RESUMEN
Background: Historically, Metal-Backed (MB) glenoid components in anatomical total Shoulder arthroplasty (aTSA) are prone to failure primarily due to loosening between the metal and bony surface. However, newer generations of MB glenoid components have performed well in reverse shoulder arthroplasty (RSA), with convertibility being considered to be the most significant benefit of MB components. Theoretically, MB components may be a viable option in "Rotator cuff at risk" cases. The aim of this study is to compare revisions versus revision-free survivorship and highlight problems associated with using convertible MB glenoid components in aTSA. Methods: Between December 2015 and September 2018, aTSA was performed on 30 patients utilizing 32 implants with convertible MB glenoid (two patients were operated bilaterally). The first investigation was performed at a mean of 55.9 months (43-76) by search in the national registry for revisions with twelve cases. The second FU on all remaining patients without revisions was conducted at a mean of 54.9 months (46-71) through physical examination with fourteen patients (sixteen implants), with four patients missing. Demographic data, indications, complications, revisions, and re-operations were recorded for each patient. Results: High rates of complications led to revisions or re-operation in aTSA in combination with MB (15/32). Seven problems were associated with polyethylene (PE), which included loosening, disengagement, or wear. Eight complications were not directly associated with the MB component. There was one with loosening on the metal-bone interface side. Conversion to RSA was possible in three cases, and secondary cuff failure was seen once. High infection rates (2/32) led to a different strategy for antibiotics and preoperative preparations. Conclusion: MB glenoid components caused unacceptably high complication and revision rates in aTSA. PE wear, disengagement, or loosening were the main reasons for revisions. Therefore, procedures with MB glenoid components were abandoned in aTSA. Level of Evidence: Level IV case series, treatment study.
RESUMEN
BACKGROUND: Previous studies have indicated an increased risk of periprosthetic joint infection (PJI) in patients treated with reverse shoulder arthroplasty (RSA) compared with patients treated with anatomic total shoulder arthroplasty. The reason for this is unclear but may be related to a high prevalence of previous rotator cuff repair in patients who are treated with RSA. The purpose of this study was to determine previous non-arthroplasty surgery as a risk factor for revision owing to PJI after RSA for cuff tear arthropathy, massive irreparable rotator cuff tears, or osteoarthritis. METHODS: Data were retrieved from the Danish Shoulder Arthroplasty Registry and medical records. We included 2217 patients who underwent RSA for cuff tear arthropathy, massive irreparable rotator cuff tears, or osteoarthritis between 2006 and 2019. PJI was defined as ≥3 of 5 tissue samples positive for the same bacteria or as definite or probable PJI evaluated based on criteria from the International Consensus Meeting. The Kaplan-Meier method was used to illustrate the unadjusted 14-year cumulative rates of revision. A Cox regression model was used to report hazard for revision owing to PJI. Results were adjusted for previous non-arthroplasty surgery, sex, diagnosis, and age. RESULTS: Revision was performed in 88 shoulders (4.0%), of which 40 (1.8%) underwent revision owing to PJI. There were 272 patients (12.3%) who underwent previous rotator cuff repair, of whom 11 (4.0%) underwent revision owing to PJI. The 14-year cumulative rate of revision owing to PJI was 14.1% for patients with previous rotator cuff repair and 2.7% for patients without previous surgery. The adjusted hazard ratio for revision owing to PJI for patients with previous rotator cuff repair was 2.2 (95% confidence interval, 1.04-4.60) compared with patients without previous surgery. CONCLUSION: There is an increased risk of revision owing to PJI after RSA for patients with previous rotator cuff repair. We recommend that patients with previous rotator cuff repair be regarded as high-risk patients when considering RSA.
