Foot & Ankle

Deformities of the lesser toes most commonly occur gradually, however, occasionally be brought on by trauma.

 

Hallux valgus can contribute to the formation and propagation of lesser toe deformities as the resultant shortening of the first ray may slacken the plantar fascia and weaken the windlass effect leading to greater strain on the lesser toes.

 

Gradually, the supporting structures of the lesser toes fail. Lesser toe deformities can also be associated with inflammatory arthropathies, synovitis, diabetes, neuromuscular disorders and ill-fitting or high-heeled footwear.

​

The relative length of the metatarsals is important in symptomatology of lesser toe disorders. In the normal foot morphotype, the second metatarsal is the longest lesser metatarsal and the fifth is the shortest.

 

The first metatarsal is often similar in length to the second (square foot morphology), or shorter (Greek type foot), or longer (Egyptian foot type). If one or more metatarsals are relatively longer or plantar-flexed, this can result in abnormal pressure and metatarsalgia.

​

Patients may present with pain, swelling, deformity, difficulty in shoewear or cosmetic appearance. It is important to assess their main concern and expectations.

 

Weightbearing plain x-rays are important initial imaging and often may require an MRI scan to delineate the accurate pathology.

​

Hammer Toe

​

Hammer toe is defined as a primary flexion deformity of the PIPJ, with or without hyperextension at the MTPJ, but with a neutral or hyperextended DIPJ.

​

The pull of the extensor tendons is mainly transmitted to the MTPJ via the extensor sling. The extensors are therefore unable to correct the PIPJ deformity, but hyperextension may occur at the MTPJ instead.

 

This may progress to MTPJ instability as the plantar plate becomes attenuated. The DIPJ remains largely unaffected, or may become hyperextended by the pull of the extensors via the lateral slips. Initially the deformity is flexible, but gradually may become rigid.

​

Dhukaram et al. described 3 types of hammer toes:

Type 1 – reducible MTPJ and PIPJ

Type 2 – reducible MTPJ but a fixed PIPJ

Type 3 – fixed or subluxed MTPJ and a fixed PIPJ

​

Conservative Treatment

​

This should always be tried as the first line of treatment as the majority of patients respond to these measures. These include footwear modifications (wider shoes with a larger toe box and off-loading shoes) which may help alleviate symptoms and prevent progression. Pressure areas may be helped by toe sleeves and padding over the dorsum of the PIPJ and under the MT heads.

 

Surgical Treatment

​

Where non-operative measures have failed, surgery may be considered depending on patient’s symptoms and functional difficulties. Treatment aims to restore normal alignment of the joints and to restore the balance between the flexors, extensors and intrinsic.

 

FDL and FDB tenotomise and tenodesis to the extensor hood was first described by Taylor in 1951. Variations of this procedure are now widely used in the treatment of hammer toes. Barbari and Brevig performed this procedure on 39 flexible claw toes and obtained an 84% satisfaction rate.

 

Boyer and DeOrio performed the procedure on 79 hammer toes with an 89% satisfaction rate and no floating toe problems. Losa et al performed a meta-analysis of 515 flexorto-extensor transfers for lesser toe deformities and found patient satisfaction to be 87%.

​

For fixed PIPJ deformities the PIPJ is excised or fused. In cases where the MTPJ is stable, this procedure is often sufficient. Coughlin et al reported on 118 toes treated with PIPJ resection and stabilised with a percutaneous wire and reported 81% fusion rates, while the rest developed a fibrous union. Pain was improved in 92% of cases, and 84% of patients were satisfied. PIPJ excision without fusion may result in malalignment and instability.

​

​

Mallet Toe

​

The DIPJ flexion deformity may occur due to direct pressure from the shoe and eventually the FDL tightens resulting in a fixed deformity. This may gradually cause callosities at the tip of the toe and pressure on the nail.

 

Surgical Treatment

​

After conservative treatment fails, surgery is usually considered due to persistent symptoms and functional difficulties. Evidence on the best treatment of an isolated adult mallet toe is sparse. Flexible mallet toes are usually treated by percutaneous flexor tenotomy.

A fixed deformity is treated by excision of the DIPJ and fusion. Coughlin reported 72 mallet toes treated with fusion and reported bony fusion in 72% cases and fibrous union in the remainder, 86% satisfaction rate and 97% symptomatic improvement. For patients with significant ulceration, terminalisation is an alternative to fusion.

​

​

Claw Toe

​

The exact mechanism behind the development of claw to is unclear however the first causative deformity is thought to be hyperextension at the MTPJ. It is commonly seen in neuromuscular disorders. When the MTPJ becomes chronically hyperextended, the intrinsics shorten, the flexors are pulled taut and flex the IPJs. Initially this clawing may be flexible and dynamic but gradually as the plantar plate ruptures, MTPJ subluxes and the deformity becomes rigid.

​

Surgical Treatment

​

Once the conservative treatment fails with persistent symptoms, surgical treatment is considered. Treatment must address the deformities at the PIPJ, DIPJ and MTPJs. If MTPJ instability exists, this should be addressed first. Myerson and Shereff suggested that for mild, flexible claw toe, the PIPJ deformity may be corrected by an FDB tenotomy. However, the unopposed pull of the intrinsics and extensors may then cause hyperextension of the toe at the MTPJ and so a flexor-to-extensor transfer is recommended.​​