Department of Orthopedics and Traumatology, St. Marguerite Hospital, Marseille, France.
Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota
J Bone Joint Surg Am. 2016 Apr 20;98(8):672-6. doi: 10.2106/JBJS.14.01099.
Osteonecrosis of the femoral head has a host of etiologies. However, in 30% of the cases, no underlying etiology is identified and the process is considered "idiopathic." Our hypothesis was that osseous anatomical abnormalities might be frequently found in patients with femoral head osteonecrosis.
A retrospective, 1:2 matched, case-control study was undertaken to compare ninety patients with idiopathic osteonecrosis who had undergone lower-limb computed tomography (CT) prior to undergoing total hip arthroplasty with 180 control patients matched for age, sex, and body mass index (BMI) who had undergone lower-limb computed tomography scanning at our radiology department for any reason except articular or bone disease. Preoperative CT scans were performed for all patients to evaluate femoral offset, femoral neck-shaft angle, femoral neck version, femoral head diameter, acetabular coverage estimated with use of the lateral center-edge angle, acetabular version, and acetabular diameter. The mean age was forty-five years, 69% of the patients were men, and the mean BMI was 26 kg/m2.
Anatomical "abnormalities" associated with osteonecrosis were determined to be a femoral neck-shaft angle of <129° (likelihood ratio [LR] = 3.6), femoral neck version of >17° (LR = 3.8), a lateral center-edge angle of <32° (LR = 5.7), and acetabular version of <19° (LR = 1.38). A combination of three of the four anatomical "abnormalities" was found in 73% of the patients with osteonecrosis but only 11% of the control cases (LR = 6).
This 1:2 matched, anatomical study suggests that acetabular and femoral anatomical factors, in isolation or combination, can be found in a large percentage of cases of "idiopathic" osteonecrosis.
In this study, isolated or combined abnormalities of the hip were observed in the group of patients with osteonecrosis. Those elements may help surgeons to understand the process underlying idiopathic osteonecrosis and thus require further investigation.
股骨头坏死有多种病因。然而，在 30%的病例中，没有发现潜在的病因，且该过程被认为是“特发性的”。我们的假设是，骨解剖异常可能在股骨头坏死患者中经常发现。
我们进行了一项回顾性、1:2 匹配的病例对照研究，比较了 90 例特发性骨坏死患者与 180 例因非关节或骨骼疾病而在我院放射科行下肢 CT 检查的对照组患者。所有患者均行术前 CT 扫描，以评估股骨偏心距、股骨颈干角、股骨颈倾斜角、股骨头直径、外侧中心边缘角估计的髋臼覆盖范围、髋臼倾斜角和髋臼直径。平均年龄为 45 岁，69%的患者为男性，平均 BMI 为 26kg/m2。
与骨坏死相关的解剖“异常”被确定为股骨颈干角<129°（似然比[LR] = 3.6）、股骨颈倾斜角>17°（LR = 3.8）、外侧中心边缘角<32°（LR = 5.7）和髋臼倾斜角<19°（LR = 1.38）。在 73%的骨坏死患者中发现了四种解剖“异常”中的三种组合，但在对照组中只有 11%（LR = 6）。
这项 1:2 匹配的解剖研究表明，髋臼和股骨的解剖因素，无论是单独存在还是组合存在，都可以在很大比例的“特发性”骨坏死病例中发现。
在这项研究中，观察到骨坏死组患者存在孤立或联合的髋关节异常。这些因素可能有助于外科医生了解特发性骨坏死的潜在过程，因此需要进一步研究。
