Baleani Massimiliano, Francesconi Dunia, Zani Lorenzo, Giannini Sandro, Snyder Stephen J
Laboratorio di Tecnologia Medica, Istituto Ortopedico Rizzoli, Bologna, Italy.
Clinica Ortopedica e Traumatologica I, Istituto Ortopedico Rizzoli, Bologna, Italy.
Clin Biomech (Bristol). 2015 Feb;30(2):188-94. doi: 10.1016/j.clinbiomech.2014.12.001. Epub 2014 Dec 8.
The interference screw technique is commonly used in tenodesis of the long head of the biceps for its well-documented robust fixation strength. Some complications may occur after tenodesis with interference screw such as persistent pain, bone fracture and cyst formation. A new technique using a small "soft anchor" has been proposed to avoid the risk of occurrence of the above-mentioned complications associated with the use of the interference screw. However, the proposed technique must provide adequate fixation strength. This study investigated the mechanical performance of the new technique and compared it with interference screw fixation.
Fourteen human humeri and proximal biceps were tested after tenodesis using the two techniques. The fixation constructs were cycled 500 times between 20N and 100N at 1Hz to simulate some level of post-operative physical activity. Then, a tensile test to failure was performed to determine the strength of the two tenodesis constructs.
The ultimate strength was 238N (SD 96N) and 172N (SD 58N) for the "soft anchor" and the interference screw, respectively (P=0.14). In two out of seven repetitions in both groups, failure occurred at low load level due to inaccuracies in performing tenodesis. Considering these cases as outliers, the strength values increased up to 290N (SD 40N) and 202N (SD 32N) for the "soft anchor" and the interference screw, respectively (P=0.02).
The "soft anchor" technique provides a fixation strength comparable with the interference screw, but without using a screw. It could be considered as an alternative for suprapectoral biceps tenodesis.
由于其可靠的固定强度已得到充分证明，干涉螺钉技术常用于肱二头肌长头肌腱固定术。使用干涉螺钉进行肌腱固定术后可能会出现一些并发症，如持续疼痛、骨折和囊肿形成。有人提出一种使用小型“软锚钉”的新技术，以避免与使用干涉螺钉相关的上述并发症的发生风险。然而，该新技术必须提供足够的固定强度。本研究调查了新技术的力学性能，并将其与干涉螺钉固定进行比较。
使用这两种技术对14例人体肱骨和肱二头肌近端进行肌腱固定术后测试。固定结构在20N至100N之间以1Hz的频率循环500次，以模拟一定程度的术后体力活动。然后，进行拉伸破坏试验以确定两种肌腱固定结构的强度。
“软锚钉”和干涉螺钉的极限强度分别为238N（标准差96N）和172N（标准差58N）（P=0.14）。在两组的七次重复试验中，有两次由于肌腱固定操作不准确，在低负荷水平下发生失败。将这些情况视为异常值后，“软锚钉”和干涉螺钉的强度值分别增加到290N（标准差40N）和202N（标准差32N）（P=0.02）。
“软锚钉”技术提供了与干涉螺钉相当的固定强度，但无需使用螺钉。它可被视为胸上肱二头肌肌腱固定术的一种替代方法。
