Simonian P T, Sussmann P S, Baldini T H, Crockett H C, Wickiewicz T L
The Sports Medicine Service, The Hospital for Special Surgery, New York, New York, USA.
Arthroscopy. 1998 Jul-Aug;14(5):459-64. doi: 10.1016/s0749-8063(98)70072-6.
Anterior cruciate ligament reconstruction with hamstring tendon graft and interference screw fixation has recently been considered. Concerns for the use of interference screws with soft tissue grafts include damage to the graft during screw insertion, decreased fixation strength, and a decrease in the bone-tendon contact area for healing within the tunnel when the screw is placed in an eccentric position. This last concern could be addressed by placing the interference screw centrally between the four limbs of the hamstring graft. The purpose of this study was to determine the mode of failure, the pullout force, and graft slippage before graft fixation failure of hamstring tendons fixed with an interference screw positioned eccentrically in relation to the hamstring tendons verses an interference screw positioned centrally between the four graft limbs. The semitendinosus and gracilis tendons were harvested from six, fresh cadaveric specimens. Each tendon was divided into two segments of equal length. Both the semitendinosus and gracilis tendon segments were looped to form four strands. The specimens were then fixed with a bioabsorbable interference screw in the two different positions and pulled from a standardized polyurethane foam. All tendons in both groups failed by pulling out from between the interference screw and tunnel, regardless of the screw position. No tendon was cut by the screw in either group. There was no significant difference between the forces required to produce specific amounts of graft slippage between the two fixation techniques tested. There was no significant difference between the average total slippage at maximum pullout, 11.8 mm for the screw placed in the eccentric position and 13.7 mm for the screw placed in the central position. The maximum pullout force averaged 265.3 N for the screw placed in the eccentric position, and 244.7 N for the screw placed in the central position; these values were not significantly different. Placement of the interference screw in the central position did not compromise strength and it improves graft contact within the bone tunnel. Interference screw fixation, when applied against a bone plug, has been shown to consistently have a pullout force of more than 400 N.
最近人们考虑采用腘绳肌腱移植和挤压螺钉固定进行前交叉韧带重建。对于在软组织移植中使用挤压螺钉存在一些担忧，包括在螺钉插入过程中对移植物的损伤、固定强度降低，以及当螺钉偏心放置时隧道内用于愈合的骨 - 肌腱接触面积减小。通过将挤压螺钉置于腘绳肌腱移植物的四个肢体之间的中心位置，可以解决最后一个问题。本研究的目的是确定相对于偏心放置在腘绳肌腱上的挤压螺钉与置于四个移植物肢体之间中心位置的挤压螺钉，腘绳肌腱在固定失败前的失效模式、拔出力和移植物滑动情况。从六个新鲜尸体标本中获取半腱肌和股薄肌腱。将每条肌腱分成两段等长的部分。半腱肌和股薄肌腱段均环绕形成四股。然后将标本用可生物吸收的挤压螺钉固定在两个不同位置，并从标准化聚氨酯泡沫中进行牵拉。无论螺钉位置如何，两组中的所有肌腱均因从挤压螺钉和隧道之间拔出而失效。两组中均没有肌腱被螺钉切断。在测试的两种固定技术之间，产生特定量移植物滑动所需的力没有显著差异。在最大拔出时的平均总滑动量在偏心位置放置的螺钉为11.8毫米，在中心位置放置的螺钉为13.7毫米，两者之间没有显著差异。偏心位置放置的螺钉平均最大拔出力为265.3牛，中心位置放置的螺钉为244.7牛；这些值没有显著差异。将挤压螺钉置于中心位置不会损害强度，并且能改善骨隧道内的移植物接触。当挤压螺钉固定在骨栓上时，已证明其拔出力始终超过400牛。
