Clinical outcomes of reverse total shoulder arthroplasty for elective indications versus acute 3- and 4-part proximal humeral fractures: a systematic review and meta-analysis.

Background: Reverse total shoulder arthroplasty (RTSA) has continued to increase in clinical utility and popularity as an effective treatment for cuff tear arthropathy (CTA), irreparable rotator cuff tears (RCTs), osteoarthritis, and acute 3- and 4-part proximal humeral fractures. Performing RTSA for acute proximal humeral fractures presents the unique challenges of tuberosity management, bone loss, and instability compared with elective indications such as CTA or irreparable RCTs. The purpose of this study was to compare the clinical outcomes, active range of motion (ROM), radiographic outcomes, and complications between patients undergoing elective RTSA (RTSA-E) and those undergoing RTSA for fracture (RTSA-F).

Methods: A systematic review of the literature was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. We queried 3 electronic databases (Embase, Cochrane, and PubMed) using the search term "reverse" AND "shoulder" AND "arthroplasty." Studies investigating the clinical outcomes of RTSA for traumatic and/or elective indications were included. Studies were excluded if they included RTSA performed for fracture sequelae, inflammatory arthritis, post-traumatic osteoarthritis, or avascular necrosis. Data collected included patient demographic characteristics, subjective outcome measurements, ROM, and complications. The pooled means and proportions along with their 95% confidence intervals were generated by a random-effects model that incorporated the between-study variations in weighting.

Results: A total of 134 studies (11,651 shoulders) investigating the clinical outcomes of RTSA-E patients and 66 studies (3117 shoulders) investigating RTSA-F patients were included in this systematic review. Analysis of patient-reported outcomes demonstrated that RTSA-F patients experienced significantly lower Constant scores than RTSA-E patients; however, relative Constant scores, Simple Shoulder Test scores, Disabilities of the Arm, Shoulder and Hand scores, American Shoulder and Elbow Surgeons scores, and visual analog scale pain scores were similar. RTSA-F patients also had significantly lower forward elevation, abduction, and external rotation. RTSA-F patients experienced tuberosity complications at a significantly higher rate than RTSA-E patients (25.9% vs. 4.1%). There was no significant difference between the 2 groups in terms of other complications such as heterotopic ossification, radiographic loosening, revision, nerve injury, postoperative stiffness, infection, dislocation, and component loosening.

Discussion: RTSA performed for acute 3- and 4-part proximal humeral fractures yields overall worse clinical outcomes and active ROM compared with RTSA performed for elective indications including CTA, massive irreparable RCTs, and osteoarthritis with deformity. Tuberosity healing may be a major contributing factor to the difference in clinical outcomes. In the setting of RTSA-F, patient and surgeon expectations may need to be tempered and appropriate measures undertaken to optimize tuberosity healing.