Effects of Native Type II Collagen Treatment on Knee Osteoarthritis: A Randomized Controlled Trial

Bakilan F, Armagan O, Ozgen M, Tascioglu F, Bolluk O, Alatas O · Eurasian Journal of Medicine

One between-group comparison reached significance: VAS during walking, in favour of the combination (p=0.002). The groups were not balanced on that measure at baseline — median 6 on the combination against 3 on acetaminophen alone (p=0.014) — and they finished at the same value, 3 against 3 (p=0.469), so the result rests on the change scores. WOMAC pain, total and physical function improved within the combination group and did not separate between the groups; WOMAC stiffness and 20 m walking time moved in neither. The urinary cartilage-degradation markers Coll2-1, Coll2-1NO2 and Fibulin-3 were flat in both groups, so the one objective measure of cartilage turnover showed nothing.

Population

Patients with knee osteoarthritis, Eskisehir, Turkey

Intervention

Acetaminophen 1500 mg/day plus 10 mg/day native type II collagen for 3 months

Comparator

Acetaminophen 1500 mg/day alone

Limitations

Single-blind, not double-blind, and severely underpowered at n=39 across two arms. No placebo — the comparator is acetaminophen alone, so this is an add-on design. The dose is 10 mg, not the 40 mg used in the manufacturer trials. Within-group improvements dominate the abstract. Academic rather than manufacturer-run, which is rare in this literature.