Graf R1*, Hammer N2,3,4 and Matthiesen D5
1Department of Orthopedics, General and Orthopedic Regional Hospital Stolzalpe, Austria
2Institute of Macroscopic and Clinical Anatomy, University of Graz, Austria
3Department of Orthopedic, University of Leipzig, Germany
4Division of Medical Technology, Fraunhofer Institute for Machine Tools and Forming Technology, Germany
5Annette Alle 24, Germany
Purpose: A broad body of risk factors exists, predisposing the onset of DDH. Literature is sparse on the subject of combining these risks into a single integrated concept. Revisiting microscopic anatomy of the growing hip joint may help determine such concepts. Methods: Based on knowledge derived from contemporary hip sonography, it has been shown that shearing forces directed caudo-cranially deform the hyaline cartilage in the preformed acetabular roof in a typical sequence. This acetabular epiphysis region comprising of the chondro-osseous junction between the growth plate and the bony acetabular roof was assessed microscopically. Sections of non-dysplastic and non-dislocated joints were compared with the different types of dislocated joints. Results: Cartilaginous cell columns in the acetabular epiphysis at the region of the chondro-osseous junction were deformed in a typical sequence, depending on the extent of loading: oblique, oblique and partially damaged or fully damaged. Conclusion: Shearing forces exerted caudo-cranially via the femur not only deform the cartilaginous acetabular roof, but also the chondro-osseous junction in a typical manner, thereby causing damage and subsequent necrosis of the cartilaginous cell columns. The mechanisms causing the femur to press against the acetabular roof and are likely related to a size disproportion of the fetus in utero or fetal positions exerting high pressures to the cartilage. Sonography should be performed as early as possible to detect borderline type IIc joints, which may have no clinical signs to prevent or minimize disease progression related to cartilage column death in the infant’s hip joint.
Risk factors; Histology; DDH; Graf sonography; Secondary dysplasia of hip joints
Graf R, Hammer N, Matthiesen D. An Integrated Concept Explaining for Risk Factors Related to the Onset of Developmental Dysplasia of the Hip Joint. Ann Orthop Musculoskelet Disord. 2021; 4(1): 1029.