Objectives : An important role of convalescent rehabilitation wards is the short-term improvement of mobility and activities of daily living (ADL). We aimed to identify predictors associated with the length of stay (LOS) in a convalescent hospital after total hip and knee arthroplasty. Methods : This study included 308 patients hospitalized in a convalescent ward following total hip or total knee arthroplasty. The following factors were examined: age, sex, orthopedic comorbidities, motor component of the functional independence measure (M-FIM), M-FIM gain, pain, 10-m walk test, timed up and go (TUG) test, functional ambulation category (FAC), cognitive function, and nutritional status. LOS was categorized as shorter (≤40 days) or longer (>40 days), based on the national average LOS in a convalescent ward, and was statistically analyzed with predictor variables. Results : In our hospital, the average LOS was 36.9 ± 21.4 days, and the average M-FIM at admission to the convalescent ward and the M-FIM gain were 71.1 ± 7.0 and 16.3 ± 6.9, respectively. In univariate analysis, there was a significant correlation between LOS and M-FIM at admission and M-FIM gain, pain, TUG time, and FAC. Logistic multivariate analysis identified M-FIM at admission (odds ratio [OR] 0.93, 95% confidence interval [CI] 0.88–0.98) and TUG time (OR 1.10, 95% CI 1.03–1.18) as independent predictors of LOS. Conclusions : The M-FIM and TUG test can be used to accurately estimate LOS and to plan rehabilitation treatment in a convalescent rehabilitation ward after lower-limb arthroplasty. Furthermore, preoperative or early postoperative intervention may lead to better quality motor activity and shorter LOS during the convalescent period.

The intensive rehabilitation of older patients after total knee arthroplasty (TKA) is vital for short-term improvement in mobility and daily living activities. We aimed to investigate the effectiveness of multidisciplinary rehabilitation and assess the early postoperative predictors that are associated with functional gain in TKA patients aged from 75 years in a postacute care setting. This study included 190 patients following primary TKA who were admitted at the postacute rehabilitation hospital. The main outcome measures were the motor component of functional independence measure (M-FIM), M-FIM effectiveness, numerical rating scale, knee extension strength and range of motion, 10-m walk test, Berg balance scale (BBS), and mini-mental state examination (MMSE). The functional gain between patient age groups of ≥75 (n = 105) and <75 (n = 85) years were compared. Although patients aged ≥75 years showed lower improvement in BBS score compared with <75 years, the M-FIM gains and other physical functions were similar in both age groups. In multivariate analysis, the results for M-FIM at admission (β: −0.703; P = 0.001), BBS (β: 0.342; P = 0.032) and MMSE (β: 0.446; P = 0.021) were independently associated with functional gain in the patients following TKA aged ≥75 years. Multidisciplinary inpatient rehabilitation was beneficial for basic functional gain except for improvement in balance ability in patients after TKA aged ≥75 years. Functional level, balance ability and cognitive status in the early postoperative period can be useful predictors for short-term functional gain in the postacute care phase.