Personalized approach to the treatment of patients with flat foot deformity: method for determining the level of osteotomy of anterior process of the calcaneus

Introduction Evans osteotomy remains one of the most common methods of surgical correction for mobile flat foot deformity by lengthening the lateral column. However, this technique is associated with damage to the articular facets (56–63 %), support of the talus (5–15 %), as well as the tendon of the flexor of the toes and the ibial nerve (11 %). The main causes of complications are insufficient visualization from the surgical approach and difficulties in accurately of the osteotomy level of the anterior process of the calcaneus. In this regard, despite the proven effectiveness of the Evans technique, further improvement of surgical techniques and the development of more accurate intraoperative control methods are required to minimize the risks.
The aim of the work is to analyze the results of surgical treatment of patients with flexible flatfoot by introducing an original method based on 3D modeling of the calcaneus and preoperative planning of the osteotomy level.
Materials and methods The study included 40 patients with mobile flat foot deformity, who were treated at the Novosibirsk Research Institute named after Y.L. Tsivyan. All participants underwent a comprehensive examination, which included a clinical examination, radiography of the feet with load (in direct and lateral projections), MSCT of the ankle joint and an assessment on the AOFAS scale. The patients were divided into two groups: the control group (n = 20), where standard Evans osteotomy was used, and the main group (n = 20) using the developed method. Postoperative follow-up was carried out for 12 months.
Results The study was dominated by patients with combined anterior and middle articular facets: 12 (60 %) cases in the main group and 13 (65 %) in the comparison group. It has been established that this type of structure of  the  subcutaneous joint is more often damaged by Evans osteotomy. In the comparison group, damage to the articular surfaces occurred in 9 (45 %) patients, while in the main group — only in 1 (5 %); p ≤ 0.05. Damage to the talus support was noted only in the comparison group — in 3 (15 %) cases out of 20. In both groups, there was a significant improvement in subjective assessment on the AOFAS scale and radiographic parameters one year after surgery.
Discussion The application of the developed method made it possible to significantly reduce the frequency of intraoperative injuries to the articular facets of the talus joint and the support of the talus bone. Stable radiological indicators of deformity correction were observed without cases of recurrence or loss of achieved correction during the 12-month follow-up period.
Conclusion The personalized surgical approach demonstrates significant benefits, including a reduction in  the  incidence of complications and recurrence of deformity, which contributes to improved clinical outcomes and improved quality of life for patients with squamous foot deformity.

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