What is osteonecrosis of the femoral head?
Femoral head necrosis is also known as aseptic necrosis of the femoral head, or ischemic necrosis of the femoral head. Osteonecrosis is caused by damage to the bone trophoblastic vessels for a variety of reasons, which further leads to ischemia, degeneration, and necrosis of the bone. Femoral head necrosis is a lesion caused by localized poor blood flow to the femoral head for a variety of reasons, leading to further ischemia, necrosis, trabecular fracture, and collapse of the femoral head. Further development can lead to functional disorders of the hip joint, which can seriously affect the quality of life and labor ability of patients, and can lead to lifelong disability if not treated in time.
What are the causes of femoral head necrosis?
Traumatic: Fracture of the femoral head or femoral neck neck, fracture or dislocation of the hip joint, or injury to the vascular branch without either fracture or dislocation after trauma to the hip can cause local ischemia of the femoral head, which can further develop into necrosis.
Non-traumatic.
(1) long-term or heavy application of glucocorticoids accounted for 43%
(2)Alcoholism
(3) decompression sickness, diving and flying personnel in high pressure situations, the dissolved nitrogen in blood and tissues increases, when the environmental pressure decreases, the dissolved excess nitrogen needs to be discharged gradually through the lungs, if the pressure decreases too fast, the nitrogen can not be discharged in time, that is, free out in the body, forming bubbles, producing gas embolism, gas embolism in the blood vessels, blood flow is blocked, the local blood supply to the femoral head becomes poor, ischemic necrosis.
Others: hypertension, diabetes, arteriosclerosis, obesity, gout, radiation therapy, and after burns, can also cause femoral head necrosis.
What are the main symptoms of femoral head necrosis?
1. Pain on the affected side. Pain can be intermittent or continuous, with no symptoms when intermittent, but intermittent for more than a year. It is aggravated after walking activities, and sometimes it is 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, but sometimes the pain point cannot be found.
2.Joint stiffness and restricted movement. The affected hip joint flexes and extends unfavorably, has difficulty squatting, cannot stand for a long time, walks with a duck stance, makes a loud noise from the hip joint and even accompanies leg cramps. The early symptoms are limited abduction and external rotation activities.
3.Crippling. Progressive shortening limp, due to hip pain and femoral head collapse, or late onset of hip subluxation. Intermittent claudication often occurs in the early stage, and is more obvious in children.
4. The skin temperature of the affected hip is lower than the normal temperature, and the affected limb is cold in individual patients.
5. Physical signs. Local deep pressure pain, pressure pain at the stopping point of the adductor muscle, positive 4-word test, positive Gaga s sign, positive A11is sign, positive TKdele叻uq 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.
6.X-ray performance. The bone texture is small or interrupted, and the femoral head is cystic, sclerotic, flattened or collapsed.
What are the clinical manifestations of femoral head necrosis?
Femoral head necrosis is characterized by hip pain and claudication as the main clinical manifestations. The pain is mostly progressive. In the early stage, there may be no clinical symptoms, but only discovered when CT films or X-rays are taken, or the pain in the hip or knee joint may appear first, and in the hip area, the pain in the adductor muscle (leg root pain) appears earlier. The pain can be continuous or intermittent, and alternating pain can occur if the lesion is bilateral.
The pain is often aggravated by prolonged standing and activity, and can be relieved by taking painkillers and resting in bed. In severe cases, the hip joint flexion and extension are also limited, and the patient is unable to squat.
How to diagnose osteonecrosis of the femoral head at an early stage?
The treatment effect of femoral head necrosis has a great relationship with the severity of the disease, the early and late detection, and the stage of the disease, the earlier the lesion is found, the lighter the disease is, the better the treatment effect is. Early diagnosis of femoral head necrosis should follow the following principles.
(1) Any adult aged 20-50 years old with pain in the groin or hip and dissipating to the thigh (or hip pain after activity of one side of the knee pain), slowly progressive aggravation, obvious pain at night, ineffective by general drug treatment, and a history of hip trauma, alcoholism, application of hormones or combination of other causes and diseases causing femoral head necrosis should first consider this disease.
(2) During the physical examination of all patients with low back pain, the function of the hip joint should be routinely checked, and if abduction and internal rotation of the affected hip joint are found to be limited, the existence of this disease should be suspected.
(3) Patients with femoral neck fracture should be followed up until 3-5 years after the injury. If diminishing height of the femoral neck, nail scar phenomenon and cystic changes are found, and clinical symptoms are present, the disease should be considered.
(4) In suspected cases, orthogonal and frog x-ray of the hip must be taken first. MRI has high sensitivity and specificity in diagnosing early femoral head necrosis, and the imaging manifestations of early necrosis can be detected before positive signs appear on x-ray.
What are the common clinical treatment methods for femoral head necrosis?
1.Non-surgical treatment
Avoiding weight-bearing: including partial weight-bearing and non-weight-bearing, it is only applied to the necrosis of femoral head before collapse, i.e. Ficat I and II. From the literature, the effect of the treatment method of avoiding weight-bearing alone is not ideal, and the success rate is less than 15%.
②Pharmacological treatment: The application of drugs for the treatment of femoral head necrosis is less reported. In short, the effect of drug treatment is not yet certain, but it is still an important research direction because of its non-invasive nature. Other treatment methods: such as electrical stimulation therapy, bloodletting therapy, hyperbaric oxygen therapy, etc., there are not many reports, and the effect needs to be further determined.
2.Surgical treatment
(1) Central decompression: The theory of central decompression for ischemic necrosis of femoral head is based on the theory of increased intraosseous pressure of osteonecrosis, which can reduce intraosseous pressure and increase blood flow in femoral head through central decompression, and central decompression can stimulate the growth of blood vessels in the decompression tunnel and promote the crawling replacement of necrotic bone. There are more articles about central decompression, and its efficacy is more controversial. Its efficacy is highly related to the stage of femoral head necrosis, and not much related to the etiology of femoral head necrosis.
(2) Osteotomy: The purpose of osteotomy is to change the main weight-bearing area of the femoral head, replacing the necrotic bone with normal bone as the main weight-bearing area. This method includes trans-rotor rotational osteotomy, inter-rotor internal osteotomy and inter-rotor external osteotomy, etc. It can also be combined with bone grafting treatment, which is mainly suitable for patients with stage II and III Ficat and small lesions.
(3) Osteotomy: Osteotomy includes autologous cancellous bone graft, autologous cortical bone graft, allogeneic bone graft and cartilage graft, which can be combined with other treatment methods such as central decompression, electrical stimulation and osteotomy. Among them, autologous cancellous bone and cortical bone graft are more commonly used. Autologous cancellous bone has good osteogenesis induction and can promote the repair of necrotic femoral head, while cortical bone plays a supporting role for articular cartilage and subchondral bone in the necrotic area during the repair of femoral head.
Bone grafting methods include bone grafting after central decompression, slotting bone grafting at the craniocervical junction, opening a window in the articular cartilage of the femoral head, lifting cartilage bone grafting and then resetting the cartilage. Bone grafting can be used in patients with Ficat stage II, early stage III and patients who have failed central decompression. The recent efficacy of this method is more certain, while the long-term efficacy is still controversial. However, it is worthwhile to accelerate the repair of the femoral head with the help of bone graft and shorten the bed rest time, and the combination of growth factors, electrical stimulation and other methods to promote bone healing can improve its efficacy.
(4) Bone graft with blood supply: There are more methods of bone graft with blood supply, and the grafted bone can come from the iliac bone, greater trochanter or fibula, and can be with myofibular or vascular tip, and the bone graft with blood supply can increase the blood supply to the femoral head and accelerate bone healing compared with ordinary bone graft. The clinical results are reported in the literature, but the X-ray improvement is not satisfactory, and a significant proportion of patients still need arthroplasty in the long-term follow-up.
(5) Hip arthroplasty: For patients with advanced Ficat stage III or IV, total hip replacement is the best choice.
Why should osteonecrosis of the femoral head be treated early?
Femoral head necrosis is a progressive disease, and without special treatment, 70% to 80% of patients show progressive disease on X-ray and in clinical practice. The natural course of femoral head necrosis includes two aspects, namely, progressive collapse of the femoral head and secondary osteoarthritis of the hip joint. If it progresses to severe osteoarthritis, only artificial total hip replacement can be performed.
Since the disease mostly occurs in young adults, the aim of treatment is to preserve the femoral head as much as possible before collapse and delay the time of artificial joint replacement, in addition to improving clinical symptoms. On the contrary, if you are afraid of surgery and take various kinds of blood-activating and pain-relieving drugs, or take some special drugs orally, you will miss the time of surgery, and when the femoral head develops into the collapsed stage or osteoarthritis stage, it will be more difficult to treat. If the patient does not receive timely and regular treatment, the best time for treatment will be missed. In addition, weight bearing (such as walking, climbing, carrying things, etc.) will cause the femoral head to collapse and form osteoarthritis, and the final result is that the patient will become disabled.