Early reduction for congenital dislocation of the knee within twenty-four hours of birth.

BACKGROUND Congenital dislocation of the knee (CDK) is a very rare condition that comprises a spectrum of deformities from subluxation to complete dislocation. The incidence of CDK is estimated at 1 per 100,000 live births, which is 1% of the incidence of developmental dysplasia of the hip (DDH). Moreover, 40-100% of patients with CDK have additional musculoskeletal anomalies, the most common being DDH and clubfoot. In general, the diagnosis is established immediately after birth according to the position of the knee recurvatum. Treatment with conservative methods at an early stage is most likely to yield successful results. We report here successful treatment of a series of CDK patients with early reduction. METHODS From July 1990 to June 2007, 19 patients with CDK (affecting 25 knees) were treated with early reduction. Of these, 6 knees had dislocation, and 19 had subluxation. Since 1990, treatment has been guided by a protocol that considers patient age and the severity of the condition. In patients examined within 24 hours of birth, early, direct reduction under gentle, persistent manual traction was attempted. Birth history and perinatal course were obtained from medical records. Associated musculoskeletal anomalies were observed and treated after reduction of the knee joint. A Pavlik harness was used for at least 4 months in the concomitant treatment of DDH and CDK. Knee function was graded as excellent, good, fair, or poor. Radiographs were used to assess DDH during follow-up. RESULTS After an average follow-up duration of 4.3 years, 18 patients showed an excellent or good outcome. One patient, whose knee could not be reduced, had severe multiple anomalies and died 16 days after birth. Fifteen of the nineteen patients had associated musculoskeletal anomalies, including DDH and foot deformity. Two cases of residual hip dysplasia after Pavlik harnessapplication required an acetabular osteotomy. CONCLUSIONS For CDK patients, early and direct closed reduction within 24 hours of birth affords outcomes graded as either excellent or good.