[Subtalare Screw Arthroereisis for the Treatment of Symptomatic, Flexible Pes Planovalgus].

Background: The purpose of this study was to determine the functional outcomes and radiographic results of the talus-stop screw method as minimally invasive subtalar arthroereisis in pediatric and juvenile flexible flatfoot.

Material And Methods: We retrospectively evaluated 73 feet from 41 children using the talus stop-screw method, for the period between 2002 and 2011. The age at time of surgery ranged between nine and 14 years. The radiological assessment included measuring the calcaneal pitch, talar declination, talo-first metatarsal angle (Meary) and calcaneal-first metatarsal angle (Costa-Bartani) in the lateral view. To evaluate talo-navicular alignment in the anteroposterior view, the talo-first metatarsalbase angles were measured. To describe the amount of planovalgus deformity in lateral and anteroposterior view, we determined a tarsometatarsal-index by adding the talo-first metatarsal and talo-first metatarsal base angles.

Results: 95% of patients were satisfied or very satisfied with postoperative results for morphology, pain and activity level. 95% of patients exhibited no limitations in daily life or sports activity due to foot pain, fatigue or repetitive distorsion. 96% of patients would undergo the surgery again, if necessary. Full weight bearing could be achieved after a mean time of 8.1 (range, 2 - 21) days. All measured postoperative angles improved significantly, except talar inclination.

Conclusions: The talus-stop screw method as a minimally invasive subtalar arthroereisis is a safe and effective treatment for the flexible pes planovalgus deformity in children and adolescents. It preserves canalis tarsi and its proprioceptive structures. The major complication rate is low and, with a vertically inserted cancellous screw, this is an economic procedure. The TMT-index incorporating both planes in pes planovalgus feet appears to be a more precise method to determine this multiplanar deformity and to evaluate treatment options and results.