HULC Bioengineering Research Laboratory, Hand and Upper Limb Centre, St. Joseph's Health Care, University of Western Ontario, London, Ontario, Canada.
Arthroscopy. 2013 Feb;29(2):309-16. doi: 10.1016/j.arthro.2012.09.007. Epub 2013 Jan 3.
The purpose of this biomechanical study was to compare the classic Latarjet technique and congruent-arc modification with respect to glenohumeral stability, joint stiffness, translation, and range of motion.
Eight cadaveric forequarters were tested on a shoulder simulator that applied loads independently to the conjoint tendon, long head of biceps, rotator cuff, and deltoid. The test conditions included: intact, 30% glenoid defect, and reconstruction of the defect with the classic and congruent Latarjets. The Latarjet techniques were randomly ordered, with the outcome variables being anterior dislocation, glenohumeral translation, rotational range of motion, and joint stiffness.
All 8 specimens dislocated after creation of a 30% glenoid defect. The classic Latarjet stabilized 7 of 8 specimens, whereas the congruent-arc modification stabilized all specimens (8/8). In abduction neutral rotation, there was no difference in joint translation between techniques (P = .613). In abduction external rotation, there was significantly greater anterior humeral head translation after the congruent technique than after the classic (9.9 and 6.5 mm, respectively, P = .013). Rotational range of motion was significantly reduced after classic (-25.8°) and congruent (-22.2°) transfers as compared with the 30% defect (P ≤ .041). Joint stiffness in the abducted, externally rotated position was significantly reduced in the 30% defect as compared with intact (P = .012), congruent (P = .015), and classic (P < .001) conditions. In all abduction positions, the intact was not significantly different from the Latarjet techniques, and the techniques did not significantly differ from each other (P ≥ .102).
The classic and congruent-arc Latarjet techniques restore shoulder stability and motion in cases of considerable bone loss. The techniques do not substantially differ in rotational range of motion or joint stiffness. The congruent-arc technique, however, does result in significantly greater anterior humeral head translation, as compared with the classic technique, before reaching a stable non-dislocated endpoint.
On the basis of this biomechanical model, both the classic and congruent-arc Latarjet techniques can be used to stabilize a shoulder with substantial glenoid bone loss. Further clinical and biomechanical studies are required to determine if particular clinical circumstances exist where 1 technique has an advantage over the other.
本生物力学研究旨在比较经典的 Latarjet 技术和一致弧形改良术在盂肱关节稳定性、关节刚度、活动度和位移方面的差异。
8 个解剖前肢在肩部模拟器上进行了测试，该模拟器可分别向联合肌腱、肱二头肌长头、肩袖和三角肌施加负荷。测试条件包括：完整、30%关节盂缺损和经典及一致 Latarjet 重建缺损。Latarjet 技术是随机排列的，结果变量是前脱位、盂肱关节位移、旋转活动度和关节刚度。
所有 8 个标本在创建 30%关节盂缺损后均发生脱位。经典 Latarjet 稳定了 8 个标本中的 7 个，而一致弧形改良术稳定了所有标本（8/8）。在外展中立位旋转时，两种技术之间的关节位移无差异（P=0.613）。在外展外旋时，一致弧形改良术后的肱骨头前向位移明显大于经典 Latarjet（分别为 9.9 和 6.5 毫米，P=0.013）。与 30%缺损相比，经典（-25.8°）和一致（-22.2°）转移后旋转活动度显著降低（P≤0.041）。在外展、外旋位，与完整状态相比，30%缺损时关节刚度显著降低（P=0.012），与一致（P=0.015）和经典（P<0.001）条件相比也显著降低。在所有外展位置，完整状态与 Latarjet 技术均无显著差异，且两种技术之间也无显著差异（P≥0.102）。
经典和一致弧形 Latarjet 技术可恢复严重骨丢失情况下的肩部稳定性和活动度。两种技术在旋转活动度或关节刚度方面无显著差异。然而，与经典技术相比，一致弧形技术在达到稳定的非脱位终点之前，会导致肱骨头前向位移明显增加。
基于该生物力学模型，经典和一致弧形 Latarjet 技术均可用于稳定严重关节盂骨丢失的肩部。需要进一步的临床和生物力学研究来确定是否存在特定的临床情况，使得一种技术比另一种技术具有优势。
