Purpose: Subacromial decompression is the standard surgical treatment of subacromial impingement syndrome. Unsatisfactory results have been reported for concomitant lesions as well as inadequate diagnosis. We sought to determine the predictive value of the preoperative examination for the results of arthroscopic subacromial decompression in impingement syndrome.
Methods: Forty-nine shoulder joints in 47 patients receiving arthroscopic subacromial decompression were prospectively followed for a mean 3.7 ± 0.4 years. Prior to surgery, the impingement tests according to Neer, Hawkins-Kennedy (in the neutral as well as abducted position), and the Jobe test (empty can position) were evaluated as well as the presence of a painful arc. The association between the presence of these sings, success of the operation, and improvement in Constant scores as well as WORC indices was analysed.
Results: Pre- to postoperative improvement in Constant scores as well as WORC indices was greater in case of a positive test result for every test studied. With the numbers available, significant greater improvements in Constant scores were observed only for patients with a positive Hawkins-Kennedy sign in the neutral position, Neer and Jobe tests, compared to patients with negative signs, respectively. No significant differences were observed for the improvement in WORC indices. Patients with at least four positive tests out of the five studied had greater improvement in Constant scores than patients with three or less positive test results. Five patients went on to receive subsequent shoulder surgery. There was no association between the necessity for revision surgery and the presence or absence of impingement signs.
Conclusion: The impingement tests according to Hawkins-Kennedy, Neer, and Jobe are valid predictors of outcome after subacromial decompression, as is the presence of multiple impingement tests. This study may aid in improving patient outcome and especially patient selection for subacromial decompression.
Level of evidence: Prognostic, Level I.