Wrapping grafting for congenital pseudarthrosis of the tibia: A preliminary report

Abstract

Objective: Treatment of congenital pseudarthrosis of the tibia (CPT) remains a challenge. The autogenic iliac bone graft is important consistent of treatment for CPT. The purpose of this study was to investigate the role of wrapping autogenic iliac bone graft in improvement of the curing opportunities of CPT.

Methods: We combined Ilizarov fixator with intramedullary rodding of the tibia and wrapping autogenic iliac bone graft for treatment 51 cases of CPT between 2007 and 2010. The mean age is 3.2 years at index operation, of which 31 patients (61%) were below 3 years old. According to Crawford classification, 5 tibia had type-II morphology; 3, type-III; 43, type-IV.

Results: In the postoperative follow-up of 3.5 months (range from 3 to 4.5 months), all cases were found that the bone graft sites of pseudarthrosis of the tibia showed a significant augmentation and spindle-shaped expansion as obvious change. All cases of this series have been followed-up, average followed-up time were 1.6 years (range from 7 to 3.1 years), of which 19 cases were more than 2 years. The average time of removed the Ilizarov ring fixator was 3.5 months (range from 3 to 4.5 months). According to Johnston Clinical evaluation system, 26 cases had grade I, 21 cases, grade II, 4 cases, grade III. Following the Ohnishi X-ray evaluation criteria, union of pseudarthrosis of the tibia were 42 cases, delayed union 5 cases, nonunion 4 cases.

Conclusion: Autogenic iliac bone graft is able to offer the activity of osteoblasts and osteogenesis induced by bone morphogenetic protein (BMP) and glycoprotein, meanwhile enclosing bone graft could help keep cancellous bone fragments in close contact around pseudarthrosis of the tibia, allowing the formation of high concentration of glycoprotein and BMP induced by chemical factors because of established the sealing environment in location, all of which could enhance the healing of pseudarthrosis of the tibia.

Figure 1

Exposure of outer table of ilium (A), harvesting a square of cortex sized 4 cm × 4 cm (B) and lots of cancellous bone curetted from supra-acetabular region (C).

Figure 2

The square of cortex was made lots of holes with Kirschner wire and sutured with absorbable sutures (A), and note the square of cortex with cylindrical shape in which there were double longer sutures on each corner for wrapping cancellous bone graft (B).

Figure 3

The cylindrical cortex wrapped pseudoarthrosis of the tibia (A), a lots of cancellous bone bad been compacted circumferentially between the cortex and the pseudarthrosis site (B), and the wrapping bong graft finished by tied the sutures (C).

Figure 4

Typical case: Preoperative frontal (A) and lateral (B) radiographs of a 2-year-old boy, showing congenital pseudarthrosis of the right tibia and fibulae with neurofibromatosis type 1. Before removing of Ilizarov apparatus no any gaps existed between wrapped graft and previous pseudarthrosis of the tibia on frontal (C) and lateral (D) radiographs at 3 months after operation. Anteroposterior (E) and lateral (F) radiographs showed union of previous pseudarthrosis with evident spindle-shaped expansion in site of wrapping graft at 6 months after operation. Anteroposterior (G) and lateral (H) radiographs exhibited some remodeling of previous pseudarthrosis with reduced expansion in site of wrapping graft at 15 months after operation. Anteroposterior (I) and lateral (J) radiographs revealed continuous remodeling of previous pseudarthrosis with apparent increase of thickness and density of cortex in site of wrapping graft at 3 years following operation. The distal tip of rod had been pushed into distal epiphysis of the tibia because of precluding functional motion of the ankle joint.