Determinants of the subjective functional outcome of total joint arthroplasty.

The aim of the study is three-fold: (i) to analyze association between early subjective functional outcome of total joint arthroplasty (TJA) and patient-related risk factors; (ii) to evaluate the six-month subjective functional outcome of TJA as compared with subjective functional status of non-operated outpatients; (iii) to evaluate TJA self-perceived amelioration rates compared to the status of an age-matched sample from a general medical practice. A prospective consecutive study was performed upon 100 elderly inpatients with recent primary total hip arthroplasty (THA) or total knee arthroplasty (TKA) for osteoarthritis. Interviews on preoperative status and short-term outcome were performed at admission and six months after surgical intervention with Western Ontario and MacMasters Universities Osteoarthritis Index (WOMAC). One hundred aged-matched consecutive outpatients were screened for osteoarthritis and interviewed with the same questionnaire in a single session. Differences between baseline and follow-up scores were evident and statistically significant for both TJA groups, although THA patients showed more improvement. The comparison between TJA patients at baseline and age-matched osteoarthritis outpatients highlighted less impairment among outpatients. The situation reversed six months after the intervention. Objective functional outcome of post-operative rehabilitation has not revealed predictive value for the six-month outcome of TJA in terms of self-perceived functional status. Logistic regression analysis indicated that preoperative status was the only significant predictor of higher WOMAC scores six months after TJA. The survey confirms the early benefit of THA or TKA for osteoarthritis, but a less favorable subjective functional outcome is expected at six months when preoperative subjective functional status is severely compromised.