In psoas abscess associated with spinal disease, or in disease of the bursa underneath the psoas, the limb is flexed and everted, there may be lordosis, and the patient may limp in walking, but the movements at the hip are restricted only in the directions of extension and inversion, while in hip disease they are restricted in all directions.
New-growths in the vicinity of the hip—especially central sarcoma of the upper end of the femur—are difficult to differentiate from hip disease without the help of the X-rays.
Among other conditions which by interfering with the free mobility of the hip may simulate hip disease, are appendicitis, inflammation of the glands in the groin, staphylococcal disease of the upper end of the femur, and sciatica.
The diagnosis from other diseases of the hip-joint is made by careful consideration of the history, symptoms, and X-ray appearances.
Prognosis.—The prognosis in hip disease is more serious than in tuberculosis of other joints, excepting only those of the spine, and it is most unfavourable when there are gross lesions of the bones and infected sinuses.
Whatever the stage of the disease, recovery is a slow process, and even in early and mild cases it seldom takes place in less than one or two years, and is liable to be attended with some impairment of function. During the process of cure, complications are liable to occur, and after apparent recovery relapses are not uncommon. When arrested during the initial stage, recovery may be complete; but when there has been destruction of the articular surfaces, there is apt to be ankylosis of the joint and shortening of the limb.
In cases which terminate fatally, death usually results from meningeal, pulmonary, or general tuberculosis, or from pyogenic complications and waxy degeneration.
Treatment.—A large proportion of cases recover under conservative treatment, and the functional results are so much better than those following operative interference that unless there are special indications to the contrary, conservative measures should always be adopted in the first instance.
Conservative Treatment.—The first essential is to take the weight off the limb and secure its fixation in the attitude of almost complete extension and moderate abduction. When the symptoms are well marked, the child is kept in bed and the limb is extended with a weight and pulley.
Extension by Weight and Pulley ([Fig. 116]).—The weight employed varies from one to four pounds in children, to ten or more pounds in adolescents and adults, and must be adjusted to meet the requirements of each case. If pain returns after having been relieved, it is due to stretching of the ligaments, and the weight should be diminished or removed for a time. If there is deformity, the line of traction should be in the axis of the displaced limb until the deformity is got rid of. The extension should be continued until pain, tenderness, and muscular contraction have disappeared, and the limb has been brought into the desired attitude.