Reverse shoulder arthroplasty renders better clinical scores at a minimum follow-up of two years for patients with no rotator cuff deficiency operated by the deltopectoral approach

Purpose The purpose of this multi-centre study was to report outcomes of a large cohort of reverse shoulder arthroplasty (RSA) at a minimum follow-up of two years and to determine patient and surgical factors that influence postoperative outcomes. The hypothesis was that surgical indication, surgical approach, and implant design would affect clinical outcomes significantly. Methods The authors reviewed records of 743 RSAs in patients with primary osteoarthritis (OA) with or without rotator cuff (RC) tears, secondary OA due to RC tears, and irreparable massive rotator cuff tears (mRCT). The deltopectoral (DP) approach was used in 540 and the anterosuperior (AS) approach in 203. Pre- and postoperative Constant scores (CS) were recorded. Multivariable linear analyses were performed to determine if CS was associated with indications for surgery, surgical approach, or implant design. Results Of the 743 shoulders, 193 (25.7%) were lost to follow-up, 16 (2.1%) died, and 33 (4.4%) were revised, leaving 501 for analysis. At a mean follow-up of 3.2 ± 0.9 years, net improvement in CS was 29.2 ± 17.0. Multivariable analyses revealed that postoperative CS decreased with age and was worse in shoulders that had preoperative rotator cuff deficiency and in shoulders operated by the AS approach. Multivariable analyses also revealed worse net improvement in shoulders operated for secondary OA due to RC tears or for irreparable mRCT, as well as shoulders operated by the AS approach. Conclusion This large multi-centre study confirms that, at two or more years following RSA, Constant scores are not associated with implant design, but rather with rotator cuff deficiency and surgical approach. Multivariable analysis revealed that postoperative CS was worse for shoulders with preoperative rotator cuff deficiency and for shoulders operated by the AS approach. Multivariable analysis also revealed that net improvement in CS was worse in shoulders treated for secondary OA due to RC tears and for shoulders with irreparable mRCT, as well as for shoulders operated by the AS approach.