The neoacetabulum in developmental dysplasia of the hip is covered with hyaline cartilage.

Autor: Plečko M; Department of Orthopaedic Surgery, University Hospital Centre Zagreb, Zagreb, Croatia., Bohaček I; Department of Orthopaedic Surgery, University Hospital Centre Zagreb, Zagreb, Croatia; Department of Orthopaedic Surgery, School of Medicine, University of Zagreb, Zagreb, Croatia., Duvančić T; Department of Orthopaedic Surgery, School of Medicine, University of Zagreb, Zagreb, Croatia., Delimar D; Department of Orthopaedic Surgery, University Hospital Centre Zagreb, Zagreb, Croatia; Department of Orthopaedic Surgery, School of Medicine, University of Zagreb, Zagreb, Croatia. Electronic address: domagoj.delimar@kbc-zagreb.hr.
Jazyk: angličtina
Zdroj: Medical hypotheses [Med Hypotheses] 2020 Sep; Vol. 142, pp. 109820. Date of Electronic Publication: 2020 May 06.
DOI: 10.1016/j.mehy.2020.109820
Abstrakt: The lack of adequate mechanical stimulation and appropriate contact between acetabulum and femoral head results with developmental dysplasia of the hip (DDH). In DDH, hip joint forms normally during the organogenesis, but deforms during the fetal development. Acetabulum remains comparable in width with normal acetabulum, but has increased length and decreased depth, resulting in a poor coverage of the femoral head. In cases of severe hip subluxation and luxation due to DDH, the femoral head articulates with the external side of the iliac bone, forming a neoacetabulum in the position that was genetically predetermined to become bony tissue. A neoacetabulum is therefore formed under intermittent mechanical pressure, but never has the depth of a physiological acetabulum due to different forces at this new location. Over time, the depth of the neoacetabulum increases, and a crest is formed that obstructs reposition of the femoral head into the anatomic acetabulum. We hypothesize that the neoacetabulum on the iliac bone in DDH patients is formed of hyaline cartilage, despite the lack of genetic predisposition for hyaline cartilage formation in this area. We assume that as the femoral head migrates during development in such patients, joint capsular tissue interposes between the external side of the iliac bone and the femoral head, and a cartilaginous metaplasia of the capsule follows. This results in elongation of the acetabular cartilage in the same direction as the femoral head migrated. This assumption is based on the finding that in patients with hip luxation such interposed joint capsule showed signs of cartilaginous transformation. Furthermore, in the inner part of such joint capsules, proteoglycan production was notably higher than that of other non-cartilaginous tissue. Also, high expression of cartilaginous genes, which are usually not expressed in this tissue, was observed. Confirmation of this hypothesis would put a new perspective on the pathogenesis of DDH and could lead to better management or even prevention of this condition.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2020 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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