Radiological outcome after treatment of juvenile flatfeet with subtalar arthroereisis: a matched pair analysis of 38 cases comparing neurogenic and non-neurogenic patients

Abstract

Purpose: Therapy of juvenile neurogenic flatfoot (JNF) with subtalar arthroereisis (SA) is currently under critical clinical investigation. In this retrospective matched pair analysis, the radiological outcome after arthroereisis in paediatric patients with infantile cerebral palsy and JNF was compared with children with juvenile flatfeet (JF) without neurological diseases.

Methods: From October 2007 to April 2018 80 patients with 149 flatfeet underwent surgery with SA. Inclusion criteria were: 1) JNF or JF with age at surgery ≤ 13 years; 2) treatment with SA; 3) presence of three sets of biplane radiographs (preoperative, postoperative and follow-up (FU)). The radiographs were analyzed for: 1) navicular-cuboidal-index (NCI); 2) talocalcaneal angle anteroposterior; 3) talocalcaneal angle lateral; 4) calcaneal-pitch (CP); and 5) talometatarsal-index (TMTI). Following this, 25 patients with 38 flatfeet could be included.

Results: The mean age at SA of the JNF group was 9.2 years (JF group: 9.3 years) and the mean time of FU was 35.2 months (JF group: 39.4 months). In comparison with preoperatively, a significant decrease of the NCI was seen in both groups (p = ≤ 0.05 and p = ≤ 0.001) in the FU radiographs. The analysis of CP and TMTI in the JF group also resulted in a significant improvement (p = ≤ 0.001 and p = ≤ 0.05). Overall, the comparison between the JNF and JF group showed no significant differences in regard to the analyzed postoperative parameters.

Conclusion: Based on this data, treatment of flatfeet by SA in patient with neurological disorders shows an improvement of radiological parameters comparable with neurologically unimpaired patients and might be considered as additional treatment option.

Level of evidence: IV.

Keywords: cerebral palsy; flatfoot; pes planus; subtalar arthroereisis.

Fig. 1

Study and control group (SA, subtalar arthroereisis; ICP, infantile cerebral palsy; FU, follow-up).

Fig. 2

(a) Preoperative lateral view of an eight-year-old boy with infantile cerebral palsy (ICP) (navicular-cuboidal-index (NCI) 53.3%; talocalcaneal angle lateral (TCA lat) 48.2°; calcaneal-pitch (CP) 8.6°); (b) postoperative control; (c) one-year postoperative; (d) two-years postoperatively and after implant removal with physiological foot position (NCI 26.3%; TCA lat 32.1°; CP 17.5°) (*CP; #TCA lat; +NCI).

Fig. 3

(a) Navicular-cuboidal-index (NCI): significant improvement of the index in comparison of preoperative with postoperative and follow-up (FU) in both groups (*p ≤ 0.05; **p ≤ 0.001); (b) talocalcaneal angle a.p. (TCA AP): improvement of the values preoperatively compared with FU in the juvenile flatfeet (JF) group, no permanent improvement (preoperative to FU); (c) talocalcaneal angle lateral (TCA lat): significant improvement of the angle in both groups, deterioration again in the JF group; (d) calcaneal-pitch (CP): improvement in the JF group preoperatively and postoperatively compared with FU. Moreover, detection of a significant higher CP in the JF group compared to the juvenile neurogenic flatfeet (JNF) group preoperatively; (e) talometatarsal-1-index (TMTI): improvement of the index in comparison between preoperative and postoperative and FU in the JF group (n = 38) (pre-OP: preoperative; post-OP: postoperative, JF: juvenile flatfeet, JNF: juvenile neurogenic flatfeet).