Anterior or Posterior Tibial Tendon Transfer to the Peroneus Tertius for Equinovarus Deformity.

BACKGROUND

Equinovarus deformity correction was performed by soft tissue release and bone deformity correction, and tendon transfer to maintain deformity correction. Because of the high complication rate of tendon fixation methods, partial or total anterior tibial tendon or posterior tibial tendon transfer to the peroneus tertius tendon was reported. The purpose of this study was (i) to review the results of this tendon transfer technique after release and correction of talipes equinovarus, and (ii) to analyze the complication of this technique.

METHODS

Between February 2017 and May 2022, 176 patients (210 feet) with equinus and/or varus foot and ankle deformities underwent anterior or posterior tibial tendon transfer to the peroneus tertius in our institute. Preoperative and postoperative foot and ankle range of motion (passive and active) were checked. The postoperative radiographic assessment included antero-posterior (AP), lateral, and hindfoot alignment radiographs. Preoperative and postoperative lateral tibio-talar, talo-calcaneal, talo-first metatarsal, tibial-sole angles, hindfoot alignment, and anterior subluxation of the talus were checked. The American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale, and visual analog scale (VAS) were used to assess pain. Paired Student's t-test was used to compare the clinical scores and radiographic angles before the operation and at the last follow-up.

RESULTS

The mean age of the patients was 23.27 ± 13.44 years (range, 3-69 years). The mean follow-up time was 25.56 ± 16.37 months (range, 12-68 months). There were significant differences between the preoperative and postoperative measurements of the lateral tibio-talar angle, lateral talo-calcaneal angle, lateral talo-first metatarsal angle, lateral tibial-sole angle, and hindfoot alignment (p < 0.001). There was significant difference between the preoperative and postoperative AOFAS and VAS scores (p < 0.001). The early complications included infection in one patient, skin necrosis in two patients, and plantar numbness in three patients. The late complications included pin infection in three patients, tibio-talar joint compression in four patients, forefoot pain in two patients, toe flexion in two patients, and plantar numbness in one patient. There were three cases of complications (1.43%) related to the transferred tendons.

CONCLUSION

Tibialis anterior or posterior tendon transfer to the peroneus tertius is a safe and effective method for equinovarus deformity correction. It yielded excellent outcomes that produced high patient satisfaction and few complications.