Clinical outcomes of shoulder arthroplasty for post-instability arthropathy after open anterior bone block stabilization

Post-instability glenohumeral arthropathy can occur after nonanatomic instability repairs. With advanced secondary arthritis, subsequent shoulder arthroplasty may be complicated by altered surgical anatomy, poor range of motion, subscapularis deficiency, unique glenoid wear patterns, and/or aberrant neurovascular anatomy. The purpose of this study was to evaluate the clinical outcomes of patients undergoing shoulder arthroplasty after previous open nonanatomic anterior shoulder stabilization, particularly glenoid bone block procedures. Between 2008 and 2014, all patients with shoulder arthroplasty for symptomatic post-instability glenohumeral arthropathy after prior open stabilizations were identified from surgical case logs of two senior shoulder surgeons. Demographic variables were extracted from electronic medical records, operative reports, and preoperative and postoperative radiographs, and a minimum 24-month follow-up with completion of patient-reported questionnaires was required. Postoperative active forward elevation and active external rotation were recorded. The primary outcome measures were the visual analog scale for pain, American Shoulder and Elbow Surgeons Shoulder score, and the Simple Shoulder Test. Perioperative complications and rates of secondary reoperation were extracted. A total of 12 patients were identified with an average age of 63 ± 12 years (range, 46-83), including 7 males and 5 females, and index surgery included open Bristow (n = 7), open Latarjet (n = 2), iliac crest bone graft (n = 1), and Putti-Platt procedure (n = 2). Seven patients underwent anatomic TSA, 4 reverse TSA, and 1 hemiarthroplasty. At an average of 44 ± 21 months follow-up, average active forward elevation and active external rotation improved from 100 ± 36 preoperatively to 132 ± 41 (P = .12) postoperatively and 19 ± 15 to 49 ± 11 (P < .01), respectively. The average visual analog scale decreased from 5 ± 3 to 1 ± 2 (P < .01) and mean American Shoulder and Elbow Surgeons improved from 44 ± 23 to 79 ± 17 (P < .01); and the average Simple Shoulder Test improved from 4 ± 2 to 9 ± 3 (P < .01). No perioperative complications or secondary reoperations were required, and only one patient experienced subsequent instability due to subsequent shoulder trauma. Despite the surgical complexity and unique challenges associated with post-instability arthropathy, shoulder arthroplasty after prior open anterior bone block procedure or nonanatomic reconstruction is a safe procedure with low risk of perioperative complication, subsequent shoulder instability, or secondary revision surgery. All patients experienced significant improvements in pain, range of motion, and self-reported function at short- to mid-term follow-up.