Understanding The Relationship Of Clubtoe To Clubfoot
Clubtoe is a term that I use to describe the big toe equinus deformity that one encounters with adolescent and adult clubfoot. It is a condition of “significant” hallux plantarflexion due to a severely rigid elevated first ray. In milder cases, the hallux will plantarflex at the metatarsophalangeal joint (MPJ) and mildly extend at the hallux interphalangeal joint (IPJ).
The hallux IPJ often becomes hypermobile. In severe cases of club toe, the hallux could be dramatically plantarflexed with the hallux (proximal phalanx) being 90 degrees to the floor, and the distal phalanx of the hallux positioned parallel with the floor. This creates a Z deformity of the hallux and first metatarsal.
Theoretically, this plantarflexion of the hallux could occur with any form of rigid first ray elevatus as the hallux attempts to compensate for the structural elevatus by plantarflexing to purchase the ground. However, the condition seems to be common with clubfoot because the congenital first ray elevatus encourages the hallux position to develop over time.
The articular cartilage of the first metatarsal head may remodel and follow the articulation of the hallux so the cartilage is then located on the plantar aspect of the joint. This is conceptually a plantar proximal articular set angle (PASA). There also seems to be a progressive nature to clubtoe due to the pull of the long flexor tendon on the hallux, which may cause retrograde buckling. Additionally, the tendon may become contracted and shortened.
Weighing The Surgical Options
The surgical treatment for clubtoe is not exactly simple and depends on the degree of the deformity. However, the reconstruction centers on the realignment of the first metatarsal. The surgeon could do this with various metatarsal osteotomies and/or plantarflexory midfoot fusion(s) depending on the clinical scenario. You will need to shorten the first ray to allow reduction of the big toe joint, especially in severe cases.
However, for patients in whom you suspect the flexor hallucis longus (FHL) to be contracted and short, you may consider lengthening this tendon. Temporary pinning of the big toe joint during the early postoperative phase may prevent recurrence from a potentially shortened FHL.
Surgeons should also consider the plantarward cartilage deviation that may occur at the first metatarsal head. These joints may be stiff postoperatively once you restore the big toe joint alignment. A congenitally chronically dislocated joint that is realigned does not automatically render this joint a normal functioning joint. The joint may become painfully arthritic.
However, surgeons should remember that the hallux interphalangeal joint is likely already hypermobile and adapted to respond to the dorsiflexory needs of that particular segment. There is no exact treatment recommendation when the cartilage has migrated significantly. Although first MPJ fusion is indeed an option, you must consider the overall biomechanical state of these feet that may have had previous fusions or malformed midfoot and hindfoot joints. You should consider each patient individually.
In my opinion, restoring the proper relationship of the first ray to the rest of the foot is the cornerstone of these reconstructions. If the first MPJ becomes symptomatic, then you can consider fusion or perhaps implant arthroplasty at a later date.
The above photos illustrate the results of plantarflexory Lapidus arthrodesis in two patients with clubtoe. For each patient, I reduced the big toe joint to a plantigrade position.