Department of Orthopaedic Surgery and Traumatology, Ghent University Hospital, De Pintelaan 185, B-9000 Ghent, Belgium.
Am J Sports Med. 2012 Jun;40(6):1329-36. doi: 10.1177/0363546512441328. Epub 2012 Apr 2.
Radiographic features specifically related to the occurrence of femoroacetabular impingement (FAI) appear to be highly prevalent in the asymptomatic population. It remains unclear, however, how these incidental findings should be interpreted clinically and which other variables might differentiate between true incidental findings and preclinical patients.
To study the association between cam and overall hip morphological characteristics and range of motion in impingement patients, asymptomatic patients (healthy patients with radiographic features specific to FAI), and healthy controls.
Cross-sectional study; Level of evidence, 3.
Morphological parameters describing cam and overall hip anatomy were obtained from 30 patients (10 per subgroup) with use of 3-dimensional computational methods. In addition, the range of internal rotation in high flexion activities was evaluated, and its relation to hip morphological variables was analyzed in a multivariate regression model.
Size of the cam lesion and range of motion significantly differed between groups (P < .05). The range of internal rotation on impingement testing was found to average 27.9° in the healthy control group compared with 21.1° in the asymptomatic control group with radiographic features specific to FAI (P < .001) and 12.3° in the patient group (P < .001). Cam size, acetabular coverage, and femoral version appeared to be predictive variables for the range of internal rotation. Seventy-five percent of variance between patients could be attributed to the combined effect of these 3 variables (R = .86). The range of motion was decreased in cam patients and asymptomatic patients, and early femoroacetabular conflict was not restricted to the area of the cam lesion but involved the entire anterior femoral head-neck junction.
Decreased range of motion, as found in FAI, is not solely dependent on the size or even the occurrence of a cam lesion but should be interpreted by taking into account the overall hip anatomy, specifically femoral version and acetabular coverage. Decreased femoral anteversion and increased acetabular coverage add to the risk of early femoroacetabular collision during sports and activities of daily living and therefore appear to be additional predictive variables, besides the finding of a cam lesion, for the risk of clinical hip impingement development. In addition, the findings suggest that surgical osteochondroplasty to restore a normal range of motion may necessitate more excessive bone resection than what simply appears to be a bump on imaging.
在无症状人群中，与股骨髋臼撞击症（FAI）发生相关的影像学特征似乎非常普遍。然而，目前尚不清楚如何对这些偶然发现进行临床解释，以及哪些其他变量可以区分真正的偶然发现和临床前患者。
研究凸轮和整个髋关节形态特征与撞击症患者、无症状患者（具有 FAI 特定影像学特征的健康患者）和健康对照组之间的运动范围之间的相关性。
横断面研究；证据水平，3 级。
使用三维计算方法从 30 名患者（每组 10 名）中获得描述凸轮和整个髋关节解剖结构的形态学参数。此外，评估了高屈曲活动中内旋的范围，并在多元回归模型中分析了其与髋关节形态学变量的关系。
凸轮病变的大小和运动范围在组间差异有统计学意义（P <.05）。在健康对照组中，撞击试验时的内旋范围平均为 27.9°，而具有 FAI 特定影像学特征的无症状对照组为 21.1°（P <.001），患者组为 12.3°（P <.001）。凸轮大小、髋臼覆盖度和股骨前倾角似乎是内旋范围的预测变量。这 3 个变量的综合效应可以解释 75%的患者之间的差异（R =.86）。凸轮患者和无症状患者的运动范围减小，并且早期股骨髋臼撞击不仅限于凸轮病变区域，而是涉及整个前股骨头颈交界处。
FAI 中发现的运动范围减小不仅取决于凸轮病变的大小，甚至不仅仅取决于凸轮病变的发生，而应考虑整个髋关节解剖结构，特别是股骨前倾角和髋臼覆盖度来解释。股骨前倾角减小和髋臼覆盖度增加增加了在运动和日常生活活动中发生早期股骨髋臼碰撞的风险，因此除了发现凸轮病变外，它们似乎是临床髋关节撞击发展风险的另外的预测变量。此外，这些发现表明，为了恢复正常的运动范围，手术骨软骨成形术可能需要比影像学上看起来的简单凸起更多的骨切除。
