Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, IL 60612, USA.
Clin Orthop Relat Res. 2013 Feb;471(2):358-62. doi: 10.1007/s11999-012-2693-9. Epub 2012 Nov 6.
Femoroacetabular impingement (FAI) can lead to labral injury, osseous changes, and even osteoarthritis. The literature contains inconsistent definitions of the alpha angle and other nonthree-dimensional (3-D) radiographic measures. We present a novel approach to quantifying cam lesions in 3-D terms. Our method also can be used to develop a classification system that describes the exact location and size of cam lesions.
QUESTIONS/HYPOTHESES: We asked whether automated quantification of CAM lesions based on CT data is a reasonable way to detect CAM lesions and whether they may be classified based on location.
We developed a method to quantify femoral head cam lesions using 3-D modeling of CT scans. By segmenting raw DICOM data, we can determine the distance from the cam lesion's surface points to the centroid of the femoral head to quantify the mean bump height, volume, and location. The resulting 3-D femoral and acetabular models will be analyzed with custom software. We then will quantify the cam lesion with 3-D parameters using a modified zoning method. The mean bump height, volume, and location on the clock face, and relative zoning will be calculated. Zonal differences will be statistically analyzed. To assess the ability of this method to predict arthroscopic findings, we will obtain preoperative CT scans for 25 patients who undergo hip arthroscopy for FAI. We will compare measurements with the method with our measurements from arthroscopy. The clinical implications of our method's measurements then will be reviewed and refined for future prospective studies.
We present a novel approach that can quantify a cam lesion's location and size. This method will be used to provide guidelines for the exact amount of bony resection needed from a specific location of the proximal femur. There is also potential to develop software for ease of use so this method can be more widely applied.
股骨髋臼撞击症（FAI）可导致盂唇损伤、骨改变，甚至骨关节炎。文献中对α角和其他非三维（3-D）放射学测量方法的定义不一致。我们提出了一种新的方法来量化 3-D 条件下的凸轮病变。我们的方法还可用于开发一种分类系统，描述凸轮病变的确切位置和大小。
问题/假设：我们想知道基于 CT 数据的 CAM 病变自动量化是否是一种检测 CAM 病变的合理方法，以及它们是否可以基于位置进行分类。
我们开发了一种使用 CT 扫描的 3-D 建模来量化股骨头凸轮病变的方法。通过对原始 DICOM 数据进行分割，我们可以确定凸轮病变表面点到股骨头质心的距离，从而量化平均凸起高度、体积和位置。生成的 3-D 股骨和髋臼模型将使用定制软件进行分析。然后，我们将使用修改后的分区方法用 3-D 参数量化凸轮病变。将计算时钟面的平均凸起高度、体积和位置，以及相对分区。将对分区差异进行统计学分析。为了评估该方法预测关节镜检查结果的能力，我们将为 25 例因 FAI 而行髋关节镜检查的患者获取术前 CT 扫描。我们将比较该方法的测量值与我们的关节镜检查测量值。然后将审查和完善该方法测量值的临床意义，以便为未来的前瞻性研究提供参考。
我们提出了一种新的方法，可以量化凸轮病变的位置和大小。该方法将用于为从股骨近端特定位置进行骨切除提供具体指导。还有可能开发出便于使用的软件，以便更广泛地应用该方法。
