Claw fingers (hammer fingers): what are they?

By Cristiano Antonino On Apr 13, 2023

Claw fingers, or hammer toes, are a particular type of bony deformity that mainly affects the second, third or fourth toe

In patients with this disorder, the toes take on a characteristic curved or claw-like appearance at the central joint.

The causes of its onset may be muscle-tendon changes, inflammatory diseases, degenerative injuries or incorrect habits and lifestyles.

It is a non-serious condition that, in general, does not pose a serious risk to the patient but can, however, be a source of discomfort and discomfort.

Several treatment options are available to resolve this type of bone deformity: in milder cases, conservative therapy consisting mainly of the use of small orthoses may be sufficient, while for more advanced patients, surgery may be necessary to return the bone segments to their anatomical position.

What are claw toes?

Claw toe syndrome, also known as claw toe or hook toe, is a foot disorder that affects the interphalangeal joints.

This condition is manifested by a deformity of the toes, which take on a folded, z-shaped appearance in the middle due to a dorsal subluxation of the metatarsophalangeal joint; the toes affected by the deformity may also be more or less overlapping or underlapping than the others.

In most cases, the disorder affects the second toe, at other times it may affect the third or fourth, but sometimes it can also affect several bone segments at the same time.

It is not uncommon for patients with claw toes to be associated with other bone diseases or foot disorders, such as arthritis, valgus or hollow foot.

Due to the constant functional load and continuous contact with footwear, deformed toes can cause pain and calluses.

What can be the causes of claw toes?

The main causes of hammertoes are an imbalance of the interosseous musculature of the foot, which can occur in various situations: in general, the deformity is caused by a misalignment of the axis of action of the intrinsic musculature, due to a plantar displacement of the interosseous tendons, which leads to a hyperextension of the basal phalanx with consequent flexion of the middle phalanx.

This alteration may be due to a particular genetic predisposition, biomechanical abnormalities of the limb, incorrect habits and lifestyle, or it may be caused by other ongoing pathological processes.

Conditions predisposing to the development of jawed fingers include:

Genetic malformations
Traumatic events or injuries
Rheumatoid arthritis
Arthrosis
Osteopathies
Arthropathies
Neurological diseases, such as Charcot-Marie-Tooth disease
Hallux valgus
Calcaneal valgism
Hollow foot syndrome
Bursitis
Postural defects
Use of unsuitable footwear
Diabetes
Tumours of the bone or marrow
Poliomyelitis

When no triggering cause for the occurrence of claw toes can be identified, we speak of idiopathic forms.

Claw fingers: what are the main symptoms?

As already mentioned, jaw toes do not constitute a particularly serious pathology and, in most cases, do not entail any risks for the patient.

Apart from foot deformities, the disease frequently presents itself asymptomatically.

However, due to the constant stress to which the joints of the limb are subjected, hammertoes can be a source of discomfort and pain of varying intensity.

Mainly, the pain is due to an abnormal contact between the toes, which can make walking particularly difficult and can lead to discomfort when wearing shoes; especially when the pathology tends to become chronic, it can lead to a progressive overloading of the corresponding metatarsal with the formation of plantar callosities.

Due to the elevated position that the toes can assume, excessive friction can also be created, which can lead to the appearance of calluses and sores on the toe tips.

In severe cases, the calluses can even ulcerate, causing metatarsalgia, inflammation and bursitis of varying degrees.

The main symptoms of claw toes therefore include:

bone deformity
joint pain
tendinitis
swelling of the affected area
inflammation
bursitis
development of calluses and sores
ulceration
walking difficulties

How to diagnose claw toes?

The first step in diagnosing a claw toe disorder is to undergo a careful orthopaedic examination during which the doctor will analyse the deformities of the limb in order to precisely establish the type and extent of the disorder; the diagnosis is usually immediate, as the deformity is easily recognisable by the typical bending posture of the middle phalanx that gives the fingers their characteristic claw shape.

The diagnosis is supplemented by a series of instrumental tests, which can be useful in determining which therapeutic approach is most suitable for resolving the pathology.

Investigations may include:

Magnetic resonance imaging (MRI)
Computerised axial tomography (CT)
Radiography of the lower limbs. It is important that the X-ray be taken both at rest and under load, i.e. in an upright position, to assess the state of deformity of the fingers. An X-ray of the healthy foot is also necessary in order to compare the anatomical arrangement of the limb.

Subsequently, the orthopaedist will assess the presence of other associated problems, such as calluses, swellings, inflammation or difficulty in performing movements and symptoms that may suggest the presence of other underlying pathologies.

For a more complete clinical picture, the patient may be prescribed additional laboratory tests to rule out osteopathy, arthropathy and other disorders that may affect the proper functioning of the interosseous musculature of the foot.

Having an accurate and timely diagnosis of the disorder is very important in order to be able to intervene before the pathology worsens, and the bones of the toes undergo a degenerative process that can lead to increasingly severe discomfort for the patient.

In the most severe cases, in fact, hooked toes that are not adequately treated can worsen to the point of leading to complete functional failure, with increasingly intense pain, plantar metatarsalgia, more pronounced and extensive callosities, possible skin ulcers and deformities of the other bones of the foot.

How to treat claw toes

As already mentioned, detecting and treating hammertoe syndrome early is essential to avoid a progressive worsening of the condition.

In the early stages of the disease, in fact, the deformity is only positional and can be easily resolved with conservative therapy.

As time goes by, however, the joints tend to stiffen and the tendons gradually retract, making the deformity permanent; in more advanced stages, the alteration may become structural and require surgery to restore it.

Conservative therapy

The conservative approach for the treatment of claw toes involves drug therapy to control the pain and fight the inflammation, combined with manual corrections to return the toes to their anatomical position; the patient may be prescribed the use of orthopaedic shoes and protective silicone orthoses to be worn in the shoes to prevent further damage to the joint structures and skin.

This approach, however, is only effective in the mildest cases of deformity or as a restraining measure: in fact, it should be emphasised that in most cases, despite orthotic and pharmacological treatment, the pathology may progress to the point of requiring surgery.

Surgical treatment

With the passage of time, the onset of increased joint stiffness due to the retraction of the ligament capsules makes the orthosis insufficient to contain the deformation of the bones, making a surgical correction necessary to re-establish the correct axis of the toes. Several surgical options are available for the treatment of claw toes.

In less severe cases, it is possible to opt for an arthrodesis operation, a non-invasive procedure that allows the correction of the toe deformity by means of the external installation of an intermediate joint block; although this technique has the advantage of not requiring invasive surgery, it results in a partial loss of toe function, and the external device may entail some limitations for the patient in performing normal daily activities.

Alternatively, it is possible to opt for a percutaneous surgical solution: this is a micro-invasive approach that makes it possible to reach the bone joint without making surgical incisions; it involves the use of small bone shaping drills, introduced into the limb through small holes in the skin.

This closed surgery allows the retracted tendons to be dissected and the abnormal bony saliencies at the level of the first and second phalanges to be remodelled to correct finger hyperextension.

The procedure lasts on average 15 minutes and is performed under local anaesthesia in day surgery.

The prognosis is about 30 to 40 days, but the patient will be able to resume walking and normal activities immediately after the operation, with the help of orthopaedic footwear.

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