|
History Patients will usually complain of increasing deformity and pain due to rubbing. In significant deformities, problems with skin breakdown can also be an issue.
Important questions are history of trauma, which can cause deformity in a single toe, inflammatory arthropathies, diabetes and a history of neurological conditions that predispose to muscle imbalance especially Charcot-Marie-Tooth disease( see figure 7). It is also important to enquire exactly what the patient’ s concerns are. A common feature in working men is increasing difficulties with safety boots. An orthotist can usually fashion accommodative work boots that completely alleviate symptoms.
Examination Assess the patient’ s feet while they are standing. Look for first ray deformity and cross over or cross under of the toes. Inspect for callosities on the toes and also under the metatarsal heads. Observe the resting attitude of the weight-bearing foot— a particularly high arch may be a sign of underlying Charcot-Marie-Tooth disease. With the patient supine, assess each toe individually, check at which joints the deformities occur and whether they are fixed or flexible. Palpate for metatarsalgia, pain under the metatarsal heads and look between the toes for skin breakdown. 14
Investigations Many lesser toe deformities can be treated initially without investigation. If unilateral or there are signs of an underlying neurological conditions, clinical assessment of the spine and nerve conduction studies or MRI spine may be warranted. Blood tests can exclude inflammatory arthropathy. If investigations are being considered as a lead-up to surgical referral, simple weightbearing radiographs are the mainstay of treatment. An ultrasound
|
Figure 6. Hammer toe.
scan may be of help in diagnosing a plantar plate tear if there is instability of a lesser metatarsophalangeal joint. However, this rarely changes management and as such, is not particularly helpful.
Management Conservative management, on the whole, consists of footwear modification. It is important to consider what the patient’ s complaint is. If the main issue is painful rubbing of the toe deformities, using wider shoes with a larger toe box may alleviate symptoms and prevent progression of the deformity.
Pressure from corns may also be relieved by toe sleeves or silicone spacers and deformities can be relieved using hammer toe splints.
If the main problem is not the toes but more proximal metatarsalgia an orthotic such as a metatarsal dome insole may be useful. All of these conservative measures can be prescribed by an orthotist.
If conservative measures fail, or in a younger patient who is unable to accept shoe wear modification and would like surgical correction, there are a variety of surgical options depending on the exact deformity. Lesser toe correction involves a careful balancing of soft tissues and bone and procedures
|
include extensor tendon lengthening, flexor tenotomies, osteotomies of the phalanges and fusion of the small toe joints. The author will perform tendon procedures in mild, flexible deformities but in more severe deformities fusion of the affected joints is preferred as this gives a good appearance to the toe with reasonable function and a low risk of recurrence.
Fusions of the lesser toes have traditionally been performed with transarticular wire fixation, however, the author now uses modern internal implants whenever feasible as they are better for patient comfort and have a lower risk of infection. These implants depend on having enough bone in the toes for adequate fixation, yet another reason to base decision-making on weight-bearing radiographs of the foot( see figure 8).
Morton’ s neuroma Aetiology Morton’ s neuroma is a common condition of compression of the small nerves that run between the toes. The term interdigital neuritis has been used more recently as this better reflects the compression and underlying inflammation in the nerve rather than a neuromatous proliferation of abnormal tissue. 15
|
Figure 8. Radiograph showing severe bunion correction with fusion first metatarsophalangeal joint and intramedullary device for proximal interphalangeal joint fusion in second toe.
The cause is multifactorial and can be due to tight shoe wear, inflammatory arthropathy, hallux valgus or overload due to athletic activity or obesity. The main differential diagnosis is metatarsalgia and this can be differentiated by history and examination. 14
History The syndrome is commonly seen in women in their late 40s to 50s. There is a complaint of a burning pain in the foot, classically radiating between the third and fourth toe which is exacerbated by footwear, particularly shoes with a tight toe box and a high heel as this puts further pressure on the nerve. Pain is relieved by removing the shoe and rubbing the foot. This is a good way to differentiate between pain from metatarsalgia and Morton’ s neuroma as metatarsalgia is usually as bad or worse when barefoot.
Examination On examination, assess the patient’ s weight. Obesity can increase forefoot pressure and exacerbate the patient’ s symptoms. When the patient is walking, monitor gait for a loss of heel strike. If the patient has a tight Achilles and plantar fascia and is landing directly on their
forefoot, this increased load can exacerbate a Morton’ s neuroma. Finally, examine the foot. Look for obvious deformity such as hallux valgus, check sensation in the toes, palpate the interspaces for pain, check the sole for metatarsal head callus and ballot the joints looking for metatarsalgia. Finally perform a Mulder’ s click test( see figure 9). Press into the web space with one finger either side and then squeeze the foot together, recreating the effect of a tight shoe. This may lead to a clicking sensation and pain shooting into the toes. Although not always present, this is a highly reliable test for Morton’ s neuroma.
Investigations Always order a weight-bearing anteroposterior and lateral radiograph of the foot. Early hallux valgus or abnormal metatarsal parabola with long lesser metatarsals, which was not apparent on clinical examination but may have been contributing to symptoms, will be picked up on this investigation. If the suspected diagnosis is Morton’ s neuroma, order an ultrasound examination at the same time. It is important to document your clinical findings clearly so the radiologist is aware which interspace was the most sympto-
|