The most important complication of treatment of developmental dysplasia of the hip (DDH) is avascular necrosis (AVN) of the femoral head, which can result in proximal femoral growth disturbances leading to pain, dysfunction, and eventually to early onset osteoarthritis. In this study, we aimed to identify morphological variants in hip joint development that are predictive of a poor outcome. We retrospectively reviewed all patients who developed AVN after DDH treatment, either by closed and/or open reduction, at a single institution between 1984 and 2007 with a minimal follow-up of eight years. Standard pelvis radiographs obtained at ages one, two, three, five, and eight years, and at latest follow-up were retrieved. The Bucholz-Ogden classification was used to determine the type of AVN on all radiographs. Poor outcome was defined by Severin classification grade 3 or above on the latest follow-up radiographs and/or the need for secondary surgery. With statistical shape modelling, we identified the different shape variants of the hip at each age. Logistic regression analysis was used to associate the different modes or shape variants with poor outcome.Aims
Methods
Open reduction is required following failed conservative treatment
of developmental dysplasia of the hip (DDH). The Ludloff medial
approach is commonly used, but poor results have been reported,
with rates of the development of avascular necrosis (AVN) varying
between 8% and 54%. This retrospective cohort study evaluates the
long-term radiographic and clinical outcome of dislocated hips treated
using this approach. Children with a dislocated hip, younger than one year of age
at the time of surgery, who were treated using a medial approach
were eligible for the study. Radiographs were evaluated for the
degree of dislocation and the presence of an ossific nucleus preoperatively,
and for the degree of AVN and residual dysplasia at one and five
years and at a mean of 12.7 years (4.6 to 20.8) postoperatively.
Radiographic outcome was assessed using the Severin classification,
after five years of age. Further surgical procedures were recorded.
Functional outcome was assessed using the Pediatric Outcomes Data
Collection Instrument (PODCI) or the Hip Disability and Osteoarthritis
Outcome Score (HOOS), depending on the patient’s age.Aims
Patients and Methods