1.What is femoral head necrosis?
Femoral head necrosis is called aseptic necrosis of the femoral head, or ischemic necrosis of the femoral head, which is a lesion caused by poor local blood flow to the femoral head for various reasons, thus causing further ischemia, necrosis of bone cells, fracture of bone trabeculae, and collapse of the femoral head. Since 1888, when the disease was first recognized by the world medical community, osteonecrosis of the femoral head has been transformed from an uncommon disease to a common and frequent disease. Especially since the introduction of hormones and their widespread use, the incidence of femoral head necrosis has gradually increased. In addition, the increase in the number of accidents after the change of transportation and the change of people’s life style have made the number of patients with this disease increase dramatically. According to incomplete statistics, there are currently 30 million people with osteonecrosis of the femoral head worldwide, and about 4 million in China. The latest survey shows that there is no significant gender difference in the occurrence of osteonecrosis of the femoral head, and the disease can occur at any age, while the incidence of the disease increases significantly in people with a history of hormone application, hip trauma, alcoholism, and related diseases.
Femoral head necrosis can occur at any age but it is most common at the age of 31-60, with no gender difference. It is mostly manifested as hidden pain or dull pain in the hip joint or its surrounding joints at the beginning, aggravated by activities, and further development can lead to dysfunction of the hip joint.
2.Staging and clinical manifestations of femoral head necrosis
The first conscious symptom of femoral head necrosis is pain, and the location of pain is around the hip joint, inner thigh, front 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 continuous pain, regardless of exertion or rest, even when lying in bed. Moreover, the pain gradually increases. In this case, although there is no obvious abnormal morphological change on the X-ray, the function of the hip joint is already limited to different degrees. 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 of femoral head necrosis, the femoral head collapses, fractures and deforms, and some of them may cause hip dislocation, and the pain is directly related to hip joint activities and weight bearing. 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 the pain is not obvious when the friction between the head and socket does not occur at rest. Therefore, the pain is aggravated by walking and activity, while the pain is relieved by movement. In short, the early stage is mainly pain with functional limitation; the late stage is mainly functional impairment with pain.
Femoral head necrosis stage I.
X-rays show disorganized and fractured bone trabecular structures in the bearing system of the femoral head, with the appearance of hairy edges of the femoral head, clinically with or without limited mild pain.
Femoral head necrosis stage II.
X-rays show small cystic shadows inside the femoral head with uneven density in the ring area around the cystic area. The trabecular structure of the bone is disturbed, sparse or blurred. Small collapses may also appear, and the area of collapse may be 10-30%. The clinical condition is accompanied by significant pain and slight limitation of movement.
Femoral head necrosis stage III:
X-rays show morphological changes of the femoral head, including incomplete, worm-like or flattened edges, partial loss of trabecular structures, uneven bone density, widening or narrowing of the acetabular and femoral head gaps, and formation of superfluous bones, with clinical manifestations of pain, intermittent claudication, restricted joint movement, and varying degrees of shortening of the affected limb.
Femoral head necrosis stage IV:
The morphology and structure of the femoral head change significantly, with large irregular collapse or flattening, and structural variation of bone trabeculae. The gap between the acetabulum and the femoral head disappears, etc. Clinical manifestations include pain, functional impairment, stiffness and inability to walk, dislocation or subluxation, and limitation of functional activities of the involved knee joint.
Since osteonecrosis often involves both sides, most patients end up with joint deformity and secondary osteoarthritic changes. Although there are numerous treatment methods available, none of them are sure of their efficacy, making treatment quite tricky. However, it has been proven that the earlier the treatment, the better the results. Because ischemic necrosis of the femoral head is common and difficult to deal with, treatment will be used as an example.
3, how to determine the early femoral head necrosis disease
Femoral head necrosis, the earliest symptom is the hip joint soreness, sleepy, sometimes intermittent pain. This is the main symptom of the disease. There are many causes of hip pain, including trauma, hip dislocation, degenerative disease, inflammation, tumor, lumbar spine disorders, medical and dermatological diseases, etc., all of which can cause hip pain. Femoral head necrosis is only one of the many causes of hip pain, and as an independent disease, it has its own specificity.
Self-examination to determine if you have osteonecrosis of the femur can be done from the following aspects.
(1) Hip pain radiating to the inguinal region or to the posterior, lateral or medial side of the hip or knee.
(2) Stiffness, weakness and limited movement of the hip joint, inflexibility in lifting the leg, early appearance of symptoms such as planking or outward skimming of the leg as well as difficulty in squatting.
(3) Limping: the affected limb does not dare to put weight on it when walking, like walking on tiptoe.
(4) After the fracture, dislocation or sprain of hip joint heals, intermittent or persistent pain in the hip appears gradually or suddenly. The pain is aggravated after walking activities, sometimes it is resting pain, and the pain is mostly pins and needles or soreness, and the above-mentioned reaction occurs.
(5) Hip joint pain occurs in people who use a lot of hormones for a long time or for a short period of time or who often use alcohol, and it is mostly vague or dull pain, often located in the groin, which is obvious when moving and relieved after rest.
If the above situation occurs, it is possible to suffer from osteonecrosis of the femoral head, need to go to the hospital to confirm the diagnosis.
4.Treatment methods of femoral head necrosis
1.Conservative treatment
(1) Avoiding weight-bearing can rely on cane, axillary cane and other supports to strictly limit weight-bearing, which can restore blood supply to ischemic tissues and protect them from pressure, so as to control the development of lesions, prevent collapse and promote the healing of ischemic necrosis of the femoral head by itself. However, it is generally believed that weight-bearing restriction cannot save the development of femoral head necrosis. This method is mainly applied to elderly patients who are not suitable for surgical treatment, poor general condition, progressive ischemic necrosis and patients with poor prognosis. The possibility of self-healing is related to the size of the lesion and its distance from the joint surface: if the lesion is small or far from the joint surface, it can mostly heal by itself; if the lesion is adjacent to the joint surface or if the lesion is large in scope, the possibility of self-healing is extremely small even without weight-bearing.
(2) Adjunctive treatment such as physical therapy.
2.Surgical treatment
(1) Treatment of preserved femoral head, applicable to early stage of femoral head necrosis.
(1) Drilling and decompression can reduce the intraosseous pressure, promote venous reflux, release the spasm of trophoblastic vessels, and enable the new blood vessels to grow into the ischemic area along the bone hole. It is mainly used for patients without joint surface collapse in the early stage, and is the simplest surgical method to treat osteonecrosis.
Bone grafting is also called drilling and decompression bone grafting because it is necessary to drill holes before bone grafting. It involves both drilling and decompression, bone grafting to provide mechanical support, and bone grafting with myotome to increase the blood supply to the femoral head.
(3) Drilled tampon implantation, the same method as before, is used to implant a tampon for support, like a steel bar in bone cement.
There are also interventional stem cell transplants with inexact results.
(2) Arthroplasty
It is applied to patients with collapsed femoral head necrosis, and metal cup arthroplasty, joint surface replacement, femoral head replacement, total hip replacement, etc. are feasible. The effect is more certain and the technology is mature.