Comparative analysis of quadriceps and hamstrings strength in knee osteoarthritis before and after total knee arthroplasty: a cross-sectional study

摘要

Objective Compare the maximal isokinetic muscle strength of knee extensor and flexor muscles between patients with knee osteoarthritis and patients submitted to total knee arthroplasty. Methods Volunteers were divided into five groups ( n =20): Control; Ahlb?ck I and II ; Ahlb?ck IV ; six months after total knee arthroplasty; 12 months after total knee arthroplasty. An isokinetic knee strength evaluation was conducted for the quadriceps and hamstrings at 60°/s. Results Significant differences in the peak torque of the quadriceps and hamstrings were found among the groups ( p <0.001). The Ahlb?ck IV , six-month, and 12-month postoperative groups demonstrated lower values when compared to the Control and Ahlb?ck I and II groups. When percentage values were compared to the Control group, mean differences ranged from 7% to 41%. Conclusion Patients with healthy knees or early stage osteoarthritis have higher quadriceps and hamstrings strengths than those with a more advanced stage of the disease, even after knee replacement. These findings suggest that the traditional rehabilitation programs do not recover strength to levels observed in individuals without knee osteoarthritis.