Early outcomes and complications of obese patients undergoing shoulder arthroplasty: A meta-analysis

The prevalence of obesity and shoulder arthroplasty have both been increasing in the United States. Although lower extremity arthroplasty literature suggests higher complication rates in these patients, there is a paucity of studies evaluating the outcome of shoulder arthroplasty in obese patients. Our purpose was to perform a meta-analysis to determine clinical outcomes and complications of these patients.

Following the PRISMA guidelines, the MEDLINE (PubMed), Embase, and Ovid libraries were used to perform a comprehensive literature review to compare complications and outcomes following shoulder arthroplasty between obese and non-obese patients. Our initial search returned 143 publications. Our inclusion criteria included full-text reports, minimum follow-up of 1 year, minimum of 10 patients, no cadaveric or biomechanical studies, only studies published in English, studies involving obese patients undergoing either anatomic or reverse shoulder arthroplasty. A total of 13 studies met the inclusion criteria. These studies were then evaluating using a methodological index for non-randomized studies (MINORS) score. Ultimately, 6 studies met our criteria and were included in the final analysis.

A total of 978 patients were identified from the 6 studies. Patients with a BMI <30 kg/m² had a complication rate of 9.7% and American Shoulder and Elbow Surgeons score (ASES) increased from 37.4 to 76.7. Patients with a BMI >30 kg/m² had a complications rate of 6.5% and ASES increased from 34.4 to 76.2. Patients with a BMI >40 kg/m² ASES increased from 29.5 to 68.6. The postoperative ASES score of 68.6 for patients with a BMI >40 kg/m² was significantly lower than the ASES score of 76.8 in patients with a BMI <40 kg/m² (p = 0.007). There were an insufficient number of patients and an insufficient number of complications to perform any meaningful statistical test on complication rates in patients with a BMI >40 kg/m².

No significant difference was observed in number of complications and follow-up ASES scores following shoulder arthroplasty between obese and non-obese patients. Morbidly obese patients (BMI > 40 kg/m²) have a significantly lower ASES follow-up score than non-morbidly obese patients; however, this difference may not be clinically significant. Future studies are needed to investigate outcomes and complications associated with morbidly obese patients undergoing shoulder arthroplasty.