Page 135 - ASOP ROT Study Guide

14 . 4 Hallux Valgus and Hallux Rigidus

The hallux refers to the big toe and really these conditions are disorders of the first
metatarsophalangeal joint. Hallux valgus refers to the turning away of the phalanges of the big toe
from the mid-line, usually because of a deformity at the joint line. Hallux rigidus refers to
osteoarthritis of the metatarsophalangeal joint. The two conditions can occur separately or together.
Treatment depends upon whether one or both conditions are present, and the age of the patient.

Hallux rigidus alone - can occur in adolescents and adults.

In adolescents it is said to be as a result of osteochondral fracture, although this is not always easy
to prove. Conservative treatment includes the use of a metatarsal bar to provide a rocker at the
front of the foot so that the toe need not bend in normal walking. This usually fails because
youngsters do not accept the cosmetic consequences on their shoes and so the same surgical
treatment given to adults is required.

In adults the condition may present at any age, although in the elderly it rarely occurs without
hallux valgus. Conservative measures are rarely sufficient and surgery is required.

Surgical removal of the osteophytes with an osteotomy of the proximal phalanx is often sufficient
for minor cases. Surgical fusion in a neutral position is most reliable and despite the folklore this
rarely gives women problems with shoe heel height. Interposition arthroplasty with a silicone
plastic (silastic) spacer is an alternative which gives mixed results.

Hallux valgus alone - may occur at any age.

This gives more problems in women than men although there is no evidence that shoes cause the
condition. Many, but not all, sufferers have a short first metatarsal, often in varus. The cause of
this common and troublesome condition is unknown.

Management depends on age. Realignment of the first metatarsal to a more lateral position and
excision of any bony prominence (an exostosis) over the first metatarsal head gives satisfactory
results at almost any age. Excision of the metatarsophalangeal joint - the Keller's procedure is to
be avoided in the young and is probably unnecessary if the joint is not painful.

Hallux valgus with rigidus - is seen in older people where joint degeneration is usually secondary
to the valgus deformity.

These older patients may well be satisfied by having their pain relieved by well fitting, extra-depth
shoes. If this fails, Keller's arthroplasty is a safe and rapid way of giving some relief. This
operation severely disrupts normal foot mechanics and should be reserved for the older, less active
patient.

14 . 5 Claw Foot and Hammer Toes

These are common conditions. The terms "claw foot" and "claw toes" describe a condition of the
foot where wasted muscles make the bones and the toe nails appear more prominent - like a dog's
foot. Clawing implies muscle weakness or deficiency. Indeed on close analysis many of these
patients do indeed have weak or denervated small muscles of the feet. This is often associated with
minor spinal abnormalities such as spina bifida occulta. This means that claw toes should be
approached with caution as far as surgery is concerned.

The term "hammer toe" is a description of the toe which, on the top, looks like the end of a
hammer. Hammer toes are secondary to the disruption of the metatarsophalangeal joints.
Abnormalities of the foot leading to prolapse of metatarsal heads and joint disruption are not
understood. The patient may present with generally sore forefeet - often called rather grandly
metatarsalgia. The cause of the primary lesion is unknown and treatment is often unsatisfactory.
Surgery to hammer toes includes fusion of the interphalangeal joints in a straight position, so that
they do not rub on the shoes. Often a good pair of soft and comfortable shoes is all that is required.