Longitudinal assessment of bone marrow edema-like lesions and cartilage degeneration in osteoarthritis using 3 T MR T1rho quantification

T1Gd is reduced in bone marrow lesions overlying cartilage in the hip

OBJECTIVE

Bone Marrow Lesions (BMLs) are areas in bone with high fluid signal on MRI associated with painful and progressive OA. While cartilage near BMLs in the knee has been shown to be degenerated, this relationship has not been investigated in the hip.

RESEARCH QUESTION

is T1Gd lower in areas of cartilage overlying BMLs in the hip?

DESIGN

128 participants were recruited from a population-based study of hip pain in 20-49-year-olds. Proton-density weighted fat-suppressed and delayed Gadolinium Enhanced MR Imaging of Cartilage (dGEMRIC) images were acquired to locate BMLs and quantify hip cartilage health. BML and cartilage images were registered and cartilage was separated into BML overlying and surrounding regions. Mean T1Gd was measured in 32 participants with BMLs in both cartilage regions and in matched regions in 32 age- and sex-matched controls. Mean T1Gd in the overlying cartilage was compared using linear mixed-effects models between BML and control groups for acetabular and femoral BMLs, and between cystic and non-cystic BML groups.

RESULTS

Mean T1Gd of overlying cartilage was lower in the BML group compared to the control group (acetabular: -105 ms; 95% CI: -175, -35; femoral: -8 ms; 95% CI: -141, 124). Mean T1Gd in overlying cartilage was lower in cystic compared to non-cystic BML subjects, but the confidence interval is too large to provide certainty in this difference (-3 [95% CI: -126, 121]).

CONCLUSIONS

T1Gd is reduced in overlying cartilage in hips from a population-based sample of adults aged 20-49, which suggests BMLs are associated with local cartilage degeneration in hips.

Delayed Gadolinium-Enhanced Magnetic Resonance Imaging of Cartilage Values in Hips With Bone Marrow Lesions

OBJECTIVE

Bone marrow lesions (BMLs) are associated with painful and progressive osteoarthritis (OA). Quantitative magnetic resonance imaging (MRI) has been used to study early cartilage degeneration in knees with BML, but similar work has not been done in hips. The purpose of this study was to compare mean delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) relaxation values (T1Gd) in hips with BML to hips without BML in a population-based study. Reduced T1Gd suggests depleted glycosaminoglycan. Our hypothesis was that mean T1Gd is lower in hips with BML compared to hips without BML.

METHODS

Study participants (n = 128) were recruited from a cross-sectional population-based study of people ages 20-49 years with and without hip pain. dGEMRIC and proton density (PD)-weighted MRI scans of 1 hip from each participant were used for this analysis. BMLs were identified from PD-weighted fat-suppressed images. We applied a sampling-weighted linear regression model to determine the association of the presence of BMLs with mean cartilage T1Gd (significance: P < 0.05). The model was adjusted for age, sex, body mass index (BMI), hip pain, cam/pincer deformity, and physical activity.

RESULTS

Thirty-two (25%) of the 128 participants had at least 1 BML. Subjects with at least 1 BML, compared to those without, had similar weighted characteristics of age, BMI, physical activity levels, and frequency of hip pain. Mean T1Gd was 75.25 msec lower (95% confidence interval -149.69, -0.81; P = 0.048) (9%) in the BML compared to the no-BML group.

CONCLUSION

Our results suggest that hips with BMLs are associated with hip cartilage degeneration early in the OA disease process.

Is bone marrow oedema in patients with labral tear an indicator of hip pain?

Background

Hip labral tear (LT) causes various degrees of hip pain, for which there are few objective measures. Bone marrow oedema (BME), characterized by a diffuse, widely spreading change in the bone marrow, is observed in some patients with LT. However, its pathological role has not been fully understood. The purpose of this study was to investigate the prevalence of BME on hip magnetic resonance imaging (MRI) in patients with LT and to determine whether BME was an objective indicator of hip pain.

Methods

In total, 84 patients with LT who underwent MRI scanning under the same conditions were included. We determined the presence or absence of BME and its size on MRI and evaluated the relationships between BME and sex, age, and pain and total scores on the modified Harris hip score (MHHS). In addition, we collected data on surgical treatments such as hip arthroscopy within a one-year follow-up period and examined whether the presence of BME affected the course of therapy.

Results

BME was found in 34.5% of patients. MHHS pain and total scores were significantly lower in patients with BME (MHHS pain score: non-BME vs. BME ≤ 1 cm: p = 0.022, non-BME vs. BME > 1 cm: p < 0.001; MHHS total score: non-BME vs. BME ≤ 1 cm: p = 0.131, non-BME vs. BME > 1 cm: p = 0.027). The presence of BME did not differ between patients who did and did not undergo surgery during follow-up (p = 0.563).

Conclusion

BME on MRI in patients with LT might be an indicator of hip pain and hip joint dysfunction.

T1ρ and T2 MRI show hip cartilage damage in adolescents with healed Legg-Calvé-Perthes disease

Legg-Calvé-Perthes disease (LCPD) is a juvenile hip disorder associated with residual femoral head deformity, cartilage degeneration and a high risk of early onset hip osteoarthritis. Assessing management of LCPD in the healed phase requires an understanding of when and where hip cartilage damage happens. While it has been shown that cartilage is degenerated in healed LCPD hips in adults, it is not clear when this degeneration begins. Our research question was: Are the MR markers of cartilage degeneration T1ρ and T2 increased in healed LCPD hips in adolescents? Twelve adolescents [10-17 years old (mean 14); 3 female 9 male] with healed LCPD (Stulberg 2-5; 8 unilateral and 4 bilateral) and 15 age- and sex-matched controls were imaged in a 3T MRI using a T1ρ and a T2 sequence. We applied a mixed-effects model adjusted for age and nested by subject to determine the effect of Stulberg grade on overall and regional mean T1ρ and T2 values. T1ρ was significantly higher overall and in the medial region of Stulberg ≥3 hips, and in the medial region of Stulberg 2 hips than in the control group. T2 was significantly higher in the medial region of Stulberg ≥3 hips than in the control group. Our results suggest that cartilage damage in LCPD has begun by adolescence and that T1ρ can detect early changes in cartilage associated with LCPD.

Changes of the end plate cartilage are associated with intervertebral disc degeneration: A quantitative magnetic resonance imaging study in rhesus monkeys and humans

Background

The end plate plays an important role in intervertebral disc degeneration progression. The aim of the study was to examine the compositional and structural changes of the end plate with age and to investigate the correlation between end plate and disc degeneration by T1ρ and T2 map magnetic resonance imaging.

Methods

There were 12 young monkeys (6-7 years old), 20 aged monkeys (14-17 years old) and 12 human participants (30-50 years old) in this study. T1ρ or T2 map values of the nucleus pulposus and end plate cartilage were analyzed according to Pfirrmann grades and age. Afterwards, micro computed tomography and histological analysis were used to confirm the end plate changes in monkeys. Pearson’s correlation was performed to investigate the relationship between end plate and disc degeneration.

Results

In monkeys, T1ρ (r=-0.794, P<0.001) and T2 map values (r=-0.8, P<0.001) of the nucleus pulposus were negatively associated with Pfirrmann grades. Moreover, the T2 map was more suitable than T1ρ for the evaluation of end plate degeneration. Age was an important influence factor of end plate and disc degeneration, which was confirmed by microcomputed tomography, Safranin O/fast green staining, and collagen II staining. The T2 map value of lower end plate degeneration positively correlated with that of the intervertebral discs in monkeys (R²=0.3133, P<0.001) and humans (R²=0.2092, P<0.001).

Conclusion

This study suggests that the compositional and structural changes of the end plate can be quantitatively evaluated by T2 map. Furthermore, cartilage end plate degeneration is associated with disc degeneration during ageing.

The translational potential of this article

A better understanding of how the cartilage end plate affects disc degeneration is needed, which may propose a new clinical application using T2 map to evaluate end plate degeneration.

Intraosseous injections of platelet rich plasma for knee bone marrow lesions treatment: one year follow-up

PURPOSE

Cartilage lesions are usually accompanied by subchondral bone alterations or bone marrow lesions (BMLs). BML associated with joint degeneration and cartilage lesions are considered to be predictors of rapidly progressing OA. Currently no existing treatment can fully halt OA progression. One of the approaches is an autologous, biological treatment based on the use of platelet rich plasma (PRP) injections. The purpose of this study is to assess the short-term effectiveness of intraosseous PRP injections, within the BML of individuals affected by OA, in ameliorating pain and improving knee functionality.

MATERIALS AND METHODS

The study involved 17 patients with an average age of 41.7 ± 14.3 years old. OA stage was determined using the Kellgren-Lawrence grading system by performing radiographic scanning of the knee joint before surgical intervention. Patients with K-L grade 3 knee joint OA prevailed. Patient OA history varied between one and nine years (average 5.2 ± 4.5 years). Clinical and functional state of the knee were assessed by pain visual analogue scale (VAS) score, the Western Ontario and McMaster Universities Score (WOMAC), and the Knee Injury and Osteoarthritis Outcome Score (KOOS) which were filled out by patients previous to the surgical procedure at one, three, six and 12 months post-operatively. Before surgery, in addition to standard blood tests, serum cartilage oligomeric matrix protein (COMP) levels were tested for all patients.

RESULTS

Evaluation of preliminary results revealed a statistically significant reduction of pain based on the VAS score. A significant improvement was also observed in the patients' WOMAC score and in the overall KOOS score. Serum marker levels were initially elevated in our experimental patient group compared to the same marker in healthy control respondents, and continued to rise one month and three months following surgery, at six and 12 month the level was similar as at three months.

CONCLUSIONS

In our opinion, first COMP increasing can be caused by injection of platelet rich plasma. It is not adequate to interpret this growth in COMP levels as increased osteochondral degeneration. One year follow-up period showed good quality of life improvement, significant pain reduction, and essential MRI changes. The long-term observation of these cohort of patients combined with an analysis of MRI images is still ongoing.

Effectiveness of intraosseous infiltration of autologous platelet-rich plasma in the area of the bone marrow edema in osteoarthritis of the knee joint

Osteoarthritis (OA) affects both elderly people, for whom it is one of the main causes of disability, and people of active working age and is an urgent clinical and social problem of resistance of pain syndrome to therapy. The disease is characterized by both destruction of intra-articular and paraarticular structures, such as subchondral bone. While OA is an important sign of pathological changes believe the bone marrow edema (BME). This work examines the effect of BME on development osteoarthritis, and therapeutic approaches to the management of patients with OA. The aim of the study was to develop a method of treatment of BME in OA of the knee joint by locally intraosseous injection of autologous thrombotic-rich plasma (PRP) into the edema zone. In this study 17 patients with the diagnosis: Osteoarthritis II-IV Grade. according to the classification of Kellgren–Lawrence, in which areas of local inflammation in the form of BME were detected on MRI in the subchondral zone in accordance with the international classification of WORMS (Whole Organ Magnetic Resonance Imaging Score). The mean age of patients was 41,7 ± 14,3 years, 10 of them were women and 7 men. Patients were treated with autological platelet-rich plasma under x-ray control injected from extra-articular intraosseous access in the area of BME. Evaluation of effectiveness of treatment performed by VAS, WOMAC and KOOS scales, before the introduction of autoplasma, after 1 and 3 months after the start of treatment. Three months after the manipulation, there was a statistically significant decrease in the intensity of inflammatory syndrome: for WOMAC by 17.5%, for KOOS by 19.4% and for VAS by 33,1% (p < 0,01). Thus, the efficiency of intraosseous Infiltration of autologous platelet-rich plasma in the treatment of patients with OA, accompanied by edema of the bone marrow in the subchondral zone, was proved.

Diabetics show accelerated progression of knee cartilage and meniscal lesions: data from the osteoarthritis initiative

OBJECTIVE

To investigate whether subjects with diabetes show accelerated knee joint structural degeneration over 4 years compared to diabetes-free controls.

MATERIALS AND METHODS

Two hundred forty-four participants with diabetes were selected from the Osteoarthritis Initiative cohort and matched with 244 diabetes-free controls. 3.0-T MRI scans of the right knee were obtained at baseline and 4-year follow-up. Evaluation of structural knee abnormalities was performed using the Whole-Organ Resonance Imaging Scoring system (WORMS). Linear regression analysis was conducted to compare structural temporal changes in each compartment, as well as the mean across all compartments by diabetes status.

RESULTS

Study groups were similar in age (63.0 vs. 63.3 years, p = 0.73), body mass index (31.5 vs. 31.0 kg/m², p = 0.21), sex (female 52.0 vs. 52.9%, p = 0.85) and radiographic Kellgren/Lawrence score distribution (p = 0.99). Structural degeneration was significantly worse in the knees of diabetics with an increase in the overall WORMS sum score (delta WORMS [95% CI]: 4.87 [4.17, 5.57], vs. 3.23 [2.60, 3.85] p = 0.001). Moreover, diabetics showed a greater increase in cartilage lesions in the global knee (p < 0.001), but also separately in the patella, lateral tibia, and both femoral compartments (lowest p value; p = 0.001). Furthermore, diabetics showed also a greater increase in meniscus lesion score, in both the medial (p = 0.01) and lateral meniscus (p = 0.01).

CONCLUSIONS

Diabetics exhibited a significantly greater increase in cartilage and meniscus lesions when compared to diabetes-free controls over 4 years. Overall, our findings suggest that diabetics exhibit a stronger deterioration of knee structure and are therefore potentially at higher risk for developing knee OA.

Subchondral Bone and the Osteochondral Unit: Basic Science and Clinical Implications in Sports Medicine

Context:

Articular cartilage injuries and early osteoarthritis are among the most common conditions seen by sports medicine physicians. Nonetheless, treatment options for articular degeneration are limited once the osteoarthritic cascade has started. Intense research is focused on the use of biologics, cartilage regeneration, and transplantation to help maintain and improve cartilage health. An underappreciated component of joint health is the subchondral bone.

Evidence Acquisition:

A comprehensive, nonsystematic review of the published literature was completed via a PubMed/MEDLINE search of the keywords “subchondral” AND “bone” from database inception through December 1, 2016.

Study Design:

Clinical review.

Level of Evidence:

Level 4.

Methods:

Articles collected via the database search were assessed for the association of bone marrow lesions and osteoarthritis, cartilage regeneration, and ligamentous and meniscal injury; the clinical disorder known as painful bone marrow edema syndrome; and the subchondral bone as a target for medical and surgical intervention.

Results:

A complex interplay exists between the articular cartilage of the knee and its underlying subchondral bone. The role of subchondral bone in the knee is intimately related to the outcomes from cartilage restoration procedures, ligamentous injury, meniscal pathology, and osteoarthritis. However, subchondral bone is often neglected when it should be viewed as a critical element of the osteochondral unit and a key player in joint health.

Conclusion:

Continued explorations into the intricacies of subchondral bone marrow abnormalities and implications for the advent of procedures such as subchondroplasty will inform further research efforts on how interventions aimed at the subchondral bone may provide durable options for knee joint preservation.

Bone marrow edema-like lesions (BMELs) are associated with higher T1ρ and T2 values of cartilage in anterior cruciate ligament (ACL)-reconstructed knees: a longitudinal study

BACKGROUND

To evaluate the longitudinal changes of bone marrow edema-like lesions (BMELs) in patients after anterior cruciate ligament (ACL) reconstruction and to investigate the effect of BMELs on cartilage matrix composition changes measured using MR T_1ρ and T₂ mapping.

METHODS

Patients with acute ACL tear were enrolled in a prospective study. MR imaging was performed at baseline (before surgeries) and at 6-month, 1-year and 2-year after ACL reconstruction. MR imaging included sagittal high-resolution, 3D fast spin-echo (CUBE) sequences for BMEL evaluation, and 3D T_1ρ mapping and T₂ mapping for cartilage assessment. BMELs were assessed using whole-organ magnetic resonance imaging score (WORMS), and the volume of BMELs was measured by a semi-automatic method. Generalized estimating equation (GEE) was used to explore association between BMELs at baseline and cartilage changes during follow-up.

RESULTS

Fifty four patients were included in the present study and 39 patients had completed 2-year follow-up. BMELs were noted in 42 injured knees (77.8%) with 105 lesions and in 7 contralateral knees (13.0%) with 9 lesions (χ²=45.763, P<0.001) at the baseline. The WORMS and volume of BMELs of the injured knees were 2.36±0.65 and 386.98±382.54 mm³ (r=0.681, P<0.001), respectively. 87 BMELs were found at baseline in 34 patients (87.2%) of the 39 patients who had completed 2 years follow-up. During the follow-up, 18 (20.7%), 12 (13.8%), and 5 (5.7%) baseline lesions were still seen at 6-month, 1-year and 2-year, respectively. The changes of BMELs prevalence regarding bone compartments over time points were statistically significant (χ²=163.660, P<0.001). Except T₂ value at 6 months, T_1ρ and T₂ values of cartilage overlying baseline BMELs in the injured knees were higher than that of anatomically matched cartilage in the contralateral knees at baseline and each follow-up time-point. In the injured knees, GEE analysis showed that baseline BMELs were significantly associated with higher T_1ρ and T₂ values of cartilage after adjustment of age, gender, body mass index (BMI), effusion and meniscus tear. The association between BMELs and Knee Injury and Osteoarthritis Outcome Scores (KOOS) scores was not statistically significant.

CONCLUSIONS

BMEL is a common finding in patients with acute ACL injury and resolves rapidly over time after ACL reconstruction. It is often associated with increased T_1ρ and T₂ values of cartilage. BMEL at baseline is an independent predictor for faster cartilage degeneration during follow-up.

Advanced Imaging in Osteoarthritis

Context:

Radiography is widely accepted as the gold standard for diagnosing osteoarthritis (OA), but it has limitations when assessing early stage OA and monitoring progression. While there are improvements in the treatment of OA, the challenge is early recognition.

Evidence Acquisition:

MEDLINE and PubMed as well as professional orthopaedic and imaging websites were reviewed from 2006 to 2016.

Study Design:

Clinical review.

Level of Evidence:

Level 4.

Results:

Magnetic resonance imaging (MRI) can provide the most comprehensive assessment of joint injury and OA with the advantages of being noninvasive and multiplanar with excellent soft tissue contrast. However, MRI is expensive, time consuming, and not widely used for monitoring OA clinically. Computed tomography (CT) and CT arthrography (CTA) can also be used to evaluate OA, but these are also invasive and require radiation exposure. Ultrasound is particularly useful for evaluation of synovitis but not for progression of OA.

Conclusion:

MRI, CT, and CTA are available for the diagnosis and monitoring of OA. Improvement in techniques and decrease in cost can allow some of these modalities to be effective methods of detecting early OA.

T1ρ magnetic resonance: basic physics principles and applications in knee and intervertebral disc imaging

T1ρ relaxation time provides a new contrast mechanism that differs from T1- and T2-weighted contrast, and is useful to study low-frequency motional processes and chemical exchange in biological tissues. T1ρ imaging can be performed in the forms of T1ρ-weighted image, T1ρ mapping and T1ρ dispersion. T1ρ imaging, particularly at low spin-lock frequency, is sensitive to B0 and B1 inhomogeneity. Various composite spin-lock pulses have been proposed to alleviate the influence of field inhomogeneity so as to reduce the banding-like spin-lock artifacts. T1ρ imaging could be specific absorption rate (SAR) intensive and time consuming. Efforts to address these issues and speed-up data acquisition are being explored to facilitate wider clinical applications. This paper reviews the T1ρ imaging's basic physic principles, as well as its application for cartilage imaging and intervertebral disc imaging. Compared to more established T2 relaxation time, it has been shown that T1ρ provides more sensitive detection of proteoglycan (PG) loss at early stages of cartilage degeneration. T1ρ has also been shown to provide more sensitive evaluation of annulus fibrosis (AF) degeneration of the discs.

T1rho mapping of entire femoral cartilage using depth- and angle-dependent analysis

Objectives

To create and evaluate normalized T1rho profiles of the entire femoral cartilage in healthy subjects with three-dimensional (3D) angle- and depth-dependent analysis.

Methods

T1rho images of the knee from 20 healthy volunteers were acquired on a 3.0-T unit. Cartilage segmentation of the entire femur was performed slice-by-slice by a board-certified radiologist. The T1rho depth/angle-dependent profile was investigated by partitioning cartilage into superficial and deep layers, and angular segmentation in increments of 4° over the length of segmented cartilage. Average T1rho values were calculated with normalized T1rho profiles. Surface maps and 3D graphs were created.

Results

T1rho profiles have regional and depth variations, with no significant magic angle effect. Average T1rho values in the superficial layer of the femoral cartilage were higher than those in the deep layer in most locations (p < 0.05). T1rho values in the deep layer of the weight-bearing portions of the medial and lateral condyles were lower than those of the corresponding non-weight-bearing portions (p < 0.05). Surface maps and 3D graphs demonstrated that cartilage T1rho values were not homogeneous over the entire femur.

Conclusions

Normalized T1rho profiles from the entire femoral cartilage will be useful for diagnosing local or early T1rho abnormalities and osteoarthritis in clinical applications.

Key Points

• T1rho profiles are not homogeneous over the entire femur.

• There is angle- and depth-dependent variation in T1rho profiles.

• There is no influence of magic angle effect on T1rho profiles.

• Maps/graphs might be useful if several difficulties are solved.

A systematic review of the relationship between subchondral bone features, pain and structural pathology in peripheral joint osteoarthritis

INTRODUCTION

Bone is an integral part of the osteoarthritis (OA) process. We conducted a systematic literature review in order to understand the relationship between non-conventional radiographic imaging of subchondral bone, pain, structural pathology and joint replacement in peripheral joint OA.

METHODS

A search of the Medline, EMBASE and Cochrane library databases was performed for original articles reporting association between non-conventional radiographic imaging-assessed subchondral bone pathologies and joint replacement, pain or structural progression in knee, hip, hand, ankle and foot OA. Each association was qualitatively characterised by a synthesis of the data from each analysis based upon study design, adequacy of covariate adjustment and quality scoring.

RESULTS

In total 2456 abstracts were screened and 139 papers were included (70 cross-sectional, 71 longitudinal analyses; 116 knee, 15 hip, six hand, two ankle and involved 113 MRI, eight DXA, four CT, eight scintigraphic and eight 2D shape analyses). BMLs, osteophytes and bone shape were independently associated with structural progression or joint replacement. BMLs and bone shape were independently associated with longitudinal change in pain and incident frequent knee pain respectively.

CONCLUSION

Subchondral bone features have independent associations with structural progression, pain and joint replacement in peripheral OA in the hip and hand but especially in the knee. For peripheral OA sites other than the knee, there are fewer associations and independent associations of bone pathologies with these important OA outcomes which may reflect fewer studies; for example the foot and ankle were poorly studied. Subchondral OA bone appears to be a relevant therapeutic target.

SYSTEMATIC REVIEW

PROSPERO registration number: CRD 42013005009.

Cartilage T1ρ and T2 Relaxation Times in Patients With Mild-to-Moderate Radiographic Hip Osteoarthritis

OBJECTIVE

To analyze region-specific T1ρ and T2 relaxation times of the hip joint cartilage in relation to presence or absence of radiographic hip osteoarthritis (OA) and presence or absence of magnetic resonance imaging (MRI)-detected cartilage defects.

METHODS

Weight-bearing radiographs and 3T MRI studies of the hip were obtained from 84 volunteers. Based on Kellgren/Lawrence (K/L) scoring of the radiographs, 54 subjects were classified as healthy controls (K/L grade ≤1) and 30 were classified as having mild or moderate radiographic hip OA (K/L grades 2 or 3, respectively). Two-dimensional fat-suppressed fast spin-echo MRI sequences were used for semiquantitative clinical scoring of cartilage defects, and a T1ρ/T2 sequence was used to quantitatively assess the cartilage matrix. The femoral and acetabular cartilage was then segmented into 8 regions and the mean T1ρ/T2 values were calculated. Differences in T1ρ and T2 relaxation times were compared between subjects with and those without radiographic hip OA, and those with and those without femoral or acetabular cartilage defects.

RESULTS

Higher T1ρ and T2 relaxation times in the anterior superior and central regions of the acetabular cartilage were seen in individuals with radiographic hip OA and those with acetabular cartilage defects compared to their respective controls (P < 0.05). In the femoral cartilage, the differences in T1ρ and T2 were not significant for any of the comparisons. Significant differences in the T1ρ and T2 values (each P < 0.05) were found in more subregions of the cartilage and across the whole cartilage when subjects were stratified based on the presence of MRI-detected cartilage defects than when they were stratified based on the presence of radiographic hip OA.

CONCLUSION

T1ρ and T2 relaxation parameters are sensitive to the presence of cartilage degeneration. Both parameters may therefore support MRI evidence of cartilage defects of the hip.

Physical activity and spatial differences in medial knee T1rho and t2 relaxation times in knee osteoarthritis

STUDY DESIGN

Cross-sectional.

OBJECTIVES

To investigate the association between knee loading- related osteoarthritis (OA) risk factors (obesity, malalignment, and physical activity) and medial knee laminar (superficial and deep) T1rho and T2 relaxation times.

BACKGROUND

The interaction of various modifiable loading-related knee risk factors and cartilage health in knee OA is currently not well known.

METHODS

Participants with and without knee OA (n = 151) underwent magnetic resonance imaging at 3 T for superficial and deep cartilage T1rho and T2 magnetic resonance relaxation times in the medial femur (MF) and medial tibia (MT). Other variables included radiographic Kellgren-Lawrence (KL) grade, alignment, pain and symptoms using the Knee injury and Osteoarthritis Outcome Score, and physical activity using the International Physical Activity Questionnaire (IPAQ). Individuals with a KL grade of 4 were excluded. Group differences were calculated using 1-way analysis of variance, adjusting for age and body mass index. Linear regression models were created with age, sex, body mass index, alignment, KL grade, and the IPAQ scores to predict the laminar T1rho and T2 times.

RESULTS

Total IPAQ scores were the only significant predictors among the loading-related variables for superficial MF T1rho (P = .005), deep MT T1rho (P = .026), and superficial MF T2 (P = .049). Additionally, the KL grade predicted the superficial MF T1rho (P = .023) and deep MT T1rho (P = .022).

CONCLUSION

Higher physical activity levels and worse radiographic severity of knee OA, but not obesity or alignment, were associated with worse cartilage composition.

Subchondral bone in osteoarthritis: insight into risk factors and microstructural changes

Osteoarthritis (OA) is a major cause of disability in the adult population. As a progressive degenerative joint disorder, OA is characterized by cartilage damage, changes in the subchondral bone, osteophyte formation, muscle weakness, and inflammation of the synovium tissue and tendon. Although OA has long been viewed as a primary disorder of articular cartilage, subchondral bone is attracting increasing attention. It is commonly reported to play a vital role in the pathogenesis of OA. Subchondral bone sclerosis, together with progressive cartilage degradation, is widely considered as a hallmark of OA. Despite the increase in bone volume fraction, subchondral bone is hypomineralized, due to abnormal bone remodeling. Some histopathological changes in the subchondral bone have also been detected, including microdamage, bone marrow edema-like lesions and bone cysts. This review summarizes basic features of the osteochondral junction, which comprises subchondral bone and articular cartilage. Importantly, we discuss risk factors influencing subchondral bone integrity. We also focus on the microarchitectural and histopathological changes of subchondral bone in OA, and provide an overview of their potential contribution to the progression of OA. A hypothetical model for the pathogenesis of OA is proposed.

Imaging following acute knee trauma

Joint injury has been recognized as a potent risk factor for the onset of osteoarthritis. The vast majority of studies using imaging technology for longitudinal assessment of patients following joint injury have focused on the injured knee joint, specifically in patients with anterior cruciate ligament injury and meniscus tears where a high risk for rapid onset of post-traumatic osteoarthritis is well known. Although there are many imaging modalities under constant development, magnetic resonance (MR) imaging is the most important instrument for longitudinal monitoring after joint injury. MR imaging is sensitive for detecting early cartilage degeneration and can evaluate other joint structures including the menisci, bone marrow, tendons, and ligaments which can be sources of pain following acute injury. In this review, focusing on imaging following acute knee trauma, several studies were identified with promising short-term results of osseous and soft tissue changes after joint injury. However, studies connecting these promising short-term results to the development of osteoarthritis were limited which is likely due to the long follow-up periods needed to document the radiographic and clinical onset of the disease. Thus, it is recommended that additional high quality longitudinal studies with extended follow-up periods be performed to further investigate the long-term consequences of the early osseous and soft tissue changes identified on MR imaging after acute knee trauma.

Bone marrow lesions: A systematic diagnostic approach

Bone marrow lesions on magnetic resonance (MR) imaging are common and may be seen with various pathologies. The authors outline a systematic diagnostic approach with proposed categorization of various etiologies of bone marrow lesions. Utilization of typical imaging features on conventional MR imaging techniques and other problem-solving techniques, such as chemical shift imaging and diffusion-weighted imaging (DWI), to achieve accurate final diagnosis has been highlighted.

Cartilage morphology and T1ρ and T2 quantification in ACL-reconstructed knees: a 2-year follow-up

OBJECTIVE

To describe cartilage matrix and morphology changes, assessed using quantitative magnetic resonance imaging (MRI), after acute anterior cruciate ligament (ACL) injury relative to controls and longitudinally during 2 years following reconstruction.

METHOD

Fifteen patients with acute ACL injuries and 16 healthy volunteers with a similar demographic profile but no history of osteoarthritis or knee injury were studied. The injured knee of each participant was imaged with a 3.0 T MR scanner at baseline (prior to ACL reconstruction); patients' knees were re-imaged 1 and 2 years after ACL reconstruction. Cartilage T1ρ and T2 values in full thickness, superficial layers, and deep layers, and cartilage thickness of the full layer were quantified within subcompartments of the knee joint.

RESULTS

In the posterolateral tibial cartilage, T1ρ values were significantly higher in ACL-injured knees than control knees at baseline and were not fully recovered 2 after ACL reconstruction. T1ρ values of medial tibiofemoral cartilage in ACL-injured knees increased over the 2-year study and were significantly elevated compared to that of the control knees. T2 values in cartilage of the central aspect of the medial femoral condyle at the 2-year follow-up were significantly elevated compared with control knees. Cartilage in the posterior regions of the lateral tibia was significantly thinner, while cartilage in the central aspect of the medial femur was significantly thicker than that of controls. Patients with lesions in the posterior horn of the medial meniscus exhibited significantly higher T1ρ values in weight-bearing regions of the tibiofemoral cartilage than that of control subjects over the 2-year period, whereas patients without medial meniscal tears did not.

CONCLUSION

Quantitative MRI provides powerful in vivo tools to quantitatively evaluate early changes of cartilage matrix and morphology after acute ACL injury and reconstruction, which may possibly relate to the development of post-traumatic osteoarthritis in such joints.

Bone and cartilage demonstrate changes localized to bone marrow edema-like lesions within osteoarthritic knees

OBJECTIVE

Our objective is to understand the biological and mechanical pathways linking cartilage, bone, and marrow changes in the progression of osteoarthritis (OA). The aim of the present study was to evaluate bone structure and composition within bone marrow edema-like lesion (BMEL) regions associated with knee OA.

METHODS

Tibial plateau specimens (n = 18) were collected from 10 subjects with knee OA during total knee arthroplasty (TKA). Magnetic resonance (MR) imaging was used to identify BMEL and quantify metrics of cartilage composition. Micro-computed tomography (μCT) and high-resolution peripheral quantitative computed tomography (HR-pQCT) were used to quantify density and microstructure of the subchondral trabecular bone. Fourier transform infrared (FTIR) spectroscopy was used to quantify tissue composition.

RESULTS

Trabecular bone within BMEL was higher in volume fraction, with more and thicker trabeculae that were more plate-like in structure compared to unaffected regions. BMEL trabecular tissue composition had decreased phosphate and carbonate content. Marrow infiltration by a fibrous collagen network and evidence of increased bone remodeling were present. Structural and compositional changes were specifically localized to regions underlying cartilage degradation.

CONCLUSION

These results support the paradigm of focal interactions among bone, marrow, and cartilage in the progression of knee OA. Quantitative evaluation of tissue changes and interactions may aid in the understanding of disease pathophysiology and provide imaging markers for disease progression.

Early diagnosis to enable early treatment of pre-osteoarthritis

Osteoarthritis is a prevalent and disabling disease affecting an increasingly large swathe of the world population. While clinical osteoarthritis is a late-stage condition for which disease-modifying opportunities are limited, osteoarthritis typically develops over decades, offering a long window of time to potentially alter its course. The etiology of osteoarthritis is multifactorial, showing strong associations with highly modifiable risk factors of mechanical overload, obesity and joint injury. As such, characterization of pre-osteoarthritic disease states will be critical to support a paradigm shift from palliation of late disease towards prevention, through early diagnosis and early treatment of joint injury and degeneration to reduce osteoarthritis risk. Joint trauma accelerates development of osteoarthritis from a known point in time. Human joint injury cohorts therefore provide a unique opportunity for evaluation of pre-osteoarthritic conditions and potential interventions from the earliest stages of degeneration. This review focuses on recent advances in imaging and biochemical biomarkers suitable for characterization of the pre-osteoarthritic joint as well as implications for development of effective early treatment strategies.

A preliminary study of the T1rho values of normal knee cartilage using 3T-MRI

INTRODUCTION

To investigate the degree of the effect of aging and weight-bearing on T1rho values in normal cartilage.

MATERIALS AND METHODS

Thirty-two asymptomatic patients were examined using 3.0-T magnetic resonance imaging (MRI) to determine knee cartilage T1rho values and T2 values. The femoral and tibial cartilage was divided into weight-bearing (WB-Rs) and less-weight-bearing (LWB-Rs) regions. Single regression analysis was used to assess the relationship between cartilage T1rho values and age and between T2 values and age. Analysis of variance and post hoc-testing were used to evaluate differences in WB-Rs and LWB-Rs cartilage T1rho values and T2 values. Multiple linear regression modeling was performed to predict cartilage T1rho values.

RESULTS

Cartilage T1rho values correlated positively with age for all cartilage regions tested (p<0.001). There were no significant correlations between cartilage T2 values and age. In both the medial femoral and tibial cartilage, T1rho values were significantly higher in WB-Rs than in LWB-Rs (p<0.05). There were no significant differences in T2 values between WB-Rs and LWB-Rs. Multiple linear regression analysis showed that both age and weight-bearing were significant predictors of increased medial knee cartilage T1rho values (p<0.001).

CONCLUSIONS

Aging and the degree of weight-bearing correlate with the change in cartilage T1rho values. Based on multiple regression modeling, aging may be a more important factor than weight-bearing for cartilage T1rho values.

A longitudinal study of the association between dietary factors, serum lipids, and bone marrow lesions of the knee

Introduction

Bone marrow lesions (BMLs) play an important role in knee osteoarthritis, but their etiology is not well understood. The aim of this longitudinal study was to describe the association between dietary factors, serum lipids, and BMLs.

Methods

In total, 394 older men and women (mean age, 63 years; range, 52 to 79) were measured at baseline and approximately 2.7 years later. BMLs were determined by using T₂-weighted fat-saturation magnetic resonance imaging (MRI) by measuring the maximal area of the lesion. Nutrient intake (total energy, fat, carbohydrate, protein, and sugar) and serum lipids were assessed at baseline.

Results

Cross-sectionally, dietary factors and lipids were not significantly associated with BMLs. Energy, carbohydrate, and sugar intake (but not fat) were positively associated with a change in BML size (β = 15.44 to 19.27 mm² per 1 SD increase; all P < 0.05). High-density lipoprotein (HDL) cholesterol tended to be negatively associated with BML change (β = -11.66 mm² per 1 SD increase; P = 0.088).

Conclusions

Energy, carbohydrate, and sugar intake may be risk factors for BML development and progression. HDL cholesterol seems protective against BMLs. These results suggest that macronutrients and lipids may be important in BML etiology and that dietary modification may alter BML natural history.

Quantitative bone marrow lesion size in osteoarthritic knees correlates with cartilage damage and predicts longitudinal cartilage loss

Background

Bone marrow lesions (BMLs), common osteoarthritis-related magnetic resonance imaging findings, are associated with osteoarthritis progression and pain. However, there are no articles describing the use of 3-dimensional quantitative assessments to explore the longitudinal relationship between BMLs and hyaline cartilage loss. The purpose of this study was to assess the cross-sectional and longitudinal descriptive characteristics of BMLs with a simple measurement of approximate BML volume, and describe the cross-sectional and longitudinal relationships between BML size and the extent of hyaline cartilage damage.

Methods

107 participants with baseline and 24-month follow-up magnetic resonance images from a clinical trial were included with symptomatic knee osteoarthritis. An 'index' compartment was identified for each knee defined as the tibiofemoral compartment with greater disease severity. Subsequently, each knee was evaluated in four regions: index femur, index tibia, non-index femur, and non-index tibia. Approximate BML volume, the product of three linear measurements, was calculated for each BML within a region. Cartilage parameters in the index tibia and femur were measured based on manual segmentation.

Results

BML volume changes by region were: index femur (median [95% confidence interval of the median]) 0.1 cm³ (-0.5 to 0.9 cm³), index tibia 0.5 cm³ (-0.3 to 1.7 cm³), non-index femur 0.4 cm³ (-0.2 to 1.6 cm³), and non-index tibia 0.2 cm³ (-0.1 to 1.2 cm³). Among 44 knees with full thickness cartilage loss, baseline tibia BML volume correlated with baseline tibia full thickness cartilage lesion area (r = 0.63, p< 0.002) and baseline femur BML volume with longitudinal change in femoral full thickness cartilage lesion area (r = 0.48 p< 0.002).

Conclusions

Many regions had no or small longitudinal changes in approximate BML volume but some knees experienced large changes. Baseline BML size was associated to longitudinal changes in area of full thickness cartilage loss.

TNF is required for the induction but not the maintenance of compression-induced BME signals in murine tail vertebrae: limitations of anti-TNF therapy for degenerative disc disease

While bone marrow edema (BME) is diagnostic of spondyloarthropathy, its nature remains poorly understood. In contrast, BME in ankylosing spondylitis is caused by tumor necrosis factor (TNF)-induced vascular and cellular changes. To investigate the relationship between chronic compression and TNF signaling in compression-induced BME we utilized a tail vertebrae compression model with WT, TNF-Tg, and TNFR1&2-/- mice to evaluate: (i) healing following release of chronic compression, (ii) induction of BME in the absence of TNFR, and (iii) efficacy of anti-TNF therapy. Compression-induced normalized marrow contrast enhancement (NMCE) in WT was significantly decreased threefold (p < 0.01) within 2 weeks of release, while the NMCE values in TNF-Tg vertebrae remained elevated, but had a significant decrease (p < 0.05) by 6 weeks after the release of compression. TNFR1&2-/- mice were resistant to compression-induced BME. Anti-TNF therapy did not affect NMCE versus placebo. Histological examination revealed that NMCE values significantly correlated with marrow vascularity and cellularity (p < 0.05), which account for 76% of the variability of NMCE. Collectively, these data demonstrate a critical role for TNF in the induction of chronic compression-induced BME, but not in its maintenance. Amelioration of BME is achieved through biomechanical stability, but is not affected by anti-TNF therapy.

The evolution of articular cartilage imaging and its impact on clinical practice

Over the past four decades, articular cartilage imaging has developed rapidly. Imaging now plays a critical role not only in clinical practice and therapeutic decisions but also in the basic research probing our understanding of cartilage physiology and biomechanics.

Natural history and clinical significance of MRI-detected bone marrow lesions at the knee: a prospective study in community dwelling older adults

Introduction

There are conflicting data on the natural history and clinical significance of bone marrow lesions (BMLs). The aims of this study were to describe the natural history of MRI-detected BMLs at the knee using a quantitative measure and examine the association of BMLs with pain, function and stiffness scores, and total knee replacement (TKR) surgery.

Methods

A total of 395 older males and females were randomly selected from the general population (mean age 63 years, range 52 to 79) and measured at baseline and approximately 2.7 years later. BMLs were determined using T2-weighted fat saturation MRI by measuring the maximum area of the lesion. Reproducibility was excellent (intraclass correlation coefficient (ICC): 0.97). Pain, function, and stiffness were assessed by Western Ontario and McMaster Universities Osteoarthritis (WOMAC) scores. X-ray was used to assess radiographic osteoarthritis (ROA) at baseline.

Results

At baseline, 43% (n = 168/395) had a BML. Of these 25% decreased in size and 24% increased. Of the remaining sample (n = 227), 7% developed a new BML. In a multivariable model, a change in BML size was associated with a change in pain and function scores (β = 1.13 to 2.55 per 1 SD increase, all P < 0.05), only in those participants without ROA. Lastly, baseline BML severity predicted TKR surgery (odds ratio (OR) 2.10/unit, P = 0.019).

Conclusions

In a population based sample, BMLs (assessed by measuring maximal area) were not static, with similar proportions both worsening and improving. A change in BML size was associated with changes in pain in those without established ROA. This finding suggests that fluctuating knee pain may be attributable to BMLs in those participants with early stage disease. Baseline BMLs also predicted TKR surgery. These findings suggest therapeutic interventions aimed at altering the natural history of BMLs should be considered.

Cartilage in anterior cruciate ligament-reconstructed knees: MR imaging T1{rho} and T2--initial experience with 1-year follow-up

PURPOSE

To longitudinally evaluate cartilage matrix changes by using magnetic resonance (MR) imaging T1(ρ) (T1 relaxation time in rotating frame) and T2 quantification and to study the relationship between meniscal damage and cartilage degeneration in anterior cruciate ligament (ACL)-reconstructed knees.

MATERIALS AND METHODS

This was an institutional review board-approved, HIPAA-compliant study. Informed consent was obtained. Twelve patients with acute ACL injuries were imaged with 3.0-T MR imaging at baseline (after injury and prior to ACL reconstruction) and 1 year after ACL reconstruction. Ten age-matched healthy subjects were studied as controls. Cartilage T1(ρ) and T2 were quantified in full thickness, superficial, and deep layers of defined subcompartments at baseline and follow-up in ACL-injured knees and were compared with measures acquired in matched regions of control knees. Meniscal lesions were graded by using modified subscores of the Whole-Organ Magnetic Resonance Imaging Score system.

RESULTS

T1(ρ) values of the posterolateral tibial cartilage in ACL-injured knees were significantly elevated at baseline compared with T1(ρ)values of control knees and were not fully recovered at 1-year follow-up. T1(ρ) values of weight-bearing medial femorotibial cartilage in ACL-injured knees were significantly elevated at 1-year follow-up compared with those of control knees. No significant differences in T2 values between ACL-injured and control knees were found. Patients with lesions in the posterior horn of the medial meniscus showed a greater increase of T1(ρ) and T2 from baseline to follow-up in adjacent cartilage than patients without lesions in the medial meniscus.

CONCLUSION

Quantitative MR imaging T1(ρ) and T2 enable detection of changes in the cartilage matrix of ACL-reconstructed knees as early as 1 year after ACL reconstruction.