Abstract
Objective: This study examined differences between hip and knee muscle recovery in the early postoperative phase after total hip arthroplasty (THA).
Methods: Fifty-three women with hip osteoarthritis who underwent unilateral cementless THA participated in this study. The maximum isometric forces of the hip abductors, extensors, and flexors and knee extensors and flexors on the involved and uninvolved limbs were measured preoperatively and again 2, 4, and 6 weeks postoperatively.
Results: The hip abductor, extensor, and flexor strengths of the involved limbs 2 weeks postoperatively were significantly lower than the corresponding preoperative values, while these three values did not differ from the preoperative values 4 and 6 weeks postoperatively. The knee extensor strengths of the involved limb 2, 4, and 6 weeks postoperatively were significantly lower than the preoperative value. There were no significant differences in the preoperative ratios between the hip abductors, extensors, and flexors and knee flexors 6 weeks postoperatively in the involved limb (range 114-124%), while the ratio of the knee extensors (86%) was significantly lower than those of the other four muscle groups.
Conclusions: The recovery of knee extensor strength was delayed in comparison with that of the hip musculature and knee flexors after THA.
