PREDICTORS OF PARTIAL WEIGHT-BEARING PERFORMANCE AFTER TOTAL HIP ARTHROPLASTY

Objective: To determine which patient characteristics, postoperative characteristics, and walking features influence patients' partial weight-bearing performance after total hip arthroplasty. Design: A descriptive prospective study. Patients: Fifty patients with total hip arthroplasty were included; partial weight-bearing was performed at a 10% body weight target load (n=33) and at a 50% body weight target load (n=17). Methods: Patient (age, gender, body weight, upper arm muscle strength) and postoperative (pain, fatigue, anxiety) characteristics, and walking features (step frequency, total walking time, total number of steps, walking aid) were measured postoperatively on day 7 (with and without a physical therapist) and on day 21 (at home). Multilevel regression analyses were conducted to identify determinants that influence partial weight-bearing. Results: Gender (female) (regression coefficient B=8.18, p=0.03) and total walking time (B=0.58,p<0.001) were positively, and pain during walking was negatively (B=-2.43, p=0.02), associated with the mean peak load. For partial weight-bearing at 10% body weight, postoperative overall anxiety (B=6.40, p=0.002) and total steps (B=0.05, p=0.02) were positively associated with the percentage of steps above the target load. For partial weight-bearing at home, postoperative overall anxiety was negatively associated with the percentage of steps above the target load (B=-5.32, p=0.001). Conclusion: Gender, pain during walking, walking time, postoperative anxiety and total number of steps influence the patient's partial weight-bearing performance.