[Application value of hinge position design of Ilizarov circular external fixator for correcting clubfoot deformity in preventing ankle dislocation].

Objective: To summarize the methods of ankle hinge position design in the correction of clubfoot deformity by Ilizarov method, and to explore its application value in the prevention of ankle dislocation.

Methods: A retrospective study was conducted including 28 patients with rigid clubfoot deformity (34 feet) who met the selection criteria and admitted between September 2021 and December 2024. There were 19 males and 9 females with an average age of 31.8 years (range, 19-47 years). According to Dimeglio classification, there were 21 feet of degree Ⅲ and 13 feet of degree Ⅳ. The causes were traumatic sequelae in 9 cases, congenital foot deformity in 15 cases, spina bifida sequelae in 1 case, peripheral neuropathy in 1 case, and cerebral palsy sequelae in 2 cases. The malformation lasted from 6 to 46 years, with an average of 29.3 years. All patients were treated with Ilizarov circular external fixator, and the hinge position of ankle joint was planned according to the standard lateral X-ray film of foot and ankle and the principle of Ilizarov limb deformity correction center of rotation angulation (CORA) before operation. The 2008 International Clubfoot Study Group (ICFSG) scoring system was used to evaluate the efficacy.

Results: The deformity of rigid clubfoot was completely corrected in all patients, and the patients could walk with plantar weight-bearing, and the ankle weight-bearing walking significantly improved when compared with that before operation. There was no complication such as ankle dislocation, talus impact or extrusion, local skin necrosis, needle tract infection, or numbness of extremities during the correction process. All patients were followed up 5-39 months, with an average of 18.1 months. At last follow-up, according to the ICFSG scoring system, 23 feet were excellent, 10 feet were good, and 1 foot was fair, and the excellent and good rate was 97%.

Conclusion: Designing the position of the ankle hinge according to the principle of CORA can effectively avoid ankle dislocation, talus impingement, tibiotalar joint extrusion, and other ankle adverse events in the process of correcting clubfoot deformity, which has good application value in clinical practice.