Tuberculous disease of the knee is next to the hip in frequency. It is
a chronic destructive process of the epiphysis of the femur or tibia,
or it may start in the patella, head of the fibula, or primarily in
the synovial membrane of the knee joint. The condition presents two
distinct types; one, the adult type beginning as a chronic synovitis,
of which the early symptoms are subacute; and the other, the childhood
or most common class, in which the symptoms of pain, muscular spasms
and deformity seem to indicate clearly a primary disease of the bone.
=Symptoms.=—This disease is commonly known as “white swelling” and
the symptoms as a rule are quite characteristic. The affection begins
with a limp and limitation of motion, and is usually slow in progress
with periods of severe pain. There is usually much swelling and
this together with the distortion of the limb by muscular spasm and
atrophy of the muscles both above and below the joint, gives a most
characteristic knock-kneed appearance. The affected limb is usually
longer at first, owing to the congestion of the epiphysis of the knee.
Local heat is always present in the more acute stages and the lameness
is usually a constant symptom. The differential diagnosis from other
joint troubles is easy because of the slow insidious onset.
=Treatment.=—Like other tubercular bone conditions the fixation
treatment is best. Rest in bed with a Buck’s extension to overcome
the deformity and the local application of hot packs until the acute
symptoms have subsided, is the best preliminary treatment of this
condition. Five- to ten-second exposures to the X-ray each day for ten
days seems to relieve the pain and in most instances causes less marked
infiltration of tissues.
When the acute stage has subsided, the ambulatory treatment by fixation
in a plaster of Paris cast extending from the groin to the ankle, with
about 10 degrees flexion, is most efficient.
The patient is allowed to walk about with the aid of crutches, having
the shoe on the sound side stilted enough so that the diseased limb
clears the floor. The functional results after conservative treatment
are in the average case excellent, that is providing proper treatment
is begun at an early stage. Useful motion is obtained in fifty per cent
of these cases, perfect motion is restored in twenty-five per cent, and
complete rigidity results in the other twenty-five per cent of cases.
Any chronic, painful inflammation confined to a single joint, in which
motion is limited by muscular spasm, and in which there is a tendency
towards deformity, is almost always tubercular in character.