Are there benefits of a 2D gait analysis in the evaluation of the subtalar extra-articular screw arthroereisis? Short-term investigation in children

BACKGROUND

A juvenile flexible flatfoot is a common abnormality during growth. For children with a pathological manifestation, subtalar extra-articular screw arthroereisis is a popular operative technique. Although this minimally invasive operation technique has been performed for >45 years, complications still occasionally occur. For this reason, we created this pilot study to investigate whether a two-dimensional (2D) gait analysis is able to identify functional movement deficits after surgery.

METHODS

Fourteen children (27 ft) with a mean age of 12.38 years (SD, 1.40 years) were analyzed. Biomechanics were examined before and 4 weeks after surgery using a 2D gait analysis. For this purpose, the patients were filmed on a treadmill. In focus were static and dynamic recordings of the heel angle, rearfoot angle, and the leg axis angle. In addition, the step length and self-selected speed were measured.

FINDINGS

After surgery rearfoot angle showed significant reduction (p < 0.001) from 12.49° to 3.63° under static conditions and from 12.65° to 4.58° under dynamic conditions. Heel angle responded similar (p < 0.001). There were no significant differences in self-selected speed or step length. Undoubtedly, gait analysis was able to identify intraindividual deficits, leading to a closer monitoring of five patients and an adjustment of the screw in one foot.

INTERPRETATION

By means of the 2D gait analysis, we were able to show functional improvement after subtalar extra-articular screw arthroereisis. Nonetheless, we identified a few children who still had functional abnormalities. Certainly, it is unclear whether this additional examination is able to reveal all complications that would have occurred later.