Obesity does not associate with 5-year surgical complications following anatomic total shoulder arthroplasty and reverse total shoulder arthroplasty

Background: Although obesity has been shown to increase the risk of short-term medical complications following total shoulder arthroplasty (TSA), evidence is lacking on the influence of obesity on longer-term surgical complications such as revision. The purpose of this study was to assess the association of increasing obesity with 2- and 5-year all-cause revision, periprosthetic joint infection (PJI), aseptic loosening, and manipulation under anesthesia (MUA) among patients undergoing reverse total shoulder arthroplasty (RTSA) or TSA. Methods: Patients who underwent RTSA or TSA with a minimum 5-year follow-up were identified in a national claims database (PearlDiver Technologies). Patients with obesity (body mass index [BMI] ≥30) were compared to patients who are normal or overweight (18.5 ≤ BMI < 30). Those with obesity were further stratified to those with class I or II obesity (30 ≤ BMI < 40) and those with class III obesity (BMI ≥ 40). Outcomes for comparison included all-cause revision, PJI, aseptic loosening, and MUA within 2 or 5 years. These cohorts were compared using univariate and multivariable analysis. Results: Patients with obesity had no significant difference in any surgical complication within 2 or 5 years for both those who underwent TSA or RTSA. After stratifying by class I or II obesity and class III obesity, there was still no significant difference in surgical complications with 2 or 5 years for both TSA patients and RTSA patients. Discussion: Obesity, when other major comorbidities are controlled for, was not associated with increased risk of long-term surgical complications after shoulder replacement surgery.