Monday, June 22, 2020

What is femoral head necrosis and what are the high-risk groups?

What is femoral head necrosis

The full name of femoral head necrosis is aseptic necrosis of the femoral head, or ischemic necrosis of the femoral head. It is a type of osteonecrosis. It is caused by various causes of poor blood flow of the femoral head, which further causes ischemic necrosis to cause trabecular bone fracture and a disease of the femoral head collapse. It can be divided into four stages:

Stage I: Progressive pain in the hip and knee joint, mildly restricted hip movement, x-ray appearance, normal appearance of the femoral head, cartilage, trabecular bone structure is slightly blurred, or spotted osteoporosis, CT shows bone in the middle of the femoral head The trabeculae are slightly thickened and have a star-like structure. They are arranged radially or pseudopod-like branches toward the cartilage of the femoral head. Some small cystic changes can be seen in the subchondral area. ECT has early concentration, arterial blood supply is low, and MRI shows low The signal changes abnormally.

Stage II: mainly hip pain, mild abduction of internal rotation, X-ray manifested as subchondral cystic changes, bone tissue destruction and loose interweaving phenomenon, also can be seen in the cartilage area half-moon-shaped translucent area, called "new "Monthly sign", CT can be seen that the trabecular bone of the sub-head bone hip changes. Cystic changes of more than 0.5 cm in the subchondral bone marrow cavity, ECT manifests as a large "hot zone" (congestion) or a large "cold zone" (ischemia) in the resting phase, with an intermediate stage of cold and heat, MRI showed large areas of low signal.

Stage III: Hip and knee pain worsened, weight-bearing endurance decreased, and limp. X-ray showed subchondral micro-fractures, some trabecular bones were continuously interrupted, the weight-bearing area outside the femoral head collapsed and flattened, or there were bone fragments under the cartilage. CT showed that the trabecular bone in the femoral head was disordered and the cystic variable area expanded. Bone fragmentation, deformed femoral head, hyperplasia and hardening of some areas, acetabular bone hyperplasia, ECT and MRI are more obvious than stage II.

Stage IV: limited hip movement, severe walking difficulties, or incapacity to work, X-ray showed joint space narrowing, flat femoral head collapse deformity, acetabular border hyperplasia, osteoarthritis changes, CT showed femoral head outline Malformation, narrow joint space, fusion of femoral head sclerosis and cystic transformation, fragmentation of bone structure, etc. ECT showed local concentration at the junction of the acetabular head, the slope of the blood pool phase was reduced, and the low-signal area of ​​MRI was more obvious than that of stage II and III.

Femoral head necrosis can occur at any age, but it is most common in children and 35-65 years old, with a male to female ratio of 4:1. At first, it usually manifested as soreness and dull pain in the hip joint or surrounding joints, which worsened after the activity. Further development can lead to dysfunction of the hip joint, which seriously affects the patient's quality of life and labor capacity, and treatment can cause life-long disability if not treated in time.

The advent of steroids for femoral head necrosis and its widespread use have gradually increased in incidence, coupled with the transformation of transportation, increased traffic accidents, and changes in people's lifestyles can cause the number of patients with the disease to increase dramatically. There are currently more than 30 million patients worldwide. There are 4 million patients in my country that have become frequently-occurring and common diseases.

Femoral head necrosis is mainly manifested by hip pain and lameness. The pain is mostly gradual, and there may be no clinical manifestations in the early stage. It is found when CT and X-rays are taken. Hip or knee pain may also occur first, and adducting myalgia (thigh root pain) occurs earlier in the hip. The pain may be continuous or intermittent. If bilateral lesions may have alternating pain, the patient's hip movement is limited, and the abduction and internal rotation are the main restrictions. Therefore, the patient appears to be unable to cross-legs, and it is difficult to get on and off the bicycle. It is inconvenient to squat and bend down. You need a toilet when you defecate.

X-ray plain film is the basic method to diagnose femoral head necrosis. Routine pelvic orthopedics and frog-style radiographs are routinely performed. On X-rays, femoral head necrosis has normal bone quality or only trabecular bone is blurred and scattered osteoporosis. Local cystic changes can be seen when the disease further develops. The bone texture is sparse, the trabecular bone is interrupted or disordered, or a small bone mass with increased bone density is seen. After that, a large mass density shadow in the center of the femoral head can be seen. The necrosis range is less than 1/3 of the total femoral head, which is local necrosis; 2/3 is most necrosis; more than 2/3 is necrosis of the whole femoral head. Femoral head necrosis can appear on the X-ray film "Crescent sign", "Snow Cup sign", "Bird-shaped" changes and joint subluxation.

What is the necrosis of the femoral head?

1. Necrosis of the femoral head is caused by trauma, taking hormones, alcoholism, etc. Some causes are the result of long-term effects, so once necrosis of the femoral head is found, you should immediately find the cause and remove those long-term morbidity factors, such as according to the original Immediately stop the use of hormone drugs and prohibit drinking alcohol. After completely removing the onset factors, the treatment will obtain satisfactory results.

2. Reduced weight-bearing, femoral head necrosis is caused by the long-term application of hormone drugs or long-term drinking and other causes of increased pressure in the femoral head, which reduces blood flow into the femoral head and causes bone tissue necrosis. After necrosis of femoral head tissue, normal bone tissue repairs necrotic tissue on its own, that is, necrosis of femoral head is to repair and heal necrotic tissue while necrosis. Reducing the pressure of the femoral head will promote bone tissue repair of the femoral head, making bone repair greater than bone necrosis. While reducing the pressure on the femoral head, it can also promote blood circulation of the femoral head and prevent the femoral head from collapsing.

3. Improve the blood flow of the femoral head. Femoral head necrosis is caused by trauma or long-term use of hormones, or alcoholism, etc., causing damage to the blood vessels supplying the blood supply of the femoral head, or due to excessive pressure on the femoral head, the blood flow of the femoral head is blocked and reduced, and the femoral skull tissue is reduced. Necrosis occurs when normal blood nutrition is lost. Therefore, necrosis of the femoral head is caused by its blood flow disorder. Improving and promoting blood flow of the femoral head will promote the repair of the necrotic tissue of the femoral head and accelerate the recovery of the necrosis of the femoral head.

What are the high-risk groups of femoral head necrosis

(1) Long-term application of glucocorticoids

One is due to the patient's last resort and long-term glucocorticoids need to be taken in large quantities. The other is due to the long-term misuse of hormone therapy by some doctors or patients themselves.

(2) Long-term heavy drinkers

With the development of society, people's interactions are becoming more and more frequent, and long-term large-scale drinking is sometimes inevitable, and alcoholics have a soft spot for drinking, and drink alcohol without restraint.

(3) Those who have a history of hip trauma

The rapid development of the transportation industry, the rapid changes in transportation, and the incidence of traffic accidents are increasing year by year. Femoral neck fracture, hip dislocation or hip trauma without fracture and dislocation can be caused by carelessness in life, work, and sports. The blood vessels supplying the femoral head were damaged, which laid a great hidden danger for the necrosis of the femoral head in the future. Among them, femoral neck fracture with femoral head necrosis is the most common, accounting for about 30% of such fractures.

(4) Other

Divers, pilots, obesity, high blood pressure, diabetes, arteriosclerosis, gout, people who need to receive radiotherapy, post-burn, hemoglobin disease, etc., are also at high risk of femoral head necrosis.

No comments:

Post a Comment