The acromial index is not predictive for failed rotator cuff repair

Background The main objective of this study was to evaluate the association between the acromial index (AI) and the incidence of recurrent tears of the rotator cuff (RC) in a cohort of patients with full thickness tears who underwent arthroscopic primary repair. Methods A prognostic study of a prospective case series of 103 patients with full thickness RC tears was undertaken. The average age was 59.5 years (39-74) and follow-up was 30.81 months (12-72). True anterior-posterior X-rays were obtained during the pre-operative evaluation. Pre and post-operative magnetic resonance imaging (MRI) were recorded. Results Eighteen cases with recurrent tears (17.4 %) were seen on post-operative MRI. The average AI for patients with recurrent tears was 0.711 +/- 0.065 and for patients without recurrent tears 0.710 +/- 0.064 (p < 0.05). A positive association between age and recurrent tears of the RC was noted (average ages: recurrent tears group 63 +/- 5.9 years; group without recurrent tears 58.8 +/- 7.5 years) (r = -0.216; p = 0.029). We did not find an association between size of the primary tear and recurrent tears (r = -0.075; p < 0.05) or between degrees of retraction of the primary and recurrent tears of the cuff (r = -0.073; p < 0.05). We observed that 38.9 % of the recurrent tears cases presented with more than one tendon affected before the arthroscopy. At follow-up, none of these recurrent tears showed more than one tendon affected on MRI evaluation. Conclusion In this study, we found that the AI radiological measurement is not a predictor for recurrent tears of the RC after primary arthroscopic repair.