Jónasson Páll Sigurgeir, Ekström Lars, Swärd Anna, Sansone Mikael, Ahldén Mattias, Karlsson Jón, Baranto Adad
Department of Orthopaedics, Institute of Clinical Sciences at Sahlgrenska Academy, University of Gothenburg and Sahlgrenska University Hospital, Gothenburg, Sweden.
Östersund Hospital, Östersund, Sweden.
J Exp Orthop. 2014 Dec;1(1):4. doi: 10.1186/s40634-014-0004-y. Epub 2014 Jun 26.
The high loads on adolescent athletes' musculoskeletal system are known to cause morphological and degenerative changes in bone, intervertebral discs and joints. It has been suggested that the cam deformity of the proximal femoral head originates from a subclinical slipped capital femoral epiphysis (SCFE) as a result of non-physiological loading. The perichondrial fibrocartilaginous complex (PFC) and the epiphyseal tubercle are believed to stabilise the proximal femoral epiphysis, but their role is still unclear. The aim of the present study was to develop an experimental, biomechanical model to evaluate the strength of the porcine proximal femoral epiphysis in different loading directions and, furthermore, to investigate the stabilising role of the PFC and the epiphyseal tubercle.
A descriptive laboratory study. An in-vitro model was developed and nine young (5 months) porcine proximal femoral epiphyses were loaded to failure; three in the anterior-posterior direction, three in the lateral-medial direction and three in the vertical direction. The injured proximal femoral epiphyses were then examined both macroscopically and histologically.
Anterior and lateral loading of the proximal femoral epiphysis resulted in failure of the epiphyseal plate, while vertical loading resulted in a fracture epiphyseolysis. The epiphysis was weakest when exposed to a lateral load and strongest when exposed to a vertical load. Despite histological epiphyseolysis, the PFC was intact in 15 of 27 (56%) slices. In histological examinations, the epiphyseal tubercle appears to halt the slide of the epiphysis.
We have developed an experimental, biomechanical model to measure the strength of the proximal femoral epiphyseal plate in different loading directions. The strength of the proximal femur was weakest through the epiphyseal plate. The epiphysis was weakest when exposed to a lateral load and strongest when exposed to a vertical load. The epiphyseal tubercle and the PFC stabilise the epiphysis when the epiphyseal plate is damaged. The findings in the present study indicate that overloading the hips in growing individuals can disrupt the epiphyseal plate. These findings may have implications when it comes to understanding the pathogenesis of cam deformity of the hip.
众所周知，青少年运动员肌肉骨骼系统承受的高负荷会导致骨骼、椎间盘和关节发生形态学和退行性变化。有人提出，由于非生理性负荷，股骨近端骨骺的凸轮畸形起源于亚临床型股骨头骨骺滑脱（SCFE）。骨膜纤维软骨复合体（PFC）和骨骺结节被认为可稳定股骨近端骨骺，但其作用仍不明确。本研究的目的是建立一个实验性生物力学模型，以评估猪股骨近端骨骺在不同加载方向下的强度，此外，研究PFC和骨骺结节的稳定作用。
一项描述性实验室研究。建立了一个体外模型，对九个年轻（5个月）猪的股骨近端骨骺进行加载直至破坏；三个沿前后方向加载，三个沿内外侧方向加载，三个沿垂直方向加载。然后对受伤的股骨近端骨骺进行宏观和组织学检查。
股骨近端骨骺的前向和侧向加载导致骨骺板破坏，而垂直加载导致骨折性骨骺溶解。骨骺在承受侧向载荷时最弱，在承受垂直载荷时最强。尽管组织学上有骨骺溶解，但在27个切片中的15个（56%）中PFC是完整的。在组织学检查中，骨骺结节似乎能阻止骨骺的滑动。
我们建立了一个实验性生物力学模型来测量股骨近端骨骺板在不同加载方向下的强度。股骨近端通过骨骺板的强度最弱。骨骺在承受侧向载荷时最弱，在承受垂直载荷时最强。当骨骺板受损时，骨骺结节和PFC可稳定骨骺。本研究结果表明，生长中的个体髋部过度负荷会破坏骨骺板。这些发现可能对理解髋部凸轮畸形的发病机制有启示意义。
