Patients and methods: Between December 2011 and May 2013, a total of 35 patients with grade 1-3 OA were included. The patients were randomly assigned into two groups as group 1 (exercise group, n=19) and group 2 (control group, n=16). The patients in group 1 performed closed kinetic chain exercises, transcutaneous electrical nerve stimulation (TENS) and hot-pack supervised by physiotherapists for three weeks in the hospital setting, followed by nine weeks of home exercises. The patients in group 2 were treated with TENS + hot-pack for three weeks. All patients were evaluated by magnetic resonance imaging at baseline and at week 12. The primary increase in the cartilage volume and thickness was analyzed. Both groups were also compared for pain and functionality.

Results: There was no significant differences in the pre- and post-treatment total cartilage volume (from 4594.73 mm³ to 4866.80 mm³) and medial and lateral tibial plateau cartilage thickness (from 2.06 mm to 2.10 mm, and from 2.30 mm to 2.35 mm, respectively) in group 1 (p=0.505, p=0.450, p=0.161, respectively). Similarly, no significant difference in the pre- and post-treatment cartilage volume and thickness between the groups was observed (p>0.05). In terms of functionality, there were significant differences between the exercise group and the control group (p<0.05).

Conclusion: Our study results show no significant effect of closed kinetic chain exercise on the cartilage volume or morphology. Keywords : Exercise; knee cartilage; magnetic resonance imaging; osteoarthritis