Femoral head necrosis is a common and difficult to treat disease in orthopedics. China is a large number of ONFH patients, medical personnel engaged in the diagnosis and treatment of the disease involves all levels of hospitals, various qualifications and levels of physicians. More distinctive is that the number of patients with ONFH treated by personnel engaged in traditional medicine is considerable. Therefore, the development of clinical, more accurate prediction of prognosis, operability, more accurate guidance for the scientific selection of patients in line with the actual and more economical treatment plan of treatment norms in China is particularly important.
The diagnosis and treatment of ONFH has been going on for several decades. In the past 20 years, the clinical features, imaging performance, especially the application of advanced technology, so that the diagnosis and treatment of ONFH have been significantly improved. Both of these aspects have prompted us to develop consultation and treatment protocols that are consistent with clinical and imaging, and to revise the staging that has been used in order to enable further improvement in the diagnosis and treatment of ONFH.
At the end of 2014, the Diagnostic and Treatment Specification for Femoral Head Necrosis was developed by the Joint Surgery Group of the Orthopaedic Branch of the Chinese Medical Association, which convened more than 20 multi-specialty experts engaged in ONFH clinical and research discussions in China and interacted with more than 300 medical professionals attending the meeting.
The distinctive features of this specification are.
1. The concept and scope of high-risk group of some ONFH patients were proposed, and the possibility and necessity of early MRI examination for high-risk group to obtain early (stage I) diagnosis were described.
2.The scope of subclinical and preclinical ONFH is defined.
3.The concept of peri-collapse phase and the diagnostic method are emphasized.
4.Operational methods were proposed for the determination of necrotic area and volume.
5.The Chinese staging and staging was developed.
6.The choice of hip preservation surgery protocol and method was proposed with clinical evidence.
The author expects that the clinical, imaging and related research personnel engaged in ONFH will read and implement this specification carefully. More eager to identify problems in practice and propose amendments for inclusion in another amendment.
Femoral head necrosis, also known as ischemic femoral head necrosis, is a common and difficult to treat disease in orthopedics. Since the pathological mechanism of non-traumatic ONFH is not fully understood, it is not possible to prevent and treat this disease at its source, but there is currently a consensus among domestic and foreign experts on the main aspects of treatment, and the expert recommendations (2007) and expert consensus (2012) published in China have played an important role in standardizing the treatment of femoral head necrosis. In order to standardize the treatment technology of osteonecrosis of the femoral head, improve the efficacy and rationalize the use of medical resources, the Joint Surgery Group of the Orthopaedic Branch of the Chinese Medical Association convened domestic experts in osteonecrosis research and treatment to discuss and formulate the Clinical Treatment Specification for Osteonecrosis of the Femoral Head for the reference of clinicians. The Code will be revised in time with the in-depth research and accumulation of clinical experience. The Code is not mandatory, has no legal effect and cannot be used as a legal basis for resolving medical disputes.
Definition
ONFH is a series of pathological changes and clinical manifestations of impaired or interrupted blood supply to the femoral head, resulting in death of bone marrow components and bone cells, followed by subsequent repair and structural changes to the femoral head, even collapse.
High risk groups for ONFH
1, hip trauma: femoral head and neck fracture; acetabular fracture; hip dislocation; severe sprain or contusion of the hip (without fracture, with intra-articular hematoma).
2.Large doses of glucocorticoids (GCs) applied for a long time.
3.Long-term heavy alcohol consumption.
4.High coagulation and low fibrinolytic tendency and autoimmune disease, using GCs.
5, History of decompression chamber work.
Diagnosis
Clinical manifestations (according to Chinese staging)
1, Pre-clinical (stage I): no symptoms and signs.
2.Early stage (stage II): no symptoms or only mild hip discomfort, including discomfort in the groin or greater trochanter, hip pain with strong internal rotation, and no significant impairment of joint movement.
3.Pre-collapse stage (middle stage, stage III): more severe hip pain, limp, limited internal rotation, and increased pain with strong internal rotation.
4.The collapse stage (middle and late stage, stage IV): moderately severe pain, obvious limp, moderate restriction of joint flexion and internal rotation and abduction.
5.Osteoarthritis stage (late stage, stage V): moderate or severe pain, severe claudication, significantly restricted joint movement (flexion, internal rotation, internal rotation), joint deformity (flexion external rotation, internal rotation).
Diagnosis method: pay attention to medical history, clinical symptoms and signs. Auxiliary examinations are recommended according to the following procedures
1.X-ray film: Recommend the orthogonal and frog position of both hips. The presence of crescent sign; or necrotic foci surrounded by sclerotic bone and segmental collapse can be diagnosed. x-ray can exclude osteoarthritis, ankylosing spondylitis, hip dysplasia, rheumatoid arthritis and other hip lesions originating from cartilage.
2, MRI: the gold standard for the diagnosis of ONFH. Its specificity and sensitivity are above 99%, and the recommended sequences are T1WI, T2WI and T2WI lipid-suppressed coronal and axial scans. Typical ONFH images are T1WI: banded low signal surrounding fat (medium and high signal) or necrotic bone (medium signal), T2WI: double line sign, and T2WI lipid suppression: high signal band at the edge of the lesion. For T1WI showing band-like low signal and T2WI lipid suppression showing bone marrow edema and joint effusion (Ⅰ°-Ⅲ°) in the femoral head neck in addition to the focal area, the lesion should be regarded as having progressed to the pre-collapse or collapse stage.
3.CT scan: Although CT scan cannot make stage I diagnosis of ONFH, it can clearly show the fracture of subchondral bone plate, the scope of necrosis foci and repair, etc. It is recommended to perform coronal and axial two-dimensional reconstruction.
4, nuclear bone scan: can provide clues to the stage I diagnosis, high sensitivity, specificity is not high. Showing cold areas in hot areas suggests ONFH, but MRI is needed to confirm.
5.Digital subtraction angiography (DSA) of femoral head: it is an invasive examination and is not recommended for routine application.
6.Histopathological examination: invasive operation, recommended to be used when making medullary core decompression and joint replacement to confirm the diagnosis.The diagnostic criteria for ONFH are osteocyte vacuolation fossa >50% in the trabeculae, involving adjacent multiple trabeculae and bone marrow tissue.
Diagnostic criteria: with or without high-risk factors, with or without clinical symptoms and signs, one of the following can be diagnosed
1.X-ray: necrotic foci surrounded by sclerotic bands; segmental collapse; crescentic sign; femoral head collapse but joint space maintenance.
2.MRI: T1WI: banded low signal, T2WI: bilinear sign, T2WI lipid suppression: high signal band around the circumference of the necrotic foci; T2WI lipid suppression: bone marrow edema and T1WI banded low signal in the femoral head neck except for the focal area.
3, CT: well-defined necrotic foci; subchondral fracture.
Diagnosis of preclinical (stage I)
1.For people at high risk of ONFH, regardless of clinical symptoms and signs, MRI scan is recommended after hip trauma (including after internal fixation); after high-dose GCs medication (from the date of medication); within 3 months to 12 months.
2, MRI should be performed at the time of consultation for those with a history of high coagulation and low fibrinolysis and decompression work, and reviewed every 6 months if necessary.
3, one hip has been clearly diagnosed as ONFH, if there is no contralateral image then MRI of both hips should be done.
4.There are no definite early diagnostic measures for heavy drinkers.
Diagnosis of bone infarction
MRI shows map-like changes in the bone marrow of the long bone stem or epiphysis, and late CT and X-ray may show bone marrow calcification or ossification shadow.
Differential diagnosis
The diagnosis of typical ONFH is not difficult, but should be differentiated from the following diseases.
MRI shows painful hip disorders with bone marrow edema in the femoral head neck
1. Transient osteoporosis. It is now collectively known as bone marrow edema syndrome (BMES). The cause is still unknown. The main point of differentiation from ONFH is that single hip onset accounts for more than 90% of the cases, T1WI of MRI has no band low signal, T2WI lipid suppression head and neck is uniform high signal, while the bone marrow edema of ONFH T1WI has band low signal, T2WI lipid suppression high signal is not uniform, necrotic lesion area is often low signal. BMES can completely dissipate on its own or 3-12 months after treatment.
2, osteochondrosis lesion (OCL). OCL is an osteochondritis lesion, which used to be called exfoliative osteochondritis and is now collectively referred to as OCL. it is usually seen in adolescents with a history of repeated bruises to the hip, unilateral, and MRI shows no banded low signal in the low signal area of the femoral head in T1WI, and CT scan shows osteochondral fragments with sclerotic edges, which is significantly different from ONFH.
3, subchondral insufficient fracture (SIF). It is commonly seen in elderly people with osteoporosis, and is more common in women. It is not easy to distinguish from ONFH because of the low signal of subchondral bone in T1WI and the high signal of lamellar T2WI suppression.
4. Intra-femoral head tumor. Isolated lesions can occur within the femoral head, benign with chondroblasts common, MRI shows T2WI lamellar high signal, T1WI no banded low signal, CT scan shows irregular osteolytic destruction, not difficult to distinguish from ONFH. Malignant tumors, such as low-grade central osteosarcoma, are sometimes more difficult to identify and should be carefully differentiated.
Differentiation with hip diseases originating from cartilage
1, young and middle-aged idiopathic osteoarthritis. This disease is easily confused with ONFH, especially before the joint space is significantly narrowed. The main point of differentiation is that the patient has no obvious cause of ONFH, and there is no band-like low signal in T1WI of MRI, but there is often a low signal area located in the middle of the femoral head joint surface, and subchondral bone cystic changes can be seen in CT scan, which is easy to distinguish from ONFH.
2, hip dysplasia secondary to osteoarthritis. X-ray shows shallow acetabular development, incomplete femoral head, narrow joint space, and secondary osteoarthritis are easier to identify.
3, ankylosing spondylitis involving the hip joint. It is common in adolescent males with bilateral sacroiliac joint involvement and HLA-B27 positivity. The femoral head remains round but the joint space is narrowed.
4, rheumatoid arthritis. Rheumatoid arthritis is a systemic polyarticular lesion. Involvement of the hip joint early manifests as joint gap narrowing, acetabulum and femoral head cartilage and subchondral bone erosion, CT scan can clearly show.
Synovial lesions of the hip
1. Pigmented villonodular synovitos (PVNS). Early on, it is often misdiagnosed as ONFH. MRI shows diffuse low signal in T1WI, and CT shows erosion of both femoral head and acetabular cortical bone. The onset of single hip is completely different from ONFH changes.
2, synovial osteochondromatosis. MRI shows T1WI diffuse low signal, T2WI lipid suppression shows synovial edema, joint effusion and multiple low signal shadows, CT can clearly show the calcified free body in the joint.
Staging
Once femoral head necrosis is diagnosed, it should be staged. The purpose of staging is to guide the formulation of treatment plans, determine the prognosis and evaluate the efficacy of treatment. Commonly used internationally are Ficat staging, ARCO staging, University of Pennsylvania staging, Marcus et al. staging, and Japanese Investigation Class of Osteonecrosis (JIC) staging, all of which have certain application value. According to the clinical practice in recent years, we propose to develop Chinese staging based on the Pennsylvania University staging and make improvements.
Description.
1, the estimation of necrosis area: Ⅰ, Ⅱ stage need to make necrosis area estimation, the method is to choose MRI or CT coronal median level to assess the necrosis area, small: <15%; medium: 15%-30%; large: >30%. Necrosis volume was assessed by the number of layers involved in necrosis.
In stage III, the risk of imminent collapse should be evaluated by the length of the crescentic sign of the articular surface in frog or ortho-anterior radiographs, minor: <15%; moderate: 15%-30%; major: >30%.
3, Stage IV need to assess the degree of collapse, by ortho or frog X-ray, measured by the depth of joint surface collapse, light: <2mm; medium: 2-4mm; heavy: >4mm.
4. For patients whose X-rays do not show femoral head collapse but present with hip pain, further MRI and CT examinations are required. The presence of bone marrow edema or changes of subchondral bone plate fracture suggests that the necrosis has progressed to will collapse (stage III).
5. Collapse has already occurred and hip pain has been present for more than 6 months, suggesting significant degeneration of articular cartilage (stage V).
Typing
Femoral head is staged according to the site occupied by the necrotic foci. Staging is important for the estimation of prognosis and prediction of femoral head collapse, and for the selection of reasonable hip preservation treatment plan. Internationally, there are Japanese Investigation Class of Osteonecrosis (JIC) staging and Central Japan Hospital (CJFH) staging, and CJFH staging is used in this standard.
Based on the three-column structure of the femoral head, the necrotic foci occupy the three-column structure, and MRI or CT scan is used to classify them into: M-type (medial type) necrotic foci occupy the medial column; C-type (central type) necrotic foci occupy the central column; L1-type (sub-lateral type) necrotic foci occupy the lateral, middle and medial columns, but the lateral column is partially preserved; L2-type (extreme lateral type) necrotic foci occupy the lateral column, the central type L3 (total femoral head type) necrotic foci occupy the whole femoral head.
Treatment
The treatment of ONFH can be divided into three parts.
Non-surgical treatment
1. Protective weight-bearing, avoiding percussive and antagonistic movements. For early and mid-stage patients, pain can be reduced, the application of double crutches is recommended, and the use of wheelchairs is not advocated.
2.Medication treatment. Including Chinese and Western medicines.
(1) Western medicine: for early necrosis, anticoagulation, increase fibrinolysis, vasodilatation and other drugs can be used, such as low molecular heparin, prostaglandin, etc. Apply drugs that inhibit osteolysis and increase osteogenesis, such as phosphate preparations, methyldopa, etc. Depending on the situation of necrosis, the drugs can be used alone or in combination with hip preservation surgery.
(2) Chinese medicine treatment: Chinese medicine prevention and treatment of femoral head necrosis emphasizes early diagnosis and early treatment and overall regulation, and the prescription of medicine is based on Chinese medical evidence. The basic method of prevention and treatment is to activate blood circulation and eliminate blood stasis, supplemented by promoting blood circulation and relieving pain, tonifying the kidneys and strengthening the bones, and strengthening the spleen and promoting dampness, etc. Specific methods of prevention and treatment are chosen according to the different clinical symptoms of patients. Chinese herbal preparations such as Epimedium and Mucuna pruriens have been used in clinical practice. Chinese herbal medicine can be used for femoral head necrosis without collapse or symptomatic but not involving the lateral column of the femoral head, and Chinese herbal medicine can also be used in conjunction with hip preservation surgery to help improve the efficacy of hip preservation.
3. Physical therapy: including extracorporeal shock wave, electromagnetic field, hyperbaric oxygen, etc.
Hip preservation surgery treatment
Hip preservation surgical treatment includes medullary decompression or combined with autologous bone marrow single nucleus cell implantation; lesion removal, bone graft with or without blood transport; and osteotomy.
1.Medullary decompression. It is effective in relieving pain, and it is recommended to apply a fine drill (3.5 mm) and drill multiple holes in the femoral head.
2.Autologous bone marrow single nucleated cell implantation. More than 200ml of bone marrow blood from the iliac bone should be taken, and single nucleated cells should be isolated in vitro (without culture medium) and implanted simply by injection or by carrier. It is still in the experimental stage and should be used with caution.
3. Necrotic lesion removal with or without hematopoietic bone grafting. The accesses for lesion removal include trans-femoral subtrochanteric, anterior trans-femoral, cervical junction opening and trans-femoral cartilage flap (trap-door), each with its own advantages and disadvantages, which can be applied optionally. Decompression should be accompanied by bone grafting.
4.Free vascularized fibula graft. The efficacy is precise and the technical requirements are high.
5.Bone graft with blood vessels. Including with spin iliac deep and superficial arteriovenous iliac bone graft, with spin lateral femoral branch greater trochanter bone, with gluteus medius branch greater trochanter bone, etc.
6, with myotubular bone graft. With femoral square muscle bone graft is the common method.
7.Homogeneous or autologous fibula graft, artificial bone product support bone graft.
8.Bone grafting with compression. Autologous bone, allogeneic bone with or without artificial bone and BMP2.
9.Osteotomy. At present, there are more applications such as rotational osteotomy of the femoral head neck via the greater trochanter and inversion osteotomy via the femoral subtrochanter.
10, the choice of tantalum rod should be cautious, not recommended through the vascular simple interventional treatment.
Arthroplasty
A significant proportion of ONFH patients eventually have to receive artificial joint replacement. With the improvement of artificial joint design, material and process, the popularization and improvement of technology, the adaptation range of hip preservation surgery is narrowing, and the adaptation range of artificial joint replacement is gradually expanding [64~66].
The types of artificial joints available for patients with ONFH are.
1. surface replacement. The scope of adaptation is limited, the necrotic volume is not applicable, and the complications on the gold-bearing surface make the application decrease.
2, femoral head replacement. Because it can not predict whether the postoperative pain and acetabular wear, to limited indications.
3, total hip replacement with short-stemmed femoral prosthesis. Under development.
4.Total hip arthroplasty. This is the most classic, most mature, the effect is certainly lasting artificial joint surgery, applicable to the majority of stage IV, V ONFH patients, for middle-aged and young patients, it is recommended to use wear-resistant load-bearing surface (ceramic to ceramic, ceramic to high cross-linked polyethylene), biological bone growing into the type of prosthesis.
Treatment selection principles
The choice of treatment plan for ONFH should be individualized according to the stage and fractionation of lesions, age, occupation and compliance with hip preservation surgery, hospital conditions, physician skills and other comprehensive considerations.
The following selection principles should also be followed for ONFH (resting hip) without clinical symptoms.
1. Stage I and II, type M. Follow up, observation or comfort treatment.
2. Stage I and II, type C. Extracorporeal shock wave, medullary decompression or lesion removal, autologous bone marrow transplantation or compression osteotomy, drug treatment.
3.Stage I, II, L1 type. Focal removal, bone grafting with blood vessels or blood transport, or compression bone grafting, drug treatment. 35 years old, internal osteotomy can be chosen.
4. Stage I, II, L2, L3. Focal clearance support bone graft (bone graft with blood vessel or blood transport) or compression bone graft, L2 type, 35 years old, can choose trans-femoral rotational osteotomy.
5, stage III. 50 years old, hip preservation is the main method, the same as 4. 50 years old, heavy pain, poor joint function, can choose artificial joint replacement.
6.Stage Ⅳa, b. 40 years old, try to preserve the hip. 40 years old, heavy pain, poor joint function, can choose artificial joint replacement.
7.Stage IVc, V. If the pain is heavy and the joint function is poor, artificial joint replacement can be chosen.
Efficacy assessment and prognosis prediction
Efficacy assessment
Clinical and imaging assessment should be done separately.
Clinical assessment can be done by Harris hip function assessment, UCLA hip activity assessment and European assessment (merle Aubigne & Post).
The imaging assessment is based on X-ray, which is used to observe the shape of the femoral head, whether it is collapsed or not, and changes in the joint space.
Clinical and imaging scores are sometimes unequal, especially in young people, and the clinical assessment should be the main reference.
Prognosis prediction
1. The following patients can be expected to have better hip preservation outcomes.
(1) Diagnosis obtained before collapse (stage I, II), appropriate choice of treatment plan and standardized application of technology.
(2) M-type and C-type are expected to have a good prognosis.
(3) Type L1, with proper treatment selection and good prognosis.
2, in the pre-collapse patients should be treated in a timely manner, the prognosis is better, such as collapse time is longer (> 6 months) and then treated patients, the prognosis is unpredictable.
3. For the same type of ONFH in the same period, the prognosis of young patients (<35 years old) is better than that of middle-aged and old patients, so the indications for hip preservation surgery for young patients can be relaxed.