Combination of Ilizarov method and intramedullary nailing for the treatment of congenital pseudarthrosis of the tibia related to Neurofibromatosis type I in adult / 中华骨科杂志

ABSTRACT

Objective:To investigate surgical methods and clinical effects of tibial pseudarthrosis due to neurofibromatosis type I (NF1) in adult using Ilizarov technique combined with intramedullary nail.Methods:A total of 12 adult with tibial pseudarthrosis due to NF1 treated by Ilizarov technique combined with intramedullary nail from October 2009 to December 2017 were retrospectively included. There were 6 males and 6 females with an average age of 27±8.3 years (range 17-44). All cases presented severe anterior arch in varus or valgus deformity with shortening in an average of 10.8±3.7 cm (range 5.6-16.5 cm). The in-volved levels were at the middle and lower part of tibia. All cases suffered from more than one treatment with failed surgery. One male patient with 5 times of unsuccessful operations. There were 4 cases with severe limping gait and 8 cases with walking with the help of brace (or single crutch) preoperatively. Regarding the family history, seven cases were inherited by father and 5 cases by mother. During surgery, the part of tibial pseudarthrosis and thickened fibrous tissue surroundings like periosteal were removed. The contracture achilles tendon was elongated in open way, and intramedullary nailing cross the ankle joint was applied when the tibial medullary cavity opened. Further, iliac bone grafting and proximal tibial osteotomy were performed with Ilizarov fixator application finally. The tibia was lengthened at a rate of 0.5-1 mm/d at 7 days postoperatively. The healing rate of pseudarthrosis and the length and alignment of limb were evaluated by X-ray routinely. The lower limb function and complications were assessed by self-made table for lower limb deformity correction and functional reconstruction.Results:All patients were followed up for 31-80 months with an average of 47.6±14.7 months. Bone union of pseudarthrosis in all cases was eventually achieved. The tibia was lengthened 5-12 cm with an average of 8.4±2.5 cm. There were 9 cases underwent second surgeries to promote bone healing and to correct residual deformities. The external fixator was used for 25-37 months with an average of 31.5±3.7 months. There was no complication, including neurovascular injury, severe soft tissue or bone infection affecting the clinical effects. All intramedullary nails were not removed finally. The limb function and gait in full weight bearing in 12 patients recovered at the latest follow-up. The evaluation score was 2.4±0.3 (range 2.1-2.8), of which 9 cases were excellent 3 were good. Thus, the excellent and good rate was 100%.Conclusion:The satisfactory clinical effects, including angular deformity correction, pseudarthrosis healing and short limb lengthening, can be achieved in adult with tibial pseudarthrosis due to NF1 by using the combination method of Ilizarov technique and intramedullary nail. However, the treatment duration could be longer.