Combination of intramedullary rod, wrapping bone grafting and Ilizarov's fixator for the treatment of Crawford type IV congenital pseudarthrosis of the tibia: mid-term follow up of 56 cases

Abstract

Background: The purpose of this study was to investigate the initial union rate, refracture rate and residual deformities of congenital pseudarthrosis of the tibia (CPT), using combined surgery including pseudarthrosis resection, intramedullary rodding, autogenous iliac bone grafting and Ilizarov's fixator, with a mean 5.2 years follow-up.

Methods: We retrospectively reviewed the records and diagrams of patients with Crawford type IV congenital pseudarthrosis of the tibia between February 2007 and March 2010. Patients managed by pseudarthrosis resection, intramedullary rod of the tibia, wrapping autogenous iliac bone grafting and Ilizarov's fixator were enrolled. We evaluated the bone union rate, tibial alignment, limb length discrepancy (LLD), valgus deformity of the ankle and the frequencies of refracture during period of follow-up.

Results: There were 56 cases enrolled in the study, with a mean follow-up 5.2 years (range, 3 to 6.7 years). The mean age of the patients at surgery was 3.5 years (range, 1.5 to 12.4 years). Fifty (89.2 %) of the 56 patients had primary bone union at site of pseudarthrosis, while 5 obtained union after second surgery and 1 failed. The average time spent to obtain pseudarthrosis initial union was 4.5 months (range, 3.0 to 10.0 months) and mean duration of Ilizarov treatment was 4.7 months (range, 3.2 to 10.4 months). Eleven (19.6 %) patients had proximal tibial valgus with a mean angle of 9.5° (range, 5 to 24°), while 10 (17.9 %) patients had ankle valgus deformities with a mean of 12.3° (range, 6 to 21°). Sixteen (28.6 %) patients had an average 2.2 cm LLD (range, 1.5-4.2 cm). Of the 50 cases who obtained initial bone union of pseudarthrosis, 13 (26.0 %) had refracture which need cast immobilization or secondary surgery.

Conclusions: This combined surgery obtained initial union rate of 89.2 % at primary surgery while the refracture rate is 26.0 %. However, residual deformities such as proximal tibial valgus, LLD and ankle valgus were also existed which should be pay more attention to and dealt with.

Trial registration: This study was registered in ClinicalTrials.gov under the name "The Effect of Combined Surgery in Management of Congenital Pseudarthrosis of Tibia" ( NCT02640040 ), which was released on August 31, 2015.

Keywords: Congenital pseudarthrosis of tibia; Ilizarov’s fixator; Intramedullary rodding; Residual deformities; Union rate.

Fig. 1

Harvesting and suturing autogenic iliac bone. Exposure of the outer table of the ilium, harvesting a rectangular cortex (a). Cancellous bone curetted from supra-acetabular region (b). Holes were made in the rectangular cortex with Kirschner wire and with doubled absorbable sutures on each corner (c). The rectangular cortex was bent to produce a cylindrical shape for wrapping the cancellous bone graft. It would have greenstick fracture on the cortex (d)

Fig. 2

Installation of Ilizarov’s fixator and wrapping bone grafting. Resection of pseudarthrosis and installation of Ilizarov fixator (a). Cancellous bone compacted circumferentially between the cylindrical cortex and the pseudarthrosis of the tibia (b). The wrapping bone graft was secured by tying the sutures (c)

Fig. 3

The evaluation on X-ray. Illustrations of the measurements of ankle valgus (a) and proximal tibial valgus (b) respectively

Fig. 4

A typical case of 2.5 years boy with congenital pseudarthrosis of the tibia. Preoperative anteroposterior and lateral X-rays shows Crawford type IV CPT and intact fibula (a, b). Anteroposterior and lateral radiograph of the same patient taken at 2 months after combined surgey (c, d). X-ray of 5.4 years post operation shows solid union of the pseudarthrosis with good alignment of the tibia without ankle valgus, tibia angulation or LLD. The rod was in the tibia medullary cavity with growth without surgical pushing of the rod (e, f)