Mismatched implants yield comparable outcomes in revision shoulder arthroplasty

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Implantology

Background:

• Revision shoulder arthroplasty presents significant surgical challenges.
• Component mismatching (using implants from different manufacturers) is a strategy to address bone loss, blood loss, and operative time.
• This study evaluates the clinical outcomes of mismatched versus matched implants in revision shoulder arthroplasty.

Purpose of the Study:

• To compare clinical outcomes between patients undergoing revision shoulder arthroplasty with matched versus mismatched implants.
• To assess the impact of component mismatching on patient-reported outcomes and revision rates.

Main Methods:

• A retrospective review of revision shoulder arthroplasty cases performed by a single surgeon (2012-2022).
• Identification of 44 'mismatched' cases (humeral and glenoid components from different manufacturers).
• Matched cohort analysis (25 mismatches vs. 281 matches) comparing outcomes including range of motion, American Shoulder and Elbow Surgeons (ASES) score, visual analog scale (VAS) pain, Simple Shoulder Test (SST), stability, and re-revision rates.

Main Results:

• No significant differences in ASES, VAS, or SST scores at 1-year postoperatively between matched and mismatched groups.
• Mismatched implants showed significantly higher stability (5.9 vs. 3.5 on a 0-10 scale, P = .039).
• Re-revision rates were comparable: 11% for mismatches and 13% for matches in the total cohort. Size-mismatched cases (11) had no re-revisions in the short-term follow-up.

Conclusions:

• Mismatched components in revision shoulder arthroplasty yield comparable clinical outcomes and revision rates to matched components.
• Component mismatching may offer improved shoulder stability.
• Larger datasets and longer follow-up are necessary to definitively conclude on the practice of implant mismatching.