Clinical and radiographic outcomes of shoulder hemiarthroplasty for patients with glenoid medialization.

BACKGROUND: Glenoid bone loss in shoulder arthroplasty is a difficult problem that is prone to complications because of challenges with achieving glenoid component fixation and stability. The purpose of this study was to evaluate the outcomes of primary shoulder hemiarthroplasty for patients with severe glenoid medialization precluding placement of a glenoid component. METHODS: This was a retrospective case series evaluating patients who underwent shoulder hemiarthroplasty for severe glenoid erosion and medialization between 2010 and 2020. Patients were evaluated via chart review and phone survey to determine if there were any reoperations at final follow-up and to obtain Single Assessment Numeric Evaluation (SANE), American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), and Simple Shoulder Test (SST) scores. Preoperative and postoperative radiographs were evaluated and compared to determine glenoid morphology, version, medialization, acromiohumeral distance, and humeral offset. Final postoperative films were also evaluated for anterosuperior migration and signs of mechanical failure, including loosening or periprosthetic fracture. RESULTS: Overall, there were 28 patients during this period who underwent shoulder hemiarthroplasty for severe glenoid medialization. Eight patients were deceased at the time of the study, 2 were unable to complete surveys because of dementia, and 7 were lost to follow-up. The final cohort included 11 shoulders and 11 patients with a mean age of 71 ± 7.1 years and mean follow-up of 6.7 years (range 1.6-13.0 years). Mean postoperative SANE, ASES, and SST scores were 80.6 ± 17.6, 71.5 ± 29.3, and 7.6 ± 2.0, respectively. There were no reoperations or revision surgeries at final follow-up. Radiographic evaluation demonstrated severe glenoid medialization and decreased lateral humeral offset, which was unchanged postoperatively. There were 2 patients with signs of anterosuperior migration at final radiographic follow-up but no signs of implant failure. CONCLUSION: Shoulder hemiarthroplasty for severe medial glenoid bone loss provides modest clinical outcomes and low rates of reoperation at mid- to long-term follow-up and is an option worth considering in cases where placement of a glenoid component is challenging because of deficient bone stock and high risk for complications.

Planned Glenoid Implant Utilization: A Comparison of Preoperative Planning with and Without Computer-Assisted Navigation.

BACKGROUND: Preoperative planning for anatomic total shoulder arthroplasty (aTSA) and reverse total shoulder arthroplasty (rTSA) is becoming increasingly common. While preoperative planning allows surgeons to determine individualized implant types, utilization of intraoperative navigation improves the accuracy of implant placement and may increase confidence in the preoperative plan. The purpose of this study was to evaluate and compare the rate at which surgeons use a glenoid implant different than their preoperative plan with and without the use of computer navigation. METHODS: A retrospective review of a multicenter prospectively collected shoulder arthroplasty database was conducted between 2016 and 2022. Inclusion criteria were primary aTSA or rTSA with an available preoperative plan and record of the actual implant used. Change in glenoid implant was defined as a deviation in the final implant from the preoperative plan in regard to backside shape (nonaugmented vs augment or differing augment shape). RESULTS: We included 1,915 shoulder arthroplasties (525 aTSA, 1,390 rTSA) performed with preoperative planning and intraoperative navigation and 110 shoulder athroplasties (37 aTSA, 73 rTSA) performed with preoperative planning alone. Overall, the final glenoid implant deviated from the preoperative plan less frequently when intraoperative navigation was used compared with preoperative planning alone (1.9% [n = 36] versus 7.3% [n = 8], P = 0.002). When stratified by procedure, deviation from the preoperative plan occurred significantly less for rTSA when preoperative planning was used with intraoperative navigation versus planning alone (2% [n = 29] versus 11% [n = 8], P < 0.001; OR = 0.17 [95% CI = 0.07 to 0.46]), but not aTSA (1% [n = 7] versus 0% [n = 0], P = 1). Use of intraoperative navigation was independently associated with lower odds of deviation from the preoperative plan on multivariable logistic regression (OR = 0.25 [95% CI = 0.11 to 0.56], P = 0.001). CONCLUSION: Use of intraoperative navigation is associated with increased adherence to the preoperative plan for primary rTSA. Use of navigation may increase surgeon confidence despite known limitations of glenoid visualization during this procedure. This may offer advantages in outpatient surgery centers and smaller hospitals where inventory space may be limited. LEVEL OF EVIDENCE: Ⅲ, retrospective cohort study.

Predictors of dislocations after reverse shoulder arthroplasty: a study by the ASES complications of RSA multicenter research group.

BACKGROUND: Instability after reverse shoulder arthroplasty (RSA) is one of the most frequent complications and remains a clinical challenge. Current evidence is limited by small sample size, single-center, or single-implant methodologies that limit generalizability. We sought to determine the incidence and patient-related risk factors for dislocation after RSA, using a large, multicenter cohort with varying implants. METHODS: A retrospective, multicenter study was performed involving 15 institutions and 24 American Shoulder and Elbow Surgeons members across the United States. Inclusion criteria consisted of patients undergoing primary or revision RSA between January 2013 and June 2019 with minimum 3-month follow-up. All definitions, inclusion criteria, and collected variables were determined using the Delphi method, an iterative survey process involving all primary investigators requiring at least 75% consensus to be considered a final component of the methodology for each study element. Dislocations were defined as complete loss of articulation between the humeral component and the glenosphere and required radiographic confirmation. Binary logistic regression was performed to determine patient predictors of postoperative dislocation after RSA. RESULTS: We identified 6621 patients who met inclusion criteria with a mean follow-up of 19.4 months (range: 3-84 months). The study population was 40% male with an average age of 71.0 years (range: 23-101 years). The rate of dislocation was 2.1% (n = 138) for the whole cohort, 1.6% (n = 99) for primary RSAs, and 6.5% (n = 39) for revision RSAs (P < .001). Dislocations occurred at a median of 7.0 weeks (interquartile range: 3.0-36.0 weeks) after surgery with 23.0% (n = 32) after a trauma. Patients with a primary diagnosis of glenohumeral osteoarthritis with an intact rotator cuff had an overall lower rate of dislocation than patients with other diagnoses (0.8% vs. 2.5%; P < .001). Patient-related factors independently predictive of dislocation, in order of the magnitude of effect, were a history of postoperative subluxations before radiographically confirmed dislocation (odds ratio [OR]: 19.52, P < .001), primary diagnosis of fracture nonunion (OR: 6.53, P < .001), revision arthroplasty (OR: 5.61, P < .001), primary diagnosis of rotator cuff disease (OR: 2.64, P < .001), male sex (OR: 2.21, P < .001), and no subscapularis repair at surgery (OR: 1.95, P = .001). CONCLUSION: The strongest patient-related factors associated with dislocation were a history of postoperative subluxations and having a primary diagnosis of fracture nonunion. Notably, RSAs for osteoarthritis showed lower rates of dislocations than RSAs for rotator cuff disease. These data can be used to optimize patient counseling before RSA, particularly in male patients undergoing revision RSA.