Clinical and Radiological Outcomes of Bony Increased Offset-Reverse Total Shoulder Arthroplasty in the Asian Population

Abstract

Background: Bony increased offset-reverse total shoulder arthroplasty (BIO-RSA) was proposed which uses autograft harvested from the patient’s humeral head to lateralize the glenoid baseplate. This technique provided the lateralization of the center of rotation and the reduction of the scapular notching. Few studies have reported outcomes of BIO-RSA in the Asian population. We reported the first report of clinical and radiological outcomes of BIO-RSA in the Asian population at mid-term follow-up. Methods: From June 2012 to August 2017, a total 38 patients with average age of 73±6 years operated by the BIO-RSA technique with minimum two-year follow-up (average 36.7±16 months) were enrolled in our study. Indications of the BIO-RSA were rotator cuff tear arthropathy, massive irreparable cuff tear without osteoarthritis, primary osteoarthritis with glenoid defect, recurrent shoulder dislocation with massive cuff tear, and glenoid fracture sequela. We excluded patients with acute proximal humerus fracture, avascular necrosis and revision RSA performed using allo- or autograft. We evaluated clinical and radiological outcomes of BIO-RSA at the last follow-up. Results: VAS, ASES, UCLA, and SST scores improved significantly from preoperative (average-5, 39.4, 16.2, 3.9) to postoperative (average- 1.7, 78.9, 28.3, 7.8, p-value < 0.05). All range of motion except internal rotation improved significantly at the last follow-up (p-value <0.05) and the bone graft was incorporated with the native glenoid in all the cases (100%). However, scapular notching was observed in 23/38 (60.5%) of patients. Intraoperative complications were three metaphyseal fractures and one inferior screw malpositioning. Postoperative complications included one heterotropic ossification, one scapula neck stress fracture, one humeral stem loosening, and one late infection. Conclusions: BIO-RSA results in improved clinical outcomes at mid-term follow-up in the Asian population. Although better cosmesis and advantage of glenoid lateralization were observed in our study along with similar complications rates as compared to conventional RTSA, we observed higher rates of scapular notching to previously reported rates in BIO-RSA studies.