Prediction of Function after Shoulder Replacement

Objective: Although shoulder arthroplasty with ensuing rehabilitation is a relatively common intervention, the factors influencing the functional outcome are still a matter of discussion. These are evaluated based on the outcome as estimated by the Constant Score and patient satisfaction. Consequently, a prediction of the outcome based on initial demographic and diagnostic parameters is shown. Methods: 57 patients received an alloplastic shoulder replacement followed by short stay in-patient rehabilitation. To estimate functional results a questionnaire including the Constant Score, clinical examination, numerical rating scale for pain estimation, radiological investigation of the shoulder joint and satisfaction were recorded. A generalized linear model was fitted to evaluate the effect of covariates Constant Score at admission, discharge and the improvement in-between. Results: 47 (82%) patients were content with the treatment received. The median Constant Score at admission of 31 (3 improved to 64 (12) at follow-up. Patients treated by senior specialist obtained 13 (2) points more at discharge than patients treated by less experienced surgeons. Patients with assisted physiotherapy between operation and rehabilitation achieved 8 (2) points more. Motivated patients did 7 (2) points. A minimal Constant Score of 40 at admission, 60 at discharge or an improvement of 30 points ensured satisfied patients. Conclusions: Motivated patients receiving assisted physiotherapy between operation by an experienced specialist and rehabilitation have better functional results. Age, gender, type of prosthesis and diagnosis have no effect. A Constant Score of 40 at admission is associated with the patients being motivated and satisfied with the treatment.