Disease etiology
The etiology of femoral head necrosis is diverse (about 60 kinds), complex and difficult to classify comprehensively and systematically, which is related to the unclear pathogenesis. In our long-term theoretical research and clinical treatment, we have summarized more than ten common pathogenic factors as follows.
① Trauma causes femoral head necrosis. For example, external impact causes femoral neck fracture, hip dislocation, hip joint sprain and contusion, etc. Trauma is the main factor causing femoral head necrosis. However, the occurrence and extent of traumatic ischemic necrosis of the femoral head mainly depend on the degree of vascular destruction and the compensatory ability of the collateral circulation.
②Drugs cause femoral head necrosis. For example, long-term use of hormonal drugs due to bronchitis, asthma, rheumatism, rheumatoid, neck, shoulder, back and leg pain, diabetes, skin disorders, etc. It is an early statement that the accumulation of hormones in the organism due to the large amount or long-term use of hormones has led to the development of the disease. Recently, it is believed that the occurrence of femoral head necrosis is directly related to the type, dosage form and route of administration of hormones, and is not directly proportional to the total amount and duration of hormones. However, the long-term use of large amounts of hormones or excessive daily doses and sudden changes in dose increases and decreases are also one of the reasons for the occurrence of femoral head necrosis.
③Alcohol stimulation causes femoral head necrosis. The accumulation of alcohol in the body due to long-term heavy drinking leads to the increase of blood lipids and damage of liver function. The elevation of blood lipids causes the increase of blood viscosity, slows down the blood flow, and changes the coagulation of blood, thus blocking the blood vessels, bleeding or fat embolism, and causing osteonecrosis. Clinical manifestations are aggravation after drinking, walking duck walk, heart failure, weakness, abdominal pain, nausea and vomiting, etc.
④ Wind, cold and dampness cause osteonecrosis of the femoral head. The clinical manifestations are hip pain, cold and dampness, and difficulty in squatting.
⑤ Liver and kidney deficiency causes osteonecrosis of the femoral head. The symptoms are generalized emaciation, yellow face, impotence, premature ejaculation, excessive dreaming, seminal emission, weakness, etc.
(6) Osteonecrosis due to osteoporosis. Clinical manifestations are weakness and weakness of lower limbs, pain, inability to bear weight, and easy to fracture.
(7) Osteonecrosis due to flat hip. Clinical manifestations are walking duck step, short lower limbs, muscle atrophy, pain gradually worsens around 50 meters, and limited function.
(8) Abnormal bone marrow hyperplasia leads to osteonecrosis. The manifestation is cold, soreness, inability to bear weight, easy to fracture, obvious atrophy of bone, etc.
⑨ Bone tuberculosis combined with osteonecrosis. The manifestation is positive nodule test, low fever in the afternoon, pain with a fixed location, wasting, night sweating, weakness, etc.
⑩Osteonecrosis after surgery. In the clinic bone necrosis occurs after three years of bone grafting, vascular grafting, and insufficient blood supply to the bone.
In addition, there are pneumatic, radiological and hematological diseases.
Among the above many factors, osteonecrosis of the femoral head caused by local trauma, hormonal drug abuse, and excessive alcohol consumption is common. The common core problem is that the blood circulation of the femoral head is impaired due to various causes, which leads to ischemia, degeneration and necrosis of bone cells.
Diagnosis and treatment criteria
Medical history
1. History of obvious trauma to the hip joint; 2. History of hormonal drug use; 3. History of long-term alcohol abuse; 4. History of genetic, developmental, metabolic and other diseases; 5. Idiopathic (non-traumatic).
Symptoms
1, progressive hip pain, aggravated by standing or walking; 2, first symptoms include hip pain, lumbosacral pain, knee pain, hip pain or pain in the groin area, respectively; 3, limited hip movement (especially internal rotation); 4, accompanied by lower extremity pain or chills (fear of cold); 5, claudication.
Physical signs
1, no obvious redness, swelling, heat, deformity of the hip joint, presence of limping gait, presence of muscle atrophy (quadriceps, and gluteus maximus); 2, greater trochanteric buckle angle (+), pressure pain in the central inguinal region (+), pressure pain in the stopping point of the adductor muscle; 3, presence of shortening of the affected limb, axial percussion pain of the affected limb (+); 4, early stage: Thomas’ sign (+), “4 ” test (+) (as described above); 5. Late stage: Allis sign (+), single leg independence test (trendelenburg) sign (+), Ober test (+).
Orthopedic examination
1. Hip joint with and without redness and swelling, deformity, atrophy of quadriceps and gluteus maximus, limping gait; 2. Length of both lower limbs: left Right, circumference of thigh: left Right, percussion pain of greater trochanter: (+), pressure pain in the central inguinal region: (+), pressure pain at the stop of the adductor muscle (+), axial percussion pain of the affected limb (+); 3. Hip joint function.
Disease symptoms
The main symptoms of femoral head necrosis are manifested in the following five points.
① Pain. Pain can be intermittent or persistent, aggravated by walking activities, and 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.
②Joint stiffness and limitation of movement. The affected hip joint has unfavorable flexion and extension, difficulty in squatting, inability to stand for a long time, and duck walk. The early symptoms are limited abduction and external rotation activities.
(iii) 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 is more obvious in children.
④Signs. Local deep pressure pain, pressure pain at the stop point of the adductor muscle, positive 4-letter test, positive Gagai s sign, positive A11is sign test. Abduction, external rotation or internal rotation activities are limited, and the affected limb may be shortened, with muscle atrophy and even signs of subluxation. Sometimes the axial stroke pain is positive.
(5) X-ray manifestations. The bone texture is thin or interrupted, and the femoral head is cystic, sclerotic, flattened or collapsed.
Femoral head film diagram
Early and late stage painful manifestations of femoral head necrosis
The first conscious symptom of femoral head necrosis is pain, which is around the hip joint, inner thigh, anterior side or knee. In the early stage, the pain starts as vague, dull or intermittent pain, which is aggravated by more activities and can be relieved or reduced by rest. However, there are also cases of persistent pain, whether it is from exertion or rest, or even when lying in bed. Moreover, the pain gradually increases. At this time, although there is no obvious abnormal morphological change on the X-ray, the hip joint has different degrees of functional limitation. For example, the patient’s hip joint on the affected side is limited in abduction and rotation, and cannot squat in place. In the advanced stage, the femoral head collapses, fractures and deforms, and in some cases, the hip joint may become subluxed. The pain is directly related to the movement and weight bearing of the hip joint. The pain is caused by the bony friction in the joint when moving, but it is not obvious when there is no friction between the head and socket at rest. Therefore, the pain is aggravated by walking and activity, while the pain is relieved by movement.
In short, the early stage is dominated by pain with functional limitation; the late stage is dominated by functional impairment with pain.
Types of disease
Femoral head necrosis diagram
① Total necrosis of the femoral head. It is less common and refers to the total necrosis of the femoral head from the joint edge. Subtrochanteric femoral neck fractures can often cause total head necrosis.
②Cone (wedge) necrosis of the femoral head. It is most common. The normal femoral head is divided into a central weight-bearing zone and internal and external pressure-free zones. Head central cone necrosis is the weight-bearing zone osteonecrosis.
(iii) Hemilunar necrosis of the top of the femoral head. The incidence is very high, osteonecrosis occurs in the anterior upper part of the femoral head, the dead bone is in the shape of half-moon, the hip joint frog external booth X-ray shows the most clear; ¾ focal osteonecrosis of the femoral head.
④ Focal osteonecrosis of the femoral head, which is the mildest. This type generally does not involve collapse of the femoral head.
⑤ core necrosis of the femoral head.
⑥Non-vascular osteonecrosis.
Differences between osteoporosis and osteonecrosis of the femoral head
Osteoporosis is a reduction in bone mass, a decrease in the ratio of organic matter (protein, etc.) to inorganic matter (calcium, phosphorus, etc.) in the bones, etc., which increases the brittleness of the bone and makes it prone to fracture. Its occurrence is related to hormonal metabolism, diet, exercise, immunity, genetics and other factors.
Its clinical manifestations are.
① low back pain, pain characterized by hooked pain on both sides of the spine.
② Shortening of height and “hunchback” deformity.
(3) Osteoporotic fractures, such as compression fractures of the thoracolumbar spine, fractures of the femoral neck, and fractures of the distal end of the burn bone, are likely to occur.
Femoral head necrosis is a frequent and difficult to treat disease in orthopedic surgery. It occurs when the blood circulation supplying the femoral head is destroyed, causing necrosis of the femoral head due to loss of blood nutrition.
Its occurrence is related to trauma to the pulp (mostly seen in femoral neck fracture), long-term use of hormones, and long-term excessive alcohol consumption.
The main clinical manifestations are localized pain in the medullary joint, a few of them are connected to the thigh or waist, and the pain is aggravated when walking too much, pressure pain in the groin, and dysfunction of the medullary joint.
Stages of the disease
First stage
The most common symptom is hip pain, about half of them are acute, progressive and heavy in the evening. Most of the joint activities are mildly restricted, especially internal rotation and abduction. In some patients, the early symptoms are unknown. X-rays show normal joint space, normal femoral head shape, normal or relatively blurred trabeculae, or speckled osteoporosis. Early X-rays are unchanged and require hemodynamics and biopsy to confirm the diagnosis. Magnetic resonance imaging can confirm the diagnosis at an early stage.
Stage II
This stage can last for several months or longer, with persistent or worsening clinical symptoms. X-rays show no change in femoral head shape or joint space, but bone changes can take many forms, including diffuse osteoporosis or osteosclerosis, vesicular changes in the femoral head, and sometimes a combination of these phenomena. If a linear translucent area under the articular surface is seen, it is called the crescent sign, which is a sign of necrosis and resorption of subchondral trabeculae, indicating that the lesion has entered the transitional stage of the stage.
Stage 3
The pain persists and further aggravates, the joint movement is obviously restricted, the function of the affected limb decreases, the limp is obvious, most of them need to use crutches, the joint space is still normal on X-ray, but due to the fracture of the subchondral bone under stress, the joint surface of the femoral head can be seen to collapse and flatten in the weight-bearing area or the step under the acetabular rim is obvious.
Stage 4
In this stage, the mobility of the joint gradually disappears. X-rays show that the mobility of the joint becomes narrower, the joint surface collapses, the bony redundancy grows, and the femoral head flattens and deforms, and the acetabular roof changes from a spherical joint to a cylindrical joint. In this stage, osteoarthritis is often combined with osteoarthritis, and it is often difficult to distinguish osteoarthritis from ischemic necrosis on X-rays.
Early signs
The main points to note are.
(1) Hip and knee pain, also known as ectopic pain, is the main manifestation of early ischemic symptoms of the femoral head, which is often overlooked because it is “far” from the hip joint and is easily misdiagnosed as arthritis or joint injury, but is actually a radiological symptom related to femoral head necrosis. This pain can be obvious due to exertion, trauma, heavy alcohol consumption, excessive activity, going up and down stairs and other triggers.
(2) Children aged 3-10 years old with a history of minor trauma or upper sensation before the onset of the disease. Sudden onset, the child refers to knee joint and inner thigh detection pain, which turns into hip pain after a few days, and later causes lameness, not high temperature and low fever, hip joint has pressure pain, the affected hip is maintained in slightly flexed and adducted position, hip joint internal rotation and abduction activities are obviously limited, the affected hip joint photo contrast, epiphysis and cartilage surface is not smooth.
(3) Skin diseases (such as psoriasis, polymorphic erythroderma, etc.) patients treated with steroid drugs can slow down the synthesis of osteoid of osteoblasts, hinder the transformation of former osteoblasts to osteoclasts, shadow 9 to the absorption of calcium from the intestine, and osteoporosis can occur, and subtle fractures of bones can occur after trauma, and the antagonistic force is reduced, causing bone compression or collapse. Due to compression of marrow cells and capillaries, obstruction of blood flow can lead to osteonecrosis, and if it occurs in the femoral head, it is osteonecrosis of the femoral head. When you find limping when walking, alleviated after rest, and hip discomfort or soreness when sitting down, most of the tips should be alert to this disease.
(4) Hyperlipidemia, which occurs after long-term excessive alcohol consumption, is increasing. According to statistics, men who drink more than 250 grams (half a city pound) of alcohol per day will have elevated free lipic acid in the blood, which can lead to vascular embolism in the bone and eventually lead to osteonecrosis. The early feeling of hip and knee pain, especially at night or after exertion, sometimes feel pain in the inner thighs or knee joints, mostly diagnosed as rheumatic disease. This abnormal feeling is the early “hip coronary artery disease”, delayed treatment will cause irremediable disability sequelae.
(5) Silent disease. It refers to the reduction of bone tissue cells, the loosening of the hip bone structure that plays a role in loading, the weakening of the physical strength of the bone, and bone ischemia caused by the repeated occurrence of tiny fractures, which are not known to the patient, and the symptoms occur only after several years, so it is called “silent disease”. The incidence is higher in urban than in rural areas. The hip joint is prone to incomplete fractures of the femur, which are not easily detected in the early stage of the disease, and after walking for a long time, the patient only feels soreness and weakness or limp, and the thigh muscles gradually atrophy and become thin. These abnormal phenomena suggest that “hip coronary artery disease” is about to occur. Prevention is better than cure. Pay attention to adequate protein, vitamin D and calcium in the diet, and often eat shrimp, small fish and crab, which can have a miraculous effect on strengthening the muscles and bones.