title: Pavlik Harness Disease Revisited: Does Prolonged Treatment of a Dislocated Hip in a Harness Adversely Affect the α Angle?
abstract: BACKGROUND
  Current dogma contends that prolonged treatment of a dislocated hip in Pavlik harness beyond 3 weeks will cause "Pavlik harness disease." To our knowledge, however, no previous studies have documented objective morphologic changes to the acetabulum from continued treatment of a persistently dislocated hip.
  
  
  METHODS
  We retrospectively reviewed a consecutive series of infants with developmental dysplasia of the hip, below 6 months old, who failed Pavlik treatment from a single, tertiary-care pediatric hospital and a multicenter, international study group. Inclusion criteria were dislocated hips confirmed by ultrasound (both initially and at Pavlik termination) and a minimum of 2 ultrasounds during harness treatment at least 3 weeks apart. As a global measure of acetabular morphology, α angle (AA) was compared between initial and final ultrasound. The final means of obtaining successful hip reduction was recorded from the medical records.
  
  
  RESULTS
  Forty-nine hips in 38 patients were identified. Median age at Pavlik initiation was 4 weeks (range, 0 to 18 wk); median time in harness was 6 weeks (range, 3 to 14 wk). Surprisingly, a mean of 4 degrees improvement in AA (95% CI, 2-6 degrees; P=0.001) was observed between first and final ultrasound. We found no difference in AA change between those in harness 3 to 5 weeks and those with prolonged wear >5 weeks (P=0.817). There was no significant association between change in AA and time in harness (P=0.545), age at Pavlik initiation (P=0.199), clinical reducibility of the hip (P=0.202), or initial percent femoral head coverage (P=0.956). Following harness failure, 22/49 hips (45%) were successfully treated with rigid abduction bracing, 16 (33%) by closed reduction/spica casting, and 10 (20%) by open reduction; 1 hip (2%) spontaneously reduced and required no further treatment.
  
  
  CONCLUSIONS
  On the basis of the lengths of harness treatment in our series, most hips did not exhibit negative changes in the acetabular AA in response to prolonged treatment of a dislocated hip in harness. Furthermore, 80% of hips failing Pavlik treatment were successfully reduced through closed means, indicating that subsequent treatment was not compromised.
  
  
  METHODS
  Level IV-retrospective case series.
authors.affiliation: Division of Orthopaedics, The Children's Hospital of Philadelphia, Philadelphia, PA.
authors.forename: Alex L
authors.initials: AL
authors.lastname: Gornitzky
authors.affiliation: Department of Orthopaedic Surgery, British Columbia Children's Hospital, Vancouver, BC, Canada.
authors.forename: Emily K
authors.initials: EK
authors.lastname: Schaeffer
authors.affiliation: University of Central Florida College of Medicine, Orlando, FL.
authors.forename: Charles T
authors.initials: CT
authors.lastname: Price
authors.affiliation: Division of Orthopaedics, The Children's Hospital of Philadelphia, Philadelphia, PA.
authors.forename: Wudbhav N
authors.initials: WN
authors.lastname: Sankar
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging; D001915:Braces; D005260:Female; D005270:Femur Head / Q000000981:diagnostic imaging; D006618:Hip Dislocation, Congenital / Q000000981:diagnostic imaging / Q000628:therapy*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009989:Orthotic Devices; D012189:Retrospective Studies; D013997:Time Factors; D017211:Treatment Failure; D016896:Treatment Outcome; D014463:Ultrasonography