Kyphectomy in myelomeningocele revisited: risk factors for failure.

PURPOSE: Lumbar kyphosis occurs in approximately 8-20% of patients with myelomeningocele (MMC). The purpose of this article is to analyze the risks and benefits of vertebrectomy and spinal stabilization in MMC children with severe lumbar kyphosis and to establish treatment guidelines. METHODS: This is an IRB-approved retrospective analysis of 59 patients with MMC who underwent kyphectomy and posterior instrumentation in three centers. Average age at surgery was 7.9 years (2 weeks-17 years). Sitting trunk position, skin status, kyphosis angle, and thoracic lordosis were analyzed preoperatively, postoperatively, and at an average follow-up of 8.2 years (range 2.5-16). The correction was maintained by applying a short posterior instrumentation in 6 patients, and extending to the pelvis in 53 cases. Pelvic fixation was achieved using the Warner and Fackler technique in 24 patients, the Dunn-McCarthy in 8, Luque-Galveston in 8, sacral screws in 2, and ilio-sacral screws in 11. RESULTS: Sitting position improved postoperatively in 47 of the 53 patients who underwent pelvic fixation and only in one patient with short instrumentation. All 6 patients with long instrumentation and poor postoperative sitting balance were in the Dunn-McCarthy fixation group. Skin sores at the apex of the deformity disappeared postoperatively in all patients but recurred in two patients with short instrumentations. Kyphosis angle improved from 109° (45°-170°) preoperatively to 10° (0°-45°) postoperatively and 21° (0°-55°) at last follow-up. The best results were seen in cases where a cross-k-wire fixation of the kyphectomy site was used, augmented with a long thoraco-pelvic instrumentation consisting of Luque sublaminar wires in the thoracic region and a Warner-Fackler type of pelvic fixation. Good results were also found with the bipolar technique and ilio-sacral screw fixation. Six over 24 patients with the Warner and Fackler technique showed gradual dislodgment or hardware failure, with subsequent nonunion of the kyphectomy site in four. Infection, with or without wound dehiscence and/or hardware exposure, occurred in 17 cases, necessitating hardware removal in 9 patients. CONCLUSION: Lumbar kyphosis in MMC children is best managed by resection of enough vertebrae from the apex to produce a flat lumbar spine, with perfect bone-to-bone contact and long thoraco-pelvic instrumentation using the Warner and Fackler technique through the S1 foramina or the bipolar technique with ilio-sacral screw fixation. Additional local fixation of the osteotomy site using cross-wires with or without cerclage increases the stability of the construct. The majority of complications occurred in patients with short instrumentations or where residual kyphosis persisted postoperatively regardless of the type of pelvic fixation or hardware density. The Dunn-McCarthy technique for pelvic fixation following kyphectomy in MMC was less successful in producing stable pelvic fixation and should not be considered in this patient category.

Aprotinin reduces blood loss during spinal surgery in children.

STUDY DESIGN: A prospective blinded, randomized controlled study compared the effect of a perioperative infusion of aprotinin versus placebo during long segment spinal fusions in children. OBJECTIVES: To determine whether aprotinin decreases blood loss and transfusion requirements in pediatric patients with spinal deformities undergoing posterior spinal fusions of seven or greater segments. SUMMARY OF BACKGROUND DATA: Blood loss is a major cause of morbidity during long segment spinal fusion. Several preoperative and intraoperative techniques are currently used to reduce blood loss and transfusion requirements. Aprotinin, an antifibrinolytic and anti-inflammatory agent, has been used to decrease blood loss in cardiac surgical patients. We designed a prospective, randomized, and blinded controlled study to evaluate aprotinin's efficacy in reducing bleeding during pediatric spine surgery. METHODS: After obtaining informed written consent, we studied 44 children and adolescents who were anticipated to be at higher risk for major blood loss during posterior spinal fusion. Children were randomly assigned to receive high dose aprotinin or placebo infusion during the perioperative period. Patients were assessed for blood loss, transfusion requirements, days in the intensive care unit, and days in hospital. RESULTS: Demographics in the two groups of patients were similar. The study demonstrated a significant reduction in estimated blood loss (aprotinin 545 cc, placebo 930 cc) and transfusion requirements (aprotinin 1.1 U, placebo 2.2 U). The duration of intensive care unit admission was similar in the two groups, as was the time until discharge. CONCLUSIONS: This randomized, blinded study suggests that aprotinin significantly decreased blood loss and transfusion requirements in pediatric and adolescent scoliosis surgical patients at increased risk for intraoperative bleeding.

Reduction of a dislocation of the hip due to developmental dysplasia. Implications for the need for future surgery.

BACKGROUND: Recent reports on the treatment of a dislocation of the hip due to developmental dysplasia have documented conflicting data on the importance of the ossific nucleus in the development of postreduction ischemic necrosis. Delaying reduction until the ossific nucleus is present bypasses the time-period of maximal osseous remodeling of the hip, thereby possibly increasing the need for future operations. We hypothesized that hips with an ossific nucleus are more likely to have subsequent reconstructive procedures. METHODS: A retrospective review of the medical records at two tertiary-care children's hospitals was completed to identify all patients who had had reduction of a dislocation of the hip due to developmental dysplasia, performed between 1979 and 1993, when they were less than two years old. Patients were excluded if the medical records or radiographs were inadequate, the duration of follow-up was less than three years after the final reduction, a previous reduction had been performed at an outside facility, or the patient had a neuromuscular disease or a teratologic dislocation. We identified 124 patients (153 hips) who satisfied the criteria for inclusion. The average age at the time of the reduction was eleven months, and the average duration of follow-up was 7.2 years. RESULTS: Overall, fourteen of the sixty-three hips without an ossific nucleus had a reconstructive procedure: thirteen had a varus rotational osteotomy of the proximal part of the femur and one had a combined pelvic and varus rotational femoral osteotomy. Forty of the ninety hips with an ossific nucleus had a reconstructive procedure: twenty-seven had a varus rotational osteotomy, eight had a pelvic osteotomy, and five had a combined pelvic and varus rotational osteotomy (p < 0.05). In addition, secondary reconstructive procedures were performed in 17% (ten) of the fifty-nine patients who were less than six months old and in 35% (thirty-three) of the ninety-four patients who were at least six months old, which was a greater than twofold increase. The effect of age was further emphasized at the other age cutoff points. CONCLUSION: Delaying the reduction of a dislocated hip until the appearance of the ossific nucleus more than doubles the need for future surgery to make the hip as anatomically normal as possible. Despite finding a slight increase in the rate of ischemic necrosis after reduction of the hips without an ossific nucleus, we advocate early reduction of a dislocation of a hip due to developmental dysplasia to optimize the development of the hip with the minimum number of operations