Trabecular edema | |
---|---|
Other names | Bone marrow edema (BME, first used in 1988 [1] ), bone marrow lesion (BML) |
![]() | |
A schematic diagram showing the mechanism of bone marrow edema, adapted from. [2] | |
Symptoms | Joint pain, effusion, warmth. |
Types | Primary bone marrow edema, secondary bone marrow edema. |
Causes | (For secondary BME) Trauma, degenerative lesions, inflammatory lesions, ischaemic lesions, infectious lesions, metabolic/endocrine lesions, iatrogenic lesions. |
Risk factors | Sex, age, occupation, history of physical trauma, obesity, previous bone marrow damage, immunosuppressive/hormonal treatments, relevant medical conditions. |
Diagnostic method | Magnetic resonance imaging (MRI). |
Differential diagnosis | Ultrasound scans, computed tomography (CT) scans. |
Treatment | Core decompression, pharmaceutical treatment, extracorporeal shock wave therapy (ESWT). |
Medication | Non-steroidal anti-inflammatory drugs (e.g. Iloprost). |
Trabecular edema, also known as bone marrow edema (BME), is a traditional term describing the interstitial fluid accumulation at the trabecular bone marrow. The term was first used in 1988, [1] referring to the changes in the bone marrow due to inflammation. [3] Bone marrow edema was later renamed to bone marrow lesion (BML), as later studies show that the increased fluid content in the trabecular bone was more likely caused by inflammatory responses (e.g. increased vascularization, lymphocyte infiltration) instead of fluid influx (i.e. edema). [2] [4] [5] Hence, this narrows down the condition to the damage at the articular surface of the trabecular bones. [2] Despite so, the terms BME and BML are still used interchangeably in radiology. [6]
This condition normally affects the musculoskeletal system, and commonly manifests in lower extremities, including but not limited to the feet, ankle joints, knee joints, and hip joints. [2] [7] Common signs and symptoms include pain, joint swelling, and limited joint functionality. [8] BME can be further separated into two types, based on their causes: primary BME and secondary BME. Primary BME, also called spontaneous BME or bone marrow edema syndrome (BMES), means bone marrow edema without obvious causes. Secondary BME meanwhile refers to bone marrow edema caused by another condition. [9] It is usually diagnosed with magnetic resonance imaging (MRI), supplemented with ultrasound scans. [2] However, BME cannot be detected by X-ray or computerized tomography (CT) scans directly, [2] [5] but they are helpful in differential diagnosis. [5] [9] Minor cases are usually treated through proper resting and taking non-steroidal anti-inflammatory drugs (NSAIDs), while steroid therapy or even surgery may be needed for more serious ones. [10] [11] [12] [13]
Pre-existing conditions like arthritis or bone cancer induce stress onto the bones, leading to a greater risk of BME within patients suffering from those conditions. [14] Other studies also list high bone density as a risk factor to some local bone marrow lesions. [15] [16] Sex, [17] [18] age, earlier immunosuppressive treatments, [19] or pre-existing physical trauma are all risk factors of bone marrow edema. [20] [21] [22] [23] Prevention of bone marrow edema is difficult due to the vast variety of causes, but detecting bone marrow edema can predict subsequent progression to bone erosion [9] [24] or the need to replace the joint. [9] [25]
Common symptoms of BME include joint effusion, joint pain, and warmth, which are related to joint inflammation. [2] Patients usually have severe pain in the bones or joints, which often leads to limitations in functionality that harm their quality of life. [8]
In primary bone marrow edema patients, initial painful symptoms usually appear in the first month, followed by a peak in pain level two months after onset. [7] The transient increase in interstitial fluid leads to increased intraosseous pressure and aggravated neurovascular bundles. [26] The symptoms typically fade a few months after the phase with maximum pain level, [7] which may be due to the bone remodelling abilities as new bone formation and vascular reconstruction steps are observed. [27]
In secondary bone marrow edema patients, repeated traumatic stress may disrupt the trabecular marrow structure, hence there is interstitial fluid leakage or haemorrhage inside the marrow spaces. Also, heightened blood flow or a congested vascular drainage at the bone marrow may cause BME. [26] The increased fluid content leads to an increase in intraosseous pressure as well as decreased perfusion, [28] which disturbs the neurovascular bundles and result in pain and swelling. Local cytokine production mediates the inflammatory response and thus worsens the symptoms. [26]
Bone marrow edema does not have similar histological characteristics as other types of edema, such as pulmonary edema. This is because it is commonly caused by inflammation and vascularization, resulting in displacement of bone marrow, originally rich in adipocytes, by hydrophilic material. Said material may be immune cells, particularly T and B lymphocytes, and microvessels. [2]
However, the exact mechanism that causes bone marrow edema is still unknown. It is only known that the presence of bone marrow edema is usually associated with the progression of various diseases such as osteonecrosis. [29] Different pathophysiology mechanisms are established based on the cause of the bone marrow edema. For example, if the cause of bone marrow edema is rheumatoid arthritis, the edema is attributed to the penetration sites caused by the resorption of mineralized cortical bone beneath articular cartilage. [2] These penetration sites allow the entry of inflammatory infiltrates, which could possibly be lymphocytic aggregates or invaded synovial tissue that are heavily vascularized, contributing to high water content in the bone marrow compartment. [2] As in some other causes such as renal transplantation, impairment of microcirculation could result in an increase of the intraosseous pressure. [2] The increased hydrostatic pressure causes more fluid leakage out of the capillaries, and bone marrow edema is the direct result.
A common characteristic among bone marrow edema patients is the pain experienced, due to the aggravation of the neurovascular bundle by increased intraosseous pressure. [10]
A crucial element for a physician to diagnose BME is the ability to differentiate whether the patient suffers from primary or secondary bone marrow edema, as primary bone marrow edema could indicate stage of progression to osteonecrosis. [6] Unfortunately, interdisciplinary guidelines and management algorithms regarding BME are currently underdeveloped, resulting in repetitive checking, delayed diagnosis or treatment.
Primary bone marrow edema is also referred to as spontaneous bone marrow edema, or bone marrow edema syndrome (BMES). This category of BME does not have a particular cause but is self-limiting in nature, meaning that symptoms usually resolve by themselves within three to nine months after onset without pathological consequences. [9]
There are theories proposing possible etiologies like vascular anomalies or thromboembolism, but they are yet to be proven. [10]
Secondary bone marrow edema is caused by pre-existing conditions, which may be interdisciplinary. Hence, this category of BME is commonly found in MRIs, in which the original intention was not to diagnose this particular condition. The different causes of secondary bone marrow edema are listed as follows: [2]
Trauma events cause frequent microfractures. For instance, in transient regional osteoporosis and bone bruises, bone marrow lesions start in one skeletal region and spontaneously appear in another skeletal region with time. [30] The cause is associated with active osteoporotic changes and low bone mineral density, which allows microfractures to occur in the affected region. [31]
Tendinitis has a strong association with bone marrow edema. A study reported around one-third of tendinitis patients have bone marrow edema, and even all cases are revealed to be an uptake in isotope scans. [32]
Osteoarthritis is another disease that has a strong association with bone marrow edema due to mechanical loading, as well as stress on the subchondral region. [33] [34]
There exist three types of inflammatory lesions: seropositive inflammatory arthropathy, seronegative arthritis, and enthesitis. Bone marrow lesions tend to be present in inflammatory arthropathy due to increased vascularisation, [2] and are often present in sites of arthritis and enthesitis as well. [35]
Avascular necrosis of bone is directly related to bone marrow lesions; the severity of bone marrow lesions is correlated with the intensity of avascular osteonecrosis. [29]
Bacterial infections and bone marrow lesion development are closely related, as infection directly leads to inflammation. [36] For example, infections of the foot in diabetic patients that spread to the bone are associated with bone marrow lesions. [37]
Hormonal imbalances such as severe hyperthyroidism and hyperparathyroidism, which lead to impairment of bone metabolism, could cause bone marrow edema. [23] Changes in connective tissue deposition such as uric acid composition in gout could cause bone marrow edema. [38]
Damage could be done to bone marrow during surgery or radiotherapy, leading to inflammation and hence bone marrow edema as in other lesions. Patients who have undergone hormone therapy are also susceptible to bone marrow edema due to insufficient bone metabolism and high bone turnover. [19]
Osteonecrosis risk may also be increased by common immunosuppressants like cyclosporine and tacrolimus, due to the induced vasoconstriction. Drugs such as sirolimus may potentiate this effect by similar action or influencing the lipid profile. [22]
Bone marrow edema is usually caused by or associated with pre-existing conditions. Numerous epidemiological studies in patients with bone marrow edema have found certain patterns of characteristics among the participants; for example, certain medical conditions such as osteoporosis are substantial risk factors for developing bone marrow edema. [39] Several common risk factors are listed as follows:
Diagnosis of trabecular edema is primarily done via magnetic resonance imaging (MRI). The presence of edema within the bone marrow yields a visible signal on the MRI, due to displacement of the normally fatty tissue within the marrow by interstitial fluid with higher water content; this change in composition is then reflected by the MRI due to differences in the T1-weighted and T2-weighted images. [5] [1]
A healthy bone is rich in fat and has lower water content, therefore it appears as bright signals on T1-weighted images and dark on T2-weighted images. [2] Conversely, regions with trabecular edema has lower fat and higher water content. Hence, they have a comparatively lower intensity than normal bone tissues on a T1-weighted image, and a higher intensity on a T2-weighted image. [42]
Being less sensitive compared to MRI scans, ultrasound scans are able to detect some abnormalities like joint effusion and capsular thickening, which are common in BME patients. [43]
Computed tomography (CT) scans cannot directly diagnose bone marrow edema, but it is sometimes used to supplement MRI scans for differential diagnosis. It is due to its ability to show any lesions or fractures in trabecular, subchondral or chondral structures, which aids physicians to understand if there are any underlying bone pathologies leading to the observed symptoms. [9]
As edema is by definition accumulation of excess fluid within body tissue, one method of treating edema is draining said excess fluid. Core decompression, otherwise often used to treat avascular necrosis, is a surgical procedure that involves drilling a hole into dead bone tissue, leading to the reduction of pressure within the bone and increase of blood flow; thus, the excess fluid can be drained and the edema treated. [13] A combination of core decompression with injection of hydroxyapatite cement into the tissue affected with bone marrow edema has been reported to significantly reduce pain levels. [44]
Another goal of treating trabecular edema is to manage the symptoms, such as pain. Nonsteroidal anti-inflammatory drugs such as Iloprost, a medication that dilates arterial vascular beds, have been proven to aid in treating bone marrow lesions when administered in an intravenous manner, resulting in reduction of pain and restoration of functionality in affected areas. [10] [11] [12]
Yet another method of treating bone marrow edema is extracorporeal shock wave therapy (ESWT), a process involving re-injury of cells via acoustic shock waves to promote regeneration of blood vessels and bone. The treatment has been proven to halve the size of areas affected by edema after six months of administration. [45]
Recent evidence found associations between vitamin status and bone marrow edema syndrome. A pathophysiological association is found between vitamin D status, which denotes osteopenia, and bone marrow edema syndrome. The association has yet to be found to be causative. As for vitamin C, vitamin deficiency in scurvy patients is a causative factor but no current literature reports acute and subacute vitamin C deficiency. For future research, more advanced study designs such as randomized clinical trials are needed to evaluate therapy by means of vitamin supplements. [46]
On the other hand, another recent literature review was performed on studies published from 2011 to 2021, investigating the efficacy of various conservative treatments of BMES. Although comparison of the studies in a highly reliable manner was difficult due to lack of standardisation of treatment methods, studies still found prospective results in treating bone marrow edema efficiently. Future studies should establish a standardised radiological score system to evaluate the areas of bone marrow edema. [47]
Arthritis is a term often used to mean any disorder that affects joints. Symptoms generally include joint pain and stiffness. Other symptoms may include redness, warmth, swelling, and decreased range of motion of the affected joints. In some types of arthritis, other organs are also affected. Onset can be gradual or sudden.
Rheumatology is a branch of medicine devoted to the diagnosis and management of disorders whose common feature is inflammation in the bones, muscles, joints, and internal organs. Rheumatology covers more than 100 different complex diseases, collectively known as rheumatic diseases, which includes many forms of arthritis as well as lupus and Sjögren's syndrome. Doctors who have undergone formal training in rheumatology are called rheumatologists.
Osteoarthritis (OA) is a type of degenerative joint disease that results from breakdown of joint cartilage and underlying bone. It is believed to be the fourth leading cause of disability in the world, affecting 1 in 7 adults in the United States alone. The most common symptoms are joint pain and stiffness. Usually the symptoms progress slowly over years. Other symptoms may include joint swelling, decreased range of motion, and, when the back is affected, weakness or numbness of the arms and legs. The most commonly involved joints are the two near the ends of the fingers and the joint at the base of the thumbs, the knee and hip joints, and the joints of the neck and lower back. The symptoms can interfere with work and normal daily activities. Unlike some other types of arthritis, only the joints, not internal organs, are affected.
Acute septic arthritis, infectious arthritis, suppurative arthritis, pyogenic arthritis, osteomyelitis, or joint infection is the invasion of a joint by an infectious agent resulting in joint inflammation. Generally speaking, symptoms typically include redness, heat and pain in a single joint associated with a decreased ability to move the joint. Onset is usually rapid. Other symptoms may include fever, weakness and headache. Occasionally, more than one joint may be involved, especially in neonates, younger children and immunocompromised individuals. In neonates, infants during the first year of life, and toddlers, the signs and symptoms of septic arthritis can be deceptive and mimic other infectious and non-infectious disorders.
Rheumatism or rheumatic disorders are conditions causing chronic, often intermittent pain affecting the joints or connective tissue. Rheumatism does not designate any specific disorder, but covers at least 200 different conditions, including arthritis and "non-articular rheumatism", also known as "regional pain syndrome" or "soft tissue rheumatism". There is a close overlap between the term soft tissue disorder and rheumatism. Sometimes the term "soft tissue rheumatic disorders" is used to describe these conditions.
A Baker's cyst, also known as a popliteal cyst, is a type of fluid collection behind the knee. Often there are no symptoms. If symptoms do occur these may include swelling and pain behind the knee, or knee stiffness. If the cyst breaks open, pain may significantly increase with swelling of the calf. Rarely complications such as deep vein thrombosis, peripheral neuropathy, ischemia, or compartment syndrome may occur.
Avascular necrosis (AVN), also called osteonecrosis or bone infarction, is death of bone tissue due to interruption of the blood supply. Early on, there may be no symptoms. Gradually joint pain may develop, which may limit the person's ability to move. Complications may include collapse of the bone or nearby joint surface.
Fibrous dysplasia is a very rare nonhereditary genetic disorder where normal bone and marrow is replaced with fibrous tissue, resulting in formation of bone that is weak and prone to expansion. As a result, most complications result from fracture, deformity, functional impairment, pain, and the impingement of nerves. Disease occurs along a broad clinical spectrum ranging from mostly asymptomatic incidental lesions, to severe disabling disease. Disease can affect one bone (monostotic), multiple (polyostotic), or all bones (panostotic) and may occur in isolation or in combination with café au lait skin macules and hyperfunctioning endocrinopathies, termed McCune–Albright syndrome. More rarely, fibrous dysplasia may be associated with intramuscular myxomas, termed Mazabraud's syndrome. Fibrous dysplasia is very rare, and there is no known cure. While fibrous dysplasia is not itself a form of cancer, in severe cases it may undergo a malignant transformation into cancers such as osteosarcoma or chondrosarcoma, so some clinicians may regard it as precancerous rather than benign.
Calcium pyrophosphate dihydrate (CPPD) crystal deposition disease, also known as pseudogout and pyrophosphate arthropathy, is a rheumatologic disease which is thought to be secondary to abnormal accumulation of calcium pyrophosphate dihydrate crystals within joint soft tissues. The knee joint is most commonly affected. The disease is metabolic in origin and its treatment remains symptomatic.
Synovitis is the medical term for inflammation of the synovial membrane. This membrane lines joints that possess cavities, known as synovial joints. The condition is usually painful, particularly when the joint is moved. The joint usually swells due to synovial fluid collection.
Osteochondritis dissecans is a joint disorder primarily of the subchondral bone in which cracks form in the articular cartilage and the underlying subchondral bone. OCD usually causes pain during and after sports. In later stages of the disorder there will be swelling of the affected joint which catches and locks during movement. Physical examination in the early stages does only show pain as symptom, in later stages there could be an effusion, tenderness, and a crackling sound with joint movement.
Transient synovitis of hip is a self-limiting condition in which there is an inflammation of the inner lining of the capsule of the hip joint. The term irritable hip refers to the syndrome of acute hip pain, joint stiffness, limp or non-weightbearing, indicative of an underlying condition such as transient synovitis or orthopedic infections. In everyday clinical practice however, irritable hip is commonly used as a synonym for transient synovitis. It should not be confused with sciatica, a condition describing hip and lower back pain much more common to adults than transient synovitis but with similar signs and symptoms.
Osteonecrosis of the jaw (ONJ) is a severe bone disease (osteonecrosis) that affects the jaws. Various forms of ONJ have been described since 1861, and a number of causes have been suggested in the literature.
Arthritis mutilans is a rare medical condition involving severe inflammation damaging the joints of the hands and feet, and resulting in deformation and problems with moving the affected areas; it can also affect the spine. As an uncommon arthropathy, arthritis mutilans was originally described as affecting the hands, feet, fingers, and/or toes, but can refer in general to severe derangement of any joint damaged by arthropathy. First described in modern medical literature by Marie and Leri in 1913, in the hands, arthritis mutilans is also known as opera glass hand, or chronic absorptive arthritis. Sometimes there is foot involvement in which toes shorten and on which painful calluses develop in a condition known as opera glass foot, or pied en lorgnette.
Spontaneous osteonecrosis of the knee is the result of vascular arterial insufficiency to the medial femoral condyle of the knee resulting in necrosis and destruction of bone. It is often unilateral and can be associated with a meniscal tear.
Femoroacetabular impingement (FAI) is a condition involving one or more anatomical abnormalities of the hip joint, which is a ball and socket joint. It is a common cause of hip pain and discomfort in young and middle-aged adults. It occurs when the ball shaped femoral head contacts the acetabulum abnormally or does not permit a normal range of motion in the acetabular socket. Damage can occur to the articular cartilage, or labral cartilage, or both. The condition may be symptomatic or asymptomatic. It may cause osteoarthritis of the hip. Treatment options range from conservative management to surgery.
Remitting seronegative symmetrical synovitis with pitting edema (or sometimes RS3PE) is a rare syndrome identified by symmetric polyarthritis, synovitis, acute pitting edema (swelling) of the back of the hands and/or feet, and a negative serum rheumatoid factor. If no underlying disorder can be identified (idiopathic RS3PE), this entity has an excellent prognosis and responds well to treatment.
Pain in the hip is the experience of pain in the muscles or joints in the hip/ pelvic region, a condition commonly arising from any of a number of factors. Sometimes it is closely associated with lower back pain.
An occult fracture is a fracture that is not readily visible, generally in regard to projectional radiography ("X-ray"). Radiographically, occult and subtle fractures are a diagnostic challenge. They may be divided into 1) high energy trauma fracture, 2) fatigue fracture from cyclical and sustained mechanical stress, and 3) insufficiency fracture occurring in weakened bone. Independently of the cause, the initial radiographic examination can be negative either because the findings seem normal or are too subtle. Advanced imaging tools such as computed tomography, magnetic resonance imaging (MRI), and scintigraphy are highly valuable in the early detection of these fractures.
Mueller–Weiss syndrome, also known as Mueller–Weiss disease, is a rare idiopathic degenerative disease of the adult navicular bone characterized by progressive collapse and fragmentation, leading to mid- and hindfoot pain and deformity. It is most commonly seen in females, ages 40–60. Characteristic imaging shows lateral navicular collapse. This disease had been historically considered to be a form of adult onset osteonecrosis, with blood flow cutoff to the navicular.