Pain in the foot

PAIN  IN THE FOOT

The feet are subjected to extreme pressures by weight bearing and inappropriate shoes .They are commonly painful.Broad ,deep .thick -soled shoes are essential for sporting activities ,prolonged walking or standing ,and in people with congenitally flat or arthritic feet.

There are two common types of foot deformity :

• Flat feet stress the ankle and throw the hind foot into a valgus ( everted ) position - a flat foot is rigid and inflexible.
• High -arched feet place pressure on the lateral border and ball of the foot .

The foot is affected by a variety of inflammatory arthritic conditions.After the hand ,the foot joints are the most commonly affected by rheumatoid arthritis ,The diagnosis depends upon careful assessment of the distribution of the joints affected ,the pattern of other joint problems , or by finding the associated condition ( e.g psoriasis  ).

PAIN IN THE FOOT CAUSES

Structural ( flat ( pronated ) or high arched ( supinated ).

Hallux valgus /rigidus ( +/- Osteoarthritis ).

Metatarsalgia.

Morton's neuroma.

Stress fracture.

Inflammatory arthritis.

-Acute ,monarticular -gout.

-chronic ,polyarticular -rhematoid arthritis.

-Chronic ,pauciarticular -seronegative spondarthritis.

Tarsal tunnel syndrome.

HALLUX VALGUS 

The great toe migrates laterally .In the congenital form the first metatarsal is displaced medially ( metatarsus primus varus ) .The shape of modern shoes causes later onset of hallux valgus .It is a common complication of rheumatoid arthritis .

HALLUX RIGIDUS 

Osteoarthritis of the first MTP joint in a normally aligned or valgus joint causes hallux rigidus - a stiff ,dorsiflexed and painful great toe .Careful choice of footwear and the help of a podiatrist suffice for most cases ,but some require surgery .

METATARSALGIA

This is common  ,especially in women who wear high heels ,after trauma and in those with hammer toes.The balll of the foot is painful to walk and stand on .Callosities and pressure -inuced bursae develop under the metetarsal  heads . Rheumatoid arthritis causes misalignment of the metatarsal bones and severe metatarsalgia.

TREATMENT is with podiatry and the wearing of appropriate shoes.Surgery is occasionally needed ,particularly in the rheumatoid forefoot.

Morton's metatarsalgia is due to a neuroma , usually between the third and fourth toes .It causes pain , burning and numbness in the adjacent surfaces of the affected toes when walking .It is helped by wearing wider , cushioned -soled shoes.

STRESS ( MARCH ) FRACTURES 

 These cause sudden ,severe weight -bearing pain in the distal shat of the fractured metatarsal bone .They occur after unaccustomed walking or with new shoes.There is local tenderness and swelling ,but initially X-rays are normal and diagnosis delayed.A radioisotope bone scan reveals the fracture earlier than X-rays .Reduced weight -bearing for a few weeks usually suffices.

TARSAL TUNNEL SYNDROME 

This is an entrapment neuropathy of the posterior tibial nerves as it rounds the medial maleolus.It produces burning ,tingling and numbness of the toes ,sole and medial arch.The nerve is tender below the maleolus and ,when tapped ,produces a shock -like pain  ( Tineli's sign ).A local steroid injection under the retinaculum ,between the medial maleolus and calcaneum ,is helpful.