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INTRODUCTION: Perthes disease (PD) is an idiopathic disorder presenting with avascular necrosis to the femoral head, which frequently results in flattening. Long-term function is directly related to the subsequent femoral head sphericity. Current treatment includes mechanical modalities and surgical procedures, which are therapeutic but are not uniformly able to prevent collapse. The use of the nitrogen-containing bisphosphonate zoledronic acid (ZA) to inhibit osteoclastic bone resorption is aimed at preserving femoral head strength, reducing collapse and thus maintaining shape. The proposed multicentre, prospective, randomised controlled trial intends to evaluate the efficacy of ZA treatment in PD. METHODS AND ANALYSIS: An open-label randomised control trial recruiting 100 children (50 each treatment arm) 5 to 16 years old with unilateral PD. Subjects are randomly assigned to either (a) ZA and standard care or (b) Standard care. The primary outcome measure is deformity index (DI), a radiographic parameter of femoral head roundness assessed at 24 months, following 12 months of ZA treatment (3-monthly doses of ZA 0.025 mg/kg at baseline, 3, 6, 9 and 12 months) plus 12 months observation (group A) or 24 months of observation (group B). Secondary outcome measures are femoral head subluxation, Faces Pain scale, Harris hip score and quality of life. Assessments are made at baseline, 3 monthly during the first year of follow-up and then 6 monthly, until the 24th month. ETHICS AND DISSEMINATION: The study commenced following the written approval from the Human Research Ethics Committee. Safety considerations regarding the effects of ZA are monitored which include the subject's symptomatology, mineral status, bone mass and turnover activity, and metaphyseal modelling. Data handling plan requires that all documents, clinical information, biological samples and investigation results will be held in strict confidence by study investigators to preserve its safety and confidentiality. TRIAL REGISTRATION NUMBER: Australian and New Zealand Clinical Trials ACTRN12610000407099, pre-results.
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BACKGROUND: The new Fassier-Duval Telescopic IM System (FD-rod) has the advantage of a single entry point over the traditional telescopic rods such as the Bailey-Dubow or Sheffield rods. Although encouraging early results were presented by the originators of the technique at international meetings, there is no formal publication in the literature as yet. METHODS: We performed a chart and x-ray review of the first 24 consecutive FD-rod insertions in 15 patients (age, 1.5 to 12.5 y) with a minimum of 1-year follow up (1 to 2.4 y) after implantation of femoral and/or tibial FD-rods. Diagnoses included with osteogenesis imperfecta (OI) (15 cases, 9 patients), and other conditions such as congenital tibial pseudarthrosis (CPT) in neurofibromatosis type 1 (NF1) (2 cases), and epidermal naevus syndrome (1 case). In patients with hypophosphataemic rickets (6 cases, 2 patients) the FD-rods were combined with an Ilizarov frame. RESULTS: We found the OI patient group associated with a 13% reoperation rate (2 of 15 cases) for proximal rod migration and a 40% complication rate (6 of 15 cases): rod migration and limited telescoping (5) and intraoperative joint intrusion (1). There were no infections. All the NF1 CPT (2) and epidermal naevus syndrome (1) cases required several reoperations for nonunion, loss of fixation, shortening (negative telescoping), migration, and/or joint intrusion-mainly due to the severe underlying pathology with insufficient longitudinal or torsional stability and diminished healing capacity. In hypophosphataemic rickets (combined with Ilizarov frame fixation) we found a 50% complication rate (3 of 6 cases) and a 17% reoperation rate (1 of 6): 2 FD-rods did not telescope and 1 case of peroneal neuropraxia required neurolysis. CONCLUSIONS: In our experience the technique of using FD rods is demanding and associated with some intraoperative and postoperative pitfalls. We are happy to continue its use in OI patients when there is longitudinal stability and sufficient bone healing. However, in circumstances of insufficient stability and bone healing potential, further stabilization that can be achieved with an Ilizarov frame may be beneficial.
