Diagnosis of femoral head necrosis (1) Advantages of X-ray examination

The commonly used examination methods of femoral head necrosis are X-ray, CT and MRI (nuclear magnetic resonance/magnetic resonance). How to choose the key time points such as disease diagnosis, condition judgment, curative effect evaluation and prognosis judgment?

X-ray inspection is the most commonly used and basic inspection method.

Typical manifestations of x-ray examination

(1) Early stage: the shape and joint space of the femoral head are normal, with patchy and strip-shaped high-density areas in the femoral head and a few mixed patchy or cystic light and shadow.

(2) Mid-stage: the femoral head collapses, with mixed sclerosis zone and cystic light band in the femoral head, simple dense sclerosis shadow in some areas, and no obvious stenosis in the hip joint space.

(3) Late stage: the femoral head collapsed and deformed, the joint space in the weight-bearing part narrowed, the mixed dead bone in the femoral head changed, and the sclerosis and light-transmitting area coexisted. Degenerative arthritis, acetabular marginal hyperplasia, subchondral cystic degeneration and narrowing of joint space occurred in hip joint.

Advantages of x-ray inspection

Low price, convenient and intuitive. X-ray is a plane image of the femoral head, which mainly observes the appearance of the femoral head. The standard posture and high-definition X-ray film can show the trabecular bone of femoral head and judge whether there is osteoporosis, uneven bone density, cystic degeneration, collapse deformation or joint space stenosis. Femoral head is a spherical structure, so it is usually necessary to take X-rays of two hip joints in normal position and frog position.

Experienced doctors can find a lot of information through X-rays, such as the location, scope, pathological stage, whether there is collapse, the scope and degree of collapse, the state of cartilage, the relationship between the head and the mortar, etc. Even roughly judge whether there is a large amount of effusion in the joint. Continuous dynamic X-ray film can also indicate the development and change (prognosis) of necrosis and judge the therapeutic effect.

Disadvantages of X-ray examination: early diagnosis of femoral head necrosis is difficult and its sensitivity is not as good as MRI, CT or ECT.

X-ray plain film is the first choice, routine and inevitable examination method for avascular necrosis of femoral head, and can be used as a basic examination method to distinguish hip dysplasia, hip osteoarthritis, ankylosing spondylitis and other related diseases.