WHAT IS IT?
Hammertoe is a common disorder of the toes mainly affecting women over the age of 50. Based on the shape of the toes, it is referred to as a claw or hammer deformity, depending on the joints affected. With the development of knowledge on the subject, this classification is gradually losing its relevance and the focus is now on determining the flexible, semi-rigid or rigid nature of the deformity, depending on the ability of the toe to easily recover its normal position.
The toe is normally in extended position of its own and this is essentially dependent on the balance between the tendons in the foot. Tendons attached to the phalanges ensure the mobility of the different joints and allow the flexion or extension of each joint. It is a delicate balance in which each tendon must receive compensation from the others so the toe remains in its normal resting position.
If one of these tendons is more powerful or has simply become shortened over time, a deformity is soon observed in flexion or extension due to the imbalance between the tendons and the body’s inability to compensate for the retraction. The shape of the toe will then depend on the tendon(s) affected.
Most often, the first sign is a retraction of the toe’s flexor muscles, which will trigger a flexion of the first interphalangeal joint. A deformity of the metatarsophalangeal joint may develop after this, at the base of the toe, and this is what gives the toe its characteristic hammer-like shape. In this position, the toe will rapidly feel uncomfortable when wearing shoes due to the excess pressure between the interphalangeal joint and the shoe. A corn (or callus), which is basically a thickening of the skin to protect the toe from this pressure will then develop.
Although the joint deformity can initially be reduced, it will gradually result in stiffening and become increasingly difficult to bear. Finally, a dislocation of the base of the toe may be observed. This type of case represents the most severe form and usually causes pain under the foot.
Although these deformities can present in an isolated form, they are generally linked to other conditions. The most common condition is hallux valgus (bunion) which systematically leads to an overloading of adjacent toes and greatly facilitates the retraction of the toe tendons and therefore their deformity. Other sources of hammertoe include high arches, neuropathy of the foot, rheumatoid arthritis,... Wearing high heels, incorrect footwear, or having a Greek foot (that is, when the second toe is longer than the first) are other circumstances that may lead to the development of hammertoe, either due to the incorrect position of the toes in shoes or an overloading of the forefoot.
The dorsal pressure of the shoe on the toe is usually the first complaint. With rigid deformities, the corn may suffer an injury and form an ulcer and eventually become infected. This is an important warning sign, especially in diabetic patients whose toes are major sources of complications.
Severe cases of hammertoe result in changes to the pressure at the terminal point of the toe. Normally, at the tip of the toe the load is carried by the fleshy part (toe-to-ground support). With hammertoes, the toe presses down on the most terminal section (apical support) which is totally unsuited for this purpose and causes severe pain.
Finally, when the metatarsophalangeal joint is affected, joint pain (second digit syndrome) is often experienced due to the instability of the joint. If this instability progresses partial dislocation followed by complete dislocation of the phalanx may occur because of failure of the plantar plate. In such cases, significant pressure is then passed on to the metatarsal head and increases the load at this level, triggering a classic case of metatarsalgia.
WHEN SHOULD YOU CONSULT A SPECIALIST?
When the hammertoe causes painful pressure in the shoe or when the metatarsophalangeal joint becomes sensitive, it is highly advisable to consult a specialist.
The toes of diabetic patients require regular monitoring and they must consult whenever skin lesions or injuries occur.
Conservative treatment consists primarily of modifying the footwear. Soft and comfortable shoes, with no areas of high pressure, are the preferred choice. Wearing narrow or high-heeled shoes aggravates the symptoms and should be avoided.
Treatment from a podiatrist will cover most of the non-surgical options. The excision of calluses can often significantly reduce symptoms. Silicone orthotic insoles can be used as they partially reduce the deformity (only for flexible toes) and act as protection against pressure and friction.
When conservative treatment is no longer adequate, surgery should be offered.
Conventional correction techniques consist of performing an arthrodesis of the proximal interphalangeal joint, i.e. removing the cartilage and placing pins while the area is healing.
Minimally-invasive techniques have recently appeared on the scene. Such techniques are excellent for corrections using minimal incisions without the need for pins and generally preserving the joint. We favour the use of such techniques. The procedure required will depend on the type of deformity and will differ in each case. If necessary, the shortened tendons will be either lengthened or selectively sectioned to restore the correct balance to the tendons. These actions may be completed by a section (osteotomy) in one or several phalanges, to shorten and re-direct the toe. Finally, other techniques may be performed at the same time depending on the type of deformity (capsulotomy, bone excision,…). It is important to be aware of the indications and limitations of these techniques; the surgeon will explain each one to you in detail.
POST SURGICAL FOLLOW UP
For cases of percutaneous correction, the dressing is particularly important because it will redirect toes perfectly and ensure they heal in the correct position. The surgeon or specialist nurse will change the dressing at 1week and at 3weeks after the operation. The toe needs guidance during 6weeks.
Patients are given an orthopaedic shoe; however, walking is possible wearing wide and comfortable shoes (trainers, etc.).
Walking and bearing full weight is possible immediately after the operation and as soon as you have gained back full control of your lower limbs (in case of loco-regional anesthesia).
Physiotherapy treatment is usually not necessary, but patients are asked to mobilize their own toes daily to prevent any stiffness to appear.
Driving a vehicle is allowed after a few weeks, after removing the medical shoe. When only one foot has been operated on, driving is allowed immediately, on condition the car is an automatic one.
Sick leave of 1 to 4 weeks will be required, depending on the surgical technique and the patient’s occupation.
Non-contact sports can resume after six weeks. In general, all activities can resume from the 3rd month.
RISKS AND COMPLICATIONS
Besides the possible complications after any type of surgery (thrombosis, infection <1%, algodystrophy <1%), it is recognised that the treatment of hammertoe involves the following risks and complications:
- Recurrence of the deformity. It will depend on the degree of injury, the surgical technique and the cause of the deformity. It may require further surgery.
- Nerve damage. Relatively common but usually spontaneously regressive.
- Loss of mobility in the toe. As the deformity is due to the shortening of the tendons, their lengthening or section often leads to reduced mobility. This sensation may be temporary and is generally very well tolerated.
- Joint stiffness. This is a frequent occurrence and must be limited by daily exercises, starting a few weeks after surgery.