Sports Medicine and Shoulder Service, Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021, USA.
Am J Sports Med. 2010 Aug;38(8):1591-7. doi: 10.1177/0363546510364402. Epub 2010 Jun 8.
The pivot shift is a dynamic test of knee stability that involves a pathologic, multiplanar motion path elicited by a combination of axial load and valgus force during a knee flexion from an extended position.
To assess the stabilizing effect of the medial and lateral meniscus on anterior cruciate ligament-deficient (ACL-D) knees during the pivot shift examination.
Controlled laboratory study.
A Lachman and a mechanized pivot shift test were performed on 16 fresh-frozen cadaveric hip-to-toe lower extremity specimens. The knee was tested intact, ACL-D, and after sectioning the medial meniscus (ACL/MM-D; n = 8), lateral meniscus (ACL/LM-D; n = 8), and both (ACL/LM/MM-D; n = 16). A navigation system recorded the resultant anterior tibial translations (ATTs). For statistical analysis an analysis of variance was used; significance was set at P < .05.
The ATT significantly increased in the ACL-D knee after lateral meniscectomy (ACL/LM-D; P < .05) during the pivot shift maneuver. In the lateral compartment of the knee, ATT in the ACL-D knee increased by 6 mm after lateral meniscectomy during the pivot shift (16.6 +/- 6.0 vs 10.5 +/- 3.5 mm, P < .01 for ACL/LM out vs ACL out). Medial meniscectomy, conversely, had no significant effect on ATT in the ACL-D knee during pivot shift examination (P > .05). With standardized Lachman examination, however, ATT significantly increased after medial but not lateral meniscectomy compared with the ACL-D knee (P < .001).
Although the medial meniscus functions as a critical secondary stabilizer to anteriorly directed forces on the tibia during a Lachman examination, the lateral meniscus appears to be a more important restraint to anterior tibial translation during combined valgus and rotatory loads applied during a pivoting maneuver.
This model may have implications in the evaluation of surgical reconstruction procedures in complex knee injuries.
髌股关节移位是一种动态的膝关节稳定性测试，涉及到一种病理的、多平面的运动路径，这种运动路径是在膝关节从伸展位屈曲时，轴向负荷和外翻力共同作用下产生的。
评估内侧和外侧半月板在前交叉韧带缺失（ACL-D）膝关节髌股关节移位检查中的稳定作用。
对照实验室研究。
对 16 个新鲜冷冻的髋关节到足的下肢标本进行 Lachman 和机械性髌股关节移位试验。膝关节在完整、ACL-D、内侧半月板（ACL/MM-D；n=8）、外侧半月板（ACL/LM-D；n=8）和两者（ACL/LM/MM-D；n=16）切除后进行测试。导航系统记录胫骨前向平移（ATT）的结果。进行方差分析进行统计学分析；显著性设为 P<.05。
在髌股关节移位过程中，外侧半月板切除后 ACL-D 膝关节的 ATT 显著增加（ACL/LM-D；P<.05）。在膝关节外侧间隙，外侧半月板切除后，ACL-D 膝关节在髌股关节移位时 ATT 增加了 6 毫米（16.6 +/- 6.0 与 10.5 +/- 3.5 毫米，ACL/LM 外与 ACL 外相比，P<.01）。相反，内侧半月板切除术对 ACL-D 膝关节在髌股关节检查中的 ATT 没有显著影响（P>.05）。然而，通过标准化的 Lachman 检查，与 ACL-D 膝关节相比，内侧半月板切除后 ATT 显著增加，但外侧半月板切除后无明显变化（P<.001）。
尽管内侧半月板在 Lachman 检查中作为胫骨前向力的关键次要稳定器，但在旋转和外翻负荷作用下进行髌股关节旋转运动时，外侧半月板似乎对胫骨前向平移的限制更为重要。
该模型可能对复杂膝关节损伤的手术重建程序评估具有重要意义。
