Femoral head necrosis is mostly called ischemic necrosis of the femoral head or aseptic necrosis of the femoral head because its main pathology is the ischemia of the head bone caused by the obstruction of blood flow to the femoral head and its destruction.
A common causes
1. Long-term use of large amounts of glucocorticoids
2. Long-term heavy alcohol consumption
3. Fracture of femoral neck
Two main symptoms
1. Pain. Pain can be intermittent or continuous, aggravated by walking activities, sometimes rest pain. The pain is mostly pins and needles, dull pain or soreness and discomfort, often radiating to the groin area, inner thigh, posterior hip and medial knee, with numbness in the area.
2. Joint stiffness and restricted movement. The affected hip joint flexes and extends unfavorably, has difficulty squatting, cannot stand for a long time, and walks with a duck walk. The early symptoms are limited abduction and external rotation activities.
3. Limp. Progressive shortening limp, due to hip pain and femoral head collapse, or late onset of hip subluxation. Intermittent claudication is often seen in the early stage, and it is more obvious in pediatric patients.
III. Main physical signs
Local deep pressure pain, pressure pain at the stop point of the adductor muscle, positive 4-letter test, positive Gagas sign, positive A11is sign, positive TKdelelatuq test. There is limitation of abduction, external rotation or internal rotation, shortening of the affected limb, muscle atrophy, and even signs of subluxation. Sometimes the axial impulse pain is positive.
IV. Diagnosis and staging
According to the X-ray manifestation and functional examination of bone (including measurement of intra-medullary pressure between femoral rotors, intramedullary venography and medullary core biopsy), it can be divided into four stages.
Stage I: is a normal X-ray presentation, or mild diffuse osteoporosis, with symptoms of pain and limited hip movement in 50% of patients, and possible positive MRI and bone scan findings.
Stage II: X-rays showing extensive osteoporosis with scattered osteosclerosis or cystic changes, normal contours of the femoral head, histopathological changes definitely present on marrow core biopsy, and obvious clinical symptoms.
Transitional lesions between stages II and III, showing subchondral fractures (hemimelia sign), focal flattening of the femoral head, and head collapse within 2 mm.
Stage III: X-ray showing sclerosis and cystic changes within the femoral head, femoral head collapse greater than 2mm, crescentic sign, normal joint space, and significant increase in clinical symptoms.
Stage IV: osteoarthritis stage, X-rays show collapse of the femoral head, narrowing of the joint space, loss of articular cartilage, obvious clinical symptoms of pain, and obvious restriction of various activities of the hip joint.
V. Treatment principles
1. Conservative treatment: Early cases can be treated conservatively, such as: traditional Chinese medicine (blood-stasis activator, geranium), lipid-lowering drugs (statins, sodium bisoprolide alginate), hyperbaric oxygen, blood purification, intervention, magnetic therapy, etc. The efficacy of such treatments varies depending on the cause of the disease. Generally speaking, the more treatment methods for a disease, the more it suggests that the effect of various methods will not be exact.
2. Surgical treatment.
The purpose of surgical treatment is to relieve pain symptoms, improve function, help patients regain their social activities and ability to live, and improve the quality of life.
According to the international osteonecrosis staging criteria of the World Society for Research in Osteocirculation (ARCO),
For stage 0 to II-A, drilling and decompression is possible. Alternatively, autologous bone marrow cell transplantation may be added.
Alternatively, metal trabecular rods made of tantalum may be used to support the femoral head.
For stages II-B to III-B, osteotomy or bone grafting, including bone grafting with a vascularized tip, is indicated.
For stage III-C and above, artificial hip arthroplasty should be considered.
For those with small lesions, artificial joint surface replacement can be used.
Metal-to-metal total artificial hip replacement is recommended for young and middle-aged patients and elderly patients with high activity levels