Arthritis
Arthritis affecting the foot is a common event in an ageing population.
The vast majority will be osteoarthritis.
Inflammatory
arthropathies frequently produce foot problems. In rheumatoid arthritis the
forefoot is the first part affected. Up to 40 per cent of patients suffering
with rheumatoid arthritis regard their feet as being their most troublesome
area. Other forms of inflammatory arthritis are also seen in the foot. Of
particular note is psoariatic arthritis, which is commonly missed. It is a
particular cause of symptoms following minor trauma. Gout is also a cause of a
sudden acute arthritis.
Rheumatoid
changes
Rheumatoid arthritis creates symptoms in three ways. In the early stages
of the disease, pain may be caused by the presence of inflamed synovium, usually
in the forefoot and the subtalar joint. It can also affect the tendon sheaths.
If the synovitis persists the ligaments and tendons can be damaged and rupture.
This means that the joints become unstable, and deform. The toes dislocate at
the metatarsophalangeal joints
Patients
suffering from an inflammatory arthropathy will complain of pain and swelling in
the affected joints. Subsequently, progressive deformity and arthritic change
result in metatarsalgia. Pain over the medial side of the foot due to the
progressive lateral tilt of the foot is common. Impingement between the
calcaneum and the lateral malleolus produces pain on the lateral side. Stress
fractures of the lateral malleolus can occur. The secondary osteoarthritis will
cause pain in its own right.
Treatment
During the early stages the aim of treatment is to reduce the synovitis
and to manage associated pain. Nonsteroidal anti-inflammatory agents are the
first-line drugs. Additional pain relief can be obtained from well-cushioned
shoes. If drugs do not bring swelling under control, synovectomy should be
considered. Once deformity has occurred the treatment is aimed at controlling
symptoms. Shoes with cushion insoles and extra depth to allow for toe
deformities should be used. If forefoot symptoms persist, surgical correction of
the toe deformities should be undertaken, aimed at reducing the symptoms of
metatarsalgia. The exact technique used for correcting the forefoot remains
controversial. The principles of surgery are to correct the alignment of the
toes over the end of the metatarsals. This provides cover for the ends of the
prominent metatarsals. The most common technique practised is to excise the
metatarsal heads through either a plantar or dorsal approach. At the same time,
the first metatarso-phalangeal joint is fused to restore the position of the
great toe and allow it to take weight.
Progressive
deformity of the hindfoot is probably best treated by surgery to correct the
position and stabilise the foot; this usually involves fusion of one or the more
hindfoot joints (Fig. 31.8). Bone grafts are frequently necessary to help
correct the deformity. Reduction of deformity has to be directed towards
keeping the foot flat to the floor. Involvement of the ankle can further
complicate matters, the ankle frequently tilting into valgus. If the ankle is
symptomatically involved then consideration should be given to either
arthrodesis or possible arthroplasty of that joint also. The choice between
surgical treatments under these conditions will depend on the general and local
state of the patient, the position of the patient’s hindfoot and their
expectation.
HaIIux
rigidus
This is the most common arthritic condition affecting the foot.
The symptoms are those of limitation of movement and pain.
It can arise as early as the adolescent years. It is associated with
Treatment
The first line of treatment is conservative. Education about the nature
of the condition is helpful. Advice about footware and stiffening of the sole of
the shoe under the first ray can be helpful.
Operative
treatment falls into three groups depending on the severity of the condition. In
mild or moderate disease dorsal wedge osteotomy of the proximal phalanx can help
to reduce pressure over the dorsum of the great toe. If there are mild to
moderate changes on the joint surface hut a significant dorsal osteophyte a
cheilectomy procedure, where the dorsal osteophyte and approximately the dorsal
third of the metatarsal head is excised, can be undertaken. If there are severe
changes two procedures can he considered. The first is to fuse the first
metatarsal to the proximal phalanx. This produces the most reliable result but
by definition there is a loss of the range of movement. Approximately 90 per
cent of patients who undergo this procedure ultimately find it satisfactory. The
second option is to undertake an arthroplasty. A variety of prostheses has been
tried without consistent success.