Background: The purpose of this paper was to determine whether acromial morphology influences anteroposterior shoulder stability. We hypothesized that a more horizontal and higher position of the acromion in the sagittal plane would be associated with posterior instability. Methods: In this retrospective study, patients with unidirectional posterior instability were age and sex-matched to a cohort of patients with unidirectional anterior instability. Both cohorts were compared with a control group of patients with no instability and no degenerative glenohumeral (rotator cuff and/or joint surface) or acromial changes. Measurements on radiographs included posterior acromial tilt, anterior and posterior acromial coverage (AAC and PAC), posterior acromial height (PAH), and the critical shoulder angle (CSA). Results: The number of patients enrolled in each instability group was 41, based on a priori power analysis. The control group consisted of 53 shoulders. Of the measured anatomic factors, PAH showed the most significant association with posterior instability (odds ratio [OR] = 1.8; p < 0.001) in the logistic regression model. PAH was significantly greater in the posterior instability group compared with the anterior instability group (30.9 versus 19.5 mm; p < 0.001). With a cutoff value of PAH of 23 mm, the OR for posterior instability was 39. Shoulders with posterior instability were also significantly different from normal shoulders with regard to PAH (p < 0.001), AAC (p < 0.001), and PAC (p < 0.001) whereas, in the shoulders with anterior instability, all of these values except the AAC (p = 0.011) did not differ from those of normal shoulders. Conclusions: Specific acromial morphology is significantly associated with the direction of glenohumeral instability. In shoulders with posterior instability, the acromion is situated higher and is oriented more horizontally in the sagittal plane than in normal shoulders and those with anterior instability; this acromial position may provide less osseous restraint against posterior humeral head translation. A steep “Swiss chalet roof-type” acromion virtually excluded recurrent posterior instability in an albeit relatively small cohort of patients. Additional investigation is needed to determine the relevance of these findings for future treatment. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Background: The purpose of this study was to analyze the long-term results of arthroscopic Bankart repair compared with an open Latarjet procedure in adolescents who are at high risk for recurrent anterior shoulder instability. We hypothesized that the long-term stability rate of an open Latarjet procedure would be superior to that of arthroscopic Bankart repair. Methods: Forty eligible patients (41 shoulders) with a mean age of 16.4 years (range, 13 to 18 years) underwent arthroscopic Bankart repair, and 37 patients (40 shoulders) with a mean age of 16.7 years (range, 14 to 18 years) underwent an open Latarjet procedure. Of these, 34 patients (35 shoulders) in the Bankart group and 30 patients (31 shoulders) in the Latarjet group with long-term follow-up were compared; the overall follow-up rate was 82%. Clinical and radiographic results were obtained after a mean follow-up of 12.2 years (range, 8 to 18 years). Results: Treatment failure occurred in 20 shoulders (57%) in the Bankart repair group and in 2 shoulders (6%) in the open Latarjet procedure group (p < 0.001), representing a significantly higher revision rate for instability in the Bankart group (13) compared with the Latarjet group (1) (p < 0.001). In patients without recurrent shoulder instability (15 in the Bankart group and 29 in the Latarjet group), there was a significant improvement in the Constant score (p = 0.006 in the Bankart group and p < 0.001 in the Latarjet group) and Subjective Shoulder Value (p = 0.009 in the Bankart group and p < 0.001 in the Latarjet group), without any significant difference between the 2 groups. Younger age was the only variable significantly correlated with failure following a Bankart repair (p = 0.01). Conclusions: Adolescents are at a high risk for treatment failure after Bankart repair, and, therefore, the Latarjet procedure should be strongly considered as a primary procedure for recurrent anterior shoulder instability in this population. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Background: One recognized salvage option in the treatment of an irreparable subscapularis tear is the pectoralis major tendon transfer (PMT). We aimed to analyze the long-term clinical and imaging outcome of PMT for irreparable subscapularis deficiency. Methods: Twenty-eight consecutive patients representing 30 shoulders underwent PMT at a mean age of 53.0 years (range, 35 to 67 years). At a mean of 19.7 years (range, 18 to 22 years) postoperatively, 24 shoulders (80%) were clinically examined and 21 were radiographically and sonographically assessed. The long-term results were compared with preoperative findings and previously published short-term results. Results: The mean relative Constant score (percentage of age and sex-matched normal scores; CS%) and the Subjective Shoulder Value (SSV) both improved significantly from preoperatively (CS%, 47%, and SSV, 22%) to postoperatively (CS%, 77%, and SSV, 71%; p < 0.001 for both). All patients rated their results as good or excellent. Active anterior elevation was improved from preoperatively (120°) to postoperatively (131°), but the difference was not significant. Active internal and external rotation decreased significantly from the short-term (32-month) follow-up to the time of the latest follow-up (p = 0.005 and p = 0.002, respectively); however, internal rotation remained at 6 points compared with the 8 points recorded at short-term follow-up and external rotation decreased only from a mean of 51° to 39°. Loss of active range of motion was not observed subjectively and was not subjectively limiting, represented by the high ultimate SSV and overall satisfaction. Four shoulders (19%) showed evidence of glenohumeral arthropathy (Samilson and Prieto grade 3), but clinically were mildly symptomatic to asymptomatic at the time of the latest follow-up (CS% range, 67% to 88%; SSV range, 70% to 80%). Rupture of the PMT was sonographically identified in 2 patients (10%) and was associated with radiographic evidence of advanced cuff tear arthropathy (Hamada stages ≥4). Six (20%) of the initial 30 shoulders were revised, and 1 (4%) of the 24 shoulders that were clinically examined underwent reverse total shoulder arthroplasty. Conclusions: At long-term follow-up, PMT for isolated and combined subscapularis tears is associated with good to excellent clinical results. Although one-third of the shoulders developed mildly symptomatic or asymptomatic osteoarthritis, the need for salvage with use of reverse total shoulder arthroplasty was rare. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.