Preoperative physical therapy in primary total knee arthroplasty

In order to evaluate the efficacy of preoperative physical therapy for patients undergoing elective primary total knee arthroplasty, 10 patients completed 6 weeks of physical therapy before surgery (PT group). Ten patients served as controls (C group). Subjects were tested at baseline (PT only), before surgery, 6 weeks after surgery, and 3 months after surgery using the Hospital for Special Surgery knee rating scale, range of motion, thigh circumference, walking speed, Cybex II isokinetic knee flexion, and extension testing, and computed tomography scanning for cross-sectional muscle area. Hospital stay and need for physical therapy after inpatient rehabilitation were also compared. Physical therapy produced modest gains in isokinetic flexion strength in these severely arthritic knees but no difference in extension strength. The decrease in isokinetic strength after surgery was not affected by preoperative physical therapy. Muscle area did not decrease significantly for the PT group, but it did decrease for the C group after surgery. While postoperative strength differences could not be demonstrated, preoperative physical therapy preserved thigh muscle area after surgery. The clinical significance of this finding is uncertain. Consequently, this study failed to support the routine use of preoperative physical therapy in knee replacement surgery.