Claw foot (pes cavus), acquired:

What Is Pes Cavus?

Pes cavus, otherwise called clawfoot or high arch, is a human foot type in which the bottom of the foot is unmistakably empty when bearing weight. A high arch is something contrary to a level foot and is fairly less common. Pes cavus is a foot deformity described by a high arch of the foot that doesn't smooth with weight bearing; the deformity can be situated in the forefoot, midfoot, hindfoot, or in a blend of every one of these destinations

What Are The Symptoms Of Pes Cavus?

• Individuals with pes cavus here and there—however not generally—experience issues discovering shoes that fit and may need help from their perspective. Youngsters with high arches who experience issues strolling may wear exceptionally planned insoles, which are accessible in different sizes and can be made to order.
• People with pes cavus every now and again report foot pain, which can prompt a huge constraint in capacity. The scope of objections announced in the writing incorporate metatarsalgia, pain under the principal metatarsal, plantar fasciitis, painful callosities, lower leg arthritis.
• There are numerous different symptoms accepted to be identified with the cavus foot. These incorporate shoe-fitting problems, sidelong lower leg instability, lower appendage stress fractures, knee pain, iliotibial band rubbing syndrome, back pain and tripping.
• Foot pain in individuals with pes cavus may result from abnormal plantar pressing factor stacking in light of the fact that, fundamentally, the cavoid foot is viewed as being unbending and non-stun retentive and having diminished ground contact region. There have recently been reports of a relationship between over the top plantar pressing factor and foot pathology in individuals with pes cavus.

Claw foot (pes cavus), acquired 

Claw foot is so named because of the abnormal appearance of the affected foot. A patient with this condition has a deformity in which the toe joint nearest to the ankle bends upward and the other toes bend downward in a fixed contracture. A claw foot is not necessarily harmful and may not require treatment, but it can cause pain, result in development of other troubling disorders, or be a sign of a more serious underlying condition.

Types of Pes cavus

Three main types of pes cavus are regularly described in the literature: pes cavovarus, pes calcaneocavus, and ‘pure’ pes cavus. The three types of pes cavus can be distinguished by their etiology, clinical signs and radiological appearance.

• Pes cavovarus, the most common type of pes cavus, is seen primarily in neuromuscular disorders such as Charcot-Marie-Tooth disease and, in cases of unknown aetiology, is conventionally termed ‘idiopathic’. Pes cavovarus presents with the calcaneus in varus, the first metatarsal plantarflexed, and a claw-toe deformity. Radiological analysis of pes cavus in Charcot-Marie-Tooth disease shows the forefoot is typically plantarflexed in relation to the rearfoot.
• Pes calcaneocavus foot, which is seen primarily following paralysis of the triceps surae due to poliomyelitis, the calcaneus is dorsiflexed and the forefoot is plantarflexed. Radiological analysis of pes calcaneocavus reveals a large talo-calcaneal angle.
• Pes cavus, the calcaneus is neither dorsiflexed nor in varus and is highly arched due to a plantarflexed position of the forefoot on the rearfoot.  A combination of any or all of these elements can also be seen in a ‘combined’ type of pes cavus that may be further categorized as flexible or rigid.

Also, types of Pes Cavus is based on the location of APEX of the deformity

• Anterior Cavus (Forefoot Cavus) –Local –Global
• Metatarsus cavus
• Posterior Cavus
• Combined

Causes of Claw Foot

Many types of claw foot are connected to damage to your feet. Your toes may curl to compensate and help you balance if the nerves or muscles in your feet are injured. This curl can become permanent over time. 

Other reasons you may develop claw toes include:

Injuries and surgery: Any type of foot or ankle surgery can damage the nerves in that area. Traumatic injuries to your legs, feet, and ankles can also cause muscle damage and nerve injuries.‌

Diabetes: Uncontrolled blood sugar can lead to nerve damage in your feet. People with uncontrolled diabetes may experience foot numbness along with curling toes. High insulin levels can damage their extremities.

Rheumatoid arthritis: This is an autoimmune condition that can cause your immune system to attack your joints. It can weaken your muscles and deform your toe joints over time.

Cerebral palsy: This condition leads to irregular muscle tone. People with cerebral palsy have muscles that are too loose or too stiff. This can cause claw foot as your toe muscles stiffen to compensate for loose foot muscles.

Stroke: A stroke can make it harder for you to control muscles throughout your body. This includes your feet and legs. Your toes may curl to help you balance.‌

Charcot-Marie-Tooth disease: This genetic disorder affects your nervous system. It makes it harder for you to control your legs and feet. One of the first signs of Charcot-Marie-Tooth disease is weakness in your legs and foot deformities like claw toes.

Symptoms 

Patients complain of pain , instability , difficulty walking and problems with footwear .The symptoms vary with the degree of deformity . Also can present with lateral foot pain from increased weight bearing on the lateral foot.

• The range of complaints reported in the literature include metatarsalgia, pain under the first metatarsal, plantar fasciitis, painful callosities, ankle arthritis, and Achilles tendonitis
• keratosis
• lateral Ankle instability
• hindfoot varus
• The forefoot plantar flexion
• hindfoot varus
• lower limb stress fractures
• knee pain
• iliotibial band friction syndrome
• back pain
• tripping

Diagnosis 

Plain film radiographs are the first investigation for the cavus foot. Recommended views include: 

• Weight-bearing views of the foot and ankle
• Calcaneal axial view (others have suggested that the Colby view may be more helpful in the evaluation of hindfoot alignment).

A standard evaluation for fractures, dislocations, and degenerative changes should begin any radiographic assessment, other specific lines, geographic measurements, and angles can help the clinician determine the relative position of the foot to its other components. Some of the more commonly used examples are listed below: 

One can determine the presence of cavus by evaluating the relative position of the inferior aspect of the medial cuneiform and the fifth metatarsal base on a lateral x-ray of the foot. When the 5th metatarsal base is closer to the floor, the foot is in cavus. 

Meary’s line (a line measured along the long axis of the talus and first metatarsal) is normally zero, but in the cavus foot, the first metatarsal is plantarflexed, increasing the angle. A mild cavus foot may have a Meary’s angle of five to ten degrees, with severe cavus feet having angles greater than twenty degrees.

A Hibb angle may also be used. This is a measurement between the longitudinal axis of the calcaneus and first metatarsal. Values in normal feet are generally less than 45 degrees. In patients in pes cavus deformities, the angle is often greater than 90 degrees.

A talocalcaneal angle on the AP radiograph will show a divergent talus and calcaneus in a normal foot with an angle of twenty to forty degrees. When the angle is decreased, this indicates that the talus and calcaneus are more parallel, and the foot is in cavus.

The Djian-Annonier angle (the angle of the medial arch) is widely used in France and is found to be less than one-hundred and twenty degrees in the cavus foot. This angle is measured from where the calcaneus rests against the ground, to the talonavicular joint at the apex and to the medial sesamoid where it contacts the ground again.

Other Imaging: 

Computed tomography (CT) scans may also be performed to allow for evaluation of the joints for arthrosis for surgical planning and a complete evaluation of the hindfoot position.

Magnetic resonance imaging has been described for the evaluation of the lateral ligamentous complex, peroneal tendon pathology, osteochondral lesions, and evaluation of fifth metatarsal base fractures.

In cases of suspected HMSNs, patients may benefit from evaluation by a neurologist for possible electromyogram and/or genetic testing.

Unilateral pes cavus without obvious explanation should prompt MRI of the brain and spinal cord.