Outcomes and weight-bearing status during rehabilitation after arthroplasty for hip fractures

Abstract

Objective: To examine the association of weight-bearing status with patient-related variables and outcomes of inpatient rehabilitation after hip arthroplasty for acute hip fracture.

Design: A multi-site prospective observational cohort study.

Setting: Eighteen skilled nursing and inpatient rehabilitation facilities.

Subjects: Patients with hip fractures (N = 224) treated with hip arthroplasty and admitted to either skilled nursing or inpatient rehabilitation facilities; a subset (N = 84) with telephone follow-up outcomes 8 months after rehabilitation discharge.

Methods: Measurements included demographic variables, medical severity using the Comprehensive Severity Index, and functional levels using the Functional Independence Measure. MAIN OUTCOMES MEASUREMENT: Cognitive, motor, and total Functional Independence Measure scores at rehabilitation discharge and at 8-month follow-up; living location at discharge and follow-up.

Results: Patients on average (standard deviation) were 76.8 ± 11.4 years old, mainly women (78%), and mainly white (87%). In unadjusted analysis, weight bearing as tolerated (WBAT) was associated with less osteoarthritis (P = .025) and lower admission medical severity (ACSI) (P = .014). One participating facility had a significant preponderance of restricted weight-bearing cases. WBAT had no bivariate association with cognitive or motor function at discharge. Therapists cited restricted weight bearing as a barrier to therapy in 11% of cases. In logistic regressions, lower medical admission severity, older age, and one specified site significantly predicted WBAT (c statistic = 0.714). Significant predictors for home discharge included lower maximum severity (P < .001), younger age (P < .001), higher cognition (P = .037), and WBAT (P = .051) (c statistic = 0.863).

Conclusions: WBAT is associated with a greater likelihood of home discharge and had similar functional outcomes compared with restricted weight bearing. These findings add support for allowing WBAT after arthroplasty for hip fracture.