Congenital Pseudarthrosis of the Tibia Associated with Neurofibromatosis-1: Treatment with Ilizarov's Device

Abstract

We reexamined 21 patients with congenital pseudarthrosis of the leg (congenital pseudoarthrosis of the tibia; CPT) associated with neurofibromatosis-1 (NF-1), > or =2 years after the termination of treatment, for a statistical study of the results obtained by using Ilizarov's external fixator. Of the 21 tibias operated on, 17 consolidated after the first treatment, whereas four did not. Of the 17 consolidated tibias, four refractured and were retreated by using a variety of methods. Only one healed. At follow-up, which occurred > or =2 years after the removal of the fixator, the results were nine consolidations without deformities or with shortening <2 cm, five consolidations with axial deviation, and seven nonconsolidations. The statistically significant results were that (a) patients who were aged 5 years or older at operation had better results, and (b) the assembly II (resection of CPT stumps and their short-term compression possibly associated with corticotomy or epiphyseal distraction to correct limb discrepancy) gave better final results compared with the other device assemblies. We conclude that treatment with Ilizarov's fixator allows (a) a good percentage of healing over time (66.7%), especially in cases of normotrophic and cystic CPT; (b) further operations with or without the fixator to correct secondary or residual axial deviation; and (c) correction of limb discrepancy. This treatment avoids risking injury to the healthy contralateral leg. Additionally, for treatments that do not achieve satisfactory results, other treatment methods are not excluded. The CPT still remains a difficult problem for the orthopedic surgeon to solve.

Ilizarov Treatment of Congenital Pseudarthrosis of the Tibia: A Multi-Targeted Approach Using the Ilizarov Technique

“…A variety of techniques based on several different frame configurations and strategies have been reported for the Ilizarov method 4-6,17,18,22,23). Although the primary aim of treatment is union of the pseudarthrosis site, the therapeutic considerations should include other associated problems, such as leg-length discrepancy, multilevel and multidirectional tibial deformity, foot deformity, associated fibular pseudarthrosis and subsequent ankle valgus 22,24,25).…”

“…The complications related primarily to the use of an external device include pin-track infection, loosening, breakage, refracture at the pin insertion site, neurovascular injury, axial deviation, osteopenia and joint stiffness. Residual limb length discrepancy and valgus deformity are commonly reported with an overall complication rate of 30 to 100% 4,16)…”

“…In atrophic-type CPT, these goals are extremely difficult to accomplish. However, primary union appears to have been improved markedly by modern treatment methods, such as, intramedullary fixation,8-11) microvascular transfer of a fibular graft,12,13) and external fixation using the Ilizarov technique 4-6,14-18). Nevertheless, regardless of the surgical options, the basic biological considerations of surgery are the same; pseudarthrosis resection, biological bone bridging of the defect with stable fixation, and correction of any angular deformity.…”

Congenital pseudarthrosis of the tibia treated with a combination of Ilizarov’s technique and intramedullary rodding

“…Treatment procedures can be broadly classified into 3 groups: (1) Intramedullary rodding (usually trans-ankle) with bone grafting (Johnston 2002, Dobbs et al 2004), (2) microvascular fibular transfer (Ohnishi et al 2005), and (3) the Ilizarov technique with its various modifications (Paley et al 1992, Boero et al 1997, Johnston and Birch 2008). However, no single treatment has been shown to be uniformly effective.…”

“…However, concerns still exist about ankle stiffness and arthritic changes in the ankle following the nailing (Dobbs et al 2005). On the other hand, various series using the Ilizarov technique have shown high union rates with good ankle function (Paley et al 1992, Boero et al 1997). However, there is a risk of refracture with this technique.…”