Introduction

Congenital hallux varus is a rare deformity, which can be associated with other deformities [1]. The child has difficulty in wearing footwear and trousers and is not cosmetically accepted to the parents. There is lack in clear definition of the deformity; the deformity also varies in severity, associated features, patho-mechanisms and the choice of surgical treatment bony or soft tissue corrections [2].

We thus report such a rare case of congenital hallux varus associated with polydactyl and syndactyl in an infant which was treated by soft tissue procedure. The aim of this report is create awareness regarding this rare entity and to review the available literature on it.

Case report

An eight months old male child presented to us with deformity present at right foot since birth. The deformity was double hallux i.e. duplication of great toe with hallux varus deformity of both the great toes (fig 1). The child’s parents were concerned, about the bad cosmetic appearance of the foot deformity and they were unable to put regular footwear into the child’s foot.

They also complain of difficulty in pulling up the trousers/pants for the child. Apart from the foot deformity, there was no any other deformity present in the body. The child was born full term normal vaginal delivery and the neonatal period was uneventful. There was no history of trauma, surgery or any treatment taken.

On examination, the child had right foot deformity, with polydactyl having total of six toes in right foot, with syndactyl of great toe. The two great toes were abnormally placed in severe varus position, projecting almost medially from the inner border of the foot toward medial side rather than distally (fig 1).

The fused great toes were perpendicular to the long axis of the first metatarsal. The proximal toe was slightly smaller than the distal toe, and it lacked proper nail plate, which was well developed in distal larger great toe. The first web space was significantly increased and the first metatarsal head was palpable in the web space.

Movements dorsiflexion and plantar flexion was present at the both the toes, but movement of the deformed toes to the lateral side towards the metatarsal head was not possible. Neurovascular examination of the foot and toes was normal.

Radiological, X-rays of the right foot AP and oblique view were done which showed, duplication of the great toes with only proximal phalanx in smaller toe and both the distal and proximal phalanges in the bigger toe. Both the toes were placed together side by side, articulating abnormally on the inner side of deformed first metatarsal head. The first metatarsal was short and thick and head was deformed.

We planned the surgical treatment of the patients, with excision of the supernumerary toe and alignment to the toe with the metatarsal head. The child was operated under general anesthesia under tourniquet in supine position. A ‘Y’ shaped incision was given with the vertical limb towards the web space (fig 2).

Following this, the deep Y-shaped flaps were elevated and the proximal smaller accessary great toe was excised. The bigger toe with proper nail was displaced laterally and temporary fixed with a k-wire (fig 2).

Post operatively, a below knee slab was given and was removed at 2 weeks at the time suture removal. The k wire was removed at 4 week. At final follow up of 4 months, child has cosmetically acceptable foot and is comfortably able to wear normal footwear and trousers. There is slight shortening of great toe.

Discussion

Hallux varus is a very rare deformity as compared to hallux valgus [1]. Among the ethological types, the congenital variety of hallux varus is further rare variety as compared to other caused of varus deformity like surgical overcorrection of hallux valgus, idiopathic, spontaneous, inflammatory arthropathy or post-traumatic type [3].

Congenital hallux varus has multifactorial causes like thickened medial cords, medial slopes to the first metatarsocuneiform joints, first metatarsal longitudinal epiphyseal bracket (LEB; delta phalanx), shortened block first metatarsals, space occupying extra metatarsals with the first web spaces and ineffective abductor halluces and adductor hallucis insertions [2,4-7].

Since the deformity is present since birth, these patients present early. But, our case presented to us only at the age of eight month, when the child started mobilization and parents tried to put regular footwear to the child, which they were unable to do, due to the deformity. Dumbre reported a case of congenital hallux varus presenting at age of 23 year, which was complicated with soft tissue contracture, bony deformities and arthritis of joints [3].

Presentation and diagnosis is quiet obvious on clinical examination. Three types of congenital hallux varus are describes by Alfred [8].

1. 1⁰ (primary) - not associated with any other deformity
2. 2⁰ (secondary) – associated with polydactyly, syndatyly, metatarsal adductus, CTEV, LEX (longitudinal epiphyseal bracket / delta phalanx)
3. 3⁰ (tertiary) – with severe deformities like diastrophic dwarfism

Our case was a secondary type, which was associated with both polydactyl and syndactyl. The deformity can range from mild (few degrees) to severe (to 90⁰), ours was a severe type who had deformity almost 90⁰.