Schraubenarthrorise nach De Pellegrin beim kindlichen Knick-Senkfuß – 1-Jahres Follow-Up-Analyse des Gangbildes und der plantaren Druckverteilung – eine Pilotstudie

Introduction: Pes planovalgus is a complex and frequent deformity in early childhood. It consists of two components: a valgus position of the rearfoot and a lowered longitudinal arch of the foot under weight. It usually occurs on both sides. Normally the pes planovalgus is clinically inapparent and self-limiting. Nevertheless, complications such as pain and dysfunction of the foot with persistence into adulthood can occur. If so, early therapy during the growth phase of the foot is essential. The diagnosis is determined by anamneses and clinical and radiological examination. The gait analysis can complete the diagnosis with detailed data on foot movement and pressure. Despite the potential of the gait analysis in the diagnosis of pes planovalgus, validated data is missing. Asymptomatic children under the age of six should not receive any form of therapy because of the hight potential of self-limiting. Therapy should be started in the event of persistence beyond the age of ten or in case of symptomatic courses. The most common invasive therapy is the screw-arthroereisis, as performed in this study. However, the evidence of therapeutic options is still deficient, especially there are no validated methods and parameters listed for determining the outcome. In a previous study by our research group, the results of the screw- arthroereisis were examined in the short term. As a result, highly significant improvements in foot position and symptoms could be demonstrated. The study´s aim is to examine the long-term results of gait analysis and standardised questionnaires one-year after screw-arthroereisis. We want to show how arthroereisis effects the symptoms and functions of the patient’s foot and whether gait analysis is a usable tool for diagnosis. Methods: The clinical evaluation was performed at gait-laboratory and included the measurement of the ankles of the rearfoot and the pressure under the foot while standing and walking. The 2D gait-analysis included an orthopedic treadmill to analyze the heel-angle, the rearfoot-angle and the leg axis in a static and dynamic recording. Step length and walking speed was determined by the lateral view. The pedobarographic measurement provides information about the pressure distribution under both feet. Clinical outcome was evaluated using the AFOAS-Score and a visual analogue scale for foot and ankle (VAS FA). Results: Overall, we analyzed 27 feet of 14 patients. No intraoperative complications were recorded. The mean age at surgery was 12.38 years, the mean follow-up period was 12.00 month. After one year the we reached a significant reduction of the rearfoot, especially in the dynamic measurements. The Heel-Angle reduces from 7.94° preoperatively to 1.22° after one year, the Rearfoot-Angle from 12.65° to 6.07°. A pressure shift from 71.65% to 91.92% load of the lateral middlefoot symbolizes a raise of the longitudinal arch. The symptomatic outcome improves significantly from 74.40 Points to 92.66 Points in the “Total”-Category of the VAS and from 67.38 Points to 95.46 Points in the RF-Score of the AOFAS. The reduced rearfoot-valgus in the dynamic gait analysis showed significant correlations to the results of the VAS und AOFAS-Score. On the contrary, the pedobarographic data could not show significant correlations to the questionnaires results. Discussion The results of our study were mostly positive. The gait analyses turned out to be an easy and detailed diagnostic method. A good overview of the pressure under the foot and the development of the longitudinal arch was shown in the pedobarography, although the usability of this method as performed in our study was complicated. The questionnaires seemed to be good and validate tools for the analysis of the subjective outcome of the children. Almost all children and parents state that they were satisfied with the result of the arthroereisis. In one case we detected a slight symptomatic overcorrection of one foot at the evaluation after 28 days, which is why a revision of this foot was necessary. Currently, all patients are out of symptoms. The rearfoot could be reduced into a physiological position in most children. A pressure-shift especially at the medial part of the foot indicated a development of the longitudinal arch. Although a slight decline of the results of the gait analysis after one year compared to the data after 28 days were detected, the symptomatology improved significantly. Summarized we conclude, that the screw-arthroereisis according to De Pellegrin is a great therapeutic method for children with flexible flatfoot. Moreover, the gait analysis is a good diagnostic tool to quantify the valgus of the rearfoot. The pedobarographic measurement is more suitable as a screening diagnostic, but is too laborious for a detailed analysis.