Prognostic Factors for Functional Outcome After Rotator Cuff Repair: A Prospective Cohort Study With 2-Year Follow-up.

BACKGROUND: Although shoulder function is reported to be generally good after rotator cuff repair, limited knowledge exists regarding which prognostic factors predict functional outcomes.

PURPOSE: To identify pre- and perioperative predictors of functional outcomes after arthroscopic rotator cuff repair.

STUDY DESIGN: Case-control study; Level of evidence, 3.

METHODS: A cohort of 733 consecutive patients treated with rotator cuff repair between 2010 and 2014 in a single orthopaedics unit was included. Data were collected prospectively and included pre- and perioperative variables. Univariate and multivariable linear regression analyses were used to predict shoulder function at 2-year follow-up, as measured by the Western Ontario Rotator Cuff Index (WORC).

RESULTS: In total, 647 (88%) patients were followed for 25 ± 5 months (mean ± SD; range, 17-66 months). In the multivariable regression model, the adjusted R2 was 0.360, indicating that 36% of the variation in the WORC at final follow-up could be explained by this statistical model. The multivariable linear regression analysis revealed that the strongest positive independent predictors of shoulder function at 2 years were preoperative WORC and Constant-Murley score in the contralateral shoulder. The model also indicated that activities of daily living, age, subacromial decompression, and biceps surgery had independent positive associations with better shoulder function at 2 years. In addition, previous surgery in the ipsilateral or contralateral shoulder, smoking, partial rotator cuff repair, preoperative pain, and atrophy in the infraspinatus were all independent factors negatively associated with shoulder function after 2 years. The overall healing rate of complete repairs per magnetic resonance imaging was 80%.

CONCLUSION: The most important finding of the present study was that the strongest prognostic factors for better WORC at 2-year follow-up were better preoperative WORC and Constant-Murley score in the contralateral shoulder. Although not all the prognostic factors identified in this study are modifiable, they can still be useful for guiding patients in shared decision making with the surgeon. This cohort study shows that if selection of patients is performed properly, it is possible to obtain a successful outcome.