The clawfoot has a morphology which is characterized by an increase of height and amplitude of the longitudinal arch of foot. Therefore, the support surface falls above all in the external longitudinal arch, where it is usual the appearance of the torn isthmus. It is usually asymptomatic but it can cause tiredness, sprains of repetition of foot or ankle, hyper-pressure points, as well as muscular and/or fascial involvement.
The etiology of clawfoot is varied:
Hypertonic (sportsmen, sportswomen and dancers).
Congenital clawfoot (not very common).
Secondary to traumatisms.
The sensory-motor hereditary neuropathies, like for example, Chacot-Marie-Tooth and the distal spinal muscular atrophies are the neuromuscular affections which cause clawfeet more frequently. It also causes neurological diseases with this affection from another etiology like poliomyelitis, cerebral palsy, the Friedreich’s ataxia or the muscular dystrophies.
The symptomatology and the effects of the clawfoot are the following:
Pain in the parts of plantar pressure (above all in the caput ossis metatarsalis -head of metatarsal bone-, or fleshy parts of clawtoes).
Hyperkeratosis and/or heloma.
Instability of foot and ankle.
It can be classified in former, subsequent or mixed, according to its layout in the sagittal plane. The former clawfoot is the most frequent shape. In this foot, the imbalance among the muscles that pull the foot, use to verticalize the metatarsal, mainly the first one. This fact makes that its heads are extremely descended with reference to the heel. The subsequent clawfoot appears in the paralysis of the sural triceps, and as a result of the lack of traction of the Achilles tendon, the calcaneal verticalizes and rises by the former side. The mixed shapes appear when the fall of the first metatarsal is more pronounced regarding the others, because the hindfoot is laid in a big supination in order to offset it and, secondly, the calcaneal gets vertical.
According to the position of the heel in the frontal plane, the clawfoot can be varus clawfoot, valgus clawfoot or neutral clawfoot.
Regarding the treatment, it is advisable a retro capital plantar support which will be able to redistribute the burdens in the planta pedis, in a way that the support will decrease under the heads of the metatarsals and a part will transfer to the distal side of the diaphysis, as well as in an increase of the stability of foot and ankle. At the same time, the raising of the heads of the metatarsals will cause a fall of the position in clawtoes which will also be more comfortable in shoes with a high and wide shape in the upper part of shoes. In the clawfoot, the main trouble for the patient is the plantar pain. An orthesis of retro capital support can also achieve a symptomatic relief. If the conservative treatment is not enough, and in feet which show an important alteration of the biomechanics of foot or the pain which causes a functional alteration and an obstacle of the daily activities, we should think about the surgical treatment.