Effect of split posterior tibialis tendon transfer on foot progression angle in children with cerebral palsy

Objectives

A common orthopedic issue for patients with spastic cerebral palsy (CP) is hindfoot varus deformity. One method of treatment is the split posterior tibialis tendon transfer (SPOTT). There is limited literature on the effect of SPOTT on foot progression angle (FPA) in children with CP who have equinovarus deformities. The objective of our study was to evaluate the change in FPA after SPOTT to determine if this procedure can improve FPA.

Research Question

This study aims to determine what axial changes are generated from a split posterior tibial tendon transfer in children with CP.

Methods

We performed a retrospective analysis of all ambulatory children with a diagnosis of CP who underwent SPOTT at our institution. Patients with bony rotational procedures were excluded. Descriptive statistics including mean and standard deviation (SD) were used to characterize continuous variables. Paired t-tests were used to evaluate outcomes, in which a target outcome was defined as a post-operative FPA between 0–10° of external rotation.

Results

44 limbs were included. Demographics were as follows: 26/13 female/male; mean age[SD] (years): 9.8[3.5]; 30 hemiplegic, 9 diplegic, and 1 triplegic. Of the 44 limbs, 18 limbs had a target outcome, 4 had no change, and 22 had a non-target outcome. Of the 22 with an outcome outside of the target, 4 limbs trended away from a target outcome. The overall change in FPA measured was − 10.9 ± 14.7° (p < 0.0001) Age at time of surgery, CP involvement, pre-operative FPA, and GMFCS level were not predictors of outcome (p > 0.05).

Conclusions

SPOTT produced a change of 10.9° external rotation in FPA post-operatively and its effects should be considered when planning a SEMLS.