return to Sport After Articular Cartilage Repair in Athletes' Knees: A Systematic Review

Campbell AB et al. · Arthroscopy

Return-to-sport rates: osteochondral autograft 89%, allograft 88%, ACI 84%, microfracture 75% (autograft and ACI significantly better than microfracture). Return timelines commonly 9-18 months depending on procedure; criteria-based progression recommended.

RCT · 2016 · n=202

Fish oil in knee osteoarthritis: a randomised clinical trial of low dose versus high dose

Hill CL et al. · Annals of the Rheumatic Diseases

High-dose fish oil was no better than low dose; the low-dose group actually had greater WOMAC pain and function improvement at 2 years, and MRI cartilage volume loss did not differ. No placebo arm, so neither dose is shown effective.

Cohort · 2016 · n=4470

Adherence to the Mediterranean diet is associated with better quality of life: data from the Osteoarthritis Initiative

Veronese N et al. · The American Journal of Clinical Nutrition

Higher Mediterranean-diet adherence was associated with modestly better physical quality of life and lower WOMAC pain and disability scores; effect sizes were small (e.g., beta = 0.10 for SF-12 physical score).

Cohort · 2016 · n=1383

Is There a Dose-Response Relationship Between Weight Loss and Symptom Improvement in Persons With Knee Osteoarthritis?

Atukorala I et al. · Arthritis Care & Research

Clear dose-response: every KOOS symptom subscale improved more with each additional weight-loss category; ~7.7% body-weight loss was needed for a minimal clinically important improvement in function.

Meta-analysis · 2016 · n=1055

Effect of Leukocyte Concentration on the Efficacy of Platelet-Rich Plasma in the Treatment of Knee Osteoarthritis

Riboh JC et al. · The American Journal of Sports Medicine

LP-PRP improved WOMAC vs HA (MD -21.14) and vs placebo (MD -17.84); LR-PRP showed no significant difference vs either. No head-to-head LP vs LR trials — the leukocyte claim rests on indirect comparison.

RCT · 2016 · n=30

Intra-articular injection of two different doses of autologous bone marrow mesenchymal stem cells versus hyaluronic acid in the treatment of knee osteoarthritis: multicenter randomized controlled clinical trial (phase I/II)

Lamo-Espinosa JM et al. · Journal of Translational Medicine

High-dose (100M) group had the clearest gains: WOMAC improved ~16.5 points (P<.01) at 12 months and joint-space narrowing progressed in controls but not the high-dose group. Safe and feasible.

Review · 2016

Product Differences in Intra-articular Hyaluronic Acids for Osteoarthritis of the Knee

Altman RD et al. · The American Journal of Sports Medicine

Argues higher-molecular-weight and cross-linked HA products show larger treatment effects than low-MW products — the main citation behind molecular-weight marketing claims.

In vitro · 2016

Peptide Regulation of Skin Fibroblast Functions during Their Aging In Vitro

Lin'kova NS et al. · Bulletin of Experimental Biology and Medicine

AED reduced MMP-9 synthesis, increased proliferation markers, and suppressed apoptosis in aging fibroblasts — skin cells, not chondrocytes.

Review · 2016

The training-injury prevention paradox: should athletes be training smarter and harder?

Gabbett TJ · British Journal of Sports Medicine

Injury risk rises when acute workload spikes well above the chronic workload an athlete is prepared for, while athletes accustomed to high chronic loads have fewer injuries — 'train harder AND smarter'.

Meta-analysis · 2016 · n=50000

Sleep Disturbance, Sleep Duration, and Inflammation: A Systematic Review and Meta-Analysis of Cohort Studies and Experimental Sleep Deprivation

Irwin MR et al. · Biological Psychiatry

Sleep disturbance was associated with higher CRP (ES 0.12) and IL-6 (ES 0.20); long sleep also associated with inflammation; effects are real but small — a systemic-inflammation pathway, not joint-specific evidence.

RCT · 2016 · n=606

Combined chondroitin sulfate and glucosamine for painful knee osteoarthritis: a multicentre, randomised, double-blind, non-inferiority trial versus celecoxib

Hochberg MC et al. · Annals of the Rheumatic Diseases

The combination was non-inferior to celecoxib: both arms cut WOMAC pain by roughly 50% at 6 months with comparable function gains.

Meta-analysis · 2016 · n=606

Efficacy of Turmeric Extracts and Curcumin for Alleviating the Symptoms of Joint Arthritis: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Daily JW et al. · Journal of Medicinal Food

About 1000 mg/day of curcumin reduced arthritis pain and improved function versus placebo, with effects comparable to NSAIDs in head-to-head trials; the authors nonetheless judged the trial base too small and short to be definitive.

RCT · 2016 · n=191

Efficacy and tolerability of an undenatured type II collagen supplement in modulating knee osteoarthritis symptoms: a multicenter randomized, double-blind, placebo-controlled study

Lugo JP et al. · Nutrition Journal

UC-II reduced total WOMAC significantly more than both placebo and glucosamine+chondroitin at day 180 (WOMAC change about -33% vs -14% placebo), with benefits across pain, stiffness, and function subscales; G+C did not separate from placebo.

Review · 2016

Oral hyaluronan relieves knee pain: a review

Oe M et al. · Nutrition Journal

All 13 reviewed trials reported symptom relief; proposed mechanisms include receptor-mediated (TLR4/CD44) intestinal signalling and increased endogenous HA synthesis, since intact high-molecular-weight HA is barely absorbed.

RCT · 2016 · n=413

Effect of Vitamin D Supplementation on Tibial Cartilage Volume and Knee Pain Among Patients With Symptomatic Knee Osteoarthritis: A Randomized Clinical Trial

Jin X et al. · JAMA

NULL on both primary endpoints: no significant difference in annual tibial cartilage volume loss or WOMAC pain change over 2 years, despite correcting deficiency.

RCT · 2016 · n=474

The effect of vitamin D supplementation on knee osteoarthritis, the VIDEO study: a randomised controlled trial

Arden NK et al. · Osteoarthritis and Cartilage

NULL: no difference in the rate of medial joint space narrowing over 3 years (-0.01 vs -0.08 mm/year; difference 0.08 mm/year, 95% CI -0.14 to 0.29, P=0.49); no meaningful symptom benefit.

RCT · 2016 · n=40

Can Creatine Supplementation Improve Body Composition and Objective Physical Function in Rheumatoid Arthritis Patients? A Randomized Controlled Trial

Wilkinson TJ et al. · Arthritis Care & Research

MIXED: creatine increased appendicular lean mass (+0.52 kg, P=0.004 vs placebo) but did NOT improve strength or objective physical function — muscle mass gain does not automatically translate to function.

Systematic review · 2016 · n=1726

Knee donor-site morbidity after mosaicplasty - a systematic review

Andrade R et al. · Journal of Experimental Orthopaedics

Pooled donor-site morbidity was 5.9% when treating knee defects and 19.6% for ankle defects; commonest problems were patellofemoral symptoms and crepitus. Morbidity did not correlate with defect size.

Systematic review · 2016 · n=610

Long-term Outcomes After Osteochondral Autograft Transfer: A Systematic Review at Mean Follow-up of 10.2 Years

Pareek A et al. · Arthroscopy

Large long-term score gains (IKDC +42.4, Lysholm +21.1) but a 28% failure rate and 19% reoperation rate at 10 years; older age, prior surgery, and larger defects predicted failure.

RCT · 2016 · n=80

A Randomized Multicenter Trial Comparing Autologous Chondrocyte Implantation with Microfracture: Long-Term Follow-up at 14 to 15 Years

Knutsen G et al. · The Journal of Bone and Joint Surgery. American Volume

No difference at 14-15 years: 17 ACI failures vs 13 microfracture; roughly half of survivors in both arms had radiographic early osteoarthritis. A major null result against first-generation ACI's superiority.

Systematic review · 2016 · n=1189

Return to Work and Sport Following High Tibial Osteotomy: A Systematic Review

Ekhtiari S et al. · The Journal of Bone and Joint Surgery. American Volume

87.2% returned to sport (78.6% at equal or higher level) and about 90% of returns happened within 1 year; complications 5.8%; 7.0% converted to arthroplasty at mean 6.7 years.

Systematic review · 2015 · n=54

Exercise for osteoarthritis of the knee

Fransen M et al. · Cochrane Database of Systematic Reviews

High-quality evidence that exercise reduces pain (SMD ~-0.49, roughly 12 points on 0-100) and moderate-quality evidence it improves physical function immediately after treatment, with benefits sustained 2-6 months. Effect size comparable to NSAIDs.

RCT · 2015 · n=6

Isometric exercise induces analgesia and reduces inhibition in patellar tendinopathy

Rio E et al. · British Journal of Sports Medicine

Isometrics reduced decline-squat pain from 7.0/10 to 0.17/10, sustained 45 minutes, and increased quadriceps force output 18.7%; isotonic loading reduced pain only from 6.3 to 3.8. Striking immediate analgesia, in a very small crossover.

RCT · 2015 · n=40

Efficacy of blood flow-restricted, low-load resistance training in women with risk factors for symptomatic knee osteoarthritis

Segal NA et al. · PM&R

BFR nearly doubled strength gains vs low-load alone (1RM +28.3 vs +15.6 kg, p=0.039; isokinetic extensor strength p=0.005) without provoking knee pain. Strength stimulus without heavy joint load in an at-risk population.

RCT · 2015 · n=192

Platelet-Rich Plasma Intra-articular Knee Injections Show No Superiority Versus Viscosupplementation: A Randomized Controlled Trial

Filardo G et al. · The American Journal of Sports Medicine

Both groups improved at 12 months with no significant between-group difference in IKDC or any secondary score; more transient post-injection pain/swelling with LR-PRP.

RCT · 2015 · n=30

Treatment of Knee Osteoarthritis With Allogeneic Bone Marrow Mesenchymal Stem Cells: A Randomized Controlled Trial

Vega A et al. · Transplantation

MSC group improved significantly on algofunctional indices vs HA at 1 year, and T2 MRI mapping showed decreased poor-cartilage area — a quantitative cartilage-quality signal.

Meta-analysis · 2015 · n=33243

Comparative effectiveness of pharmacologic interventions for knee osteoarthritis: a systematic review and network meta-analysis

Bannuru RR et al. · Annals of Internal Medicine

IA hyaluronic acid ranked highest for pain (ES 0.63 vs oral placebo), but IA placebo itself outperformed oral placebo — much of every injection's apparent benefit is the needle, not the contents.

Meta-analysis · 2015 · n=1767

Intra-articular corticosteroid for knee osteoarthritis

Jüni P et al. · The Cochrane Database of Systematic Reviews

Pain benefit of SMD -0.40 (~1 cm on 10-cm VAS, NNT 8): moderate at 1-2 weeks, small by 4-6 weeks, and no detectable effect at 26 weeks. No quality-of-life improvement.

Animal · 2015

Tripeptide-copper complex GHK-Cu (II) transiently improved healing outcome in a rat model of ACL reconstruction

Fu SC et al. · Journal of Orthopaedic Research

Reduced knee laxity at 6 weeks (p=0.009) but the benefit disappeared by 12 weeks — a transient effect only, and the closest GHK-Cu has come to joint evidence.

Review · 2015

GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration

Pickart L et al. · BioMed Research International

Summarizes wound-healing and cosmetic-dermatology evidence and broad gene-modulation claims; contains no joint, tendon, or cartilage clinical data.

Review · 2015

Advances in the basic and clinical applications of thymosin β4

Goldstein AL et al. · Expert Opinion on Biological Therapy

Human trials of pharmaceutical Tβ4 (RegeneRx) target eyes, skin wounds, and heart — none target tendon, ligament, or cartilage; musculoskeletal use remains hypothetical.

Cohort · 2015 · n=1846

Effects of prescription nonsteroidal antiinflammatory drugs on symptoms and disease progression among patients with knee osteoarthritis

Lapane KL et al. · Arthritis & Rheumatology

Sustained prescription NSAID use showed small, non-significant trends toward better pain/function and 0.28 mm less joint-space narrowing — no evidence of accelerated radiographic progression in this OAI analysis.

Cohort · 2015 · n=208

Sleep, Pain Catastrophizing, and Central Sensitization in Knee Osteoarthritis Patients With and Without Insomnia

Campbell CM et al. · Arthritis Care & Research

Knee-OA patients with insomnia and low sleep efficiency showed the greatest central sensitization (amplified pain processing), especially with high catastrophizing — sleep quality shapes how loudly an arthritic joint hurts.

Cohort · 2015 · n=791

The association between vitamin K status and knee osteoarthritis features in older adults: the Health, Aging and Body Composition Study

Shea MK et al. · Osteoarthritis and Cartilage

Very low plasma vitamin K (<0.2 nM) was associated with greater progression of MRI cartilage damage (OR 1.7) and meniscus damage (OR 2.6) over 3 years vs sufficient levels.

Meta-analysis · 2014 · n=48

Impact of exercise type and dose on pain and disability in knee osteoarthritis: a systematic review and meta-regression analysis of randomized controlled trials

Juhl C et al. · Arthritis & Rheumatology

Aerobic, resistance and performance exercise gave similar pain relief; programs focusing on a single exercise type, supervised, at 3+ sessions/week were more effective than mixed low-dose programs. Quadriceps-specific programs were among the most effective.

RCT · 2014 · n=42

Effect of isometric quadriceps exercise on muscle strength, pain, and function in patients with knee osteoarthritis: a randomized controlled study

Anwer S et al. · Journal of Physical Therapy Science

Isometric training significantly improved quadriceps strength, pain (VAS), and WOMAC function versus control (p<0.05) after 5 weeks. Isometrics are a viable low-tech entry point when joint-angle-specific loading is needed.

Cohort · 2014 · n=1788

Daily walking and the risk of incident functional limitation in knee osteoarthritis: an observational study

White DK et al. · Arthritis Care & Research

Each extra 1,000 steps/day was associated with 16-18% lower risk of developing functional limitation two years later; walking ≥6,000 steps/day best discriminated those who stayed functional. More walking predicted better, not worse, outcomes.

RCT · 2014 · n=144

Matrix-Applied Characterized Autologous Cultured Chondrocytes Versus Microfracture: Two-Year Follow-up of a Prospective Randomized Trial

Saris D et al. · The American Journal of Sports Medicine

MACI produced significantly greater improvement in KOOS pain and function than microfracture at 2 years.

Registry · 2014

Survey of the therapeutic approach and efficacy of pentosan polysulfate for the prevention and treatment of equine osteoarthritis in veterinary practice in Australia

Kramer CM et al. · Australian Veterinary Journal

PPS is entrenched in equine OA practice; about half of vets rated its prophylactic efficacy highly — perception data, not outcome data.

RCT · 2014 · n=367

Efficacy and safety of Curcuma domestica extracts compared with ibuprofen in patients with knee osteoarthritis: a multicenter study

Kuptniratsaikul V et al. · Clinical Interventions in Aging

Turmeric extract was non-inferior to ibuprofen on WOMAC pain and function at 4 weeks, with significantly fewer abdominal pain/GI adverse events in the curcumin group.

Animal · 2014

Disruption of Sirt1 in chondrocytes causes accelerated progression of osteoarthritis under mechanical stress and during ageing in mice

Matsuzaki T et al. · Annals of the Rheumatic Diseases

Loss of the NAD+-dependent deacetylase SIRT1 in chondrocytes accelerated OA progression with ageing and under mechanical stress, with increased chondrocyte apoptosis — establishing the pathway NMN supplementation is hypothesised to support.

Animal · 2014 · n=15

Increasing the Dose of Autologous Chondrocytes Improves Articular Cartilage Repair: Histological and Molecular Study in the Sheep Animal Model

Guillén-García P et al. · Cartilage

Higher cell dose produced more hyaline-like repair tissue with higher type II collagen and aggrecan expression and less variability — the preclinical rationale for the CEMTRO high-density approach. Does not establish human efficacy.

Case series · 2014 · n=63

Distal Femoral Fresh Osteochondral Allografts: Follow-up at a Mean of Twenty-two Years

Raz G et al. · The Journal of Bone and Joint Surgery. American Volume

Kaplan-Meier graft survival of 91% at 10 years, 84% at 15, 69% at 20, and 59% at 25 years; surviving grafts had good function (mean HSS 86).

Systematic review · 2013 · n=29

The basic science of continuous passive motion in promoting knee health: a systematic review of studies in a rabbit model

Knapik DM et al. · Arthroscopy

In rabbits, CPM after cartilage injury improved cartilage nutrition and healing quality versus immobilization — the basic-science rationale (Salter's work) behind post-cartilage-repair CPM protocols. Animal support only; human benefit unproven.

In vitro · 2013

The risk of lead contamination in bone broth diets

Monro JA et al. · Medical Hypotheses

Broth made from organic chicken skin/cartilage contained 9.5 ug/L lead and bone broth 7.01 ug/L, versus 0.89 ug/L in the cooking water — several-fold concentration of lead by the broth-making process.

RCT · 2013 · n=454

Effects of intensive diet and exercise on knee joint loads, inflammation, and clinical outcomes among overweight and obese adults with knee osteoarthritis: the IDEA randomized clinical trial

Messier SP et al. · JAMA

Diet+exercise produced 10.6 kg mean loss and less pain (WOMAC 3.6 vs 4.7, p = .004), better function, lower IL-6, and lower knee compressive forces than exercise alone. One of the strongest food/weight interventions ever tested in knee OA.

RCT · 2013 · n=78

Treatment with platelet-rich plasma is more effective than placebo for knee osteoarthritis: a prospective, double-blind, randomized trial

Patel S et al. · The American Journal of Sports Medicine

Both PRP groups improved significantly on all WOMAC parameters vs saline (P<.001); one injection was as effective as two. Benefit deteriorated after 6 months.

Review · 2013

Treatment of osteoarthritis of the knee: evidence-based guideline, 2nd edition

Jevsevar DS · The Journal of the American Academy of Orthopaedic Surgeons

The 2013 AAOS guideline could not recommend hyaluronic acid for symptomatic knee OA — a STRONG recommendation against, based on meta-analysis showing effects below clinical significance thresholds.

RCT · 2013 · n=90

Dextrose prolotherapy for knee osteoarthritis: a randomized controlled trial

Rabago D et al. · Annals of Family Medicine

WOMAC composite improved 15.3 points with prolotherapy vs 7.6 (saline) and 8.2 (exercise) at 52 weeks (P<.05), exceeding the MCID. No adverse events.

Animal · 2013

Thymosin β4 enhances the healing of medial collateral ligament injury in rat

Xu B et al. · Regulatory Peptides

Better-organized collagen fibrils and significantly improved biomechanical properties of the healing ligament at 4 weeks.

Cohort · 2013 · n=216

Increased thymosin β4 levels in the serum and SF of knee osteoarthritis patients correlate with disease severity

Wei M et al. · Regulatory Peptides

Endogenous thymosin β4 was higher in OA patients and highest in the most severe (KL grade 4) knees — an association consistent with TB4 rising in damaged joints, not evidence that adding more helps.

RCT · 2013 · n=55

Undenatured type II collagen (UC-II®) for joint support: a randomized, double-blind, placebo-controlled study in healthy volunteers

Lugo JP et al. · Journal of the International Society of Sports Nutrition

UC-II increased average knee-extension range of motion versus placebo (81.0 vs 74.0 degrees at day 120) and lengthened time to exercise-induced knee pain; joint pain at rest did not differ.

Cohort · 2013 · n=1180

Vitamin K deficiency is associated with incident knee osteoarthritis

Misra D et al. · The American Journal of Medicine

Subclinical vitamin K deficiency predicted incident radiographic knee OA (RR 1.56, 95% CI 1.08-2.25) and incident MRI cartilage lesions (RR 2.39, 95% CI 1.05-5.40).

RCT · 2013 · n=146

Effect of vitamin D supplementation on progression of knee pain and cartilage volume loss in patients with symptomatic osteoarthritis: a randomized controlled trial

McAlindon T et al. · JAMA

NULL: knee pain declined similarly in both arms (-2.31 vs -1.46 WOMAC points, no significant difference at any timepoint) and MRI cartilage volume loss was identical (P=0.96).

Meta-analysis · 2013

Betaine supplementation decreases plasma homocysteine in healthy adult participants: a meta-analysis

McRae MP · Journal of Chiropractic Medicine

Betaine lowered plasma homocysteine by a pooled 1.23 umol/L (95% CI -1.61 to -0.85, P=.01) — a real but modest biochemical effect with no joint outcomes measured in any included trial.

Cohort · 2013 · n=77

Preoperative MRI underestimates articular cartilage defect size compared with findings at arthroscopic knee surgery

Campbell AB et al. · The American Journal of Sports Medicine

MRI underestimated defect area by about 70% versus arthroscopy; 74% of lesions were larger at surgery (mean underestimation about 1 cm²). The scan sets expectations; the scope sets the plan.

Systematic review · 2013 · n=3122

Evidence-based status of microfracture technique: a systematic review of level I and II studies

Goyal D et al. · Arthroscopy

Good short-term results in young patients with small lesions, but treatment failures and osteoarthritis appeared at 5-10 years regardless of lesion size. Authors recommend restricting microfracture to small lesions with low postoperative demand.

Case series · 2013 · n=122

Do fresh osteochondral allografts successfully treat femoral condyle lesions?

Levy YD et al. · Clinical Orthopaedics and Related Research

Graft survivorship 82% at 10 years, 74% at 15, 66% at 20; 47% needed some reoperation and 24% ultimately failed. Age over 30 and prior surgery predicted worse results.

Systematic review · 2013 · n=644

Outcomes of osteochondral allograft transplantation in the knee

Chahal J et al. · Arthroscopy

86% patient satisfaction and 18% failure at mean 58 months; best outcomes in younger patients with unipolar traumatic or OCD lesions.

Cohort · 2013 · n=43

A non-randomized controlled clinical trial on autologous chondrocyte implantation (ACI) in cartilage defects of the medial femoral condyle with or without high tibial osteotomy in patients with varus deformity of less than 5°

Bode G et al. · Archives of Orthopaedic and Trauma Surgery

At about 6 years, survival was 89.5% with combined ACI+HTO vs 58.3% with ACI alone (P = .023) — offloading protected the repair even in minor malalignment.

Case series · 2012 · n=9

Loading of the knee joint during ergometer cycling: telemetric in vivo data

Kutzner I et al. · Journal of Orthopaedic and Sports Physical Therapy

Peak tibiofemoral force at 60W/40rpm was ~119% bodyweight — roughly half the load of level walking — with tiny shear forces (5-7% BW); force rose with power and fell with higher cadence. Direct in vivo proof that cycling is a genuinely low-load way to move the knee.

RCT · 2012 · n=63

A randomized trial comparing accelerated and traditional approaches to postoperative weightbearing rehabilitation after matrix-induced autologous chondrocyte implantation: findings at 5 years

Ebert JR et al. · The American Journal of Sports Medicine

At 5 years the accelerated group had LESS knee pain (VAS) and no worse graft outcomes; ~94-95% patient satisfaction in both. Getting people back on their feet ~3 weeks earlier was safe and slightly better.

Cohort · 2012 · n=472

Association of plasma n-6 and n-3 polyunsaturated fatty acids with synovitis in the knee: the MOST study

Baker KR et al. · Osteoarthritis and Cartilage

Higher total n-3 and DHA levels were inversely associated with patellofemoral cartilage loss; the n-6 arachidonic acid was positively associated with synovitis. No association with tibiofemoral cartilage loss.

Cohort · 2012 · n=111

Weight loss in obese people has structure-modifying effects on medial but not on lateral knee articular cartilage

Anandacoomarasamy A et al. · Annals of the Rheumatic Diseases

Greater weight loss was associated with preserved medial femoral cartilage thickness (p = .029) and improved cartilage proteoglycan quality on dGEMRIC (p = .008); authors estimated >=7% loss as the threshold for measurable cartilage benefit.

Meta-analysis · 2012 · n=12667

Viscosupplementation for osteoarthritis of the knee: a systematic review and meta-analysis

Rutjes AW et al. · Annals of Internal Medicine

Overall pain effect size -0.37, but the 18 large blinded trials (5,094 patients) showed a clinically irrelevant -0.11, and unpublished trials -0.03 — the apparent benefit lives in small, unblinded, published trials. Serious adverse events were increased (RR 1.41).

Case series · 2012 · n=62

Application of bioregulating therapy in complex treatment of temporomandibular joint diseases in people of elderly and senile age

Iordanishvili AK et al. · Advances in Gerontology (Uspekhi Gerontologii)

Authors report faster pain resolution and improved mouth opening/chewing — the only indexed human joint study naming Sigumir, and it cannot isolate Sigumir's contribution from co-treatments.

Systematic review · 2012

The effect of smoking on ligament and cartilage surgery in the knee: a systematic review

Kanneganti P et al. · The American Journal of Sports Medicine

Every ligament study, basic-science and clinical, found smoking harmful; the cartilage-surgery literature was thinner but still pointed to an overall negative influence on healing and outcomes.

RCT · 2012 · n=60

Oral administration of polymer hyaluronic acid alleviates symptoms of knee osteoarthritis: a double-blind, placebo-controlled study over a 12-month period

Tashiro T et al. · The Scientific World Journal

JKOM symptom scores improved in both groups; the HA group improved more, with the difference reaching significance mainly in the subgroup aged 70 or younger.

Case series · 2012

Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women

Sato T et al. · Nutrition Journal

MK-4 was undetectable in serum at every time point at nutritional doses, while MK-7 was well absorbed (serum peak ~6 h) and accumulated with daily dosing — the key pharmacokinetic argument for MK-7 over MK-4 at supplement-label doses.

RCT · 2012 · n=57

Ten-year follow-up of a prospective, randomized clinical study of mosaic osteochondral autologous transplantation versus microfracture for the treatment of osteochondral defects in the knee joint of athletes

Gudas R et al. · The American Journal of Sports Medicine

OAT stayed superior at 10 years (P < .005): failure 14% vs 38%; 75% vs 37% maintained pre-injury activity level. Both arms declined after year 3 — even the winner is not a cure.

In vitro · 2011

The promoting effect of pentadecapeptide BPC 157 on tendon healing involves tendon outgrowth, cell survival, and cell migration

Chang CH et al. · Journal of Applied Physiology

Accelerated tendon fibroblast outgrowth, improved survival under oxidative stress, and dose-dependent increases in migration via FAK-paxillin signaling.

Systematic review · 2011 · n=16184

Ciprofloxacin safety in paediatrics: a systematic review

Adefurin A et al. · Archives of Disease in Childhood

Musculoskeletal adverse events (mainly arthralgia/arthropathy) occurred in 1.6% (95% CI 0.9–2.6%); all reported cases resolved or improved — the dramatic juvenile-animal chondrotoxicity has not translated into documented permanent human cartilage injury.

Meta-analysis · 2011 · n=537730

Does smoking protect against osteoarthritis? Meta-analysis of observational studies

Hui M et al. · Annals of the Rheumatic Diseases

Pooled analysis found a modest inverse (apparently 'protective') association between smoking and OA (OR 0.87, 95% CI 0.80–0.94) — but the effect was confined to hospital-based case-control studies and the authors conclude it is likely false, driven by selection bias.

RCT · 2011 · n=49

Efficacy of methylsulfonylmethane supplementation on osteoarthritis of the knee: a randomized controlled study

Debbi EM et al. · BMC Complementary and Alternative Medicine

Small but statistically significant improvements in WOMAC physical function and total score versus placebo; WOMAC pain improved within the MSM group but gains were modest, and the authors questioned whether they were clinically meaningful.

RCT · 2011 · n=24

Beneficial effect of creatine supplementation in knee osteoarthritis

Neves M Jr et al. · Medicine and Science in Sports and Exercise

Creatine + training improved physical function (timed-stands: 15.7 to 18.1 reps vs no change on placebo, between-group P=0.004), WOMAC function and stiffness subscales, lower-limb lean mass and quality of life; pain improved in BOTH groups (training effect, not creatine).

Case series · 2011 · n=413

Long-term survival of high tibial osteotomy for medial compartment osteoarthritis of the knee

Hui C et al. · The American Journal of Sports Medicine

Survival 95% at 5 years, 79% at 10, 56% at 15; 85% of patients satisfied and 84% would repeat the surgery. Age under 50, BMI under 25 predicted longer survival.

Cohort · 2010 · n=1829

Effect of quadriceps strength and proprioception on risk for knee osteoarthritis

Segal NA et al. · Medicine and Science in Sports and Exercise

Greater quadriceps strength protected against development of symptomatic knee OA over 30 months, but did not protect against radiographic (structural) OA. Strength appears to protect symptoms more than joint-space imaging.

Systematic review · 2010 · n=4

The use of continuous passive motion following knee cartilage defect surgery: a systematic review

Fazalare JA et al. · Orthopedics

Despite near-universal use in cartilage-repair protocols, the human evidence could not support definitive conclusions about CPM benefit — only 4 heterogeneous low-level studies existed. CPM is tradition-and-theory driven, not proven.

Animal · 2010

Pentadecapeptide BPC 157 (PL 14736) improves ligament healing in the rat

Cerovecki T et al. · Journal of Orthopaedic Research

Functional, biomechanical, macroscopic, and histological improvement of MCL healing across intraperitoneal, oral, and topical routes.

In vitro · 2010

Pentosan polysulfate promotes proliferation and chondrogenic differentiation of adult human bone marrow-derived mesenchymal precursor cells

Ghosh P et al. · Arthritis Research & Therapy

PPS at 2.5 µg/mL stimulated proteoglycan synthesis ~130% and drove type II collagen deposition while suppressing osteogenic drift — a plausible cartilage-anabolic mechanism.

Cohort · 2010 · n=20

High-field magnetic resonance imaging assessment of articular cartilage before and after marathon running: does long-distance running lead to cartilage damage?

Luke AC et al. · The American Journal of Sports Medicine

T1rho and T2 relaxation times (biochemical cartilage stress markers) rose significantly after the marathon (T1rho 37.0 to 38.9 ms, p<0.001) and T1rho remained elevated at 3 months — cartilage matrix changes outlast the event, arguing for real recovery windows.

RCT · 2010 · n=662

Clinical efficacy and safety of glucosamine, chondroitin sulphate, their combination, celecoxib or placebo taken to treat osteoarthritis of the knee: 2-year results from GAIT

Sawitzke AD et al. · Annals of the Rheumatic Diseases

Over 2 years no treatment arm, including celecoxib, was significantly better than placebo on WOMAC pain or function; odds of response for glucosamine+chondroitin were similar to placebo.

Meta-analysis · 2010 · n=3803

Effects of glucosamine, chondroitin, or placebo in patients with osteoarthritis of hip or knee: network meta-analysis

Wandel S et al. · BMJ

Pooled pain effects were small (about 0.3-0.5 cm on a 10 cm scale) and below the prespecified threshold for clinical relevance (0.9 cm); joint-space effects were minimal. Authors concluded the supplements do not meaningfully reduce joint pain or affect narrowing.

RCT · 2010 · n=60

Comparative efficacy and tolerability of 5-Loxin and Aflapin against osteoarthritis of the knee: a double blind, randomized, placebo controlled clinical study

Sengupta K et al. · International Journal of Medical Sciences

Both extracts improved pain and function scores versus placebo by day 90 (improvements beginning around day 7), with Aflapin numerically superior to 5-Loxin.

RCT · 2010 · n=60

Matrix-induced autologous chondrocyte implantation versus microfracture in the treatment of cartilage defects of the knee: a 2-year randomised study

Basad E et al. · Knee Surgery, Sports Traumatology, Arthroscopy

Both groups improved at 24 months, but MACI improved significantly more on Lysholm, Tegner, and ICRS scores (P = .005 to .04) — an independent, smaller RCT pointing the same way as SUMMIT.

Case series · 2010 · n=224

Autologous chondrocyte implantation: a long-term follow-up

Peterson L et al. · The American Journal of Sports Medicine

92% said they would have ACI again and 74% reported being better or the same as pre-surgery; mean Lysholm improved modestly (60.3 to 69.5). Bipolar lesions fared worse.

Cohort · 2009 · n=2275

Knee extensor strength does not protect against incident knee symptoms at 30 months in the multicenter knee osteoarthritis (MOST) cohort

Segal NA et al. · PM&R

Neither knee-extensor strength nor H:Q ratio predicted incident knee symptoms at 15-30 months (307 knees developed symptoms). A null result that tempers strong claims about quadriceps strength as sole protective factor.

Review · 2009

A weak link in metabolism: the metabolic capacity for glycine biosynthesis does not satisfy the need for collagen synthesis

Meléndez-Hevia E et al. · Journal of Biosciences

Calculates that endogenous glycine synthesis (~3 g/day) plus typical dietary intake (1.5-3 g/day) falls well short of the ~10 g/day a 70 kg human needs for collagen turnover, arguing glycine is 'semi-essential'. A hypothesis paper, not an outcome study.

Systematic review · 2009

Knee osteoarthritis after anterior cruciate ligament injury: a systematic review

Øiestad BE et al. · The American Journal of Sports Medicine

At 10+ years, radiographic knee OA prevalence was 0–13% after isolated ACL injury but 21–48% with combined ACL+meniscal injury — joint injury, especially with meniscal damage, multiplies OA risk.

Cohort · 2009 · n=271

Smoking is associated with increased cartilage loss and persistence of bone marrow lesions over 2 years in community-based individuals

Davies-Tuck ML et al. · Rheumatology (Oxford)

Smoking was associated with greater annual medial cartilage volume loss (+13.4 microlitres/year, p=0.03) and an 11.4-fold higher odds of bone marrow lesions persisting over 2 years (95% CI 1.54–89.9).

Cohort · 2009 · n=114

Does smoking influence outcome after autologous chondrocyte implantation?: A case-controlled study

Jaiswal PK et al. · The Journal of Bone and Joint Surgery. British Volume

Smokers had worse knee scores before and after surgery, less improvement at 2 years, and all graft failures occurred in smokers (p=0.016); heavier smoking correlated strongly with worse outcome (r=-0.65).

RCT · 2009 · n=8

Vibration training intervention to maintain cartilage thickness and serum concentrations of cartilage oligometric matrix protein (COMP) during immobilization

Liphardt AM et al. · Osteoarthritis and Cartilage

Just 14 days of bed rest thinned weight-bearing tibial cartilage by ~8%; brief daily vibration loading counteracted the loss — evidence in healthy humans that cartilage needs load, quickly.

RCT · 2009 · n=52

Safety and efficacy of undenatured type II collagen in the treatment of osteoarthritis of the knee: a clinical trial

Crowley DC et al. · International Journal of Medical Sciences

UC-II reduced total WOMAC by about 33% at 90 days versus about 14% with glucosamine+chondroitin, with parallel differences in VAS and Lequesne scores.

RCT · 2009 · n=67

Eggshell membrane in the treatment of pain and stiffness from osteoarthritis of the knee: a randomized, multicenter, double-blind, placebo-controlled clinical study

Ruff KJ et al. · Clinical Rheumatology

NEM produced statistically significant reductions versus placebo in pain (about 15-22% mean reduction at days 10-60) and stiffness (about 27% at day 60); absolute effects were modest and roughly a third of patients were non-responders.

Case series · 2009 · n=39

Eggshell membrane: a possible new natural therapeutic for joint and connective tissue disorders. Results from two open-label human clinical studies

Ruff KJ et al. · Clinical Interventions in Aging

Participants reported large reductions in joint pain (mean ~72% at 30 days in one cohort) and improved flexibility, but without any control group these numbers cannot be separated from placebo response.

Systematic review · 2009 · n=3122

Clinical efficacy of the microfracture technique for articular cartilage repair in the knee: an evidence-based systematic analysis

Mithoefer K et al. · The American Journal of Sports Medicine

Microfracture reliably improved knee function in the first 24 months, but durability beyond that was conflicting, with deterioration reported after 5 years; only 5 of 28 studies followed patients that long.

RCT · 2008 · n=147

24-Week study on the use of collagen hydrolysate as a dietary supplement in athletes with activity-related joint pain

Clark KL et al. · Current Medical Research and Opinion

Significant improvements in several joint-pain parameters vs placebo, largest in the subgroup with knee arthralgia.

Cohort · 2008 · n=98

Long distance running and knee osteoarthritis. A prospective study

Chakravarty EF et al. · American Journal of Preventive Medicine

After 18 years, runners did not have more knee OA than controls (20% vs 32%, p=0.25); severe OA was rarer in runners (2.2% vs 9.4%, p=0.21). Decades of running did not wear out these knees.

RCT · 2008 · n=75

A double blind, randomized, placebo controlled study of the efficacy and safety of 5-Loxin for treatment of osteoarthritis of the knee

Sengupta K et al. · Arthritis Research & Therapy

Both doses significantly improved VAS pain, Lequesne index, and WOMAC scores versus placebo, with the 250 mg dose showing benefit as early as day 7; synovial-fluid MMP-3 fell in treated patients.

RCT · 2008 · n=20

Effect of a natural extract of chicken combs with a high content of hyaluronic acid (Hyal-Joint) on pain relief and quality of life in subjects with knee osteoarthritis: a pilot randomized double-blind placebo-controlled trial

Kalman DS et al. · Nutrition Journal

WOMAC pain and some quality-of-life measures improved numerically more with Hyal-Joint, but with n=20 most between-group comparisons were not statistically significant; the authors framed it as hypothesis-generating.

RCT · 2008 · n=378

Vitamin K in hand osteoarthritis: results from a randomised clinical trial

Neogi T et al. · Annals of the Rheumatic Diseases

NULL primary result: no overall effect on radiographic hand OA. In the subgroup who were vitamin-K insufficient at baseline and reached sufficiency, there was ~47% less joint space narrowing (P=0.02) — hypothesis-generating only.

In vitro · 2008

Crucial role of visfatin/pre-B cell colony-enhancing factor in matrix degradation and prostaglandin E2 synthesis in chondrocytes: possible influence on osteoarthritis

Gosset M et al. · Arthritis and Rheumatism

COMPLICATING EVIDENCE: extracellular NAMPT (visfatin) — the same enzyme that makes NMN endogenously — drove prostaglandin E2 release and matrix-degrading activity in chondrocytes, showing the NAD+ pathway is not uniformly 'good' for cartilage.

Meta-analysis · 2007 · n=454

Effect of weight reduction in obese patients diagnosed with knee osteoarthritis: a systematic review and meta-analysis

Christensen R et al. · Annals of the Rheumatic Diseases

Pooled effect sizes were modest: 0.20 for pain (95% CI 0.00-0.39, borderline) and 0.23 for disability (95% CI 0.04-0.42); disability improved reliably when weight loss exceeded ~5% of body weight within 20 weeks.

Animal · 2007

Evaluation of pentosan polysulfate sodium in the postoperative recovery from cranial cruciate injury in dogs: a randomized, placebo-controlled clinical trial

Budsberg SC et al. · Veterinary Surgery

PPS-treated dogs recovered ground-reaction forces faster and showed lower cartilage/bone degradation markers at 6 weeks; a genuinely randomized, blinded veterinary trial.

RCT · 2007 · n=38

Continued sports activity, using a pain-monitoring model, during rehabilitation in patients with Achilles tendinopathy: a randomized controlled study

Silbernagel KG et al. · The American Journal of Sports Medicine

Continuing to train within defined pain limits produced no worse outcomes than rest at any timepoint over 12 months — moderate, monitored pain during loading is tolerable; the harm signal belongs to sharp/escalating pain, not all pain.

Review · 2007

The long-term consequence of anterior cruciate ligament and meniscus injuries: osteoarthritis

Lohmander LS et al. · The American Journal of Sports Medicine

On average ~50% of patients with an ACL or meniscus tear have knee OA 10–20 years later, typically in their 30s–40s; reconstruction has not been shown to prevent it.

Animal · 2007 · n=48

Diminished ciprofloxacin-induced chondrotoxicity by supplementation with magnesium and vitamin E in immature rats

Pfister K et al. · Antimicrobial Agents and Chemotherapy

Ciprofloxacin produced typical juvenile cartilage lesions (17 lesions in the standard-diet group); magnesium and vitamin E supplementation cut lesion counts by 41–82% — supporting a chelation/oxidative mechanism for quinolone chondrotoxicity.

Cohort · 2007 · n=159

Cigarette smoking and the risk for cartilage loss and knee pain in men with knee osteoarthritis

Amin S et al. · Annals of the Rheumatic Diseases

Current smokers had roughly 2.3–2.5-fold higher odds of MRI cartilage loss at medial tibiofemoral (OR 2.3, 95% CI 1.0–5.4) and patellofemoral (OR 2.5, 1.1–5.7) compartments, and reported more pain at baseline and follow-up.

RCT · 2007 · n=18

Elevated inflammatory markers in response to prolonged sleep restriction are associated with increased pain experience in healthy volunteers

Haack M et al. · Sleep

Sleep restriction raised IL-6 and increased spontaneous pain ratings; elevated IL-6 correlated strongly with pain (r=0.67, p<0.01) — experimental evidence that sleep loss amplifies pain via inflammation.

Cohort · 2007 · n=992

Low levels of vitamin D and worsening of knee osteoarthritis: results of two longitudinal studies

Felson DT et al. · Arthritis and Rheumatism

NULL: no association between baseline vitamin D level and radiographic worsening or cartilage loss in either cohort — an early observational check on the vitamin D-OA hypothesis.

Cohort · 2007 · n=25124

Articular cartilage defects: study of 25,124 knee arthroscopies

Widuchowski W et al. · The Knee

Chondral lesions in 60% of arthroscopies, most often patella (36%) and medial femoral condyle (34%); classic focal defects suitable for repair surgery were a small minority (about 7% under age 40).

Animal · 2006

Achilles detachment in rat and stable gastric pentadecapeptide BPC 157: Promoted tendon-to-bone healing and opposed corticosteroid aggravation

Krivic A et al. · Journal of Orthopaedic Research

Improved tendon-to-bone healing on functional and biomechanical measures and counteracted corticosteroid-impaired healing.

RCT · 2006 · n=1583

Glucosamine, chondroitin sulfate, and the two in combination for painful knee osteoarthritis

Clegg DO et al. · The New England Journal of Medicine

Neither glucosamine, chondroitin, nor the combination beat placebo on the primary endpoint (20% WOMAC pain reduction: 60.1% placebo vs 64-66.6% supplement arms, ns). An exploratory subgroup with moderate-to-severe pain responded better to the combination (79.2% vs 54.3%, p=0.002).

RCT · 2006 · n=50

Efficacy of methylsulfonylmethane (MSM) in osteoarthritis pain of the knee: a pilot clinical trial

Kim LS et al. · Osteoarthritis and Cartilage

MSM reduced WOMAC pain (-14.6 vs -7.2 points, p=0.041) and improved physical function versus placebo; stiffness and aggregated total symptoms did not differ significantly.

Cohort · 2006 · n=672

Low vitamin K status is associated with osteoarthritis in the hand and knee

Neogi T et al. · Arthritis and Rheumatism

Higher plasma vitamin K was associated with lower prevalence of radiographic hand OA (prevalence ratio falling from 1.0 to 0.7 across quartiles, P=0.005) and knee osteophytes (PR 1.0 to 0.6, P=0.01).

Cohort · 2006 · n=85

Results after microfracture of full-thickness chondral defects in different compartments in the knee

Kreuz PC et al. · Osteoarthritis and Cartilage

Scores improved significantly to 18 months, then significantly deteriorated between 18 and 36 months everywhere except femoral condyle defects — early direct evidence that the repair tissue does not hold.

RCT · 2006 · n=68

A prospective, randomised study comparing two techniques of autologous chondrocyte implantation for osteochondral defects in the knee: Periosteum covered versus type I/III collagen covered

Gooding CR et al. · The Knee

Clinical results equivalent at 2 years (74% vs 67% good/excellent), but 36.4% of periosteal grafts needed re-operation for graft hypertrophy vs none with collagen — the finding that killed the periosteal flap.

RCT · 2005 · n=30

Positive effects of moderate exercise on glycosaminoglycan content in knee cartilage: a four-month, randomized, controlled trial in patients at risk of osteoarthritis

Roos EM et al. · Arthritis and Rheumatism

Cartilage GAG content (dGEMRIC T1(Gd)) improved in the exercise group vs control (+15 vs -15 msec, p=0.036); change in activity level correlated with GAG improvement (r=0.70). First human RCT suggesting cartilage adapts positively to moderate loading.

Case series · 2005 · n=28

In vivo cartilage deformation after different types of activity and its dependence on physical training status

Eckstein F et al. · Annals of the Rheumatic Diseases

Cartilage deforms 2.8-5.9% depending on activity and recovers afterwards; deformation magnitude did not differ by training status, suggesting adult cartilage modulates its biology more than its thickness in response to chronic loading.

Case series · 2005

Identification of food-derived collagen peptides in human blood after oral ingestion of gelatin hydrolysates

Iwai K et al. · Journal of Agricultural and Food Chemistry

Hydroxyproline-containing peptides (mainly Pro-Hyp) appeared in blood, peaking at 20-60 nmol/mL at 1-2 h — direct evidence that collagen peptides from foods including chicken feet are absorbed intact. Absorption is not efficacy.

Cohort · 2005

Is there an association between the use of different types of nonsteroidal antiinflammatory drugs and radiologic progression of osteoarthritis? The Rotterdam Study

Reijman M et al. · Arthritis & Rheumatism

Long-term diclofenac use was associated with faster radiologic progression of hip and knee OA; no such signal for most other NSAIDs examined.

RCT · 2005 · n=114

Effects of pentosan polysulfate in osteoarthritis of the knee: A randomized, double-blind, placebo-controlled pilot study

Ghosh P et al. · Current Therapeutic Research, Clinical and Experimental

Significant improvements vs placebo in stiffness duration, pain at rest, and patient global assessment, with some functional gains persisting 8–12 weeks after the last dose.

In vitro · 2005

Fluoroquinolones cause changes in extracellular matrix, signalling proteins, metalloproteinases and caspase-3 in cultured human tendon cells

Sendzik J et al. · Toxicology

Both drugs caused dose- and time-dependent decreases in matrix and signalling proteins with increased matrix metalloproteinases and caspase-3 (apoptosis) — a plausible cellular mechanism for tendon degeneration at concentrations near therapeutic.

RCT · 2005 · n=37

Creatine monohydrate supplementation does not improve functional recovery after total knee arthroplasty

Roy BD et al. · Archives of Physical Medicine and Rehabilitation

NULL: creatine produced no significant benefit for body composition, muscle strength, or functional recovery after knee replacement.

RCT · 2005 · n=57

A prospective randomized clinical study of mosaic osteochondral autologous transplantation versus microfracture for the treatment of osteochondral defects in the knee joint in young athletes

Gudas R et al. · Arthroscopy

At mean 37 months, 96% excellent/good results with OAT vs 52% with microfracture; 93% vs 52% returned to pre-injury sport (P < .001).

RCT · 2005 · n=91

Autologous chondrocyte implantation versus matrix-induced autologous chondrocyte implantation for osteochondral defects of the knee: a prospective, randomised study

Bartlett W et al. · The Journal of Bone and Joint Surgery. British Volume

At 1 year both improved similarly (Cincinnati +17.6 vs +19.6); MACI's advantage is surgical simplicity, not proven clinical superiority over membrane ACI.

Cohort · 2004 · n=20

Cartilage atrophy in the knees of patients after seven weeks of partial load bearing

Hinterwimmer S et al. · Arthritis and Rheumatism

Knee cartilage of the unloaded (but uninjured) limb thinned measurably in 7 weeks — from -2.9% (patella) to -6.6% (medial tibia) — alongside 11% quadriceps atrophy; even partial unloading is enough to shrink cartilage.

RCT · 2004 · n=118

Randomised, Double-Blind, Parallel, Placebo-Controlled Study of Oral Glucosamine, Methylsulfonylmethane and their Combination in Osteoarthritis

Usha PR et al. · Clinical Drug Investigation

Both MSM and glucosamine reduced pain and swelling versus placebo, and the combination reduced the pain index more than either alone (from 1.7 to 0.36 vs 0.9-1.0 on monotherapy).

Animal · 2003

Gastric pentadecapeptide BPC 157 accelerates healing of transected rat Achilles tendon and in vitro stimulates tendocytes growth

Staresinic M et al. · Journal of Orthopaedic Research

Treated tendons showed higher load to failure, better functional (Achilles functional index) scores, and improved collagen organization than saline controls.

Registry · 2003 · n=51367

Increased risk of achilles tendon rupture with quinolone antibacterial use, especially in elderly patients taking oral corticosteroids

van der Linden PD et al. · Archives of Internal Medicine

Current quinolone use carried an adjusted OR of 4.3 (95% CI 2.4–7.8) for Achilles rupture; risk rose to OR 6.4 at age 60–79 and 20.4 at 80+, and was amplified by concurrent oral corticosteroids.

RCT · 2003 · n=30

Efficacy and tolerability of Boswellia serrata extract in treatment of osteoarthritis of knee--a randomized double blind placebo controlled trial

Kimmatkar N et al. · Phytomedicine

All patients receiving boswellia reported decreased knee pain, increased knee flexion, and increased walking distance versus placebo; pain scores fell substantially during active treatment.

Review · 2003

Evaluation of cartilage injuries and repair

Brittberg M et al. · The Journal of Bone and Joint Surgery. American Volume

Defines the ICRS classification now standard in cartilage repair trials: grade by depth from superficial softening (1) to full-thickness/subchondral bone exposure (3-4), plus lesion mapping and repair-tissue scoring.

Case series · 2003 · n=72

Outcomes of microfracture for traumatic chondral defects of the knee: average 11-year follow-up

Steadman JR et al. · Arthroscopy

At average 11.3 years, Lysholm improved from 59 to 89 and Tegner from 3 to 6; 80% rated themselves improved at 7 years. Younger patients did best.

Case series · 2003 · n=831

Autologous osteochondral mosaicplasty for the treatment of full-thickness defects of weight-bearing joints: ten years of experimental and clinical experience

Hangody L et al. · The Journal of Bone and Joint Surgery. American Volume

Good-to-excellent results in 92% of femoral condyle, 87% of tibial, 79% of patellofemoral, and 94% of talar cases; donor-site morbidity reported at 3%.

In vitro · 2002

The effect of thymosin beta4 on articular cartilage chondrocyte matrix metalloproteinase expression

Blain EJ et al. · Biochemical Society Transactions

Thymosin β4 increased expression and activation of pro-MMP-9, a matrix-degrading enzyme — a cautionary signal that in cartilage the peptide may be catabolic rather than regenerative.

In vitro · 2002

Selective COX-2 inhibition prevents proinflammatory cytokine-induced cartilage damage

Mastbergen SC et al. · Rheumatology (Oxford)

Celecoxib reversed cytokine-induced proteoglycan loss up to complete normalization and had no direct adverse effect on healthy cartilage — suggesting COX-2-selective agents may be cartilage-neutral or protective in vitro.

Animal · 2002

Synergistic effect of ofloxacin and magnesium deficiency on joint cartilage in immature rats

Lozo E et al. · Antimicrobial Agents and Chemotherapy

Ofloxacin alone caused no cartilage lesions on a standard diet, but produced lesions in 10 of 12 magnesium-deficient rats — quinolone chondrotoxicity depends heavily on functional magnesium status.

Cohort · 2002 · n=11

Knee cartilage of spinal cord-injured patients displays progressive thinning in the absence of normal joint loading and movement

Vanwanseele B et al. · Arthritis and Rheumatism

Knee cartilage thinned progressively without any joint disease: patellar cartilage -10% at 6 months and -21% to -23% by 12–24 months; medial tibia -16% at 6 months and -24% to -25% by 12–24 months.

RCT · 2002 · n=202

Glucosamine sulfate use and delay of progression of knee osteoarthritis: a 3-year, randomized, placebo-controlled, double-blind study

Pavelká K et al. · Archives of Internal Medicine

Replicated the Reginster findings: significantly less joint-space narrowing over 3 years with glucosamine sulfate and modest symptom improvement (Lequesne/WOMAC) versus placebo.

In vitro · 2001

Biosynthetic response and mechanical properties of articular cartilage after injurious compression

Kurz B et al. · Journal of Orthopaedic Research

High strain-rate overload significantly suppressed proteoglycan and protein synthesis, degraded mechanical properties, and increased cell death — mechanistic evidence that supraphysiologic loading rate, not just magnitude, injures cartilage.

RCT · 2001 · n=212

Long-term effects of glucosamine sulphate on osteoarthritis progression: a randomised, placebo-controlled clinical trial

Reginster JY et al. · Lancet

Placebo knees lost about 0.31 mm of joint-space width over 3 years while glucosamine knees showed no significant narrowing (-0.06 mm); WOMAC symptoms improved slightly on glucosamine and worsened slightly on placebo.

Case series · 2000 · n=10

Patellar cartilage deformation in vivo after static versus dynamic loading

Eckstein F et al. · Journal of Biomechanics

In vivo patellar cartilage deforms measurably under load and the pattern differs between static and dynamic loading; fluid-flow-driven deformation and recovery is the plausible route by which cyclic load nourishes cartilage.

In vitro · 2000

n-3 fatty acids specifically modulate catabolic factors involved in articular cartilage degradation

Curtis CL et al. · The Journal of Biological Chemistry

n-3 (but not n-6 or saturated) fatty acids dose-dependently reduced aggrecanase activity and expression of IL-1alpha, TNF-alpha, and COX-2 in cartilage — a clean mechanistic rationale that human trials have so far failed to convert into symptom benefit.

Animal · 2000

Incomplete restoration of immobilization induced softening of young beagle knee articular cartilage after 50-week remobilization

Haapala J et al. · International Journal of Sports Medicine

Immobilization cut cartilage shear stiffness by up to 30%; after nearly a year of remobilization the lateral femoral condyle remained ~15% softer than controls — disuse damage is only partly reversible.

Animal · 1999

Osteogenic effect of a gastric pentadecapeptide, BPC-157, on the healing of segmental bone defect in rabbits

Sebecić B et al. · Bone

Bone healing on radiographic and histomorphometric measures was comparable to autologous bone-marrow or graft treatment.

In vitro · 1999

The effects of NSAID on the matrix of human articular cartilages

Dingle JT · Zeitschrift für Rheumatologie

NSAIDs split into three classes by effect on glycosaminoglycan synthesis in OA cartilage: stimulatory (aceclofenac, tenidap, tolmetin), neutral (piroxicam, tiaprofenic acid, aspirin), and inhibitory (naproxen, ibuprofen, indomethacin, nimesulide).

Animal · 1997

Pentadecapeptide BPC 157 positively affects both non-steroidal anti-inflammatory agent-induced gastrointestinal lesions and adjuvant arthritis in rats

Sikiric P et al. · Journal of Physiology, Paris

Attenuated development and course of adjuvant arthritis; the only joint-disease (rather than tendon/ligament) BPC-157 animal model published.

Animal · 1997

Spontaneous calcification of arteries and cartilage in mice lacking matrix GLA protein

Luo G et al. · Nature

MGP-null mice developed spontaneous, inappropriate calcification of arteries and cartilage, dying of vascular rupture within about two months — the foundational evidence that a vitamin-K-dependent protein keeps cartilage from mineralising.

Cohort · 1997 · n=31516

Cartilage injuries: a review of 31,516 knee arthroscopies

Curl WW et al. · Arthroscopy

Chondral lesions were extremely common (53,569 lesions documented); grade IV lesions clustered on the medial femoral condyle, and 36.6% of under-40s with grade IV damage had no ligament or meniscus injury.

RCT · 1995 · n=812

Effects of antiinflammatory drugs on the progression of osteoarthritis of the knee. LINK Study Group. Longitudinal Investigation of Nonsteroidal Antiinflammatory Drugs in Knee Osteoarthritis

Huskisson EC et al. · Journal of Rheumatology

More than twice as many patients showed radiographic deterioration on indomethacin as on placebo (40/85 vs 19/85 among completers, p=0.009); tiaprofenic acid did not differ from placebo.

Case series · 1994 · n=23

Treatment of deep cartilage defects in the knee with autologous chondrocyte transplantation

Brittberg M et al. · The New England Journal of Medicine

At mean 39 months, 14 of 16 femoral condyle patients had good-to-excellent results and 11 of 15 femoral biopsies showed hyaline-like cartilage; patellar results were poor (2 of 7 good). The paper that launched cell therapy for cartilage.

Animal · 1993

In vivo stimulation of connective tissue accumulation by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+ in rat experimental wounds

Maquart FX et al. · The Journal of Clinical Investigation

Concentration-dependent increases in dry weight, DNA, collagen, and glycosaminoglycan content of granulation tissue — the core in-vivo wound-healing result behind GHK-Cu's reputation.

In vitro · 1992

Stimulation of sulfated glycosaminoglycan synthesis by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+

Wegrowski Y et al. · Life Sciences

Dose-dependent increase in total glycosaminoglycan synthesis (maximal 10^-9–10^-8 M), mainly dermatan and heparan sulfate — not the aggrecan-type chondroitin sulfate that dominates cartilage.

Animal · 1989

Pentosan polysulfate (Cartrophen) prevents the hydrocortisone induced loss of hyaluronic acid and proteoglycans from cartilage of rabbit joints as well as normalizes the keratan sulfate levels in their serum

Kongtawelert P et al. · The Journal of Rheumatology

PPS prevented steroid-induced loss of cartilage proteoglycan and hyaluronic acid and normalized serum keratan sulfate — early evidence of a chondroprotective mechanism.

RCT · 1989 · n=105

Effect of non-steroidal anti-inflammatory drugs on the course of osteoarthritis

Rashad S et al. · Lancet

Indomethacin-treated hips lost joint space faster than contralateral hips and patients came to arthroplasty sooner; the difference was not seen with azapropazone.

In vitro · 1988

Stimulation of collagen synthesis in fibroblast cultures by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+

Maquart FX et al. · FEBS Letters

Stimulated collagen synthesis from picomolar concentrations, maximal around 10^-9 M, independent of proliferation.

Animal · 1986

Softening of canine articular cartilage after immobilization of the knee joint

Jurvelin J et al. · Clinical Orthopaedics and Related Research

Eleven weeks of immobilization softened femoral and tibial cartilage (deformation rate up 42%) and thinned it by ~9% — mechanical competence of cartilage degrades rapidly without load.

Animal · 1986

Suppression of type II collagen-induced arthritis by intragastric administration of soluble type II collagen

Nagler-Anderson C et al. · Proceedings of the National Academy of Sciences of the United States of America

Oral native type II collagen suppressed the incidence and severity of collagen-induced arthritis, the foundational demonstration of the oral-tolerance mechanism invoked for UC-II.

Animal · 1982

Aspirin aggravates the degeneration of canine joint cartilage caused by immobilization

Palmoski MJ et al. · Arthritis and Rheumatism

Aspirin significantly worsened immobilization-induced cartilage degeneration — greater loss of uronic acid (proteoglycan) and greater suppression of proteoglycan synthesis (p<0.01) than immobilization alone.

Cohort · 1979 · n=186

Indomethacin treatment in osteoarthritis of the hip joint. Does the treatment interfere with the natural course of the disease?

Rønningen H et al. · Acta Orthopaedica Scandinavica

Radiographic hip-OA progression was more frequent, and by one parameter more severe, in indomethacin-treated hips than untreated hips — an early 'analgesic arthropathy' signal.

Case series · 1961

The etiology of chondromalacia patellae

Outerbridge RE · The Journal of Bone and Joint Surgery. British Volume

Origin of the Outerbridge I-IV grading (softening, fissuring <1/2 inch, fissuring >1/2 inch, exposed bone) still quoted in operative reports 60+ years later.