Department of Orthopaedic Surgery, Kobe Kaisei Hospital, 11-15, Shinohara-Kitamachi, 3-chome, Nada-ku, Kobe, 657-0068, Japan.
Department of Orthopaedic Surgery, Graduate School of Medicine, Kobe University, Kobe, Japan.
Knee Surg Sports Traumatol Arthrosc. 2018 Apr;26(4):1145-1151. doi: 10.1007/s00167-017-4543-5. Epub 2017 Apr 11.
Final tunnel location in the anterior cruciate ligament (ACL) reconstruction is unpredictable due to tunnel widening and/or transposition. The mechanical stress around the tunnel aperture seems to be a major factor but is not fully investigated. The purpose of this study was to measure the stress from the ACL graft around the tunnel aperture when the ACL graft tension reaches its peak.
Six cadaveric knees were used. Single-bundle ACL reconstruction was performed using a hamstrings graft. Both femoral and tibial tunnels were created at the centre of the original ACL footprint. A 7-mm-internal-diameter aluminium cylinder with pressure sensors was placed in the femoral tunnel. Hamstrings graft with a microtension sensor was inserted. After fixation, passive extension-flexion was performed while monitoring the tunnel aperture pressure and the graft tension simultaneously. The pressure on the femoral tunnel aperture when the ACL graft tension reach its peak was compared between four directions.
The ACL graft tension peaked (67 ± 49 N) at full extension (-5.8 ± 4.1°). Pressure at the femoral tunnel aperture was different between different directions (p < 0.01). Distal part had significantly larger pressure (1.7 ± 1.3 MPa) than the other directions (p < 0.01). Second largest pressure was carried in the anterior part (0.6 ± 0.5 MPa), followed by proximal and posterior parts (0.4 ± 0.3, 0.2 ± 0.2 MPa respectively).
The stress distribution at the femoral tunnel aperture is not equal in different directions, while the distal part dominantly bears the stress from the ACL graft. Surgeons should pay close attention to the distal edge of the femoral tunnel which should be inside the anatomic ACL footprint eventually.
由于隧道扩张和/或易位，前交叉韧带（ACL）重建中的最终隧道位置不可预测。隧道开口周围的机械应力似乎是一个主要因素，但尚未得到充分研究。本研究的目的是测量 ACL 移植物在 ACL 移植物张力达到峰值时在隧道开口周围的应力。
使用 6 个尸体膝关节。使用腘绳肌移植物进行单束 ACL 重建。在原始 ACL 足迹的中心创建股骨和胫骨隧道。将直径为 7 毫米的带有压力传感器的铝制圆柱体放置在股骨隧道中。插入带有微张力传感器的腘绳肌移植物。固定后，同时监测隧道开口压力和移植物张力，进行被动伸屈运动。比较了 ACL 移植物张力达到峰值时四个方向的股骨隧道开口处的压力。
ACL 移植物张力在完全伸展时达到峰值（67±49N）（-5.8±4.1°）。股骨隧道开口处的压力在不同方向上有所不同（p<0.01）。远侧部分的压力明显大于其他方向（p<0.01），为 1.7±1.3MPa；前侧部分次之，为 0.6±0.5MPa；后侧和前侧部分分别为 0.4±0.3MPa 和 0.2±0.2MPa。
股骨隧道开口处的应力分布在不同方向上不均匀，而远端主要承受 ACL 移植物的应力。外科医生应密切注意股骨隧道的远端边缘，最终应位于解剖学 ACL 足迹内。
