Clinical Study Of Arthroscopically-assisted Treatment For Developmental Dysplasia Of Hip In Children Who Unresponed To Close Reduction

ObjectiveTo explore the indications, operative technique and clinic effectiveness of arthroscopy in children with developmental dysplasia of the hip(DDH) for those whom had failed to be reduced by manipulative close reduction.MethodsA retrospective investigation was conducted on 17 children suffering from DDH ,who had been treated with arthroscopic debridement of the acetabulum and acetabular labrum plasty from May 2005 to June 2007 in our hospital, including 2 cases of male and 15 cases of female.The mean age of all patients was 19.1 months (range 4~48 months ). Fourteen hips were involved the right side and 9 the left. Eleven cases were single hip dislocation and 6 were bilateral dislocation. Manipulative reduction under general anesthesia were tried and failed in all cases. We used anterior and anterosuperior great trochanter portals to excise the hypertrophic, elongated, and abrased ligamentum tere, remove fibrosis and fat tissue on the acetabular bottom, resect the transverse ligament of acetabulum. At last the posterior outer two-thirds ram of labrum was incised except in the first case in whom the inner two-thirds ram was incised. Manipulative reduction and plaster cast immobilization within safe and stable position were done. Adductor tendon was released on 18 hips.ResultsReduction was achieved successfully in all 23 hips and all patients have not been developing avascular necrosis of the femoral head(ANF) in duration of 18 to 36 months(average of 26 months) postoperative follow-up but in one who had suffered from ANF before the surgery. According to the national clinical outcome score scale of developmental dysplasia of the hip in children , excellent result was in 16 cases, good in 1, fair in 2 and poor in 4. Statistical analysis for the effective factors between successful group and failure group was carried out in respects of anteversion, angulus acetabularis , center-edge angle and Zionts grade. The anteversion and angulus acctabularis were statistically significant defferent between two groups before surgery and the center-edge angle and Zionts grade were not statistically significant defferent between two goups(Significant level is 0.05).ConclusionBased on our primary observation, less than 40 degree acetabular anteversion and less than 35 degree angulus acctabularis are implied to be good indications for arthroscopic surgery. Center-edge angle and Zionts grade before the surgery seems to be no significant effect on the surgical result. Arthroscopically-assisted excising ligamentum tere, acetabular debridement, resecting the transverse ligament of acetabulum and labrum plasty procedures are a safe and effective method to help reduction in developmental dysplasia of the hip in children if appropriate indications are selected. Compared with the other open procedure, it has advantages of minimal invasion and faster wound healing. Posterior two-thirds of outer-ram incision of the acetabular labrum is appreciated for keeping the rest inner-ram integrity of the labrum which may prevent the femoral head redislocation from acetabulum.