Local Subcutaneous Fat Depth Is Associated With Increased Complications After Total Shoulder Arthroplasty

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Surgical Risk Assessment

Background:

• Increased Body Mass Index (BMI) is a known risk factor for lower extremity surgery complications.
• Existing literature on total shoulder arthroplasty (TSA) shows varied results regarding BMI's predictive utility.
• Subcutaneous fat depth at the incision site has been linked to complications in spine surgery.

Purpose of the Study:

• To investigate the association between tissue depth and postoperative complications in primary total shoulder arthroplasty (TSA).
• To determine if subcutaneous fat depth is a better predictor of TSA complications than BMI.

Main Methods:

• Retrospective analysis of 219 patients undergoing primary TSA between January 2018 and December 2021.
• Measurement of total tissue depth and subcutaneous fat depth at the coracoid and bicipital groove using preoperative advanced imaging.
• Statistical analysis (univariate and multivariate) to correlate tissue depth with postoperative complications (SSI, PJI, stress fracture, instability).

Main Results:

• Twenty-nine patients (13.2%) experienced 31 postoperative complications.
• The complication group exhibited significantly greater subcutaneous fat depth at the coracoid (18.82 mm vs. 15.05 mm) and bicipital groove (17.53 mm vs. 11.77 mm) compared to the control group.
• Multivariate analysis confirmed the statistical significance of these findings.

Conclusions:

• Local subcutaneous fat depth at the coracoid process and bicipital groove is associated with increased complication rates after primary TSA.
• BMI did not show a significant association with complications in this TSA cohort.
• Upper extremity weight distribution may limit BMI's effectiveness in risk stratification for TSA.