METHODS
This study was a secondary analysis of two pooled prospective randomized clinical trials.11,12 All patients were assessed 1–2 wks preoperatively (preoperative time point) and 6 mos postoperatively (long-term time point) in the Clinical and Translational Research Center at the University of Colorado Hospital. The patients were also assessed 48 hrs after surgery (acute time point) on the inpatient orthopedic floor of the University of Colorado Hospital. Postoperative day 2 was chosen because the mean hospital length of stay is 3 days, and this enabled all patients to be tested; some were discharged on postoperative day 2. The 6-mo time point was chosen as the long-term time point because recovery after TKA usually plateaus by this time point.13–15 Informed consent was obtained from all participants. Both studies were approved by the Colorado Multiple Institutional Review Board.
Participants and Interventions
Sixty-four patients (mean [SD] age, 64.6 [8.5] yrs; 32 men and 32 women; body mass index, 30.6 [4.8] kg/m2) were recruited from the community and with assistance of three participating orthopedic surgeons between June 2006 and June 2010. Eligible volunteers were those between the ages of 50 and 85 yrs and scheduled to receive a primary unilateral TKA secondary to end-stage osteoarthritis of the knee. Patients were excluded for any of the following criteria that could affect long-term functional performance: significant cardiac or neurologic impairments, contralateral knee osteoarthritis (as defined by pain greater than 5/10 with activity), other unstable lower extremity orthopedic conditions, body mass index of 40 kg/m2 or greater, uncontrolled diabetes, or uncontrolled hypertension.
All patients underwent surgery in the same hospital using a tricompartmental, cemented TKA with a medial parapatellar surgical approach. After surgery, the patients participated in a standardized rehabilitation protocol beginning on postoperative day 1 as previously described.16 The patients were seen twice daily in the acute setting for 2–4 days before discharge to home. In the acute setting, rehabilitation consisted of patient education, passive and active ROM, gait training, transfer training, and stair training, if necessary. The patients were then seen in the home and outpatient setting for a total of 16–18 visits during 8 wks. Rehabilitation in the home and outpatient settings consisted of passive and active ROM, lower extremity flexibility exercises, patellofemoral mobilization, incision mobilization, gait training, functional training (transfers and stairs), weight-bearing and non–weight-bearing exercises, and modalities (ice and heat) as needed. All patients were given a home exercise program to be completed twice daily until discharge from therapy.