Why can’t X-ray and CT detect early femoral head necrosis?
In the early stage of femoral head necrosis, bone marrow necrosis occurs, but the structure of trabecular bone has not disappeared. At this time, ordinary X-ray and CT scan cannot show Changes in the structure of the femoral head, X-ray and CT cannot detect 1 stage femoral head necrosis. The diagnosis of early femoral head necrosis is very dependent on MRI.
What is the most accurate test for early femoral head necrosis?
MRI is currently the most accurate method for early detection of femoral head necrosis.
In the early stage of femoral head necrosis, some bone marrow changes appear. At this time, some corresponding signal changes will appear on the MRI. Sexual abnormalities are very sensitive, but lack specificity. On the other hand, the sensitivity of MRI for subchondral bone fractures and femoral head collapse is relatively poor, which is the defect of MRI.
What are the characteristic MRI findings of femoral head necrosis?
Hip MRI T2-weighted image shows a high signal band within the low signal surrounding the bone necrosis, which is the so-called “double-line sign”. Similarly, a band-like or annular low-intensity band appears in the femoral head on T1-weighted images, which surrounds a signal area, which is a double-line sign of early ischemic changes in femoral head necrosis.
How should femoral head necrosis be treated?
Femoral head necrosis is a difficult orthopaedic disease with complex etiology and pathology. The key points of the hip: restore the root blood supply and block the necrosis mechanism; repair the damaged bone and block the collapse mechanism, so as to achieve long-term pain relief, realize the patient’s demands, and achieve the purpose of preserving the hip without replacement.
Block the necrosis mechanism and restore the normal blood supply of the femoral head: Osteonecrosis is rooted in the bone tissue, and the root is the blood supply problem. The key to promoting the further development and deterioration of femoral head necrosis is the ischemia problem. Therefore, only when the femoral head returns to normal blood supply can the disease progress be terminated.
Block the collapse mechanism to achieve hip preservation without replacement: due to excessive osteoclast activity and insufficient osteoblast capacity, bone resorption and osteogenesis The imbalance between the two will reduce the mechanical properties and eventually lead to collapse. Therefore, the treatment needs to reduce osteoclast bone resorption, promote osteoblast activity, and increase bone density until new bone grows.
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