Intra-articular membranous interposition detected by MRI in developmental dysplasia of the hip

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Published on: September 2, 2025

W Watanabe1, E Itoi, K Sato

  • 1Department of Orthopedic Surgery, Akita University School of Medicine, Japan.

Skeletal Radiology
|March 29, 2001
PubMed

Insights

A rare case of intra-articular membranous interposition in a child's hip joint was identified using MRI. This finding in residual hip subluxation may represent early cartilage development.

Area of Science:

  • Pediatric Orthopedics
  • Radiology
  • Developmental Biology

Background:

  • Residual hip subluxation in children can lead to long-term complications.
  • Understanding the pathological changes in early hip subluxation is crucial for effective management.
  • Magnetic Resonance Imaging (MRI) is a key diagnostic tool in pediatric hip disorders.

Observation:

  • MRI revealed an intra-articular membranous interposition within the hip joint of a 5-year-old girl with residual subluxation.
  • This interposition displayed low signal intensity on both T1- and T2-weighted MRI sequences.
  • The membrane effectively separated the femoral head from the acetabulum.

Findings:

  • Histological examination of the interposition demonstrated chondrometaplasia.
  • This suggests the membrane may be a precursor to the surface cartilaginous tissue observed in secondary acetabulum formation.
  • The findings link the observed MRI structure to a potential developmental process in hip subluxation.

Implications:

  • This case highlights a potential mechanism for acetabular development in pediatric hip subluxation.
  • Early identification of such interpositions via MRI could inform treatment strategies.
  • Further research is warranted to understand the long-term implications of this finding.

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