Congenital Pseudarthrosis of the Tibia: Long-term Outcome of Treatment With Intramedullary Vascularized Fibular Graft Combined With Ilizarov Distraction

Abstract

Background: Late presenting cases of congenital pseudarthrosis of the tibia, are further complicated with severe shortening. Limb length discrepancy (LLD) cannot be corrected by vascularized fibular grafting and the use of Ilizarov distraction is associated with a high rate of complications. The aim of this study was to report the long-term follow-up of a combined technique previously published under the name "telescoping vascularized fibular graft".

Materials and methods: Eleven patients operated at an average age of 10.2±3.2 years were reviewed. All cases were Crawford type IV affected by neurofibromatosis 1. Nine patients had an average of 4.3 previous operations. Preoperative LLD averaged 7.9±2.5 cm.

Results: Follow-up averaged 10±5.4 years. Seven cases (63.6%) reached skeletal maturity before final follow-up. Primary union was achieved in all cases after an average of 7.2±1.3 months. Full weightbearing was possible after an average of 10.6±2.2 months. Recurrent stress fractures occurred in 9 cases (81.8%) and healed with casting in 6 cases and required internal fixation in 3 cases. Eight cases (72.8%) developed tibial shaft deformities, mainly procurvatum that required corrective osteotomy in 2 cases. Final LLD averaged 2.7±1.3 cm. Complete tibialization of the graft was achieved after an average of 17.0 ± 3.6 months. Valgus deformity of the ipsilateral ankle averaged 12.4 degrees±7.5.

Conclusion: The presented technique avoids osteotomy of the diseased bone and allows simultaneous treatment of the pseudarthrosis and correction of shortening. Compared with conventional bone transport, it requires shorter time of frame application and therefore better patient tolerability because there is no waiting for consolidation of the regenerate. The dis-impaction of the doweled fibula occurs proximally, allowing the less active site located at the distal aspect of the pseudarthrosis to heal without displacement. A shortcoming of the presented technique is the more propensity for axial deviation and refractures that seldom require surgery.

Level of evidence: Level-IV.