TITLE:
Redislocation Following Zigzag Osteotomy Combined with Fibular Allograt for Dislocation of the Hip in Children
AUTHORS:
Nguyen Ngoc Hung
KEYWORDS:
DDH, Redislocation, Anteromedial Approach, Salter Innominate Osteotomy, Femoral Shortening
JOURNAL NAME:
Open Journal of Orthopedics,
Vol.6 No.4,
April
20,
2016
ABSTRACT: We have reviewed 17 patients (18 hips) who required repeated open reduction for recurrent or persistent dislocation after a previous attempt at zigzag osteotomy combined with fibular allowgraft for developmental dysplasia of the hip (DDH). The purposes of this study were to examine predictors of redislocation and to evaluate the long-term outcomes after revision surgery. The mean age at primary open reduction was 24 months (13 to 36). The median time to the recognition of failure was 4.6 months. The second reduction was performed at a mean age of 26.3 months (17 to 42) and the mean age at final follow-up was 79.7 months (58 to 105) and the mean time follow-up was 42.4 months (37 to 76). We treated the hips with a new open reduction through an anteromedial approach. A constricted anteromedial capsule was always found as the main factor; all had an intact anteromedial capsule, and there was an inverted transverse ligament in five cases and a very tight psoas tendon in another four cases, eversion of the limbus in six cases, densing anterior capsule in five cases. We perform with the condition that all hips were cleared of scar tissue; five hips had adductor tenotomy; four hips required release of the psoas tendon, five eversion of the limbus. Release of the transverse ligament was required in five cases each. All hips with Kirschner wire through the femoral head into the acetabulum. Three hips required femoral shortening (average of 1.5 cm); a derotation varus osteotomy was performed in two hips from ten and twelve weeks after repeated open reduction. Postoperative results according to modified McKay criteria for clinical: excellent: 3 of 18 hips (16.7%); good: 8 of 18 hips (44.4%); fair: 6 of 18 hips (33.3%); and poor: 1 of 18 hips (5.6%). We suggest that technical failure is usually the cause for redislocation with all that has an intact anteromedial capsule. There was an inverted transverse ligament, tight psoas tendon, eversion of the limbus, and densing anterior capsule. We believe that abnormal femoral version and femoral head dysplasia are also important factors for redislocation too.