For many years, in clinical practice, I often encounter people who confuse osteonecrosis of the femoral head with secondary osteoarthritis of the hip joint, and when I correct them, I am often met by patients and their families who wonder if the previous doctors were wrong. In fact, they are wrong! I hope that after reading this article you will no longer doubt. First, the causes of the two diseases are different First of all, I would like to tell you that due to various propaganda reasons, the public has a lot of knowledge about the disease of ischemic necrosis of the femoral head, and also knows that drinking and eating hormones can cause necrosis of the femoral head. Many clinics and hospitals in the society are treating this disease, why? This disease is really difficult to treat, and in many cases the more you take the medicine the worse it gets. Therefore, some so-called “ancestral” and “stem cell technology” have emerged in the society. In any case, the incidence of osteonecrosis of the femur in our country is very high, and its causes are mostly the use of glucocorticoids (clinically needed for many systemic diseases, from life-saving brain surgery, down to common skin diseases, to most rheumatic immune system diseases, for which hormones are almost irreplaceable drugs), alcohol (especially drinking wussy wine, often drunk) and trauma (fracture of the femoral neck). Other causes are relatively less common. Those who drink alcohol do not necessarily get osteonecrosis of the femoral head, and those who have received hormone therapy may not all develop osteonecrosis of the femoral head, but there is certainly a risk, and whether or not they develop the disease depends largely on their physical condition and susceptibility. Secondary osteoarthritis of the hip joint is different in that it develops because of structural defects in the hip joint at birth or during development, abnormal joint correspondence, and arthritic changes that occur as the joint ages and ages prematurely. Of course, these people may also receive hormone therapy in their daily lives, also drink alcohol, and even have fallen, but these are not the cause of arthritis, the real reason is that the joint did not develop well at the age of development, and it came to the door when they were older. Second, the age of onset and gender is different Femoral head necrosis mostly develops in young adults, and is more common in men. Why? Look at the reason to know, drinking and trauma in men have a greater chance. Men drink more drunkenness. Women with osteonecrosis of the femoral head tend to have rheumatic immune diseases such as lupus erythematosus, rheumatoid arthritis, etc. and must receive hormone therapy. Secondary osteoarthritis of the hip joint is mostly seen in women. In the north of China, developmental hip dislocation is common in children, and arthritic symptoms can occur after middle age, regardless of treatment. If treated properly at a young age, the problem may last a lifetime, but if not, secondary osteoarthritis of the hip joint is bound to occur. If the abnormal development of the joint is mild at a young age and there is no discomfort, the patient may not be examined at all until the age of 30-40, when he or she goes to the hospital with symptoms such as weakness and pain and learns that his or her joint is different from others. The age span for the onset of this disease is very large and depends on a variety of factors such as the degree of defective joint development, weight, and occupation. Third, the pathological mechanism is different Femoral head ischemic necrosis is a bone tissue necrosis disease caused by the interruption of blood circulation supplying the femoral head for some reason. Because the blood supply system of the femoral head has multiple channels, and the degree and extent of blood supply interruption varies, so the site, extent and degree of necrosis occurs varies from person to person. Once necrosis occurs, the body’s repair response is initiated, just as with a bacterial invasion, there is an inflammatory response. The reparative response of the organism is like a two-sided sword, which has both good and bad effects on the tissue and is not at our disposal. When the necrotic lesion is small and limited, the necrotic tissue can be absorbed and new bone can grow slowly, even if it does not, because the lesion is small and does not affect the local mechanical distribution, does not cause deformation and instability of the joint structure, and can “peacefully coexist” for many years. If the necrosis is extensive, the outcome is different. The loosening of the necrotic bone can cause mechanical instability, and daily activities can cause deformation and collapse of the femoral head, which in turn can cause destruction of the entire joint. It has been reported in the literature that once femoral head necrosis occurs, deformation and collapse of the femoral head and even joint destruction will inevitably occur within 1-2 years after the diagnosis. One should know that for femoral head necrosis, the joint structure is normal and free of structural defects before the onset of the disease. With the development of necrosis, the direction of the lesion has the femoral head in the direction of the joint, which is the last to have the destruction of the joint space. As mentioned earlier, secondary osteoarthritis of the hip joint is preceded by structural abnormalities, just like a machine that has defects and hidden problems at the beginning of the factory, and can be made to work, but then fails and ages. During this process, the body also initiates a repair response, with growth and wear occurring side by side. There can be a reduction in joint space without the femoral head collapsing as in necrotizing disease. However, the disease starts with an onset on the joint and then can develop cystic changes on the femoral head or acetabular side due to mechanical abnormalities. The symptoms of the disease can last for years or even decades, with symptoms ranging from mild to persistent. Fourth, the changes on the X-ray film The early diagnosis of femoral head necrosis is difficult, ordinary X-ray may not find the lesion at all, and because the early stage of necrosis can simply not have any pain symptoms cause, so there are many opportunities for missed diagnosis and misdiagnosis. Experienced physicians can detect the early signs of disease in these patients and give timely advice and further examination. MRI is currently considered to be an effective test for diagnosing early femoral head necrosis. In any case, in terms of plain radiographs, osteonecrosis of the femoral head must develop along the following directions: abnormalities in the density of the femoral head followed by abnormalities in the contour line of the subchondral bone of the femoral head; abnormalities in the internal structure of the femoral head followed by abnormalities in the hip joint space; no abnormalities in the composition of the hip joint before the onset of the disease, and arthritic changes are only seen in the middle and late stages of the disease. In the case of secondary osteoarthritis of the hip joint, the abnormalities of the bony structures of the joint are present first, which is already present on the first plain radiograph. There can be joint space abnormalities followed by internal structural abnormalities of the femoral head, and most often there are cystic changes on the acetabular side. Osteosclerosis must be more pronounced than in cases of femoral head necrosis. The important point is that the femoral head may not be squarely round, regardless of the history, but it is definitely not collapsed and the portion of the femoral head that is not contained by the acetabular bone on the outside is large. The contour of the acetabulum must be abnormal. V. Treatment and regression The prognosis of femoral head necrosis depends on the extent and degree of necrosis. Generally speaking, rest has basically little effect on the healing of the disease. The repair and further destruction of femoral head necrosis will develop and worsen unknowingly, regardless of interventional treatment. The correct concept of treatment is to administer different treatments according to the extent and degree of necrosis staging and to avoid the necessity of joint replacement surgery at a late stage. Therefore, an aggressive combination of Chinese and Western medicine treatment is necessary before the femoral head collapses. The goal of treatment is to avoid or reduce the chance of femoral head deformation and collapse. As long as the femoral head does not deform and collapse, the hip joint can be preserved. Secondary osteoarthritis of the hip is a different story. Once diagnosed, orthopedic surgery is performed if the opportunity arises. Surgery can correct the mechanical instability of the joint and prevent rapid aging of the joint. If you really can’t make up your mind, once diagnosed, at least pay attention to reducing weight, avoiding prolonged standing and physical work, which can reduce the load on the joint and can play a role in slowing down the development of arthritis. If the contour of the femoral head is not square and the joint wear is obvious, joint replacement surgery can be performed at an appropriate age. There is a phenomenon that can tell you that the disease of femoral head necrosis develops much faster than secondary arthritis, secondary osteoarthritis of the hip joint is a disease that can be properly “waited and seen”, while femoral head necrosis is a disease that “can’t afford to wait”. Six, the causes and details of the confusion of the two diseases Clinical confusion of the two diseases is wrong. The cause of this phenomenon is fundamentally a lack of understanding of the etiology, pathology, diagnostic points, treatment principles and regression of the two diseases. It is very wrong to diagnose femoral head necrosis when you see cystic changes in the femoral head. Pathologically, femoral head necrosis can be seen microscopically as dead bone cell structures and repair of inflammatory reactions. Arthritis, on the other hand, is typically an inflammatory change. In the former, there is necrotic and granulation tissue within the cystic area, while in the latter, there is more mucus-like tissue. There is another issue to be addressed. It is not easy to see the effect of taking medication for osteonecrosis of the femoral head, whereas it is easy to see the effect of treating osteoarthritis as osteonecrosis of the femoral head because secondary osteoarthritis is more sensitive to painkillers and rest. Some doctors will consciously or unconsciously rely on the effectiveness of medication for osteoarthritis to boast how effective they are in treating osteoarthrosis of the femoral head.