Which factors affect the duration of inpatient rehabilitation after total knee arthroplasty in the absence of complications?

OBJECTIVE: The aim of this study was to determine which preoperative factors might predict the duration of inpatient rehabilitation for total knee arthroplasty (TKA) patients in the absence of complications.
METHODS: We included 282 patients who had undergone primary TKA for osteoarthritis. The aim of the rehabilitation program was to recover 90 degrees of active knee flexion and good enough functional status to allow direct discharge to the patient;s home. Patients presenting complications were excluded. The following preoperative parameters were recorded: demographic factors, comorbidity, previous lower limb arthroplasty, the presence of a home help, the pain level (on a visual analogue scale, VAS) and functional scores. The length of stay in the orthopaedic surgery unit was also taken into consideration. Predictive factors for the duration of inpatient rehabilitation were analyzed using univariate and then multivariate linear regression.
RESULTS: In a univariate analysis, the length of stay (24.1 +/- 8.1 days) depended on female gender, living alone, the presence of a home help and previous arthroplasty ( p < 0.25). However, when these factors were introduced into a multivariate predictive model, only 2% of the variation in the length of stay was accounted for.
CONCLUSION: The duration of inpatient rehabilitation for TKA patients in the absence of complications cannot be statistically modelled from the preoperative parameters studied here.