[Congenital hip dysplasia in newborns : Clinical and ultrasound examination, arthrography and closed reduction].

OBJECTIVE: Early diagnosis and rapid closed reduction under arthrographic control to initiate retention in a new position during the interval of maximum subsequent maturation power. This allows a (nearly) physiological ripening of the femoral head and acetabulum (AC) with restoration of the congruence of the joint partners (containment) and joint stability. INDICATIONS: Clinically- and ultrasound-proven dislocation of the hip in the newborn. CONTRAINDICATIONS: Increased bleeding, increased risk of anesthesia due to immaturity/prematurity, inability to use a retention cast due to malformations of the urogenital system, spinal deformities, or hernias requiring treatment or supervision. SURGICAL TECHNIQUE: Palpation of the tuberosity of the ischium in 110° flexion and 40-50° abduction of the leg and then puncture lateral to this point. Advance the needle parallel to the plane of the table in the direction of the empty acetabulum and x-ray control. Control of intra-articular needle position by injection of isotonic saline solution. Test reflux by disconnection. Cautious instillation of 0.2-0.4 ml of contrast medium under X-ray control. Closed reduction under X-ray control by pulling slightly, flexion and abduction of the hip joint. Cast applied in approximately 110° hip flexion and 40° abduction. POSTOPERATIVE MANAGEMENT: MRI control on postoperative day 1. Spica cast for 4 weeks. Then cast removal, clinical and ultrasound examination and immediate start of further treatment with a hip splint in 110° hip flexion and 30-40° abduction. Ultrasound follow-up every 3-4 weeks. RESULTS: A total of 40 patients (female:male = 33:7) with 49 hip dislocations were analyzed. The mean age at reduction was 73 days (range 1-334 days). In 21 cases, treatment was started at another hospital. Intra- or immediate postoperative complications were not detectable. According to the control MRI on the first postoperative day, the cast had to be removed in 7 cases (17.7 %) due to insufficient reduction, although no classical need for repositioning could be identified in the MRI analysis. Instead, compared to cases with sufficient hip reduction, significantly reduced acetabular articular surfaces were found, so that in these cases, a lack of stability due to the lack of congruency between the femoral head and the AC must be considered. Signs of a fulminant avascular necrosis (AVN, grade 3 and 4 according to Kalamchi) and a pathological acetabular angle (grade 3 and 4 according to Tonnis) were observed during follow-up in 17.3 and 40.7 % of cases, respectively.