Beck Paul R, Thomas Andre L, Farr Jack, Lewis Paul B, Cole Brian J
University of Utah Orthopaedic Center, University of Utah, Salt Lake City, USA.
Am J Sports Med. 2005 Nov;33(11):1710-5. doi: 10.1177/0363546505278300. Epub 2005 Aug 10.
Anteromedialization is recommended for cartilage restoration of patellofemoral defects, with the presumption that it decreases contact pressures across the trochlea. No study has evaluated pressures on the trochlear side of the patellofemoral joint after anteromedialization of the tibial tubercle.
Anteromedialization of the tibial tubercle decreases contact pressure across the trochlea.
Controlled laboratory study.
Ten cadaveric knees were tested by placing an electroresistive pressure sensor on the femoral side of the patellofemoral joint. A validated model of nonweightbearing resisted extension was simulated by loading the extensor mechanism at 89.1 N and 178.2 N. Knees were tested 3 times per load at 30 degrees , 60 degrees , 90 degrees , and 105 degrees . The center of force and pressure across the patellofemoral articulation were compared before and after a reproducible and consistent anteromedialization.
The mean center of force shifted medially after anteromedialization at 89.1 N and 178.2 N. At 89.1 N, the mean total contact pressure decreased significantly (P < .05) at all angles, and at 178.2 N, it decreased significantly at 30 degrees , 60 degrees , and 90 degrees of knee flexion. The mean lateral trochlear contact pressure decreased significantly (P < .05) at all flexion angles at both 89.1 N and 178.2 N. The mean central trochlear contact pressure decreased significantly (P < .05) at 30 degrees with the 89.1-N and 178.2-N loads but increased significantly (P < .05) at 90 degrees with the 89.1-N load. The mean medial trochlear contact pressure increased significantly (P < .05) at all flexion angles at 89.1 N and 178.2 N.
Anteromedialization shifts the contact force to the medial trochlea and decreases the mean total contact pressure.
Anteromedialization decreases the mean total contact pressure while shifting contact pressure toward the medial trochlea. This study suggests that anteromedialization is appropriate for unloading the lateral trochlea. However, this procedure appears to have minimal benefit on central chondral defects, and it may actually increase the load in patients with medial defects.
对于髌股关节缺损的软骨修复，推荐采用胫骨结节前内侧移位术，其假定是该手术可降低滑车表面的接触压力。尚无研究评估胫骨结节前内侧移位术后髌股关节滑车侧的压力情况。
胫骨结节前内侧移位术可降低滑车表面的接触压力。
对照实验室研究。
在10具尸体膝关节的髌股关节股骨侧放置一个电阻式压力传感器进行测试。通过以89.1 N和178.2 N的力加载伸膝装置，模拟一种经过验证的非负重抗伸展模型。在30°、60°、90°和105°时，每个负荷下对膝关节进行3次测试。比较在可重复且一致的胫骨结节前内侧移位术前和术后髌股关节的力中心和压力。
在89.1 N和178.2 N负荷下，胫骨结节前内侧移位术后力的平均中心向内移动。在89.1 N时，所有角度的平均总接触压力均显著降低（P < 0.05）；在178.2 N时，膝关节屈曲30°、60°和90°时平均总接触压力显著降低。在89.1 N和178.2 N时，所有屈曲角度的平均滑车外侧接触压力均显著降低（P < 0.05）。在89.1 N和178.2 N负荷下，30°时平均滑车中央接触压力显著降低（P < 0.05），但在89.1 N负荷下90°时显著升高（P < 0.05）。在89.1 N和178.2 N时，所有屈曲角度的平均滑车内侧接触压力均显著升高（P < 0.05）。
胫骨结节前内侧移位术将接触力转移至滑车内侧，并降低了平均总接触压力。
胫骨结节前内侧移位术在将接触压力向滑车内侧转移的同时降低了平均总接触压力。本研究表明，胫骨结节前内侧移位术适用于减轻滑车外侧的负荷。然而，该手术对中央软骨缺损似乎益处不大，实际上可能会增加内侧缺损患者的负荷。
