X-ray diagnosis of osteoarthritis of the hip joints (coxarthrosis)

Accuracy evaluation of x-ray joint space width in the hip joints is determined by the correct positioning of the patient, turn the limbs and centration of X-rays during radiography. The position of the patient standing gap width articular significantly lower than in the supine position. Articular the gap narrowed to a greater extent by turning the foot inward. It is recommended that the central X-ray beam passing through the center of the femoral head because displacement of the X-ray tube toward the center of the joint can significantly change the width of the joint gap. However, separate hip radiography leads to an increase in radiation exposure to the patient.

In the initial stages of coxarthrosis (I-II stage by Kellgren) determined by X-ray examination:

• A slight narrowing of the gap articular,
• Bland subchondral osteosclerosis,
• Point calcifications in the area of the outer edge of the roof of the acetabulum (the initial phenomenon osteophytosis) - round ligament of the femoral head.

In the later stages of osteoarthritis of the hip joints (III-IV stage according to Kellgren) observed:

• The progressive narrowing of the gap articular,
• Formation of different shapes and sizes of osteophytes at the edges of the articular surfaces of the acetabulum, the femoral head, why she can take the form of a mushroom. In the middle part of the acetabulum, the formation of a wedge-shaped osteophyte, which can cause lateral displacement of the femoral head,
• Deepening of the acetabulum, which may be caused by the growth of osteophytes (it can be a protrusion on the background of osteoporosis or thinning of the bones that make up the bottom of the acetabulum)
• Pronounced subchondral osteosclerosis, which manifests itself first in the roof of the acetabulum, and then in the upper part of the femoral head,
• In advanced cases - a decrease in the volume and the flattening of the articular surface of the femoral head against the background of severe cystoid bone restructuring, alternating with areas of subchondral osteosclerosis,
• Bone cysts - single or multiple - occur at the top of the acetabulum or in the busy area on the articular surface of the femoral head,
• Aseptic necrosis of the femoral head,
• Subluxation of the femur: often up / laterally, rarely up / medially,
• Compaction of bone tissue and shortening of the femoral neck,
• Intra-articular loose bodies (in coxarthrosis identified rare).

In secondary dysplastic coxarthrosis all radiological symptoms develop early (in young or middle age) and may result in osteonecrosis of the femoral head and subluxation or complete dislocation of the hip.

Also described is a rapid ischemic coxarthrosis joint space narrowing, bone restructuring and the head structure in the femoral neck, osteosclerotic early changes, without significant osteophytosis, with sufficiently rapid development destruction of the femoral head.