Avascular Necrosis of Bone: A Review1

The Many Faces of Marrow Necrosis

Depending on the age and location within the skeleton, bone marrow can be mostly fatty or hematopoietic, and both types can be affected by marrow necrosis. This review article highlights the magnetic resonance imaging findings of disorders in which marrow necrosis is the dominant feature.Fatty marrow necrosis is detected on T1-weighted images that show an early and specific finding: the reactive interface. Collapse is a frequent complication of epiphyseal necrosis and detected on fat-suppressed fluid-sensitive sequences or using conventional radiographs. Nonfatty marrow necrosis is less frequently diagnosed. It is poorly visible on T1-weighted images, and it is detected on fat-suppressed fluid-sensitive images or by the lack of enhancement after contrast injection.Pathologies historically "misnamed" as osteonecrosis but do not share the same histologic or imaging features of marrow necrosis are also highlighted.

Approach to a patient with monoarticular disease

PURPOSE

To reassess the diagnostic approach to a patient with a monoarticular disease in light of the up-to-date medical literature and to examine the practical utility of traditional and newer imaging tools in the setting of monoarthritis.

RESULTS

The monoarticular disease can represent a medical emergency on the one hand and be a diagnostic conundrum on the other. The management rules of patients with monoarthritis have been established long ago, but various pitfalls still lead physicians off the right diagnosis at times. Septic, pseudoseptic arthritis and hemarthrosis are the most common diagnoses made in patients with an acute presentation, and a decision not to perform a diagnostic arthrocentesis is the most prevalent cause of misdiagnosis in this setting. Many rheumatic and infectious diseases can present with more indolent monoarthritis; careful history and physical examination frequently provide clues to the straightforward diagnosis in some cases, but the extensive investigation is needed in others. Imaging methods become indispensable in individuals with the non-inflammatory monoarticular disease, with magnetic resonance imaging being the gold standard for diagnosing pigmented villonodular synovitis, lipoma arborescence, avascular necrosis, or neuropathic arthropathy.

CONCLUSIONS

A great variety of medical disorders can present as a monoarticular disease. The disease presentation dictates different diagnostic behavior, while knowing the available imaging methods' diagnostic potential should further shorten the diagnostic process.

Osteonecrosis

Younger patients are affected more often by osteonecrosis than by osteoarthritis, and osteonecrosis has significantly greater long-term morbidity.

Corticosteroids are the most common cause of nontraumatic osteonecrosis.

The femoral head is the most common site of osteonecrosis.

In rare instances, osteonecrosis of the jaw has been associated with bisphosphonate exposure. This phenomenon is more common with repeated intravenous infusions of bisphosphonates.

Case reports of osteonecrosis of the jaw in association with other medications, such as denosumab, have been reported.

The final common pathway in the pathogenesis of osteonecrosis is disruption of blood supply to a segment of bone.

Abnormalities in lipid metabolism, bone homeostasis, regulation of apoptosis, coagulopathies, innate immunity, and oxidative stress may play a role in the pathogenesis of osteonecrosis.

Epigenetics may alter the predisposition to develop osteonecrosis.

MRI is currently the optimal test for early diagnosis and identification of the extent of osteonecrosis.

Nonsurgical treatment of osteonecrosis does not change the natural history of the disease.

Although surgical treatment of femoral head osteonecrosis has many variations, most symptomatic patients eventually require total hip arthroplasty.

Knowledge of risk factors and early detection are crucial to the successful management of osteonecrosis.

Because of the lack of successful treatment options, new modes of management focus on the prevention of osteonecrosis.

One-sided hip-preserving and concurrent contralateral total hip arthroplasty for the treatment of bilateral osteonecrosis of the femoral head in different stages: short-medium term outcomes

Background

We aimed to evaluate the clinical and radiological short-medium term outcomes for the treatment of bilateral osteonecrosis of the femoral head (ONFH) with hip-preserving surgery of core decompression followed by tightly impaction bone grafting combining with non-vascularized fibular allografting in one hip and concurrent one-stage total hip arthroplasty (THA) in the contralateral side. We hypothesized the aforementioned surgery showed benefits of protecting the preserved hip from collapsing and thereafter THA was delayed or avoided.

Methods

We retrospectively reviewed a consecutive series of 18 non-traumatic bilateral ONFH patients (36 hips) who had undergone previous mentioned surgeries between July 2004 and June 2013. Preoperative and the last follow-up Harris Hip Score (HHS) and Visual Analogue Scale (VAS) Score were obtained for clinical outcomes evaluation and X-rays of antero-posterior and frog-leg lateral views of bilateral hips were compared for radiological outcomes assessment.

Results

All patients were telephone contacted for out-patient clinic return visit at an average follow-up time of 53.3 months (ranged from 20 months to 107 months). Of the 18 patients (15 men and 3 women), there were 5 patients were diagnosed preoperative IIB stages according to classification of the Association Research Circulation Osseuse classification (ARCO) and the remaining 13 patients were in ARCO IIIC stages. The mean age of the included patients was 40.7 years (range from 22 to 59 years). No age and followed-up time difference existed in genders. The postoperative HHS were 83.8 ± 17.9 points, and it revealed statistical significance when compared to preoperative 61.6 ± 17.0 points (p < 0.05). The VAS scores were reduced from preoperative 6.2 ± 2.0 points to postoperative 2.8 ± 2.3 points, which also manifested outcomes significance (p < 0.05). From radiological aspects, 14 patients acquired well repairmen of the necrotic areas of the femoral head. However, the other 4 patients ultimately suffered femoral head collapse, and the severe pain was gotten rid of after THA surgeries were performed.

Conclusions

The un-collapsed hip can achieve biological stability and sufficient blood supply through the hip-preserving surgery and obtain longtime repairmen of the necrotic bone as well as early non-weight-bearing function training, which benefits from distributing the whole body weight load to the hip of one-stage THA. Consequently, we recommend this sort of surgery for clinical practice trial when faced bilateral ONFH in different stages though longer time follow-up and larger samples are essentially needed to address its efficacy.

Emergency department evaluation and treatment of acute hip and thigh pain

Although the incidence of hip fractures is decreasing, the overall prevalence continues to increase because of an aging population. People older than 65 suffer fractures at a rate of 0.6% per year--2% per year for persons older than 85. One in 5 patients suffering a hip fracture will die within a year. Additionally, the emergency physician must consider entities such as avascular necrosis, compartment syndrome, and muscular disruption. This article reviews patterns and complications of acute hip and thigh injuries and clinically relevant diagnostic, anesthetic, and treatment options that facilitate timely, appropriate, and effective emergency department management.

The enigmas of bone without osteocytes

One of the hallmarks of tetrapod bone is the presence of numerous cells (osteocytes) within the matrix. Osteocytes are vital components of tetrapod bone, orchestrating the processes of bone building, reshaping and repairing (modeling and remodeling), and probably also participating in calcium-phosphorus homeostasis via both the local process of osteocytic osteolysis, and systemic effect on the kidneys. Given these critical roles of osteocytes, it is thought-provoking that the entire skeleton of many fishes consists of bone material that does not contain osteocytes. This raises the intriguing question of how the skeleton of these animals accomplishes the various essential functions attributed to osteocytes in other vertebrates, and raises the possibility that in acellular bone some of these functions are either accomplished by non-osteocytic routes or not necessary at all. In this review, we outline evidence for and against the fact that primary functions normally ascribed to osteocytes, such as mechanosensation, regulation of osteoblast/clast activity and mineral metabolism, also occur in fish bone devoid of these cells, and therefore must be carried out through alternative and perhaps ancient pathways. To enable meaningful comparisons with mammalian bone, we suggest thorough, phylogenetic examinations of regulatory pathways, studies of structure and mechanical properties and surveys of the presence/absence of bone cells in fishes. Insights gained into the micro-/nanolevel structure and architecture of fish bone, its mechanical properties and its physiology in health and disease will contribute to the discipline of fish skeletal biology, but may also help answer questions of basic bone biology.

Osteonecrosis

Osteonecrosis affects younger patients more often than osteoarthritis and has significantly greater long-term morbidity.

Corticosteroids constitute the most common cause of nontraumatic osteonecrosis.

The femoral head is the most common site of osteonecrosis.

Bisphosphonate use is associated with osteonecrosis of the jaw.

The final common pathway in the pathogenesis of osteonecrosis is disruption of blood supply to a segment of bone.

Abnormalities in lipid metabolism, bone homeostasis, regulation of apoptosis, coagulopathies, and oxidative stress may play a role in the pathogenesis of osteonecrosis.

Magnetic resonance imaging is currently the optimal test for early diagnosis and identification of the extent of osteonecrosis.

Nonsurgical treatment of osteonecrosis does not change the natural history of the disease.

Although there are many variations on surgical treatment of femoral head osteonecrosis, most patients eventually require total hip arthroplasty.

Knowledge of risk factors and early detection are crucial to the successful management of osteonecrosis.

Due to the lack of successful treatment options, new modes focus on prevention of osteonecrosis.

Management of osteonecrosis in children and young adults with acute lymphoblastic leukaemia

Osteonecrosis is a disabling complication in children and young adults with acute lymphoblastic leukaemia. It can affect any or multiple joints but the hip and knee are most frequently involved and a cause of long-term disability. The problem is almost exclusively that of older children and young adults of whom over 70% have asymptomatic changes on screening magnetic resonance imaging and 15-20% have resulting symptoms. Dexamethasone is associated with a higher risk than prednisolone in US but not European or UK trials and alternate week scheduling of dexamethasone in the intensification course is associated with a lower risk than a continuous 3-week schedule in US trials. Genetic factors and obesity contribute to the risk, as do metabolic abnormalities caused by drugs, such as asparaginase, which increase tissue exposure to steroids. Management is primarily supportive but a minority of patients require surgical intervention including replacement of the affected joint. A variety of surgical techniques and, latterly, bisphophonates, have been tried to prevent progression but their efficacy remains uncertain. Whether patients should continue to receive steroids after diagnosis of osteonecrosis is uncertain but most trial investigators recommend stopping them after completion of the intensification phase of treatment.

Osteonecrosis in children and adolescents with cancer

Osteonecrosis is recognized increasingly as a complication of the treatment of cancer in young people, especially those with acute lymphoblastic leukemia and non-Hodgkin lymphoma, reflecting a probable pathogenetic role of steroid therapy. Children >/=10 years of age and Whites are at particular risk, and genetic predispositions have been identified. The disorder affects weight-bearing joints predominantly. It is commonly bilateral and multi-articular. Treatment options include both surgical and non-surgical interventions.

Osteonecrosis in children and adolescents with cancer - an adverse effect of systemic therapy

Osteonecrosis (ON) is recognised increasingly as a complication of the treatment of cancer in children and adolescents. It is especially prevalent among survivors of acute lymphoblastic leukaemia and non-Hodgkin lymphoma, in whom as many as 1/3 may be affected, likely reflecting the cumulative exposure to glucocorticosteroid therapy. The pathogenesis is complex and includes suppression of bone formation, expansion of the intra-medullary lipocyte compartment and a direct effect on nutrient arteries. Children > or =10 years of age are at particular risk and the disorder is substantially more common in Whites than in Blacks. Genetic predispositions have been identified. ON is often multi-articular and bilateral, affecting weight-bearing joints predominantly. Surgical management options are of concern in young growing subjects, although injection of autologous marrow into affected sites offers promising results. Other novel approaches include the use of anti-resorptive drugs and strategies for prevention, such as with lipid-lowering agents, are being explored.

Diagnosis and management of the osteonecrotic triad of the knee

Generalized osteonecrosis of the knee may include, in addition to osteonecrosis of the medial femoral condyle that occurs most frequently, osteonecrosis of the patella or the tibial plateau. Such involvement is known as the osteonecrotic triad of the knee. Although the clinical picture of idiopathic osteonecrosis of the medial femoral condyle seems similar to several other disorders, certain distinct features, including its typical location,clinical symptoms, and late onset of cartilaginous erosion, facilitate differential diagnosis. Despite the progress made in the diagnosis and treatment of idiopathic osteonecrosis of the medial femoral condyle, the prognosis remains severe. More than 80% of the patients deteriorate to the extent that surgical reconstruction is necessary, whereas only about 20%of the patients demonstrate spontaneous resolution or no additional deterioration of the osteonecrotic lesion.

Magnetic resonance imaging detection of avascular necrosis of the bone in children receiving intensive prednisone therapy for acute lymphoblastic leukemia or non-Hodgkin lymphoma

The purpose of this study was to determine the frequency with which magnetic resonance (MR) imaging detects avascular necrosis of the bone (AVNB) in children with acute lymphoblastic leukemia (ALL) or advanced-stage non-Hodgkin lymphoma (NHL) who receive prednisone during remission induction, reinduction, and maintenance chemotherapy; to assess the clinical significance of these findings; and to identify factors predictive of AVNB. We prospectively obtained MR imaging of the hips and knees of 116 children who had completed at least 1 year of treatment for ALL or advanced-stage NHL on identical prednisone-containing regimens between December 1991 and October 1994. MR imaging findings of AVNB were compared with clinical outcomes, and the effect of therapeutic and patient factors on the frequency of AVNB was analyzed. The MR imaging findings of 17 of the 116 participating patients were consistent with AVNB. The most common clinical manifestation was joint pain (11 patients). Only one patient had progressive joint deterioration that necessitated surgical replacement. Only age 10 years or more at the time of the primary diagnosis was significantly associated with the development of AVNB (P = 0.004). MR imaging showed changes consistent with AVNB in approximately 15% of this patient population. However, most patients in this study who had MR imaging signs of AVNB did not experience progressive joint destruction, even with continued prednisone therapy. Therefore, the clinical usefulness of MR imaging as a screening tool for AVNB in this set of patients remains uncertain.

Osteonecrosis of the femoral head associated with pregnancy. A preliminary report

BACKGROUND

Osteonecrosis is usually associated with trauma, use of corticosteroids, or alcohol abuse. We investigated the rare association of osteonecrosis of the femoral head and pregnancy, and we defined differences between the disorder in pregnant women and that in women of childbearing age who were not pregnant. The results of treatment with a free vascularized fibular graft were evaluated in terms of relief of pain and improvement of the Harris hip score after a minimum of two years of follow-up.

METHODS

Thirteen women (seventeen hips) had the onset of pain in the hip during pregnancy or within the first four weeks after delivery, and the pain persisted until a diagnosis of osteonecrosis of the femoral head was made on the basis of magnetic resonance imaging. No patient had any other risk factor for this disease. Information was obtained by means of clinical assessment, a review of the records and radiographs, and a telephone survey. Eleven women (fifteen hips) were managed with a free vascularized fibular graft, and nine of them (eleven hips) were evaluated, with regard to relief of pain and the Harris hip score, at a minimum of two years postoperatively.

RESULTS

The average age when the pain began was 31.5 years (range, twenty-five to forty-one years). Eleven of the thirteen women were primigravid, and the patients typically first had the pain late in the second trimester or in the third trimester of pregnancy. The women tended to have a small body frame and a relatively large weight gain during the pregnancy. Eight of the thirteen patients had swelling and varicosity of the lower extremities. The diagnosis was delayed an average of 10.3 months, with a range of three to thirty months. A common misdiagnosis was transient osteoporosis of the hip during pregnancy. A correct diagnosis was established for all hips on the basis of the finding of a double-density signal on magnetic resonance imaging or evidence of progression of the disease on plain radiographs. According the system of Marcus et al., the stage at the time of diagnosis ranged from II to V. All women had involvement of the left hip, and four had bilateral involvement. Of the eleven women (fifteen hips) who were managed with a free vascularized fibular graft, nine noted marked or complete relief of the preoperative pain. Two hips in a patient who had progressive pain were treated with a total hip arthroplasty. Two hips (one patient) were lost to follow-up. The nine patients (eleven hips) who were available for follow-up at a minimum of two years had an average improvement in the Harris hip score of 24 points.

CONCLUSIONS

Occasionally, pain in the hip that begins during pregnancy is caused by osteonecrosis of the femoral head. A high index of suspicion and use of magnetic resonance imaging may lead to an earlier diagnosis and a better prognosis in this population of women. In this study, treatment with a free vascularized fibular graft was a useful option with which to obviate or postpone the need for total hip arthroplasty.

Bone marrow changes on MRI in children with acute lymphoblastic leukaemia 5 years after treatment

T1-weighted magnetic resonance imaging (MRI) of the lower extremities was performed 5 years after the cessation of therapy on 25 children treated for acute lymphoblastic leukaemia (ALL). Signal intensity pathologies considered to be related with the leukaemia itself or the treatment of ALL were found in nine of 25 children (36%). Two of these children had findings of osteonecrosis, five had a patchy signal pattern, one had diffuse inhomogeneity of the bone marrow signal intensity in complete remission and one had diffusely decreased signal intensity preceding the diagnosis of relapse. MRI unexpectedly revealed many bone marrow pathologies in symptomless children successfully treated for ALL. Especially, osteonecrosis might cause significant disability, and the aetiology, clinical course and prognosis of this complication are not well known. The intensive dexamethasone medication included in the treatment protocols may be responsible for the development of osteonecrosis. However, the prognosis of osteonecrosis in the long run requires further studies.

Osteonecrosis in children treated for acute lymphoblastic leukemia: a magnetic resonance imaging study after treatment

The purpose of the study was to find out the prevalence of osteonecrosis in children with acute lymphoblastic leukemia (ALL) in complete bone marrow remission at the end of the treatment. Twenty-eight children with ALL underwent MRI of the upper and/or lower extremities. Bone marrow signal intensity was analyzed on T1-weighted images, where circumscribed lesions with a rim of low signal intensity were considered typical of osteonecrosis. Osteonecrosis was found in 9 of the 28 children (32%, 95% CI 16% to 52%). Five of them were asymptomatic. They had been treated with high risk and intermediate risk protocols, both of which include a delayed intensification phase with dexamethasone. None of the patients with standard risk ALL were found to have developed osteonecrosis. Osteonecroses occurred unexpectedly in symptomless patients and in patients with mild transient symptoms treated with high risk and intermediate risk protocols. Our study suggests that the intensification phase of the treatment protocols with intensive dexamethasone medication might be responsible for the development of osteonecrosis.

Osteonecrosis: current perspectives on pathogenesis and treatment

Nontraumatic osteonecrosis results from impairment of circulation to the affected bone. The femoral head is affected most frequently. The underlying cause for the circulatory defect in osteonecrosis varies and may involve both local and systemic changes. Steroid use, alcohol consumption, pancreatitis, and lipid disorders appear to lead to bone death either by development of fat emboli in the microcirculature surrounding the affected bone or by fatty infiltration of the marrow. Decompression syndrome results from the presence of gaseous emboli in the microcirculature. In Legg-Calvé-Perthes disease other associated features are present such as short stature, suboptimal growth velocity, and/or hormonal imbalances, and it is likely that osteonecrosis may be secondary to systemic abnormalities, although specific factors have not been identified. Other frequently suggested pathogenic factors that play a role in the development of osteonecrosis include increased intraosseous pressures, the presence of cytotoxic cellular factors, intravascular coagulation, venous stasis, and the hyperviscosity syndrome. Some investigators have attempted, without success, to find a common etiology for all cases of osteonecrosis. In addition, patients have developed osteonecrosis without any known risk factors; this syndrome has been coined idiopathic avascular necrosis. In advanced stages of femoral head osteonecrosis, total hip arthroplasty appears to be the best therapeutic modality, particularly in older individuals.

Bone scan hot spots in a patient with lung cancer: ischaemic necrosis of bone mimicking metastatic carcinoma

A 62-year-old man complained of a pain in his leg four months after radical surgery for a bronchial adenocarcinoma. Skeletal scintigraphy showed increased uptake of isotope in the lower femur and upper tibia corresponding to an abnormal area on the plain radiographs. Bone metastases were thought to be the most likely cause of these findings. Since the appearances were not entirely typical, bone biopsy was undertaken to confirm the diagnosis. This showed ischaemic necrosis of bone, related to a previous acute arterial occlusion. In view of the serious implications for a patient if an erroneous diagnosis of metastatic disease is made following potentially curative treatment for cancer, such a diagnosis should be proven, not assumed. Bone biopsy should be considered when solitary skeletal lesions develop in radically treated cancer patients with no other evidence of metastasis.

Aseptic necrosis of the femoral head associated with pregnancy; a case report

A documented case of beginning aseptic necrosis of the femoral head associated with pregnancy together with a review of the literature about this rare complication of pregnancy is presented. The patient complained of increasing pain in the right hip and limitation of movement of the affected joint. After delivery, the diagnosis of beginning avascular necrosis of the right femoral head was confirmed on X-ray, technetium-99 bone scan and CT-scan of the hips. Three weeks after delivery the patient was treated with drilling of the femoral head. Recovery was complete.

Osteonecrosis in pediatric patients with acute lymphoblastic leukemia

The authors report five pediatric patients with acute lymphoblastic leukemia (ALL) in whom symptomatic aseptic osteonecrosis developed on therapy. All patients had been on treatment with a modified BFM protocol and developed osteonecrosis in the maintenance phase of the protocol. The avascular necrosis was multifocal in all. The authors' data suggest that dexamethasone used in the reinduction phase of the protocol may be the responsible agent although no definite proof exists. Since only symptomatic patients are reported, the true frequency of this complication may be significantly higher.

Mystery deepens--blood on the space-shuttle Discovery's flight STS 26 at zero gravity and some deductions or extrapolations

The second "aggregation of red cells" experiment that was performed on the National Aeronautics and Space Administration's space-shuttle Discovery's flight STS 26 confirms the results that were obtained in 1985; however, some new features have come to light, in particular, the observation of a clot or thrombus which, so far, remains unexplained. An attempt has been made to link observations on the cell-to-cell interaction and blood viscosity under zero gravity to some of the problems that are facing astronauts and to some new dimensions in medical science.

Avascular necrosis of bone following short-term dexamethasone therapy for brain edema. Case report

The authors present a case of avascular necrosis of both femoral and humeral heads which developed after short-term steroid treatment for brain edema. A vascular necrosis of bone may develop after short-term as well as after maintenance steroid therapy. Early diagnosis with bone scanning and management may in some cases prevent joint destruction.