In Reverse Shoulder Arthroplasty (RSA) is crucial to avoid a higher inclination of the baseplate and reach a neutral position of the glenoid implant. However, the optimal method to correct native glenoid inclination is still debated.
Different procedures to manage bone defect have been described in the literature. In this study, two surgical techniques have been compared: the Standard BIO-RSA technique, where an eccentric reaming of the glenoid is performed along with a cylindric glenoid bone graft augmentation (BIO-RSA) versus the Angled BIO-RSA technique, including a concentric reaming of the glenoid and the correction of the defect by an angled bone graft.
A total of 165 patients who underwent Reverse shoulder arthroplasty were analyzed. According to inclusion criteria we excluded 27 patients and finally enrolling 141 shoulders (6 patients underwent surgery for both shoulders). Based on the technique used to manage the glenoid, the patients were divided into two groups: Standard BIO-RSA group and Angled BIO-RSA group. Functional outcome data (ASES, Constant, VAS and ROM) as well as radiographic data were collected pre-operatively, and at 6 months, 1 year and 2 years post-operatively.
Constant score, ASES and VAS did not show significant differences between the two groups (P> 0.05). As regards ROM, statistically significant differences were found in terms of anterior flexion and abduction, with better results for angled BIO-RSA group compared to Standard BIO-RSA group (anterior flexion 149.9° +/- 25.3° versus 139.3° +/- 26.8,° p = 0.019 and abduction 136.4° +/- 24.2° versus 126.7° +/- 29.3°, p = 0.040). Focusing on inferior tilt correction, a statistically significant difference in Postoperative RSA Angle values was found in favour of Angled BIO-RSA (1.252° +/- 6.14° versus 4.09° +/- 8.85°; p = 0.03).
The present comparative cohort study demonstrated that the both techniques were able to correct the glenoid inclination and shows excellent short-term results in patients with rotator cuff injury arthropathy. However, the angled BIO-RSA technique is more effective in ensuring a correct inclination of the prosthetic glenoid component and allows to achieve better results in terms of flexion and abduction