Does isolated arthroscopic anterior acromioplasty modify critical shoulder angle?

Abstract

IntroductionCritical shoulder angle (CSA)>35° correlates significantly with primary rotator cuff tear and re-tear after repair. Acromial axial orientation varies between individuals. The present study aimed to assess the impact of strictly anterior acromioplasty on CSA. HypothesisCSA is reduced by arthroscopic anterior acromioplasty. Material and methodsA single-center retrospective study included patients receiving isolated arthroscopic acromioplasty between January 2016 and December 2017. Exclusion criteria comprised history of surgery and fracture or dislocation of the shoulder. Pre- and post-operative AP shoulder radiographs were taken. The angle subtended by a line between the inferior and superior edges of the glenoid and a line between the inferior edge of the glenoid and the most lateral point on the acromion was measured. ResultsOne hundred and two patients were included: mean age, 50.5±10.1 years (range, 23–82 years). Mean CSA was 34.7±4.4° (range, 26–48°) preoperatively and 31.7±3.7° (range, 23–40°) postoperatively (p<0.001). In the group with CSA >35°, the decrease was significant: 34.4±3.2° (range, 28–40°) versus 38.9±2.8° (range, 36–48°) (p<0.001), with 64% CSA <35° after isolated anterior acromioplasty. DiscussionCSA was decreased by arthroscopic acromioplasty. However, in 36% of cases with preoperative CSA >35°, CSA was not normalized. ConclusionAnterior arthroscopic acromioplasty significantly reduced CSA in the overall population, and especially in case of high CSA. Level of evidenceIV; retrospective study.