Mittelsteadt Marcus, Nelson Bradley J, Rohman Eric M, Arciero Robert A, Tompkins Marc A
Department of Orthopedic Surgery, University of Minnesota, Minneapolis, Minnesota, USA.
TRIA Orthopedic Center, Bloomington, Minnesota, USA.
Orthop J Sports Med. 2022 May 13;10(5):23259671221096682. doi: 10.1177/23259671221096682. eCollection 2022 May.
Augmentation of anterior glenoid defects with bone graft can improve shoulder stability and reduce the risk of redislocation. Several characteristics of the scapular spine may make it a suitable harvest site, avoiding the disadvantages associated with other glenoid augmentation procedures.
To evaluate the capacity of scapular spine autograft to restore the stabilizing joint-reaction forces of the shoulder in simulated scenarios of bony anterior shoulder instability.
Controlled laboratory study.
We obtained 6 matched pairs of fresh-frozen cadaveric shoulders. Skin, subcutaneous tissues, and non-rotator cuff muscles were removed from the specimens, leaving intact the rotator cuff musculature and shoulder capsule. A customized testing device was used to translate the humerus 1 cm anteriorly on the glenoid under 25 N of axial compression force. The peak joint-reaction force of the glenohumeral joint was then measured under 3 conditions: (1) specimen with intact glenoid, (2) specimen after a bone defect measuring 25% of the maximal width of the glenoid was made in the anteroinferior glenoid, and (3) specimen after size-matched glenoid augmentation with a scapular spine tricortical autograft. The primary outcome was the change in peak joint-reaction forces between the defect state and augmented state.
One matched pair was removed from final analysis secondary to anatomic concerns that undermined the accuracy of test results. Among the 10 remaining specimens, all showed a significant decrease in peak joint-reaction force after the glenoid defect was created compared with the intact state ( < .001). All remaining specimens showed an increase in peak joint-reaction force in the augmented state compared with the defect state ( < .001). On average, the augmented state restored 81% of the peak reaction force of the glenohumeral joint compared with the intact state, a nonsignificant difference ( = .07).
The study findings indicated that autograft harvested from the scapular spine increased the bony restraint to anterior shoulder dislocation in shoulders with glenoid bone loss.
The scapular spine is an alternative for bony augmentation of glenoid defects in shoulder instability.
用骨移植填充肩胛盂前方缺损可改善肩部稳定性并降低再脱位风险。肩胛冈的一些特性可能使其成为合适的取材部位，避免了与其他肩胛盂增强手术相关的缺点。
评估在模拟骨性前肩不稳的情况下，肩胛冈自体骨移植恢复肩部稳定关节反应力的能力。
对照实验室研究。
我们获取了6对新鲜冷冻的尸体肩部标本。从标本上移除皮肤、皮下组织和非旋转袖带肌肉，保留旋转袖带肌肉组织和肩囊完整。使用定制的测试装置，在25 N的轴向压缩力下，将肱骨在肩胛盂上向前平移1 cm。然后在3种情况下测量盂肱关节的峰值关节反应力：（1）肩胛盂完整的标本；（2）在前下肩胛盂制造一个占肩胛盂最大宽度25%的骨缺损后的标本；（3）用肩胛冈三皮质自体骨进行尺寸匹配的肩胛盂增强后的标本。主要结果是缺损状态和增强状态之间峰值关节反应力的变化。
由于解剖学问题影响了测试结果的准确性，一对标本被排除在最终分析之外。在其余10个标本中，与完整状态相比，所有标本在制造肩胛盂缺损后峰值关节反应力均显著降低（P <.001）。与缺损状态相比，其余所有标本在增强状态下峰值关节反应力均增加（P <.001）。平均而言，与完整状态相比，增强状态恢复了盂肱关节峰值反应力的81%，差异无统计学意义（P =.07）。
研究结果表明，从肩胛冈获取的自体骨增加了肩胛盂骨质缺损的肩部对前肩脱位的骨性限制。
肩胛冈是肩部不稳时肩胛盂缺损骨性增强的一种替代方法。
