Department of Orthopaedic Surgery, University Hospitals, Cleveland Medical Center, Case Western Reserve University, Cleveland, Ohio, USA.
Division of Pediatric Orthopaedics, Rainbow Babies and Children's Hospitals at Case Western Reserve University, Cleveland, Ohio, USA.
Am J Sports Med. 2018 Feb;46(2):478-486. doi: 10.1177/0363546517697689. Epub 2017 Mar 23.
Cam morphology of the proximal femur is an abnormal contour of the femoral head-neck junction present in approximately 15% to 25% of the asymptomatic population, predominantly in males. Alpha angle and femoral head-neck offset ratio are 2 objective measurement tools that define cam morphology. Both primary (idiopathic) and secondary cam deformity develops through distinct mechanisms. The cause of primary (idiopathic) cam morphology remains incompletely understood. Mounting evidence suggests that idiopathic cam morphology develops during adolescence through alterations in the capital femoral epiphysis in response to participation in vigorous sporting activity. While the exact cause of epiphyseal extension has not yet been determined, preliminary evidence suggests that epiphyseal extension may reflect a short-term adaptive response to provide stability to the physis at the long-term cost of the development of cam morphology. Commonly recognized causes of secondary cam deformity include frank slipped capital femoral epiphysis, Legg-Calve-Perthes disease, and deformity after fracture of the proximal femur. Recent studies also support subtle slipped capital femoral epiphysis as a unique and silent cause of a small percentage of subjects previously thought to have idiopathic cam deformity.
股骨近端的凸轮形态是指股骨颈-股骨头交界处的异常轮廓，约占无症状人群的 15%至 25%，主要见于男性。α角和股骨头颈偏移比是定义凸轮形态的 2 个客观测量工具。原发性（特发性）和继发性凸轮畸形通过不同的机制发展。原发性（特发性）凸轮形态的原因仍不完全清楚。越来越多的证据表明，特发性凸轮形态在青少年时期通过股骨头骨骺的改变发展，以应对剧烈运动的参与。虽然尚未确定骺板延伸的确切原因，但初步证据表明，骺板延伸可能反映了短期适应性反应，以提供稳定性，但长期来看会发展成凸轮形态。公认的继发性凸轮畸形的原因包括明显的股骨颈骨骺滑脱、Legg-Calve-Perthes 病和股骨近端骨折后的畸形。最近的研究还支持轻微的股骨颈骨骺滑脱是一小部分以前被认为患有特发性凸轮畸形的患者的独特和无声的原因。
