Section of Young Adult Hip Surgery, Division of Sports Medicine, Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois, U.S.A.
Department of Orthopedic Surgery, Wake Forest Baptist Health, Winston-Salem, North Carolina, U.S.A..
Arthroscopy. 2020 Sep;36(9):2425-2432. doi: 10.1016/j.arthro.2020.05.021. Epub 2020 May 24.
To compare the biomechanical properties of the hip joint with an intact femoral cam lesion, partial cam resection, and complete cam resection.
A cadaveric study was performed using 8 hemipelvises with cam-type morphology (alpha angle > 55°) and intact labra. Intra-articular pressure maps were produced for each specimen under the following conditions: (1) native cam morphology (intact), (2) cam morphology with incomplete resection (partial), and (3) cam morphology with complete resection (complete). By use of an open technique, resection of the superior portion of the cam morphology was performed with a 5.5-mm burr to create the partial resection, followed by the inferior portion to create the complete resection. In each condition, 3 biomechanical parameters were obtained: contact pressure, contact area, and peak force within a region of interest. Measurements were performed 3 times in each condition, and the average value was used for statistical analysis. Analysis of variance was used to compare biomechanical parameters between conditions.
A statistically significant difference was found between the pre- and post-resection alpha angles (62.2° ± 3.9° vs 40.9° ± 1.4°, P < .001). Repeated-measures analysis of variance showed that the normalized average pressure values of hips with complete resection of cam lesions were significantly lower than those of hips with incomplete femoral cam lesions and hips with intact cam morphology (100% vs 93.6% ± 8.3% and 82.6% ± 16.2%, respectively; P < .0001). The percentage reduction of contact pressure in the complete and partial groups was 17.4% and 6.4%, respectively, compared with the intact group. Contact area and peak force showed no statistically significant differences across the 3 conditions (P > .05).
Complete cam resection results in significantly lower intra-articular hip contact pressures than incomplete cam resection and native cam morphology in a cadaveric hip model. These observations underscore the importance of ensuring complete resection of femoral cam lesions in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome.
Previous studies have shown that the most common reason for revision hip arthroscopy in patients with femoroacetabular impingement syndrome is incomplete femoral cam resection during the index operation. This study shows biomechanical differences associated with partial cam resection compared with the complete cam resection state that may translate to persistent symptoms.
比较髋关节在完整股骨凸轮病变、部分凸轮切除和完全凸轮切除情况下的生物力学特性。
使用 8 个具有凸轮形态（α角>55°）和完整唇的半骨盆进行尸体研究。在以下情况下为每个标本生成关节内压力图：（1）天然凸轮形态（完整），（2）凸轮形态伴不完全切除（部分），（3）凸轮形态伴完全切除（完全）。使用开放式技术，使用 5.5mm 球头钻切除凸轮形态的上部以形成部分切除，然后切除下部以形成完全切除。在每种情况下，获得 3 个生物力学参数：接触压力、接触面积和感兴趣区域内的峰值力。在每种情况下进行 3 次测量，取平均值进行统计分析。方差分析用于比较条件之间的生物力学参数。
术前和术后α角有统计学显著差异（62.2°±3.9°与 40.9°±1.4°，P<.001）。重复测量方差分析显示，完全切除凸轮病变的髋关节的归一化平均压力值明显低于不完全切除股骨凸轮病变和完整凸轮形态的髋关节（100%比 93.6%±8.3%和 82.6%±16.2%，P<.0001）。与完整组相比，完全组和部分组的接触压力降低百分比分别为 17.4%和 6.4%。接触面积和峰值力在 3 种情况下无统计学显著差异（P>.05）。
在尸体髋关节模型中，完全切除凸轮导致关节内髋关节接触压力明显低于不完全切除凸轮和天然凸轮形态。这些观察结果强调了在接受髋关节镜检查治疗股骨髋臼撞击综合征的患者中确保完全切除股骨凸轮病变的重要性。
先前的研究表明，股骨髋臼撞击综合征患者髋关节镜翻修最常见的原因是指数手术中股骨凸轮不完全切除。本研究显示了与完全凸轮切除状态相比，部分凸轮切除相关的生物力学差异，这可能导致持续存在症状。
