Fig. 131.—Contracture Deformities of Upper and Lower Limbs resulting from Spastic Cerebral Palsy in infancy.
(Photograph taken after death by Dr. Thomson of Norwich.)
Contractures and Ankyloses of the Hip.—Various forms of contracture are met with as a result of cicatricial contraction, or from shortening of the fasciæ, muscles, and ligaments when the hip has been maintained in the flexed position for long periods—for example, in psoas abscess, chronic rheumatism, or hysteria. The majority, however, result from tuberculous disease of the hip-joint. In osseous ankylosis, an attempt may be made to restore movement by the operation of Murphy, which consists in chiselling through the osseous junction between the bones, deepening the acetabulum if necessary, and then interposing between the bony surfaces a portion of fat-bearing fascia derived from the fascia lata over the great trochanter. The operation of Jones consists in detaching the great trochanter (the insertions of the glutei into it being left intact), dividing the neck of the femur, and then securing the separated portion of the trochanter to the proximal end of the neck to prevent union of the fragments.
Coxa Vara and Coxa Valga
These deformities depend on abnormalities of the angle of the neck of the femur; the average or normal elevation is 125° for the adult and 135° for the child; variations between 120° and 140° are considered normal. If the angle is less than 120° the condition is one of coxa vara; if greater than 140°, coxa valga. The angle of inclination of the neck of the femur is dependent upon the adjustment of certain forces, namely, the weight of the body, the action of muscles, and the resistance of the bone. The most obvious cause of deviation of the neck from the normal angle is some condition which causes softening of the bone so that it yields under weight-pressure, the most common being partial fractures, rickets, and other diseases of the bone.
Coxa Vara—Incurvation of the Neck of the Femur.—There may be a simple adduction bend of the neck, the head sinking to, or even below, the level of the great trochanter ([Fig. 132]); or this may be combined with a curve of the neck, of which the convexity is upwards and forwards, so that the lower border of the neck is greatly shortened and the head approximated to the lesser trochanter. At the same time the shaft of the femur is adducted and rotated outwards.
Fig. 132.—Rachitic Coxa Vara.
(Sir Robert Jones' case. Radiogram by Dr. Morgan.)
Adolescent Coxa Vara.—This, the most common clinical type, is met with in boys between the ages of twelve and eighteen. The unilateral form is nearly always the result of injury to the neck of the femur or to the epiphysial junction, although the deformity may not show itself for months or a year or two after the injury. The deformity may be the first indication, or it is preceded by pain and stiffness; the patient complains of being easily tired, of difficulty in kneeling and sitting, difficulty in riding, and of an increasing limp in walking. On examination, the limb is found to be shortened, the great trochanter is displaced upwards and backwards and is unduly prominent, and the muscles of the buttock and thigh are a little smaller and softer than on the normal side. The limb is adducted, its normal range of abduction, and sometimes also of flexion, is restricted, and there is, as a rule, some degree of lateral rotation, so that the toes point outwards. It should be noted that the same picture—shortening with eversion and stiffness at the hip—results from the common fracture of the neck of the bone in old people. The adduction element of the deformity is partly compensated for by upward tilting of the pelvis on the affected side and curvature of the spine with its concavity towards the affected limb.