The tibialis anterior tendon transfer (TATT) is a common surgical intervention aimed at correcting dynamic varus deformity in patients with congenital talipes equinovarus (CTEV). In our previous work (Brierty et al 2022) we identified two clear subgroups within a CTEV cohort being considered for TATT surgery, one group more impacted by hindfoot inversion (varus) and one more impacted by hindfoot adduction. To date, no studies have compared outcomes between differing kinematic presentations of CTEV following TATT surgery. The aim of this research was to determine whether differences in surgical outcomes were evident between these two groups.
Of the 17 participants (23 feet) who underwent gait analysis pre-operatively, 13 participants (19 feet) progressed to having tendon transfer surgery, and 11 of the 13 participants (15 feet) attended post-operative gait analysis at the Queensland Children’s Motion Analysis Service (QCMAS). Post-operative Plug-in-Gait and Oxford Foot Model kinematics and kinetics were collected. Data analysis was performed using Vicon Nexus and dedicated Mathworks Matlab codes. Statistical analysis included Statistical Parametric Mapping (SPM) for time-series comparisons between cohorts.
In subgroup one, there were no significant differences pre- to post-operatively, however there was a trend towards a decrease in hindfoot and forefoot inversion during swing, and decreased variability, supporting the efficacy of tendon transfer surgery for this subgroup. In subgroup two, we observed decreases in the two most affected variables, hindfoot adduction/abduction and forefoot dorsiflexion/plantarflexion, falling within the typical bands across the majority of the gait cycle. Evaluation of individual traces showed that despite positive results in hindfoot adduction, inversion/eversion results were unpredictable following tendon transfer surgery.
Patients who presented with a predominate hindfoot inversion deformity at baseline appeared to have predictably positive results, whereas patients who presented with a predominate hindfoot adduction deformity at baseline had less convincing outcomes that should be considered in future investigations.