Bone marrow oedema of the knee

Bone marrow edema of the knee: a narrative review

Bone marrow edema (BME) is a frequent MRI finding in patients with knee pain. According to the etiology, BME of the knee can be classified into three main categories: ischemic, mechanic, and reactive. The diagnosis may be difficult, because of the specificity of symptoms and the poor radiographic findings. MRI is the gold standard, showing an area of altered signal of the bone with an high signal intensity on fat-suppressed, T2 weighted images, usually in combination with an intermediate or low signal intensity on T1 weighted images. Bone marrow edema tends to be self-limiting and, in most cases, resolves without any consequences in a varying amount of time. However, since it may evolve to complete joint destruction, early diagnosis and correct treatment are crucial to prevent the articular degeneration. Conservative therapy is the first step, with no weight-bearing for 3 to 6 weeks on the affected side, in combination with the administration of anti-inflammatory drugs or painkillers to manage symptoms. In non-responding forms and more advanced stages, minimally invasive preservative surgery can provide significant results, with subchondroplasty and core decompression being the two main procedures available. Knee arthroplasty, both total (TKA) or unicompartmental (UKA), is the only effective option when the degradation of cartilage is diffuse and in patients with subchondral bone collapse.

The Effectiveness of Endovenous Thermal Ablation for the Knee Symptoms of the Osteoarthritis with Varicose Veins

Patients with varicose veins of the lower extremities with osteoarthritis of the knee often experience improvement in knee joint symptoms after endovascular treatment. We considered that it was important to decide the operation indication of lower extremity varices, to know the correlation between the two diseases in the treatment of varicose veins. To investigate the postoperative improvement of knee symptoms related to varicose veins with knee osteoarthritis, we conducted a questionnaire survey for a total of 12 months, from December 2014 to May 2015 and from October 2018 to March 2019. The participants were 35 patients (7 men and 28 women) with varicose veins complicated with knee osteoarthritis. We classified knee osteoarthritis according to a grading scale and compared the improvement of knee symptoms after endovenous thermal ablation. The higher the knee grade, the lower the degree of improvement. However, the improvement was observed in all knee osteoarthritis grades, and as a whole, 25 patients (71.4%) have experienced improvement of subjective symptoms. For patients with knee osteoarthritis, we strongly recommend surgical treatment of the varicose veins regardless of the progression of knee grade. (This is a translation of Jpn J Phlebol 2019; 30(3): 279–283.)

Traumatic and non-traumatic bone marrow edema in ankle MRI: a pictorial essay

Bone marrow edema (BME) is one of the most common findings on magnetic resonance imaging (MRI) after an ankle injury but can be present even without a history of trauma. This article will provide a systematic overview of the most common disorders in the ankle and foot associated with BME.

The presence of BME is an unspecific but sensitive sign of primary pathology and may act as a guide to correct and systematic interpretation of the MR examination. The distribution of BME allows for a determination of the trauma mechanism and a correct assessment of soft tissue injury. The BME pattern following an inversion injury involves the lateral malleolus, the medial part of the talar body, and the medial part of the distal tibia. In other cases, a consideration of the distribution of BME may indicate the mechanism of injury or impingement. Bone in direct contact with a tendon may lead to alterations in the bone marrow signal where BME may indicate tendinopathy or dynamic tendon dysfunction. Changed mechanical forces between bones in coalition may lead to BME. Degenerative changes or minor cartilage damage may lead to subchondral BME. Early avascular necrosis, inflammation, or stress fracture may lead to more diffuse BME; therefore, a detailed medical history is crucial for correct diagnosis.

A systematic analysis of BME on MRI can help to determine the trauma mechanism and thus assess soft tissue injuries and help to differentiate between different etiologies of nontraumatic BME.

Surgical modalities for the management of bone marrow edema of the knee joint

Background

Bone marrow edema (BME) is a radiological term which can be found in many conditions with varied pathogenesis and histopathological images. It usually presents with pain in the affected joint and is diagnosed with MRI. Subchondroplasty (SCP) and core decompression (CD) are the surgical methods that are available to achieve pain relief and functional improvement. Both surgical methods have their own indications and are used depending on the patient's history. The aim of this literature review article is to discuss the surgical modalities for the management of bone marrow edema focusing on the knee joint. Such topic which analyzes both surgical methods for treatment of bone marrow edema of the knee joint has never been described in a review article before.

Materials and methods

For the purpose of our manuscript we thoroughly searched electronic databases such as Pubmed and Medline to acquire the appropriate material for our review paper. Only English articles were used in this review. In our study we included every article that had described the surgical management of BME of the knee by CD and SCP. In the discussion we included 18 studies (9 CD and 9 SCP) with a total number of patients equal to 397, while 206/397 had undergone surgical intervention (169 underwent SCP and 37 CD).

Results

Follow-up of 180 patients out of 206 were available for our review. A total number of 166 patients (92.2%) were successfully treated. Specifically, 29 (100%) patients were treated by CD and 137 (90.7%) by SCP. In a study, 10 patients who underwent SCP for BME secondary to advanced osteoarthritis (OA) yielded poor results. In other studies, pain persistency was observed in 2 patients, 1 patient had postoperative infection and another patient eventually underwent total knee arthroplasty (TKA). 70% prevention of TKA was achieved by SCP in a study of 66 patients with BME secondary to advanced OA. Thus, a total number of 166 patients were considered as clinical success and 14 patients as clinical failure.

Conclusions

The included studies that have been published referred to the surgical methods of CD or SCP for the management of BME of the knee but none of that summarizes all current studies on both methods. Those studies seem that CD is a surgical technique that is proposed to perform in patients without findings of OA that usually fail to respond to conservative treatment. On the other hand, the option of SCP technique is carried out in patients with varied stage of OA associated with subchondral BME. Both methods aim to reduce the pain and to improve function in the setting of subchondral BME. Nevertheless it is not clear in literature which method is the best according to the criteria of the use. This literature review shows a lack of standardized guidelines with respect to diagnosis and surgical treatment.

Effects of surgical treatment for acromegaly on knee MRI structural features

Acromegalic arthropathy is a common complication of acromegaly and harms the quality of life of the patients even after acromegaly is in long-term remission. A recent study demonstrated by knee MRI the characteristic structural features of acromegalic arthropathy. However, the effects of treatment for acromegaly on such structural features are almost unknown. This study was undertaken to analyze the effects of transsphenoidal surgery (TSS) on acromegalic arthropathy and elucidate whether knee MRI findings are reversible or irreversible. We analyzed 22 patients with acromegaly (63.7% females, median age 58 years) by knee MRI at diagnosis. Out of these 22 patients, 16 who underwent TSS (68.9% female, median age 58 years) were also subjected to knee MRI 2 months after TSS. As for X-ray undetectable findings, MRI detected synovial thickening, bone marrow lesion, ligament injury and meniscus injury in 22.7%, 22.7%, 4.7% and 59.1% of the patients, respectively. With respect to the 16 patients who underwent TSS, clinical and structural improvements were observed respectively in 100%, 66.7% and 66.7% of the patients who showed knee joint pain, synovial thickening and bone marrow lesion before TSS. However, no patient showed structural improvement of meniscus injury after TSS. In acromegalic arthropathy, synovial thickening and bone marrow lesions are reversible while meniscus injury is irreversible. Because all those findings are associated with the exacerbation of arthropathy, they may be therapeutic targets for preventing the progression of arthropathy by endocrinological and orthopedic intervention.

High Prevalence of Vitamin D Deficiency in Patients With Bone Marrow Edema Syndrome of the Foot and Ankle

BACKGROUND

Bone marrow edema syndrome (BMOS) is a phenomenon primarily affecting the lower extremity. It is characterized by a sudden onset of pain and an ill-defined osseous hyperintense signal in magnetic resonance imaging. The main cause of BMOS is still largely unknown. Its pathophysiology is presumably multifactorial and it has recently been demonstrated that it usually involves an increase in bone turnover and alterations within the bone microenvironment. Vitamin D plays a pivotal role in maintaining a healthy and well-balanced bone microenvironment. However, to date only limited information has been reported on vitamin D status in patients with BMOS. Moreover, it is still uncertain whether hypovitaminosis D is associated with the etiology and course of the disease. For this reason, the aim of this study was to determine serum vitamin D levels (25(OH)D) of patients diagnosed with BMOS of the foot and ankle.

METHODS

Patients were identified and laboratory results collected by retrospective review of the medical records between year 2011 and 2015. Diagnosis was based on clinical examination, the existence of prolonged foot pain, the presence of abnormal bone marrow signal intensity in T1- and T2-weighted magnetic resonance imaging, and the patient's medical history. All patients who demonstrated other concomitant diagnoses were excluded from the study.

RESULTS

Overall, 31 patients were affected by BMOS with a mean age of 44.4 (range, 18-76) years. Notably, 84% of patients (26/31) had low vitamin D levels with a mean 25(OH)D level of 19.03 ng/mL. Specifically, 61% of patients (19/31) were vitamin D deficient, 23% (7/31) vitamin D insufficient, and only 5 patients (16%) had sufficient vitamin D levels. Statistical analysis showed no significant difference comparing vitamin D levels with patient age, sex, and time of diagnosis. Moreover, there was no correlation between vitamin D status and the number of bony foci or location of BMOS.

CONCLUSION

We found a widespread rate of vitamin D deficiency in patients presenting with BMOS of the foot and ankle. Comparing these data to the vitamin D status of the general population in Germany and to patients living in comparable latitudes, this raises the possibility that BMOS might be associated with low vitamin D status.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

MRI appearance of presumed self-inflicted trauma in the knees of military recruits

When knee bone marrow edema is observed on magnetic resonance imaging (MRI), it usually follows a pattern that can be explained by certain etiologies. This article describes a series of unusual knee bone marrow edemas in soldiers presumed to represent self-inflicted trauma.Ten soldiers (9 men and 1 woman; age range, 19-24 years) underwent knee MRI. None reported recent trauma or stress, and all presented with nonspecific pain or failure to respond to therapy. All showed a similar unusual pattern of bone marrow edema in the medial femoral condyle. Three observers evaluated the location of the bone marrow edema within the medial femoral condyle and its distance from the articular surface, dimensions, overlying soft tissue abnormality, and internal derangements. The edema was always subcortical and located in the middle aspect (n=7) or mid-anterior aspect (n=3) of the medial femoral condyle but was never centered subarticularly. Edema size ranged between 8 × 10 × 8 and 32 × 46 × 40 mm. Overlying soft tissue abnormalities were common (n=4) and included organizing (n=1) and residual hematoma (n=3). Concomitant MRI abnormalities were seen in 3 patients, usually minor. Eight patients reported longstanding pain with no antecedent trauma, and 2 reported remote trauma. One patient had a negative 4-month follow-up MRI, and another had a negative arthroscopy. Poor correlation existed between MRI findings and the absence of stress and trauma. Soldier chat rooms were found that describe how to induce fractures at this location.

Use of gamma correction pinhole bone scans in trauma

(99m)Tc-hydroxydiphosphonate (HDP) bone scanning is a classic metabolic nuclear imaging method and the most frequently performed examination. Clinically, it has long been cherished as an indispensable diagnostic screening tool and for monitoring of patients with bone, joint, and soft tissue diseases. The HDP bone scan, the pinhole scan in particular, is known for its ability to detect increased, decreased, or defective tracer uptake along with magnified anatomy. Unfortunately, however, the findings of such uptake changes are not specific in many traumatic bone disorders, especially when lesions are minute and complex. This study discusses the recently introduced gamma correction pinhole bone scan (GCPBS), emphasizing its usefulness in the diagnosis of traumatic bone diseases including occult fractures; cervical sprains; whiplash injury; bone marrow edema; trabecular microfractures; evident, gaping, and stress fractures; and fish vertebra. Indeed, GCPBS can remarkably enhance the diagnostic feasibility of HDP pinhole bone scans by refining the topography, pathologic anatomy, and altered chemical profile of the traumatic diseases in question. The fine and precise depiction of anatomic and metabolic changes in these diseases has been shown to be unique to GCPBS, and they are not appreciated on conventional radiographs, multiple detector CT, or ultrasonographs. It is true that MR imaging can portray proton change, but understandably, it is a manifestation that is common to any bone disease.

Bone bruise of the knee associated with the lesions of anterior cruciate ligament and menisci on magnetic resonance imaging

BACKGROUND/AIM

Bone bruise is a common finding in acutely injured knee examined by magnetic resonance (MR). The aim of the study was to determine the association of bone bruise frequency with postinjury lesions of anterior cruciate ligament (ACL) and menisci. Bone bruise involves posttraumatic bone marrow change with hemorrhages, edema and microtrabecular fractures without disruption of adjacent cortices or articular cartilage. MR imaging is a method of choice for detecting bone bruises which can not be seen on conventional radiographic techniques.

METHODS

A representative review of 120 MR examinations for the acute knee trauma was conducted. All the patients were examined within one month of trauma. All MR examinations were performed by using a 0.3T MR unit.

RESULTS

Posttraumatic bone bruise was seen in 39 (32.5%) patients out of 120. Three patients had fracture of the cortex, so-called "occult" fracture (not seen on plain radiography). We analyzed only bone bruises without these fractures of the cortex. Bone bruise was associated with the lesion of ACL in 27 (69%) patients. In 28 (72%) patients bone bruise was in combination with the lesion of menisci. Only two patients with bone bruise had neither ACL nor menisci lesions. There were 78 patients without bone bruise but 33 (43%) of them had lesions of ACL and 49 (63%) had lesions of menisci.

CONCLUSION

Bone bruise is best seen in STIR (Short TI Inversion Recovery) images and is very often found in acute knee trauma. Very often it is associated with posttraumatic lesions of ACL and menisci, so attention must be paid to this when bone bruise is seen. The difference in frequency of internal structures of the knee lesions in patients with bone bruise is highly statistically significant as compared to patients with no bone bruise.