Pes cavus deformity describes a foot condition characterized by an abnormally high arch that does not flatten when weight is applied. This structural deviation can affect one or both feet and may progress over time.
Understanding Pes Cavus Deformity
Pes cavus deformity is defined by a foot morphology featuring a high arch that remains elevated even during weight-bearing activities. This high arch can be located in the forefoot, midfoot, hindfoot, or a combination of these areas. A common variation, pes cavovarus, involves both an elevated arch and an inward turning of the foot, which can further impact alignment and lead to issues with walking and balance.
The structural changes in pes cavus often include clawing of the toes, an increased calcaneal angle in the hindfoot, and a contracture of the plantar fascia. In some cases, the hindfoot may be overly extended or dorsiflexed, while the forefoot is plantarflexed, creating a significant angle between the front and back of the foot. These anatomical alterations disrupt normal foot mechanics, causing uneven weight distribution and placing increased pressure on the heel and the ball of the foot. The foot may also become less flexible due to these changes.
Causes of Pes Cavus Deformity
Neurological Causes
Pes cavus deformity often arises from an imbalance between the agonist and antagonist muscles within the foot. While a family history is often present and the condition is typically bilateral, it can also be a sign of an underlying neurological disorder. Neurological conditions frequently linked to pes cavus include hereditary sensorimotor neuropathies, such as Charcot-Marie-Tooth (CMT) disease, which can lead to muscle weaknesses and subsequent deformities.
Spinal cord issues like tumors, trauma, or syringomyelia can also contribute to the development of pes cavus. Other neurological causes include cerebral palsy, stroke, and poliomyelitis. In these cases, muscle imbalances result in elevated arches, and a new-onset unilateral deformity without prior trauma may prompt evaluation for spinal tumors.
Other Causes
Beyond neurological origins, pes cavus can be idiopathic, meaning its cause is unknown, or it may stem from factors like foot trauma or tarsal coalition.
Recognizing Pes Cavus Deformity
Individuals often report pain, instability, and difficulties with walking or running. Finding suitable footwear can also be a significant challenge. Common areas of pain include the side of the foot and the metatarsals, which are the long bones in the forefoot. The uneven weight distribution frequently leads to the development of calluses on the sole of the foot, particularly on the metatarsal heads. Patients may also experience ankle sprains or even stress fractures of the ankle or metatarsals.
A physical examination typically reveals the characteristic high arch, clawed toes, and an increased calcaneal angle, which is the angle of the heel bone. Imaging studies, such as X-rays, help assess the severity and specific characteristics of the deformity, though a precise radiographic definition of pes cavus can be challenging due to its varied components.
Treatment Approaches for Pes Cavus Deformity
Conservative Treatments
Treatment for pes cavus deformity aims to create a foot that can bear weight evenly and without pain. Conservative approaches are often the first line of management. Custom orthotics, which are specialized shoe inserts, can help distribute pressure more evenly across the foot and provide support to the arch. Bracing may also be employed to stabilize the foot and ankle, particularly in cases with significant instability.
Physical therapy plays a significant role in improving foot mechanics and strength. This can involve exercises to stretch tight muscles and tendons, strengthen weak muscles, and improve balance and gait. Pain management strategies, such as over-the-counter pain relievers or anti-inflammatory medications, may be used to alleviate discomfort.
Surgical Intervention
When conservative treatments do not adequately address the deformity or symptoms, surgical intervention may be considered. Surgery aims to correct the structural abnormalities. The decision to proceed with surgery depends on the severity of the deformity, the presence of rigidity, muscle strength, and the specific types of deformities present.
Surgical procedures are broadly categorized into soft-tissue and bony procedures, and often multiple procedures are performed concurrently. Soft-tissue procedures might include tendon transfers, where tendons are moved to different locations to rebalance muscle forces, or releases of tight soft tissues like the plantar fascia. Bony procedures, such as osteotomies, involve cutting and reshaping bones to correct alignment, while fusions may be performed to stabilize joints that are severely deformed or arthritic. The specific surgical plan is individualized.