Background: Treatment of posterior shoulder instability (PSI) associated with excessive glenoid retroversion is a rare, challenging problem in shoulder surgery. One proposed technique is posterior open wedge glenoid osteotomy to correct excessive glenoid retroversion as described by Scott. However, this operation is rarely performed, and limited long-term outcomes using this approach are available. The goal of this study was to analyze the long-term outcomes of posterior open wedge glenoid osteotomy for PSI associated with excessive glenoid retroversion. Methods: Six consecutive patients (7 shoulders) with a mean age of 24 years (range 19-34) were treated with posterior open wedge glenoid osteotomy for PSI associated with a glenoid retroversion greater than 15 and followed up clinically and radiographically at a mean age of 15 years (range 10-19). Results: Recurrent, symptomatic PSI was observed in 6 of 7 shoulders (86%). One necessitated revision with a posterior (iliac crest) bone block procedure and was rated as a failure and excluded from functional analysis. One patient rated his result as excellent, 3 as good, 1 as fair, and 1 as unsatisfactory. Mean relative Constant Score (CS%) was unchanged from preoperation to final follow-up (CS% ¼ 72%) and pain did not significantly decrease (Constant Score ¼ 7-10 points; P ¼ .969). The mean Subjective Shoulder Value (SSV) improved postoperatively, but with 6 patients the improvement did not reach statistical significance (SSV ¼ 42%-67%, P ¼ .053) and the total Western Ontario Shoulder Instability Index averaged 30% at the final follow-up. Mean glenoid retroversion of all 7 shoulders was corrected from 20 (range 16 -26 ) to 3 (range À3 to þ8 ) (P ¼ .018). In the 5 shoulders with preoperative static posterior subluxation of the humeral head, the humeral head was not recentered. All 7 shoulders showed progression of glenoid arthritic changes.Conclusions: Posterior open wedge glenoid osteotomy for PSI associated with excessive glenoid retroversion neither reliably restored shoulder stability nor recentered the joint or prevent progression of osteoarthritis. Alternative treatments for PSI associated with excessive glenoid retroversion have to be developed and evaluated.

Background Atraumatic posterior shoulder instability in patients with pathologic glenoid retroversion and dysplasia is an unsolved problem in shoulder surgery. Questions/purposes In a preliminary study of a small group of patients with atraumatic posterior shoulder instability associated with glenoid retroversion ≥ 15° and glenoid dysplasia who underwent posterior open-wedge osteotomy and glenoid concavity reconstruction using an implant-free, J-shaped iliac crest bone graft, we asked: (1) What proportion of the patients had persistent apprehension? (2) What were the improvements in patient-reported shoulder scores? (3) What were the radiographic findings at short-term follow-up? Methods Between 2016 and 2018, we treated seven patients for atraumatic posterior shoulder instability. We performed this intervention when posterior shoulder instability symptoms were unresponsive to physiotherapy for at least 6 months and when it was associated with glenoid retroversion ≥ 15° and dysplasia of the posteroinferior glenoid. All seven patients had a follow-up examination at a minimum of 2 years. The median (range) age at surgery was 27 years (16 to 45) and the median follow-up was 2.3 years (2 to 3). Apprehension was assessed by a positive posterior apprehension and/or posterior jerk test. Patient-reported shoulder scores were obtained and included the subjective shoulder value, obtained by chart review (and scored with 100% representing a normal shoulder; minimum clinically important difference [MCID] 12%), and the Constant pain scale score (with 15 points representing no pain; MCID 1.5 points). Radiographic measurements included glenohumeral arthropathy and posterior humeral head subluxation, bone graft union, correction of glenoid retroversion and glenoid concavity depth, as well as augmentation of glenoid surface area. All endpoints were assessed by individuals not involved in patient care. Results In four of seven patients, posterior apprehension was positive, but none reported resubluxation. The preoperative subjective shoulder value (median [range] 40% [30% to 80%]) and Constant pain scale score (median 7 points [3 to 13]) were improved at latest follow-up (median subjective shoulder value 90% [70% to 100%]; p = 0.02; median Constant pain scale score 15 points [10 to 15]; p = 0.03). Posterior glenoid cartilage erosion was present in four patients (all four had Walch Type B1 glenoids) preoperatively and showed no progression until the final follow-up examination. The median (range) humeral head subluxation index decreased from 69% (54% to 85%) preoperatively to 55% (46% to 67%) postoperatively (p = 0.02), and in two of four patients with preoperative humeral head subluxation (> 65% subluxation), it was reversed to a centered humeral head. CT images showed union in all implant-free, J-shaped iliac crest bone grafts. The median preoperative retroversion was corrected from 16° (15° to 25°) to 0° postoperatively (-5° to 6°; p = 0.02), the median glenoid concavity depth was reconstructed from 0.3 mm (-0.7 to 1.6) preoperatively to 1.2 mm (1.1 to 3.1) postoperatively (p = 0.02), and the median preoperative glenoid surface area was increased by 20% (p = 0.02). No intraoperative or postoperative complications were recorded, and no reoperation was performed or is planned. Conclusion In this small, retrospective series of patients treated by experienced shoulder surgeons, a posterior J-bone graft procedure was able to reconstruct posterior glenoid morphology, correct glenoid retroversion, and improve posterior shoulder instability associated with pathologic glenoid retroversion and dysplasia, although four of seven patients had persistent posterior apprehension. Although no patients in this small series experienced complications, the size and complexity of this procedure make it likely that as more patients have it, some will develop complications; future studies will need to characterize the frequency and severity of those complications, and we recommend that this procedure be done only by experienced shoulder surgeons. The early results in these seven patients justify further study of this procedure for the proposed indication, but longer term follow-up is necessary to continue to assess whether it is advantageous to combine the reconstruction of posterior glenoid concavity with correction of pathological glenoid retroversion and increasing glenoid surface compared with traditional surgical techniques such as the posterior opening wedge osteotomy or simple posterior bone block procedures. Level of Evidence Level IV, therapeutic study.

Background: Primary traumatic anterior shoulder dislocations can be associated with displaced anterior glenoid rim fractures. Nonoperative treatment of such fractures has been shown to have excellent results in a small cohort of patients; as such, we have been treating these fractures nonoperatively, regardless of fragment size and degree of displacement, provided that post-reduction computed tomography scans revealed an anteroposteriorly centered humeral head. The aim of this study was to analyze the medium- to long-term results of nonoperative treatment of displaced anterior glenoid rim fractures, assessing in particular the residual instability and development of osteoarthritis. Methods: In a 2-center study, 30 patients with a mean age of 48 years (range, 29 to 67 years) were evaluated clinically with use of the Subjective Shoulder Value, Constant score, American Shoulder and Elbow Surgeons score, and Western Ontario Shoulder Instability index, as well as radiographically with use of radiographs and computed tomography scans at a mean follow-up of 9 years (range, 5 to 14 years). Results: Fracture-healing was documented in all patients. Seven patients (23%) had post-fracture onset of osteoarthritis (5 with Samilson grade I and 2 with Samilson grade IV). Of these, 1 patient had recurrent instability that was successfully treated with hemiarthroplasty 9 years after the index injury (relative Constant score, 101%), and was excluded from further analysis. No other patient had a recurrent redislocation, subluxation, or positive apprehension. The other 6 patients with new-onset radiographic osteoarthritis were pain-free (mean Constant score pain scale, 15 points) with good shoulder function (relative Constant score, 84% to 108%). A total of 26 patients (90%) rated their functional outcome as good or very good, and 3 patients (10%) rated it as fair. The mean relative Constant score was 97% (range, 61% to 108%), the mean American Shoulder and Elbow Surgeons score was 92 points (range, 56 to 100 points), and the mean Western Ontario Shoulder Instability index score was 126 points (range, 0 to 660 points). All patients returned to full-time work. Conclusions: Nonoperative treatment of anterior glenoid rim fractures following primary traumatic anterior shoulder dislocation results in excellent clinical outcomes with a very low rate of residual instability and, thus, treatment failure. Asymptomatic radiographic osteoarthritis occurred in roughly 1 of 4 patients. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.