From the Shoulder and Elbow Service, Department of Orthopaedics, MedStar Union Memorial Hospital, Baltimore, MD.
J Am Acad Orthop Surg. 2021 Feb 1;29(3):89-99. doi: 10.5435/JAAOS-D-20-00671.
Since the advent of Paul Grammont medialized reverse shoulder prosthesis in the 1980s, shoulder surgeons have had a reliable option for treating glenohumeral joint disease in the rotator cuff-deficient shoulder. However, the prosthesis is not without complications, including scapular notching, instability, and limited rotational motion. Implants have been modified from the original design in an effort to reduce the risk of these complications. Increasing the offset, or lateralization, of the glenosphere may reduce the rate of scapular notching, reduce impingement, increase stability, and improve rotational motion. However, a more lateralized glenosphere could lead to baseplate loosening, decreased deltoid efficiency, and increased risk of acromial fracture. Increasing the offset on the humeral side, rather than the glenosphere side, may be able to reduce the rate of scapular notching and improve rotational motion without an increased risk of baseplate loosening. Humeral lateralization also improves tension of the rotator cuff and maintains good deltoid efficiency. However, humeral lateralization provides little stability benefit, and acromial fracture remains a risk. Ultimately, the surgeon must be familiar with the implants he or she is using and the options for both glenosphere and humeral lateralization to ensure that risks and benefits can be weighed for each patient.
自 20 世纪 80 年代保罗·格拉蒙特（Paul Grammont）推出内侧化反式肩关节假体以来，肩关节外科医生在治疗肩袖缺损的肩胛盂关节疾病时已经有了一种可靠的选择。然而，该假体并非没有并发症，包括肩胛切迹、不稳定和旋转运动受限。为了降低这些并发症的风险，已经对植入物进行了从原始设计的修改。增加关节盂窝的偏心距或外侧化可能会降低肩胛切迹的发生率，减少撞击，增加稳定性并改善旋转运动。然而，更外侧化的关节盂窝可能导致底座板松动、三角肌效率降低和肩峰骨折风险增加。增加肱骨侧而不是关节盂窝侧的偏心距可能能够降低肩胛切迹的发生率并改善旋转运动，而不会增加底座板松动的风险。肱骨外侧化还可以改善肩袖的张力并保持良好的三角肌效率。然而，肱骨外侧化几乎没有提供稳定性益处，并且仍然存在肩峰骨折的风险。最终，外科医生必须熟悉他或她正在使用的植入物以及关节盂窝和肱骨外侧化的选择，以确保可以为每个患者权衡风险和收益。
