Ageing in the forefoot

As the foot ages it undergoes a number of changes that relate to original shape of the foot and to changes which occur in the ligaments of the foot. There is a general tendency for the foot to become flatter and broader. The forefoot tends to abduct and the toes deform. The hallux gradually goes into increasing valgus and lesser toes become relatively crowded and longer. The consequence is increasing deformity of the lesser toes (Fig. 31.9). The hindfoot deformities that occur are largely covered by the sections on developmental and arthritic conditions.

HaIIux valgus

This is probably the commonest condition seen affecting the forefoot. A wide variety of factors is involved in its aetiology.

These include:

  wearing shoes — hallux valgus is commoner in shod populations;

  hereditary predisposition;

  metatarsus primus varus;

  increased length of the first metatarsal; and

  hypermobility of the first ray.

  Although all of these factors come into play the pathology of the progressing deformity is essentially the same, there are only two structures which prevent the toe going into valgus, the medial collateral ligament and the abductor muscle of the great toe. If the toe starts to deviate into valgus because of any of the above factors, then the medial capsule stretches and the abductor moves under the metatarsal head by virtue of its attachment to the medial sesamoid. The first metatarsal displaces medially in relation to the great toe and its associated seamoids. Their position is maintained in relationship to the rest of the foot by both primary restraints (the plantar fascia and the transverse tarsal ligament) and the secondary restraints (the intrinsic and extrinsic muscles). The valgus displacement of the great toe exposes the metatarsal head creating a bony prominence, and an adventitious bursa can then form. In some patients the increasing deformity damages the joint producing a secondary osteoarthritis. As the great toe deviates further it impinges on the second toe producing hammering and ultimately dislocation of the second metatarsophalangeal joint. A cascade of increasing deformity then ensues. Associated with the increasing width of the foot a bunionette may form over the fifth metatarsal.

Treatment

Conservative treatment always has to be considered first. Advice about ill-fitting or tight shoes may relieve symptoms or prevent episodes of infection or minor ulceration. There is a perception that this advice will not be tolerated by women who wish to wear fashion shoes. This is incorrect. If properly advised about the potential risks and complications of sur­gery many patients will modify their expectations and their footwear. The relationship of the forefoot to the hindfoot has to be considered and can he improved while wearing suitable footware by the use of suitable insoles.

Surgical treatment should be considered for persistent symptoms, recurrent ulceration or infection, or increasing deformity leading to increasing symptoms in the lateral part of the foot (Fig. 31.10).

No one operation is the answer to all cases of hallux valgus and a protocol of management should be assumed if results are going to be consistent (Table 31.2). Factors such as age, sex, hallux valgus angle, the angle between the first and  second metatarsal, hypermobility of the first tarsometatarsal joint and degenerative changes in the first metatarsopha­langeal joint have to be taken into account. Lesser toe deformities

These include:

  hammer toe;

  mallet toe;

  claw toe;

  curly toe;

•metatarsalgia;

•Morton’s neuritis and neuroma.