Predicting discharge outcome after elective hip and knee arthroplasty.

The objective of this prospective study was to determine if differences exist between individuals who require an inpatient rehabilitation program after elective hip and knee arthroplasty from those patients who can be discharged directly home. Multiple variables consisting of baseline demographics, social status, insurance status, medical history, pain level, quantitative strength, range of motion, and functional ability were examined. The primary outcome measure was the discharge destination from the orthopedic service and consisted of either a discharge to home or a discharge to an inpatient rehabilitation unit. Of the 162 patients followed, 65 (40%) were discharged to an inpatient rehabilitation unit, whereas 97 were discharged to home. The patients discharged to inpatient rehabilitation tended to live alone, were significantly older (mean difference = 6.3 yr), and had increased comorbid conditions (p < 0.001 for all variables). Patients discharged to a rehabilitation unit reported significantly greater pain levels than those discharged to home (P < 0.001). The attainment of a supervision level of function demonstrated greater differences between groups than the attainment of independent function for all functional measures. A logistic regression model was developed that predicted 76% of the discharges to rehabilitation by the third physical therapy session postsurgery. In conclusion, predictive markers do exist that differentiate individuals who require further inpatient therapy services after joint replacement surgery.