This is a chronic tubercular condition of the head of the femur or of
the acetabulum commonly known as =hip-joint disease=.
=Pathology.=—Primarily the head of the femur is the seat of the
disease, the epiphysis being attacked in seventy-five per cent of
the cases and the acetabulum in twenty-five per cent. The irritated
pelvic femoral muscles which are in a state of chronic contraction
crowd the head of the femur against the upper and back border of the
acetabulum. Under this continual pressure, absorption of that portion
of the rim takes place with actual enlargement of the acetabulum from
below upwards. This is spoken of “migration of the acetabulum” and is
one cause for the shortening of the limb. Changes in the head of the
femur are the result of inflammation and pressure. Partial destruction
of the head also helps shortening of the limb and elevation of the
trochanter above its proper level the same as the wearing away of the
acetabulum. The synovial membrane is found to be reddened and thickened
and granulation tissue is present, and usually the cartilage is gone
from the head of the femur. Rarely does perforation of the floor of the
acetabulum take place, but if such is the case a dense wall of fibrous
tissue and thickened periosteum shuts off the head of the femur from
the pelvic cavity. A natural cure results in two ways,—by absorption
or calcification of the tubercular tissue, or by the evacuation and
discharge by an external opening. This latter suppuration seems to
be nature’s effort to eliminate the disease, and when a cure is
established this way it is usually characterized by malpositions and
shortening of the limb, and, of course, an ankylosed joint.
=Early Symptoms.=—The most characteristic symptoms of the disease
are the ‘night cries’, stiffness and limping, shortening of the leg,
atrophy of the muscles of the hip, leg, and thigh, and the unconscious
protection of the joint. A referred pain is usually present to the
inside and front of the thigh near the knee or directly at the knee
joint itself, due to the intimate relations and anastamosis of sciatic,
obturator, and anterior crural nerves.
=Diagnosis.=—The chief diagnostic sign is muscular spasms or the
presence of stiffness of the joints and limitations of its proper arc
of motion, due to the tonic contraction of the muscles controlling the
joint. If there is no limitation of motion it is almost safe to say
there is no hip-joint disease. The lameness may be intermittent. The
attitudes or abnormal positions of the diseased limb are caused by the
action of muscles holding the limb stiffly in a distorted position.
The pelvis is usually tilted and always one will find the patient
assuming attitudes which will favor the diseased limb. Atrophy is
very significant and a comparison of the two limbs should be made by
measuring at the middle of the thigh and the middle of the calf. Nearly
always one will find a deep thickening over the front of the hip joint
and behind the trochanter.
=Physical Examination.=—1. Observe the general condition of the patient.