Elevated body mass index and clinical outcomes after surgical stabilization for shoulder instability: A systematic...

Obesity is understood to be a potential risk factor that negatively impacts outcomes across various orthopaedic procedures including weightbearing joint arthroplasty, and even in non-weightbearing joints, such as total shoulder arthroplasty and rotator cuff repair. However, there is limited understanding of the role obesity plays in the incidence and outcomes of shoulder instability.

The purpose of this study is to characterize the relationship between body mass index (BMI) and shoulder instability outcomes following operative stabilization.

This systematic review was conducted using the MEDLINE, Embase, and Cochrane databases to identify studies investigating shoulder instability surgery. Studies were included that involved patients undergoing shoulder stabilization surgery and investigated BMI or obesity as a variable. Exclusion criteria included non-stabilizing shoulder procedures, joints other than the shoulder, case reports or case series with less than 5 cases, and secondary literature.

Two authors independently reviewed all relevant articles using the inclusion and exclusion criteria mentioned above and any discrepancies were addressed by a third independent reviewer. Data extracted from each study included patient demographics, procedure type and operative findings, and functional outcome measures, including patient-reported outcomes (PROs).

A total of 936 patients were identified across the 7 included studies and the mean BMI for this cohort was 29.74 kg/m². Increased BMI did not emerge as an independent predictor of surgical failure or recurrent instability following operative stabilization. However, several meaningful trends did reach statistical significance in the elevated BMI group. We found that individuals with increased BMI were more likely to need surgical intervention, demonstrated higher levels of surgical complexity, and decreased subjective improvement thresholds determined by MCID. They also showed higher rates of specific injury patterns including partial rotator cuff tears, Bankart lesions, and bone and cartilage lesions (BCLs). Patients with elevated BMI were also less likely to return to sport following certain procedures.

Our findings suggest that while obesity may not directly drive surgical failure, it has a significant role in determining technical complexity and the rehabilitation experience for the patient.