You, the great toe of this assembly?

1. Discussion 

	Menenius:	What do you think,
		You, the great toe of this assembly?
	[First] Citizen:	I, the great toe? Why the great toe?
	Menenius:	For that, being one o’th’lowest, basest, poorest
		Of this most wise rebellion, thou goest foremost.
	Coriolanus: Act 1 Sc.1 45–9

Shakespeare made good use of “the great toe” to insult the Plebians in their revolt against the Patricians, in the famous analogy of ‘the belly’ employed by Menenius Agrippa. The great toe does have some peculiar features that make it ‘lack its champion’ [17] and thus stand out of the assembly it constitutes.

The pre-axial polydactyly, i.e. supernumerary toes on the medial side of the foot involving the first ray can be grossly classified into pre-hallux and bifid hallux.

Kidner [1] used the term pre-hallux to describe an enlarged scaphoid (navicular) bone associated with an accessory navicular bone. The tibialis posterior tendon was attached to the pre-hallux, which was ascribed to as the cause of flat foot. Later on Cobey and Cobey [2] described the first reported case of pre-hallux. According to them the term pre-hallux should only be employed in describing an entire great toe arising from the scaphoid (navicular) bone. In their case, there was a true articulation of a two-phalanx great toe with the medial border of the navicular, which was treated by amputation. The presence of such an appendage in our patient is a matter of conjecture only as we did not have any documentation before he had this removed.

The other spectrum of deformity is bifid hallux. The term has been in use for a deformity involving the first ray and the great toe itself. Venn-Watson, [3] classified their 65 patients by using a morphological classification based mainly on the anatomic configuration of the metatarsal. A large series of 125 patients was reported by Phelps et al. [4], employing the same classification. Watanabe et al. [5] published a review of 265 patients with polydactyly of the foot. They found, in medial-ray polydactyly, a bilateral occurrence was commoner and it was associated with other skeletal anomalies. They reported only a single case of a true pre-hallux arising from the navicular bone as described by Cobey et al. In contrast there were 13 (36%) cases of metatarsal type, which included 8 with a hypoplastic lateral and a single case of hypoplastic medial member. In four cases, both the metatarsals were highly deformed. Our case can be regarded as the first category of the metatarsal type, i.e. with a (proximally) hypoplastic lateral member.

The association of ipsilateral duplication of the hallux with anterolateral tibial bowing was reported by Kardon et al. about two decades ago [6]. Some authors have documented similar cases with great detail of the tibial deformities [7], [8], [9], [10]. Lewin and Opitz [11], [12] have hypothesized a tibial and fibular field during the development of the lower limb. The tibial field involved the distal femur, tibia and pre-axial toes.

Weaver et al. [10] described a pair of such cases with bifid halluces associated with tibial bowing which were both treated by amputation and K-wire fixation. There was intermittent foot pain and both patients complained of continued difficulty with shoe wear at the last follow-ups. The authors regarded it as a difficult condition to be managed surgically and anticipated the need for subsequent orthotic management.

Recently, Manner et al. [13] reported three cases of unilateral anterolateral tibial bowing associated with ipsilateral bifid great toe. The duplicated medial anlage of the great toe was resected at the age of 1-year because of interference with shoe wear. The authors mentioned about metatarsal hypoplasia and duplication of the medial cuneiform and navicular leading to marked shortening of the first ray in these patients but did not report the subsequent management. Our case was different because of absence of any leg-length discrepancy or clinical evidence of tibial bowing.

Mann and Coughlin [14] delineated basic principles to guide the surgical management of supernumerary toes: excision should be done at walking age, appropriately at an age of 1-year or later; the contour of the entire foot should be considered and for the most part, the peripheral digit is to be excised. They also recommended an appropriate excision and reconstruction of the metatarsals if an abnormality is encountered to obtain a normal contour of the entire foot.

It is important to avoid damage to remaining growth plates and articular cartilage. Our case posed a different challenge. All the metatarsals and phalanges ossify by shaft centres in utero and their epiphyses are as in the hand (the epiphyses of first metatarsal and the phalanges are at the base in contrast to the other four where they are in the head) [15]. In our case the short first ray was identified by the presence of an epiphysis at the base.

We recognized the need for lengthening of the first ray as its growth did not match up with the other rays. By employing a diaphyseal SCARF osteotomy with bone grafting, we were able to achieve a good and comparable length. A further lengthening procedure might be needed in the future. SCARF osteotomy has been employed for lengthening [16] of the first metatarsal before but has never been reported for bifid hallux. The persistence of short first metatasal and pes planus in the previous reports also highlights the need for a lengthening procedure in the subsequent management of these cases.