I. Overview Yan Denglu, Department of Orthopaedic Surgery, The First Hospital of Guangdong Pharmaceutical University
The definition of osteonecrosis of the femoral head (ONFH) by the International Society of Bone Circulation (ARCO) and the American Academy of Osteologists (AAOS): ONFH is a disease in which the blood supply to the femoral head is interrupted or damaged, causing the death of bone cells and bone marrow components and subsequent repair, which then leads to structural changes in the femoral head and collapse of the femoral head, causing joint pain and joint dysfunction in patients, and is a common and intractable disease in the field of orthopedics.
ONFH can be divided into two categories: traumatic and non-traumatic. The former is mainly caused by hip trauma such as femoral neck fracture and hip dislocation, while the latter is mainly caused by corticosteroid application, alcoholism, decompression sickness, sickle cell anemia and idiopathic in China.
Second, the diagnostic criteria
Referring to the diagnostic criteria proposed by the Japanese Ministry of Health and Welfare Osteonecrosis Research Society (JIC) and Mont, the following diagnostic criteria are formulated in China.
1.Clinical symptoms, signs and history Arthralgia mainly in the groin, hip and thigh area, occasionally accompanied by knee pain and limited internal rotation of the hip joint, often with a history of hip trauma, history of corticosteroid application, history of alcoholism and occupational history such as divers.
2.MRI T1WI shows band-like low signal or T2WI shows double line sign.
3.X-ray film changes Common sclerosis, cystic changes and crescentic signs and other appearances.
4.CT scan changes: sclerotic bands around necrotic bone, repaired bone, or subchondral bone fracture.
5.Nuclear bone scan shows perfusion defect (cold area) at the initial stage; necrosis repair stage shows cold area in hot area, i.e. “bagel-like” changes.
6. Bone biopsy shows more than 50% osteocyte vacuoles in the trabeculae and involvement of adjacent trabeculae with bone marrow necrosis.
Expert advice: meeting two or more criteria can confirm the diagnosis: except for 1, 2, 3, 4 and 6 can be diagnosed by meeting one of them.
Differential diagnosis
Patients with similar clinical symptoms, x-ray changes or MRI changes should be differentiated.
1, intermediate and advanced hip osteoarthritis When the joint space is narrowed and subchondral cystic changes appear, it may be confused, but its CT shows sclerosis with cystic changes and Mill changes are mainly low signal, which can be differentiated accordingly.
2, acetabular dysplasia secondary to osteoarthritis Femoral head wrapping incomplete, narrowing and loss of joint space, osteosclerosis, cystic changes, the corresponding area of the acetabulum appears similar changes, easy to identify.
3, ankylosing spondylitis involving the hip joint Common in adolescent males, mostly bilateral sacroiliac joint involvement, which is characterized by HLA-B27 positive, the femoral head remains round, but the joint space is narrowed, disappeared or even fused, easy to distinguish. Some patients with long-term application of corticosteroids can be combined with ONFH, the head of the femur can appear collapsed but often not heavy.
4, rheumatoid arthritis Most commonly seen in women, the femoral head remains round, but the joint space becomes narrow and disappears; common femoral head joint surface and acetabular bone erosion, easy to distinguish.
5, chondroblastoma within the femoral head MRI T2WI shows lamellar high signal, CT scan shows irregular osteolytic destruction.
6.Transient osteoporosis (ITOH) can be seen in middle-aged and young people, and is a temporary painful bone marrow edema; X-ray shows reduced bone mass in the femoral head, neck and even rotor: MRI shows uniform low signal in T1WI and high signal in T2WI, which can range to the femoral neck and rotor, without banded low signal, and can be differentiated from ONFH. The lesion can be dissipated within 3-12 months.
7, subchondral incomplete fracture Most commonly seen in elderly patients over 60 years old, without obvious history of trauma, showing sudden onset of hip pain, inability to walk, and limited joint movement. x-ray shows slight flattening of the upper outer femoral head, T1 and T2-weighted phase of MRI shows subchondral low signal lines, surrounding bone marrow edema, and T2 lipid suppression phase shows lamellar high signal.
8, hyperpigmented villous nodular synovitis Most often occurs in the knee joint, and hip joint involvement is rare. CT and radiographs may show cortical bone erosion of the femoral head, neck or acetabulum and mild to moderate narrowing of the joint space. MRI shows extensive synovial hypertrophy with a uniform distribution of low or moderate signal.
9, synovial herniation pit This is a benign lesion of synovial tissue proliferation invading the cortex of the femoral neck, MRIT, T1WI low signal, T2WI high signal small circular lesion, located in the upper cortex of the femoral neck, usually asymptomatic.
10, bone infarction Osteonecrosis occurring in the long bone stem has different imaging manifestations at different times, MRI manifestations are: ① acute stage: the center of the lesion shows equal or slightly high signal with normal bone marrow in T1WI, high signal in T2WI, long T1 and long T2 signal at the edge; ② subacute stage: the center of the lesion shows similar or slightly low signal with normal bone marrow in T1WI, similar or slightly high signal with normal bone marrow in T2WI, and long T1 and long T2 signal at the edge. (2) subacute stage: T1WI of the center of the lesion showed similar or slightly low signal to normal bone marrow, T2WI showed similar or slightly high signal to normal bone marrow, and long T1 and long T2 signal at the edge.
IV. Staging and staging
Once the diagnosis of femoral head necrosis is confirmed, staging should be made to guide the development of a reasonable treatment plan and accurately determine the prognosis. Experts recommend mainly using ARCO staging and Steinberg staging, with reference to Ficat staging. Regarding the staging criteria of femoral head necrosis, domestic experts refer to the aforementioned staging and JIC staging, and put forward improved staging, which can be referred to.
Five, the treatment of femoral head necrosis
There are many treatment methods for femoral head necrosis, and the development of a reasonable treatment plan should take into account factors such as staging, necrosis volume, joint function and patient age, occupation and compliance with joint preservation treatment.
(I) Non-surgical treatment
It is mainly applied to patients with early stage of femoral head necrosis.
1.Protective weight-bearing The use of double crutches can effectively reduce pain, but the use of wheelchairs is not advocated.
2.Medication Non-steroidal anti-inflammatory drugs, low-molecular heparin, alendronate sodium, etc. have certain efficacy, and vasodilator drugs also have certain efficacy.
3.TCM treatment Take the holistic view of Chinese medicine as the guide, follow the basic principles of “combining movement and static, tendons and bones, internal and external treatment, and cooperation between doctors and patients”, and emphasize early diagnosis, combination of disease and evidence, and early standardized treatment. For patients in the subclinical stage, Chinese herbal medicines are mainly used to activate blood circulation and resolve blood stasis, supplemented by removing phlegm and dampness and tonifying kidney and bone, which can promote necrosis repair and prevent or reduce collapse; for femoral head necrosis with pain and other symptoms before collapse, on the basis of protective weight-bearing, Chinese herbal medicines are used to activate blood circulation and resolve blood stasis, promote water and dampness, which can relieve pain and improve joint function; for post-collapse femoral head necrosis, together with surgical repair surgery, can improve surgical effect.
4.Physical therapy includes extracorporeal shock wave, high frequency electric field, hyperbaric oxygen, magnetic therapy, etc., which are beneficial to relieve pain and promote bone repair.
5.Braking and appropriate traction are suitable for ARCO stage I and II cases.
(B) Surgical treatment
Most patients with ONFH will face surgical treatment, which includes two major types of surgery: preserving the patient’s own femoral head and artificial hip joint replacement. Preservation of the femoral head surgery includes medullary core decompression, bone grafting, osteotomy, etc. It is suitable for patients with ARCO stages I and II and IIIa and IIIb, and patients with ONFH with a necrosis volume of 15% or more. If the method is appropriate, artificial joint replacement can be avoided or postponed.
1, femoral head medullary core decompression The history of medullary core decompression is long and the efficacy is certain. At present, it can be divided into fine needle drilling decompression surgery and coarse channel medullary decompression surgery. The difference mainly lies in the different diameter of the decompression channel. The diameter of the solitary channel of fine needle drilling decompression is 3mm, 3.5mm or 4mm; the diameter of the pore channel of coarse channel medullary core decompression is 6mm or more. Experts recommend using a fine needle (about 3mm in diameter) and drilling multiple holes under fluoroscopic guidance. It can be combined with implant material. Core decompression combined with stem cell transplantation (or concentrated autologous bone marrow single nucleus cell transplantation) is currently a Class III medical technology under the control of the Ministry of Health and is not widely performed in China. Based on the good results of clinical application in some domestic units, experts suggest that it should be applied with caution after the establishment of a multicenter long-term follow-up reporting system with large samples.
2.Bone grafting without hemorrhage There are more applications such as trans-femoral rotor decompression bone grafting and trans-femoral head neck bulb decompression bone grafting. Bone grafting methods include compression bone grafting and support bone grafting. The applied bone grafting materials include autologous cancellous bone, allograft bone and bone replacement material.
3.Osteotomy The necrotic area is moved out of the weight-bearing area of the femoral head. The osteotomies used in clinical practice include internal or external osteotomy and transfemoral rotational osteotomy. Osteotomy is chosen on the principle of not altering the femoral medullary cavity.
4, with blood transport autologous bone graft Autologous, gastric? transplantation can be divided into periprosthetic bone flap transplantation and fibula transplantation: there are various choices of periprosthetic bone flap with vascular tip: ① iliac bone (membrane) flap transfer with ascending branch of the lateral vessels of the rotating femur; ② greater trochanteric bone flap transfer with ascending branch of the lateral vessels of the rotating femur to the gluteus medius branch; ③ greater trochanteric bone flap transfer with transverse branch of the lateral vessels of the rotating femur; ④ iliac bone (membrane) flap transfer with deep vascular tip of the rotating iliac; ⑤ the whole femoral head or even part of the femoral neck is are involved, the transverse branch greater trochanteric flap combined with ascending branch iliac (membrane) flap can be used to reconstruct the femoral head (neck); (6) deep branch greater trochanteric flap of the medial vessels of the rotator femur and deep superior branch iliac flap of the superior gluteal vessels in the posterior approach to the hip joint; (7) bone flap (column) with femoral squared muscle tip: periacetabular bone flap with vascular tip is less invasive, more effective, and the surgical method is easy to master, and it is recommended: to increase the strong support within the femoral head, in the application of The periprosthetic hip flap can be combined with the implantation of tantalum metal rods, which can effectively avoid postoperative femoral head collapse, and this method has good short-term efficacy, while the long-term efficacy is yet to be determined: the surgical effect of anastomotic vascularized fibula graft is also more certain: if this method is properly applied, the efficacy is better, and it is recommended: the choice of different vascularized bone flaps can be based on their advantages and disadvantages, the operator’s proficiency and other factors.
5, artificial joint replacement Once the femoral head collapses heavily (ARCO stage IIIc, stage IV), there is a serious loss of joint function or pain, artificial joint replacement should be selected: it is generally believed that the medium and long-term efficacy of non-cemented or hybrid prostheses is better than cemented prostheses; the human subtrochanteric joint replacement of femoral head necrosis is different from the joint replacement of other diseases, some related issues should be noted: ① patients long-term application of corticosteroids, or have underlying diseases need to continue treatment, so the infection rate is increased; ② long-term non-weight-bearing, osteoporosis and other reasons lead to easy penetration of the prosthesis into the acetabulum; ③ had performed surgery to preserve the femoral head, will bring a variety of technical difficulties; ④ hormonal ONFH, alcoholic ONFH is not only the lesion of the femoral head, its surrounding that is, the whole body bone has also been damaged: Therefore, hormonal ONFH, alcoholic ONFH to perform artificial joint replacement of long-term results, may not be as osteoarthritis or traumatic ONFH:.
Sixth, the principles of treatment plan selection
The choice of treatment plan should be based on the stage of necrosis, the age of the patient, the patient’s compliance with joint preservation therapy and other comprehensive considerations.
(A) Treatment options for different stages of femoral head necrosis
For non-traumatic ONFH cases, if the diagnosis is confirmed on one side, the contralateral side should be highly suspected and bilateral MRI examination is advisable, and follow-up every 3-6 months is recommended.
Treatment of asymptomatic ONFH is recommended for ONFH with large necrosis volume (>30%) and necrosis located in the weight-bearing zone should be treated aggressively and should not wait for symptoms to appear: a combination of medullary core decompression or non-surgical treatment tools is recommended.
ARCO stage I: if it belongs to asymptomatic, non-weight-bearing area, lesion area <15%, it can be closely observed and regularly followed up; those with symptoms or lesions >15% should be actively treated with non-surgical treatment such as lower limb traction and drugs, and also feasible to preserve joint surgical treatment, and medullary core decompression (stem cell transplantation or concentrated white body bone marrow single nucleus cell transplantation) is recommended.
ARCO stage II: In cases where the femoral head has not yet collapsed, marrow core decompression (stem cell transplantation or concentrated autologous bone marrow single nucleus cell transplantation), autologous bone grafting with hematopoiesis, bone grafting without hematopoiesis (15% < necrosis extent < 30%) are recommended.
ARCO stage IIIa, IIIb: various autologous bone grafts with hematopoiesis are recommended.
ARCO stage III and IV: In ONFH cases, if the symptoms are mild and the age is young, joint preservation surgery can be chosen and bone grafting with vascularized autologous bone is recommended (e.g., greater trochanteric bone flap with vascularized tip combined with iliac bone graft, etc.); artificial total hip replacement is recommended for severe collapse of the femoral head.
Femoral head preservation surgery can often apply one or two of several surgical procedures to 』: the combination is recommended, such as medullary core decompression with bone flap grafting: non-surgical treatment should also be within the scope of comprehensive treatment.
(B) Age factors and the choice of treatment options
Young and middle-aged ONFH cases, due to the greater activity of the patient, should choose the treatment plan that can preserve the head and does not adversely affect the possible human ding arthroplasty: recommended: medullary core decompression (stem cell transplantation), white body bone grafting with hemorrhage, bone grafting without hemorrhage (15% < necrosis range < 30%).
Middle-aged ONFH cases, if in the earlier stages of ONFH (no collapse) should do their best to preserve the head, such as medullary core decompression, bone grafting with or without blood transport; if in the middle and late stages of ONFH, should be combined with the patient’s subjective desire and technical conditions to choose head preservation treatment or human ding arthroplasty: when deciding to perform human thousand joint replacement, preoperative prosthesis selection should fully consider the possibility of secondary revisions.
For elderly (>55 years old) ONFH cases, artificial total hip arthroplasty is recommended.
For elderly ONFH cases, it depends on the patient’s original daily activity status, the bone quality of the hip, and the expectation of the longevity of life. It is recommended to perform bipolar (tripolar) artificial femoral head replacement or artificial total hip arthroplasty.
VII. Efficacy evaluation and rehabilitation exercise
The evaluation of the efficacy of ONFH can be divided into clinical evaluation and imaging evaluation. Clinical evaluation adopts hip function score (such as Harris score, WOMAC score, Chinese Medical Association Orthopedic Branch percentage method for efficacy evaluation, etc.), and should be evaluated on a case-by-case basis according to the same stage, similar necrosis area, and the same treatment method. Gait analysis information is also recommended. Imaging evaluation can be applied to x-ray films, using concentric circle templates to observe femoral head shape, joint space and acetabular changes. MRI data should be available for the evaluation of lesions up to stage II. For patients with hemorrhagic bone graft, DSA should be performed and used to evaluate hemorrhagic recovery. Experts recommend the establishment of case files for ONFH patients to accumulate more valuable information, which can help evaluate the efficacy of different etiologies, different necrosis periods, different ages, and different treatment methods, and help reach a consensus on more standardized treatment of ONFH.
Rehabilitation exercise can prevent wasting muscle atrophy in patients with ONFH, and is an effective means to promote early recovery of function. The functional exercise should be mainly active, supplemented by passive, from small to large, from less to more, gradually increasing, and according to the stage of femoral head ischemic necrosis, treatment modality, hip function score and gait analysis data, choose the appropriate exercise method.
(1) Reclining leg lift method: lie on your back, lift the affected leg, flex the hip and knee 900, and repeat the action. 200 times a day in 3 to 4 sessions. Apply to: ONFH conservative treatment as well as surgical treatment after the bedridden period.
(2) Sitting splitting law: sitting on a chair, hands on knees, feet shoulder-width apart, left leg to the left, right leg to the right while fully abducting and adducting. Perform 300 times daily in 3 to 4 sessions. Application: ONFH conservative treatment and post-surgical treatment can be partially weight-bearing period.
(3) Standing leg lift method: hold the fixation with your hand, keep your body upright, lift the affected leg so that your body is at a right angle to your thigh, flex your hip and knee 900, and repeat the action. 300 times daily in 3-4 sessions. Apply to: ONFH conservative treatment and surgical treatment can be partially weight-bearing period.
(4) hold the object squatting method: hand hold the fixed object, body upright, feet shoulder-width apart, squat and then stand up, the action repeated. 300 times a day, in 3 to 4 times. Apply to: ONFH conservative treatment and surgical treatment can be fully weight-bearing period.
(5) Internal rotation and abduction method: hand holding the fixation, legs are doing full internal rotation, abduction and circle movement. 300 times a day, divided into 3-4. Apply to: ONFH conservative treatment and surgical treatment can be fully weight-bearing period.
(6) Adhere to the training of walking with crutches or cycling exercise. Apply to: ONFH conservative treatment and surgical treatment can be fully weight-bearing period.