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, Dahlberg L · Arthritis and Rheumatism

Cartilage GAG content (dGEMRIC T1(Gd)) rose in the exercise group and fell in controls (+15 vs -15 ms, p=0.036), and the change tracked self-reported change in activity (Spearman rS=0.70, 95% CI 0.31-0.89 in the exercise group). Symptoms did not follow: no KOOS subscale separated the groups, and of five objective performance measures only the one-leg jump did (+17 vs +7 cm, p=0.009), with knee-extensor peak torque and aerobic capacity unchanged. The first human randomised evidence that adult cartilage composition responds to a change in loading.

Population

Adults (mean age 46) 3-5 years after partial medial meniscectomy, at high risk of knee OA; 56 randomised, 45 examined at baseline, 30 imaged at both timepoints (16 exercise, 14 control)

Intervention

Supervised group exercise classes offered every weekday for 4 months with three attendances expected; the 16 analysed attended a mean of 31 sessions (range 0-54) and reported a mean of 22 further sessions of their own

Comparator

No-exercise control, no intervention

Limitations

26 of the 56 randomised reached no follow-up MRI; the imaging assessor was blinded, participants could not be; the trial was not powered for clinical outcomes, and the exercise group began higher on KOOS Symptoms (90 vs 81, p=0.047); surrogate imaging endpoint, single center, at-risk population rather than established OA.