Can Isokinetic Testing Lead to More Precise Monitoring of Chondromalacia Patella? Prospective, Cross-sectional Study

Objective: Chondromalacia patella, one of the most common musculoskeletal problems encountered in clinical practice. The isometric test using the isokinetic dynamometer can be used for a valid assessment and follow-up of knee strength during the rehabilitation of chondromalacia patella. Our study investigates the effectiveness of the isokinetic dynamometer as a monitoring tool for individuals with chondromalacia patella. Methods: Twenty-eight patients with chondromalacia patella (mean age 39±10.84 years, mean symptom duration 11.75±7.38 months) were included in the study. All patients had physical therapy and rehabilitation program that was applied for 15 sessions, 5 days a week during 3 weeks. Knee flexion and extension strengths were measured at 60°/second and 180°/second (5 sets) angular velocity with an isokinetic dynamometer system before and after physical therapy and rehabilitation program. Visual analog scale (VAS)-pain value was used for clinical assessment. Modifies magnetic resonance imaging (MRI) staging system was used in the staging of chondromalacia patella. The relationship between VAS pain value and isokinetic dynamometer parameters was analyzed, as well as correlation in radiological MRI staging, treatment effectiveness, symptom duration. A value of p<0.05 was considered significant. Results: Statistically significant improvement was observed in the knee flexion and extension muscle strengths at 60°/second and the 180°/the second angular velocity (PTE_60, PTF_60, PTE_180, PTF_180) after the physical therapy and rehabilitation program in affected knees (p=0.0001 for all). Analysis of correlation and interaction of chondromalacia patella MR stages, VAS pain value, body mass index, duration of symptoms, and treatment efficacy was also statistically significant (p<0.05). Conclusion: Our study results suggest that physical therapy and rehabilitation program improves the strength of both knee extensors and flexors, and isokinetic parameters have a significant effect on the treatment effectiveness. The isokinetic dynamometer may provide a precise monitoring to assess treatment efficacy of patients with chondromalacia patella. More studies are needed for further scientific evidence.