Ilizarov Distraction for Congenital Pseudoarthrosis of the Tibia in Adults.

OBJECTIVE

The clinical evidence on the management for congenital pseudoarthrosis of the tibia (CPT) in adults is limited. The aim of this study is to assess the functional and radiological outcomes of Ilizarov distraction for treating CPT in adults.

METHODS

A retrospective analysis was conducted. Between 2013 and 2022, an Ilizarov distraction technique was performed on 14 adults (14 limbs) with CPT in our limb deformity center. There were seven females and seven males with a mean age of 33.7 (range, 18 ~ 53) years. The diagnosis of NF-1 was confirmed in seven (50.0%) patients. Eight patients had a history of previous surgical failure. The pseudoarthrosis occurred in the middle and lower tibia in all limbs (six left and eight right). The CPT was classified by Crawford classification and Paley classification. The surgical procedures, external fixation time (EFT), and all outcomes and complications were recorded. The Kolmogorov-Smirnov test was performed to test the normality of the data. The American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score at the preoperative and final follow-up was compared by using the Wilcoxon's signed-rank test. The limb-length discrepancy (LLD) and a self-made exercise capacity score at the preoperative and final follow-up were compared by using the student's t-test. The clinical and radiological outcomes were assessed by the Inan scale.

RESULTS

The mean EFT of Ilizarov fixator was 19.5 months (range, 7.3 ~ 39.1). At a median follow-up of 26.8 months (IQR, 20.2 ~ 34.3), bone union of the pseudarthrosis and consolidation of the distraction zone were achieved in all patients. The mean LLD was decreased from 11.3 cm (range, 3.4 ~ 17.3) preoperatively to 1.1 cm (range, 0.3 ~ 3.7) (p < 0.05). The mean or median AOFAS ankle-hindfoot score was improved from 53.5 (IQR, 26.5 ~ 60.5) preoperatively to 63.9 (range, 53 to 73) at final follow-up (p < 0.05). The mean score for exercise capacity were improved from 4.9 (range, 1 to 8) preoperatively to 9.6 (range, 7 ~ 12) at final follow-up (p < 0.05). According to the criteria described by Inan et al., the clinical results were classified as good in 10 and fair in 4, while the radiological results were classified as excellent in three, good in 8, and fair in 2. The success rate was 92.9%, as refracture was defined as treatment failure and occurred in one patient.

CONCLUSION

Ilizarov distraction provided a suitable treatment option for the CPT in adults, as it could achieve a high rate of bone union, a good correction of secondary deformity, a low risk of refracture, and consequently restore a relatively functional limb.