Claw toe

What is a claw toe?

A claw toe, or hammer toe, is in a deformed position that can be painful. It is a flexion deformity of the toe that can be flexible, partially reducible, or fixed.

How to recognize a claw toe?

The deformity is characteristic; the toe may present with a flexible and reducible claw, so the toe deformity is completely reducible by manual maneuvers. There may be skin thickening on the top of the toe corresponding to areas of friction in closed shoes.

The deformity may be fixed and is not reducible by manual maneuvers. The pain is frequently caused by friction in closed shoes, resulting in inflamed red patches on the top of the toe called bursitis.

Claw toes are deformities at the joint level, and there are 3 types:

• Proximal claw toes involving the proximal interphalangeal joint.
• Distal claw toes involving the distal interphalangeal joint.
• Total claw toes combining both deformities.

What are the causes of claw toe?

Claw toe deformity can be congenital.

• Claw toe deformity may be present at birth and generally affects the 2nd toe.

The morphology of the foot can encourage the development of hammer toe deformity.

• High-arched feet may show hypertonicity of the toe extensors with defective pulp support. The toes are spontaneously in a flexible claw position with a risk of deformity.
• Long toes are considered an aesthetic criterion of the foot. However, when they are long, the toes may bump against the end of the shoe, causing them to assume a functional claw position. This toe position may progress to stiffening of the toes in a hammer toe deformity.

Claw toes can be associated with certain forefoot deformities.

• Hallux valgus, commonly called a "bunion," is a deformity of the big toe or hallux. As the deformity progresses, a conflict may occur between the big toe and the 2nd toe inside the shoe. The 2nd toe can become clawed to make room for the big toe inside the shoe. The 2nd toe may also cross over the hallux, known as a supradductus of the 2nd toe associated with a claw.
• Excessive pressure at the front of the foot can cause pain known as metatarsalgia. This refers to pain in the plantar pads. Plantar plates are powerful stabilizers of the toes during plantar flexion. Injury to the plantar plates causes metatarsophalangeal extension, compensated by flexion of the affected toe’s interphalangeal joints. The resulting claw is therefore flexible and functional but may stiffen and become painful.

Claw toes can appear after correction of forefoot deformities.

• The long flexor tendons of the toes and the long flexor tendon of the hallux, or big toe, are connected to the sole of the foot at the attachment point. In the case of surgery involving the 1st metatarsal with shortening, a postoperative claw deformity of the 2nd toe may appear, initially flexible.

Claw toes can be post-traumatic.

• Some time after a leg fracture, claw toe deformities may appear. These are claws secondary to ischemic contracture of the toe flexor muscles. This is probably a complication of a deep compartment syndrome of the leg.
• Phalangeal fractures may heal poorly, with joint malunion, and cause a rigid claw toe deformity.

Claw toe deformity can be neurological.

• In hypertonic neurological syndromes, such as Parkinson's disease, rigid claw toes may occur.
• Spasticity corresponds to a dysfunction of the motor nerve command secondary to central involvement of the spinal cord or brain. Spastic toe claws in patients with spinal cord injury or after a stroke are classic findings.

Which surgeries for claw toes?

There are different surgical interventions for hammer toe depending on whether the deformity is fixed or not and on the causes of the claw toe.

When there is a reducible claw toe deformity due to flexor tendon contracture, a tendon release procedure is performed. This may involve cutting the bands of the short flexor of the toes for proximal claws or the long flexor for distal claws. These procedures are performed percutaneously.

In the case of a non-reducible claw deformity, we perform interphalangeal arthroplasty or interphalangeal arthrodesis of the foot. Arthroplasty aims to preserve a small residual interphalangeal mobility. Arthrodesis of the foot consists of locking the interphalangeal joint of the toes; it is used in the treatment of congenital claw deformities due to significant tissue contraction.

If there is a lesion of the plantar plate, it may be necessary to perform a metatarsal osteotomy for shortening and translation, in addition to the treatment of the hammer toe.

When the claw is due to the harness phenomenon, it is initially flexible and can then be treated by resecting the fibrous connecting bands of the flexors to the sole of the foot. If the claw is fixed, releasing the harness will not correct the deformity.

Spastic clawing of the toes is visible when bearing weight, with true painful curling of the toes. The joints are flexible, and treatment involves percutaneous sectioning of the flexors at the base of the lateral toes. Spastic clawing of the big toe is treated by intra-muscular lengthening of its flexor.

Which exercises for claw toe?

Rehabilitation and self-rehabilitation measures can limit the risk of claw formation or their stiffening:

• Stretching hammer toes in extension
• Strengthening the intrinsic muscles of the foot
• Stretching the posterior muscle chains