From the Department of Orthopaedics, Stanford University Hospitals, Redwood City, CA (Truntzer), the Department of Orthopaedics, University of Kansas Medical Center, Kansas City, KS (Vopat, Barnds), the Department of Orthopaedics, Brown University, Providence, RI (Schwartz, Anavian, Green), and the Department of Orthopaedic Surgery, Yale University, New Haven, CT (Blaine).
J Am Acad Orthop Surg. 2021 Oct 1;29(19):848-854. doi: 10.5435/JAAOS-D-20-00782.
The importance of anatomic reconstruction of the proximal humerus on shoulder biomechanics and kinematics after anatomic total shoulder replacement (aTSR) has been highlighted by a number of investigations. The humeral head designs of current-generation shoulder arthroplasty emphasize either anatomic or soft-tissue balancing total shoulder arthroplasty (sbTSR) philosophies. The purpose of this study was to compare the postoperative anatomy of TSR systems used to treat primary glenohumeral osteoarthritis.
This was a matched cohort study of 60 patients treated with either press-fit aTSR or sbTSR by two shoulder surgeons. The analysis of postoperative true AP radiographs was performed to calculate multiple representative anatomic parameters of the TSR.
A significant difference was observed in the average measurements between the sbTSR and aTSR designs about the humeral head center offset (5.2 ± 0.4 mm versus 3.9 ± 0.3 mm; P = 0.02), implant-humeral shaft angle (0.3 ± 0.3 varus versus 1.7 ± 0.3 valgus, P < 0.001), and humeral head to tuberosity height (8.8 ± 0.4 mm versus 6.2 ± 0.4, P < 0.001), respectively. No significant difference was observed in the average measurements between the two systems' designs regarding the head-shaft angle (133.4° ± 0.8° versus 135.0° ± 1.0°, P = 0.16) and the relation of humeral head to lateral humeral cortex (0.15 ± 0.6 mm inside the lateral cortex versus 0.19 ± 0.6 outside the lateral cortex; P = 0.69), respectively.
Despite differing design philosophies of these systems, and some notable differences, the absolute differences between the measured anatomic parameters were small and not likely clinically relevant. Anatomic and soft-tissue balancing humeral arthroplasty implants can both reliably reconstruct proximal humeral anatomy.
解剖型全肩关节置换（aTSR）后，肩部生物力学和运动学对肱骨近端解剖重建的重要性已被多项研究强调。目前一代肩关节假体的肱骨头设计强调解剖型或软组织平衡型全肩关节置换（sbTSR）理念。本研究的目的是比较用于治疗原发性肩关节炎的 TSR 系统的术后解剖结构。
这是一项由两位肩关节外科医生治疗的 60 例患者的配对队列研究，他们分别接受压配型 aTSR 或 sbTSR 治疗。对术后的真 AP 射线照片进行分析，以计算 TSR 的多个代表性解剖参数。
sbTSR 和 aTSR 设计之间在肱骨头中心偏移（5.2 ± 0.4mm 与 3.9 ± 0.3mm；P = 0.02）、假体-肱骨干角（0.3 ± 0.3 度内翻与 1.7 ± 0.3 度外翻，P < 0.001）和肱骨头至结节高度（8.8 ± 0.4mm 与 6.2 ± 0.4mm，P < 0.001）方面的平均测量值存在显著差异。在头干角（133.4° ± 0.8°与 135.0° ± 1.0°，P = 0.16）和肱骨头与外侧肱骨皮质的关系（0.15 ± 0.6mm 位于外侧皮质内与 0.19 ± 0.6mm 位于外侧皮质外，P = 0.69）方面，两个系统设计之间的平均测量值无显著差异。
尽管这些系统的设计理念不同，且存在一些显著差异，但测量解剖参数之间的绝对差异较小，且可能在临床上无意义。解剖型和软组织平衡型肱骨假体均可可靠重建肱骨近端解剖结构。
