Department of Orthopaedic Surgery, University of Berne, Berne, Zürich, Switzerland.
J Bone Joint Surg Am. 2011 May;93 Suppl 2:10-6. doi: 10.2106/JBJS.J.01799.
Hips with coxa profunda can develop a pincer-type impingement with linear impact between the proximal part of the femur and the acetabulum, leading to bone apposition on the acetabular rim.
Twenty hips with radiographic features of rim ossification were isolated from a pilot cohort of 220 patients for histologic assessment of the acetabular rim and the labrum. In the second part of the study, the prevalence of radiographic signs of bone apposition in a cohort of 148 hips treated for femoroacetabular impingement was assessed.
Histologic analysis confirmed that the labrum may become displaced and replaced by the appositional bone formation. The double-line sign and the recess sign are suggestive of an ongoing process of this bone formation, and the described phenotypes of bone apposition indicate the site of the impingement problem. Morphological anomalies of the proximal part of the femur, such as a low neck-shaft angle or a short femoral neck, may further contribute to the mechanism of pincer impingement.
In later stages, this bone formation cannot be distinguished from the native bone and the labrum may appear to be nearly absent on imaging studies. While the bone apposition on the rim is first reactive to chronic impingement, the impingement then increases and may lead to further bone apposition.
髋臼过深会导致股骨近端和髋臼之间发生钳式撞击，从而导致髋臼缘骨赘形成。
从 220 例患者的初步队列中分离出 20 个具有边缘骨化放射学特征的髋关节，对髋臼缘和关节盂唇进行组织学评估。在研究的第二部分，评估了 148 例髋关节撞击综合征患者的放射学骨赘形成的患病率。
组织学分析证实，盂唇可能移位并被骨赘形成所取代。双线征和凹陷征提示骨形成的持续过程，描述的骨赘形成表型表明了撞击问题的部位。股骨近端的形态异常，如颈干角低或股骨颈短，可能进一步促成钳式撞击的机制。
在后期，这种骨形成与原生骨无法区分，在影像学研究中，盂唇可能几乎消失。虽然边缘的骨赘形成最初是对慢性撞击的反应，但撞击随后会增加，并可能导致进一步的骨赘形成。
