J. L. Koh, T. A. Zimmerman, S. Patel, Y. Ren, D. Xu, L.-Q. Zhang, Department of Orthopaedic Surgery, Northshore University HealthSystem, Evanston, IL, USA D. Xu, L.-Q. Zhang, Department of Physical Therapy and Rehabilitation Science and Department of Orthopaedics, University of Maryland, Baltimore, MD, USA.
Clin Orthop Relat Res. 2018 Nov;476(11):2262-2270. doi: 10.1097/CORR.0000000000000464.
Partial meniscectomy is one of the most commonly performed orthopaedic procedures for a meniscus tear. Decreased contact area and increased contact pressure have been seen in partial meniscectomies from treatment of various types of meniscal tears; however, the biomechanical effect of a horizontal cleavage tear in the lateral meniscus and subsequent treatment are unknown.
QUESTIONS/PURPOSES: This study asked whether a horizontal cleavage tear of the lateral meniscus, resecting the inferior leaf, and further resecting the superior leaf would (1) decrease contact area and (2) increase peak contact pressure.
Eleven fresh-frozen human cadaveric knees were evaluated under five conditions of intact meniscus, horizontal cleavage tear, inferior leaf resection, and resection of the inferior and superior leaves of the lateral meniscus. Tibiofemoral contact area and pressure were measured at 0° and 60° knee flexion under an 800-N load, normalized to that at the intact condition of the corresponding knee flexion, and compared across the five previously described conditions.
At 0° knee flexion, normalized contact area with inferior leaf resection (65.4% ± 14.1%) was smaller than that at the intact condition (100% ± 0.0%, p < 0.001); smaller than horizontal cleavage tear (94.1% ± 5.8%, p = 0.001) contact area; and smaller than repaired horizontal tear (92.8% ± 8.2%, p = 0.001) contact area. Normalized contact area with further superior leaf resection (50.5% ± 7.3%) was smaller than that at the intact condition (100% ± 0.0%, p < 0.001); smaller than horizontal cleavage tear (94.1% ± 5.8%, p < 0.001) contact area; and smaller than repaired horizontal tear (92.8% ± 8.2%, p < 0.001) contact area. At 60° flexion, normalized contact area with inferior leaf resection (76.1% ± 14.8%) was smaller than that at the intact condition (100% ± 0.0%, p = 0.004); smaller than horizontal cleavage tear (101.8% ± 7.2%, p = 0.006) contact area; and smaller than repaired horizontal tear (104.0% ± 13.3%, p < 0.001) contact area. Normalized contact area with further superior leaf resection (52.1% ± 16.7%) was smaller than that at the intact condition (100% ± 0.0%, p < 0.001); smaller than horizontal cleavage tear (101.8% ± 7.2%, p < 0.001) contact area; and smaller than repaired horizontal tear (104.0% ± 13.3%, p < 0.001) contact area. At 60° flexion, contact area with both leaf resection (52.1% ± 16.7%) was smaller than that with inferior leaf resection (76.1% ± 14.8%, p = 0.039). At 0° knee flexion, peak pressure increased to 127.0% ± 22.1% with inferior leaf resection (p = 0.026) and to 138.6% ± 24.3% with further superior leaf resection (p = 0.002) compared with that at the intact condition (100% ± 0.0%). At 60° flexion, compared with that at the intact condition (100% ± 0.0%), peak pressure increased to 139% ± 33.6% with inferior leaf resection (p = 0.035) and to 155.5% ± 34.7% (p = 0.004) with further superior leaf resection.
Resection of the inferior leaf or both leaves of the lateral meniscus after a horizontal cleavage tear resulted in decreased contact area and increased peak contact pressure at 0° and 60° knee flexion.
In vitro resection of one or both leaves of a horizontal cleavage tear of the lateral meniscus causes increases in peak pressure, consistent with other types of partial meniscectomies associated in a clinical setting with excessive loading and damage to knee cartilage. Clinical outcomes in patients undergoing partial leaf meniscectomy could confirm this theory. Avoidance of resection may be relatively beneficial for long-term function. The findings of this in vitro study lend biomechanical support for nonoperative management.
半月板部分切除术是治疗半月板撕裂最常用的骨科手术之一。在各种类型的半月板撕裂的治疗中，已经观察到半月板部分切除术后接触面积减小和接触压力增加；然而，外侧半月板水平撕裂的生物力学效应及其后续治疗尚不清楚。
问题/目的：本研究旨在探讨外侧半月板水平撕裂后切除下叶，进一步切除上叶是否会（1）减少接触面积，（2）增加峰值接触压力。
在 0°和 60°膝关节屈曲时，对 11 个新鲜冷冻的人尸体膝关节进行了完整半月板、水平撕裂、下叶切除和外侧半月板下叶和上叶切除 5 种情况下的评估。在 800-N 负载下，将胫骨股骨接触面积和压力归一化为相应膝关节屈曲状态的 100%，并与之前描述的 5 种情况进行比较。
在 0°膝关节屈曲时，下叶切除后的归一化接触面积（65.4%±14.1%）小于完整状态（100%±0.0%，p<0.001）；小于水平撕裂（94.1%±5.8%，p=0.001）接触面积；小于修复性水平撕裂（92.8%±8.2%，p=0.001）接触面积。进一步切除上叶后的归一化接触面积（50.5%±7.3%）小于完整状态（100%±0.0%，p<0.001）；小于水平撕裂（94.1%±5.8%，p<0.001）接触面积；小于修复性水平撕裂（92.8%±8.2%，p<0.001）接触面积。在 60°膝关节屈曲时，下叶切除后的归一化接触面积（76.1%±14.8%）小于完整状态（100%±0.0%，p=0.004）；小于水平撕裂（101.8%±7.2%，p=0.006）接触面积；小于修复性水平撕裂（104.0%±13.3%，p<0.001）接触面积。进一步切除上叶后的归一化接触面积（52.1%±16.7%）小于完整状态（100%±0.0%，p<0.001）；小于水平撕裂（101.8%±7.2%，p<0.001）接触面积；小于修复性水平撕裂（104.0%±13.3%，p<0.001）接触面积。在 60°膝关节屈曲时，两叶切除后的接触面积（52.1%±16.7%）小于下叶切除后的接触面积（76.1%±14.8%，p=0.039）。在 0°膝关节屈曲时，下叶切除后峰值压力增加至 127.0%±22.1%（p=0.026），进一步切除上叶后峰值压力增加至 138.6%±24.3%（p=0.002），与完整状态（100%±0.0%）相比。在 60°膝关节屈曲时，与完整状态（100%±0.0%）相比，下叶切除后峰值压力增加至 139%±33.6%（p=0.035），进一步切除上叶后峰值压力增加至 155.5%±34.7%（p=0.004）。
外侧半月板水平撕裂后切除下叶或两叶，在 0°和 60°膝关节屈曲时，接触面积减小，峰值接触压力增加。
体外切除外侧半月板水平撕裂的一叶或两叶会导致峰值压力增加，与临床实践中其他类型的半月板部分切除术一致，这些切除术与膝关节软骨过度负荷和损伤有关。接受部分叶切除术的患者的临床结果可能证实这一理论。避免切除可能对长期功能相对有益。本体外研究的结果为非手术治疗提供了生物力学支持。
