Progression of planovalgus deformity in patients with cerebral palsy

Abstract

Background: Analyzing radiographic changes of pes planovalgus(PV) deformity of cerebral palsy(CP) patients according to age and influencing factors.

Methods: CP patients with PV deformity younger than 18 years old who had undergone more than a year of follow-up with at least two standing foot radiographs were included. Anteroposterior and lateral talo-first metatarsal(talo-1stMT), talo-second metatarsal(talo-2ndMT), and hallux valgus(HV) angles were measured on the radiographs. The rate of progression was adjusted by multiple factors using the linear mixed model, with the Gross Motor Function Classification System(GMFCS) level as the fixed effect and age and each subject as random effects.

Results: Overall, 194 patients were enrolled in this study, and 1272 standing foot radiographs were evaluated. The AP talo-2ndMT angle progressed by 0.59° (p < 0.0001) and 0.64° (p = 0.0007) in GMFCS level II and III patients, respectively; however, there was no significant change in GMFCS level I patients (p = 0.3269). HV was significantly affected by age in all three GMFCS groups; it increased by 0.48° (p < 0.0001), 0.66° (p < 0.0001), and 1.19° (p < 0.0001) for levels I, II, and III, respectively. The lateral talo-1stMT angle showed improvements in GMFCS level I and II patients (0.43°, p < 0.0001, and 0.61°, p < 0.0001, respectively). In GMFCS level III patients, there was no significant improvement in the lateral talo-1stMT angle (p = 0.0535).

Conclusions: The GMFCS level was the single most important factor influencing the progression of radiographic indices in PV deformity in CP. The AP talo-1stMT and talo-2ndMT angles progressed in patients with GMFCS levels II and III. Physicians should take this result into consideration when planning the timing of the surgery.

Level of evidence: Prognostic Level IV.

Keywords: Cerebral palsy; Pes planovalgus; Progression; Talo-first metatarsal angle; Talo-second metatarsal angle.

Conflict of interest statement

The authors declare that they have no competing interests.

Figures

Fig. 1

Inclusion and exclusion criteria. GMFCS, Gross Motor Function Classification System; Uni, unilateral; Bi, bilateral; TAL, tendo-Achilles lengthening; AP, anteroposterior; Lat, lateral; AP talo-1MT, AP talo-first metatarsal angle; AP talo-2MT, AP talo-second metatarsal angle; HV, hallux valgus angle; Lat talo-1MT, lateral talo-first metatarsal angle

Fig. 2

a The anteroposterior talo-first metatarsal angle is the angle between the line bisecting the longitudinal axis of the first metatarsal bone and the line bisecting the longitudinal axis of the talus on standing anteroposterior plain foot radiograph. b The anteroposterior talo-second metatarsal angle is the angle between the line bisecting the longitudinal axis of the second metatarsal bone and the line bisecting the longitudinal axis of the talus on standing anteroposterior plain foot radiograph. c The hallux valgus angle is the angle between the longitudinal axis of the first proximal phalanx and the longitudinal axis of the first metatarsus

Fig. 3

The lateral talo-first metatarsal angle is the angle between the line bisecting the longitudinal axis of the first metatarsal bone and the line bisecting the longitudinal axis of the talus on the standing lateral plain foot radiograph

Fig. 4

Scatterplots showing the progression of the talo-second metatarsal angles according to age for Gross Motor Function Classification System (GMFCS) levels I (a), II (b), and III (c). There is a positive correlation between the talo-second metatarsal angle and the follow-up duration for GMFCS levels II and III. The points represent all the foot radiographs obtained. The solid lines represent an estimation of the progression by a linear follow-up duration effect