title: Residual hip dysplasia at 1 year after treatment for neonatal hip instability is not related to degenerative joint disease in young adulthood: a 21-year follow-up study including dGEMRIC.
abstract: OBJECTIVE
  Developmental dysplasia of the hip (DDH) is associated with an increased risk of early hip osteoarthritis (OA). We aimed to examine the outcome at the completion of growth in a cohort of children who had residual acetabular dysplasia at age 1 year following early treatment for neonatal instability of the hip (NIH).
  
  
  METHODS
  We examined 21 of 30 subjects who had been treated with the von Rosen splint neonatally for NIH and had residual acetabular dysplasia at age 1 year. Mean follow-up time was 21 years (range 17-24). Signs of OA and acetabular dysplasia were assessed by radiography. Cartilage quality was assessed by delayed Gadolinium Enhanced Magnetic Resonance Imaging of Cartilage (dGEMRIC), a tool for molecular imaging of cartilage quality, at 1.5 T. Patient reported outcome (PRO) was assessed by the 12-item WOMAC score.
  
  
  RESULTS
  No study participant had radiographic OA (defined as Kellgren-Lawrence grade ≥2) or minimum joint space width (JSW) ≤2 mm. The mean dGEMRIC index was 630 ms (95% CI: 600-666, range: 516-825) suggesting good cartilage quality. The mean 12-item WOMAC score was 1.2. Two of three radiographic measurements of DDH correlated positively to the dGEMRIC index.
  
  
  CONCLUSIONS
  Children treated neonatally for NIH have good hip function and no signs of cartilage degeneration at 21-year follow-up, despite residual dysplasia at age 1 year. Unexpectedly, radiographic signs of dysplasia were associated with better cartilage quality, as assessed with dGEMRIC. This may indicate cartilage adaptation to increased mechanical stress in mild hip dysplasia.
authors.affiliation: Dept. of Orthopedics, Skåne University Hospital, Sweden and Lund University, Malmö, Sweden; Dept. of Clinical Sciences, Skåne University Hospital, Sweden and Lund University, Lund, Sweden. Electronic address: daniel.wenger@med.lu.se.
authors.forename: D
authors.initials: D
authors.lastname: Wenger
authors.affiliation: Dept. of Medical Radiation Physics, Lund University, Malmö, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Siversson
authors.affiliation: Dept. of Orthopedics, Skåne University Hospital, Sweden and Lund University, Malmö, Sweden; Dept. of Clinical Sciences, Skåne University Hospital, Sweden and Lund University, Lund, Sweden.
authors.forename: L E
authors.initials: LE
authors.lastname: Dahlberg
authors.affiliation: Dept. of Orthopedics, Skåne University Hospital, Sweden and Lund University, Malmö, Sweden; Dept. of Clinical Sciences, Skåne University Hospital, Sweden and Lund University, Lund, Sweden.
authors.forename: C J
authors.initials: CJ
authors.lastname: Tiderius
mesh_terms: D002358:Cartilage, Articular / Q000000981:diagnostic imaging; D003287:Contrast Media; D005260:Female; D005500:Follow-Up Studies; D019786:Gadolinium DTPA; D006618:Hip Dislocation, Congenital / Q000150:complications* / Q000000981:diagnostic imaging / Q000628:therapy; D006801:Humans; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging / Q000209:etiology*; D011379:Prognosis; D011859:Radiography; D012720:Severity of Illness Index; D013165:Splints; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
keywords: Cartilage; DDH; Dysplasia; dGEMRIC