Adult ischemic necrosis of the femoral head (ANFH) is not an isolated disease, but mostly a pathological process caused by a combination of diseases or etiological factors that lead to the destruction of the blood supply to the femoral head or the degeneration of bone cells, which in turn leads to the death of the viable components of bone (osteocytes, bone marrow hematopoietic cells and adipocytes); the disease occurs mostly in young adults, with an average age of onset of 38 years. The pathological process is complex, and if timely and effective treatment is not received in the early stage, the femoral head will collapse, the joint space will narrow, and finally lead to osteoarthritis, and most patients will eventually need total hip replacement.
Therefore, active treatment should be taken in the early stage of the disease to relieve or cure the disease, so that the patient’s femoral head can be preserved or the time of artificial joint replacement can be delayed, because the artificial total hip joint has a limited service life and its effect is worse than that of artificial joint replacement due to other diseases. Most of the patients are very young, and once the artificial joint is replaced, it is often necessary to perform several revision surgeries, which brings great physical and mental pain to the patients and their families, and also creates a heavy economic burden.
Although the clinical results of various treatments for osteonecrosis of the femoral head are not satisfactory, it is certain that the final outcome will be worse if surgery is not taken, and eventually about 80% of cases will develop into cartilage collapse of the osteoarticular surface. In this paper, we review the progress of treatment of femoral head necrosis.
I. Non-surgical treatment
(1). Various measures to reduce or avoid weight-bearing in order to wait for the femoral head to repair itself, but the results are not good. Femoral head necrosis even without weight-bearing still suffers from considerable muscle pressure, which can cause the femoral head to collapse, and some people think there is no difference between weight-bearing, non-weight-bearing and partial weight-bearing. Foreign statistics of 182 hip follow-ups in 21 hospitals showed that the improvement rate of clinical signs was only 35% in stage I, 31% in stage II and 13% in stage III.
(2) Pulsed electromagnetic field therapy. many scholars began to use pulsed electromagnetic field therapy to treat ischemic necrosis of the femoral head in the early 1980s. Aaron et al. compared electromagnetic field and medullary decompression to treat 100 patients with Ficat stage II and III respectively, and followed up for 24-36 months, confirming that both methods were effective, but the former effect was significantly greater than the latter. It was confirmed that electromagnetic field can slow down the process of femoral head collapse, which is not a bad choice for pre-surgical treatment, but there is still a lack of longer follow-up data, and further research and observation are needed.
(3) Hyperbaric oxygen therapy. Iapicca et al. first reported in 1990 that the application of hyperbaric oxygen (HBO) was effective in the treatment of ANFH, and HBO has been widely used in clinical practice. Reis et al. reported 12 patients with stage I ANFH (hip pain, no abnormal X-ray manifestations, positive bone scan and MRI) who received HBO therapy 100 times (0.2.-0.24Mpa. 90 min/time, 6 times a week), 81% of the patients recovered normal MRI examination, while only 17% of the control group recovered; they concluded that HBO therapy can be used with methods such as medullary core decompression and should not be used only as an adjuvant therapy.
Jiang Xiuqin et al. randomly divided 88 patients with femoral head necrosis into 48 cases in the HBO group and 40 cases in the drug group; the results showed that the cure rate of the HBO group (0.25 MPa, 60 min/time, 30-80 times) was 4.2% and the efficiency rate was 95.8%, while the efficiency rate of the control group was 60%, which was a very significant difference. HBO therapy is a non-invasive physical therapy, and numerous studies have shown that HBO combined with HBO therapy is a non-invasive physical therapy, and numerous studies have shown that HBO combined with other non-surgical or surgical treatments is one of the best options for the treatment of early ANFH, but the optimal protocol and mechanism of action of HBO for the treatment of ANFH need to be further investigated in depth in order to better utilize its therapeutic advantages.
(4) Extracorporeal shock wave therapy. Extracorporeal shock wave has been widely used in clinical practice for the treatment of osteonecrosis, delayed bone healing and some soft tissue tendon inflammation. Although its mechanism for treating ischemic necrosis of the femoral head is not clear, many scholars have used it in clinical treatment. ludwig et al. used shock wave for treating 22 cases of ischemic necrosis of the femoral head (10 women and 12 men, mean age 54.9 years), and the follow-up after 1 year of shock wave treatment showed that the patients’ pain score decreased from 8.5 points before treatment to 1.2 points. The Harris hip score increased from 43.3 to 92.
After 4 years, 21 more patients were followed up, of whom the mean Harris hip score reached 88 and the nociceptive score was 2.2. Ludwig et al. concluded that shockwave had a good cure rate in patients with low bone circulation study session staging (stage I, II), consistent with surgical outcomes; 23% of patients could delay the time to surgery for total hip replacement. The cytological and molecular mechanisms of extracorporeal shock wave therapy for ischemic necrosis of the femoral head, and what kind of energy and intensity of shock wave is the best source for this disease are still unclear and need to be further explored.
(5) Interventional therapy. Interventional therapy is the application of Seldinger technique, under the surveillance of TV X-ray machine, to inject a variety of effective drugs directly into the blood vessels supplying blood flow to the femoral head, such as the internal and external femoral arteries, in order to achieve the purpose of treating femoral head necrosis. Local application of thrombolytic, antispasmodic and vasodilatory drugs can improve the blood supply to the femoral head, lower the intraosseous pressure, promote necrotic bone resorption and new bone formation, and create an environment conducive to the repair and regeneration of the osteonecrotic area. Most of the reported interventional methods for the treatment of ANFH are effective, and almost all patients are effective after treatment, with an excellent rate of 70-80% or more.
In these articles, the efficacy was judged from symptoms and angiography, etc. Zuo Lixin et al. studied the changes of blood gas analysis values in the medullary cavity before and after the interventional treatment of ANFH and found that the interventional treatment could temporarily increase the blood circulation in the femoral head, but could not improve the blood circulation in the femoral head for a long time.
Liu Cangjun et al. retrospectively analyzed the imaging stages of 80 patients, and observed that the pain relief Ficat I-II stage was 94% and III-IV stage was 12% through 12-36 months of follow-up. The therapeutic mechanism of interventional drug injection is still not very clear, the change of intramedullary pressure before and after treatment lacks accurate data, the pathological process of osteonecrosis in interventional treatment is still unclear, and the interventional treatment of ANFH is still in the exploratory stage, and many problems need further exploration and research.
II. Surgical treatment
2.1 Intramedullary decompression is a common surgical treatment for osteonecrosis of the femoral head based on the pathological basis of increased intramedullary pressure of femoral head necrosis.
Bozic et al. reported the results of 34 cases (54 hips) with up to 10 years of treatment, and the success rates were 69% (9/13) in stage I, 43% (10/23) in stage IIA, and 10% (1/10) in stage IIB, with symptomatic improvement or no radiological malignancy as the success evaluation point. Failure rates were analyzed by KaplanMerier femoral head survival curves, statistical significance was determined by Log rank test, and risk factors for clinical and imaging progression after medullary core decompression were identified and evaluated using Cox proportional hazards and chi-square tests.
The results suggested that hormones were the cause of deterioration from the etiology; from the staging, the procedure was suitable for patients with femoral head sclerosis predominantly in Ficat stage I and IIA, while it was difficult to prevent head collapse in patients with cystic degeneration predominantly in stage IIA and in stage IIB. With the widespread use of this procedure, it has been suggested that the extent of necrosis is closely related to the outcome.
The results showed that 13 of the 15 hips collapsed in 50% of the necrotic extent. Therefore, the authors concluded that medullary core decompression is effective in preventing head collapse in cases with a small extent of necrosis. Markel et al. analyzed the outcome of 45 cases (54 hips) undergoing core decompression, of which 11, 32, and 7 hips each had Ficat stage I, IIA, and IIB, and 6, 20, and 6 hips each had head collapse at a mean of 11.1 months after surgery, with a recent failure rate of 64%. The recent failure rate was 64%.
The authors concluded that medullary decompression can accelerate the collapse of the femoral head. In the repair of the necrotic area of the femoral head, with the reconstruction of blood flow, the rate of bone breakdown and bone resorption is often greater than that of new bone formation, and medullary decompression can further weaken the mechanical support of the already weak subchondral bone, thus accelerating the collapse of the femoral head; especially in patients with hormone-induced AVN, the osteoporosis of the femoral head is obvious, and medullary decompression will lead to stress concentration and accelerate the collapse of the femoral head. Therefore, simple medullary decompression of the femoral head is rarely used at present.
2.2 Core decompression + simple bone grafting. After the bone graft is decompressed and the dead bone is removed, the femoral head lacks the necessary mechanical support. Bone grafting without vascular tip is to fill the bone with autologous or allogeneic cortical bone or cancellous bone and lift the collapsed femoral head joint surface to support and induce osteogenesis. It was once a popular treatment for ischemic necrosis of the femoral head because it removed necrotic bone and reduced intraosseous pressure, while providing limited mechanical support.
Rosenwasser et al. reported a case of ischemic necrosis of the femoral head in stages II-III treated by complete removal of dead bone from the necrotic area of the femoral head with cancellous bone grafting, in which a window was made at the femoral head-neck junction with an anterolateral approach and the dead bone was completely removed under the monitoring of an image intensification device. This procedure is considered to be suitable for Ficat stage II-III cases.
Mont et al. reported that the treatment of ischemic necrosis of the femoral head in Ficat stages III-IV was performed by window decompression with autologous cortical bone grafting, and after an average follow-up of 56 months, 86% of the stage III cases had excellent results according to the Harris scale, while only 33% of the stage IV cases had excellent results.