Effect of critical shoulder angle, glenoid lateralization, and humeral inclination on range of movement in reverse shoulder arthroplasty

Bone & Joint Research

article

Alexandre Lädermann¹  Eileen Tay⁴  Philippe Collin⁵  Sébastien Piotton¹  Chih-Hao Chiu⁶  Aude Michelet⁷  Caecilia Charbonnier⁸ 

[1] Division of Orthopedics and Trauma Surgery, La Tour Hospital;Faculty of Medicine, University of Geneva;Orthopedics and Trauma Service, University Hospitals of Geneva;Department of Orthopaedic Surgery, Ng Teng Fong General Hospital;Centre Hospitalier Privé Saint-Grégoire;Department of Orthopaedic Sports Medicine, Chang Gung Memorial Hospital;ReSurg SA;University of Geneva;Medical Research Department, Artanim Foundation

关键词: Critical shoulder angle;    Reverse shoulder arthroplasty;    Range of movement;    Scapular morphology;    Impingement;   

DOI  :  10.1302/2046-3758.88.BJR-2018-0293.R1

学科分类：骨科学

来源: British Editorial Society Of Bone And Joint Surgery

【 摘 要 】

ObjectivesTo date, no study has considered the impact of acromial morphology on shoulder range of movement (ROM). The purpose of our study was to evaluate the effects of lateralization of the centre of rotation (COR) and neck-shaft angle (NSA) on shoulder ROM after reverse shoulder arthroplasty (RSA) in patients with different scapular morphologies.Methods3D computer models were constructed from CT scans of 12 patients with a critical shoulder angle (CSA) of 25°, 30°, 35°, and 40°. For each model, shoulder ROM was evaluated at a NSA of 135° and 145°, and lateralization of 0 mm, 5 mm, and 10 mm for seven standardized movements: glenohumeral abduction, adduction, forward flexion, extension, internal rotation with the arm at 90° of abduction, as well as external rotation with the arm at 10° and 90° of abduction.ResultsCSA did not seem to influence ROM in any of the models, but greater lateralization achieved greater ROM for all movements in all configurations. Internal and external rotation at 90° of abduction were impossible in most configurations, except in models with a CSA of 25°.ConclusionPostoperative ROM following RSA depends on multiple patient and surgical factors. This study, based on computer simulation, suggests that CSA has no influence on ROM after RSA, while lateralization increases ROM in all configurations. Furthermore, increasing subacromial space is important to grant sufficient rotation at 90° of abduction. In summary, increased lateralization of the COR and increased subacromial space improve ROM in all CSA configurations.

【 授权许可】

CC BY-NC