Great tuberosity fixation does not affect healing and clinical outcomes in RSA performed in proximal humeral fractures in elderly patients.

PURPOSE: Aims of our study were to define whether the great tuberosity (GT) positioning fixation in reverse shoulder arthroplasty (RSA) after proximal humeral fracture (PHF) could predict tuberosity healing and its impact on clinical outcomes. METHODS: We enrolled 59 patients treated with cementless reverse shoulder arthroplasty after PHF in our institute between 2012 and 2018. The mean follow-up was 57 months (± 23.4). We divided patients into two groups according to GT positioning after fixation: Group 1 GT in contact and Group 2 GT detached at least 1 mm from humeral diaphysis. Clinical and radiographic evaluations were conducted at last follow-up. RESULTS: Overall GT healing rate was 64.4%, (Group 1 70.7%-Group 2 50%). A statistically significant difference (P = 0.047) was found in cortical thickness narrowing at one-third of stem length. We found a correlation between lateral cortical narrowing and GT fixation in non-anatomical position, but we observed no statistically significant differences about GT healing according to GT anatomical or non-anatomical fixation. No differences were found in shoulder function in patients whose tuberosity was healed or failed to heal. CONCLUSION: GT reduction is not a predictive factor for GT healing; external stress shielding, instead, seems to be decreased in patients with postoperative anatomically reduced GT. In our study, GT healing did not affect clinical outcomes or patient's satisfaction in elderly low-demanding patients.

Navigation in reverse shoulder arthroplasty: how the lateralization of glenosphere can affect the clinical outcome.

INTRODUCTION: One of the main causes of RSA failure is attributable to the malpositioning of the glenoid component. Initial experiences with computer-assisted surgery have shown promising results in increasing the accuracy and repeatability of placement of the glenoid component and screws. The aim of this study was to evaluate the functional clinical results, in terms of joint mobility and pain, by correlating them with intraoperative data regarding the positioning of the glenoid component. The hypothesis was that the lateralization more than 25 mm of the glenosphere can led to better stability of the prosthesis but should pay in term of a reduced range of movement and increased pain. MATERIALS AND METHODS: 50 patients were enrolled between October 2018 and May 2022; they underwent RSA implantation assisted by GPS navigation system. Active ROM, ASES score and VAS pain scale were recorded before surgery. Preoperative data about glenoid inclination and version were collected by pre-op X-Rays an CT. Intraoperative data-inclination, version, medialization and lateralization of the glenoid component-were recorded using computer-assisted surgery. 46 patients had been further clinically and radiographically re-evaluated at 3-months, 6-months, 1-year, and 2-years follow-up. RESULTS: We found a statistically significant correlation between anteposition and glenosphere lateralization value (DM - 6.057 mm; p = 0.043). Furthermore a statistically significant correlation has been shown between abduction movement and the lateralization value (DM - 7.723 mm; p = 0.015). No other statistically significant associations were found when comparing the values of glenoid inclination and version with the range of motion achieved by the patients after reverse shoulder arthroplasty. CONCLUSION: We observed that the patients with the best anteposition and abduction results had a glenosphere lateralization between 18 and 22 mm. When increasing the lateralization above 22 mm or reducing it below 18 mm, on the other hand, both movements considered decreased their range. LEVEL OF EVIDENCE: Level IV; Case Series; Treatment Study.