Flexible flatfoot in children and adolescents

Abstract

Flexible flatfoot is a normal foot shape that is present in most infants and many adults. The arch elevates spontaneously in most children during the first decade of life. There is no evidence that a longitudinal arch can be created in a child's foot by any external forces or devices. Flexible flatfoot with a short Achilles tendon, in contrast to simple flexible flatfoot, is known to cause pain and disability in some adolescents and adults. Joint-preserving, deformity-correcting surgery is indicated in flexible flatfeet with short Achilles tendons when conservative measurements fail to relieve pain under the head of the plantar flexed talus or in the sinus tarsi area. Osteotomy is the fundamental and central procedure of choice. In almost all cases, Achilles tendon lengthening is required. In some cases, rigid supination deformity of the forefoot is present, requiring identification and concurrent treatment.

Keywords: Achilles tendon contracture; Adolescent; Arthroereisis; Calcaneal lengthening osteotomy; Flatfoot.

Fig. 1

Flexible flatfeet. a Convex medial border with midfoot sag. b Valgus hindfoot (Fig. 10-3, p. 139, from ref. [127], with permission)

Fig. 2

Jack’s toe-raising test. An arch is created in a flexible flatfoot (FFF) by the windlass action of the great toe and plantar fascia (Fig. 10-6, p. 141, from ref. [127], with permission)

Fig. 3

a Weight-bearing left FFF. b In toe-standing, heel valgus converts to varus and the longitudinal arch can be seen (Fig. 10-5, p. 140, from ref. [127], with permission)

Fig. 4

Forefoot supination can best be appreciated when the hindfoot is inverted to neutral (Fig. 10-7, p. 142, from ref. [127], with permission)

Fig. 5

The subtalar joint must be held in neutral position and the knee extended in order to accurately assess ankle dorsiflexion (Fig. 10-8, p. 142, from ref. [127], with permission)

Fig. 6

Standing lateral radiograph showing three fairly reliable angular measurements: the calcaneal pitch (CP), talo-horizontal angle (T-H), and Meary’s talus–first metatarsal angle (T-1MT) (Fig. 4, p. 507, from ref. [110], with permission)

Fig. 7

Standing radiographs of a flatfoot showing talus and first metatarsal axis lines crossing at the center of rotation of angulation (CORA) in the center of the head of the talus, indicating a single deformity at the talo-navicular joint. a Anteroposterior view. b Lateral view (Fig. 10-10, p. 144, from ref. [127], with permission)

Fig. 8

Standing radiographs of a skewfoot showing two opposite direction angular deformities between the talus and the first metatarsal, making the CORA for those bones meaningless. a Anteroposterior view. b Lateral view (Fig. 3A, B, p. 506, from ref. [110], with permission)

Fig. 9

Radiographic and computed tomography (CT) scan images showing resorption of adjacent cortical surfaces of talus and calcaneus due to the presence of a Maxwell–Brancheau arthroereisis (MBA) implant (Fig. 10-11, p. 147, from ref. [127], with permission)

Fig. 10

Painful FFF. a, c Anteroposterior (AP) and lateral preoperative sketches of actual radiographs. The talo-first metatarsal angle is markedly abducted on the AP view. The lateral view shows severe talo-navicular sag and a 0° calcaneal pitch. b, d AP and lateral sketches of actual radiographs following a calcaneal lengthening osteotomy and tendo-Achilles lengthening. All components of the deformity are corrected, subtalar motion is preserved, and symptoms are relieved (Fig. 2A–D, p. 502–503, from ref. [110], with permission)