A combined surgical technique for congenital pseudarthrosis of the tibia: analysis of middle-term outcomes

Abstract

Objective To evaluate the middle-term outcomes of a combined surgical technique, including sleeve resection of pathological soft tissues, retrograde intramedullary rodding, packaged iliac bone autograft and llizarov external fixation, in the treatment of congenital pseudarthrosis of the tibia(CPT). Methods A total of 35 CPT patients underwent a combination of sleeve resection of pathological soft tissues, retrograde intramedullary rodding, packaged iliac bone autograft and Ilizarov external fixation at our center from March 2007 to April 2009. The mean operative age was 42(10-149) months. According to the Crowford classification, the types were Ⅱ(n=2), Ⅲ(n=2) and Ⅳ(n=31). And 31 cases were associated with type1 neurofibromatosis(NF1) while another 25 cases had fibular lesion. During a mean postoperative follow-up period of 5.5(5-6.2) years, they were evaluated clinically and radiographically. And Johnston clinical evaluation system and Ohnishi radiology grading standards were used to assess the outcomes. Results At the last follow-up, 30 cases achieved complete bony union. Their average healing time was 4.1 months(2 months and 3 days to 10 months). Ten cases had limb malalinement with an angulation of above 5°. And 4 cases had severe limb length discrepancy of over 4 cm. Among 4 cases of refrature, 2 of them occurred at the primary pseudarthrosis site. Among 29 cases of ankle valgus, the grades were Ⅰ(n=3), Ⅱ(n=14) and Ⅲ(n=12) according to the Malhotra classification. Three cases had ankle stiffness. Johnston's evaluation indicated that the grades were Ⅰ(n=25), Ⅱ(n=5) and Ⅲ(n=5). Furthermore, Ohnishi radiological study showed union(n=30), delayed union(n=3) and nonunion(n=2). Our union rate was similar to what was reported in recent literatures. However, our study had fewer complications, especially refracture. Conclusions Combined surgical technique is efficacious for primary treatment CPT and failed cases after multiple operations. Since the course of CPT lasts until skeletal maturity, the long-term effectiveness of this combined surgical procedures requires further studies. Key words: Congenital pseudarthrosis of the tibia; External fixation; Follow-up studies