Association between medial meniscal extrusion and knee structural progression in adults with symptomatic knee osteoarthritis - a prospective cohort study

OBJECTIVE

To examine the association between medial meniscal extrusion and structural progression in adults with symptomatic knee osteoarthritis (OA).

METHODS

This prospective cohort study examined 176 participants with symptomatic knee OA recruited into a randomised controlled trial. The participants underwent magnetic resonance imaging (MRI) of the study knee at baseline and approximately 2 years later. Meniscal extrusion, tibial cartilage volume, and tibiofemoral bone marrow lesions (BMLs) were measured from MRI using validated methods.

RESULTS

Participants with medial meniscal extrusion ≥ 3 mm had a higher prevalence of lateral tibiofemoral BMLs at baseline (OR = 2.21, 95% CI 1.06-4.61, p = 0.035), and those with medial meniscal extrusion 2-3 mm had a higher likelihood of lateral BML worsening over 2 years (OR = 3.76, 95% CI 1.35-10.52, p = 0.011), compared with those with medial meniscal extrusion < 2 mm. Participants with stable medial meniscal extrusion had a lower likelihood of lateral BML worsening compared with those with regression of medial meniscal extrusion over 2 years (OR = 0.20, 95% CI 0.07-0.56, p = 0.002). There were no associations between medial meniscal extrusion and tibial cartilage volume or medial tibiofemoral BMLs.

CONCLUSIONS

Our study showed associations between medial meniscal extrusion and baseline prevalence and worsening over 2 years of lateral tibiofemoral BMLs in people with symptomatic knee OA. Although the reasons for the lack of associations in the medial compartment are not clear, our results suggest a role of medial meniscal extrusion in predicting structural progression in lateral knee OA and that meniscal extrusion might be a potential target in the management of knee OA.

Strategic application of imaging in DMOAD clinical trials: focus on eligibility, drug delivery, and semiquantitative assessment of structural progression

Despite decades of research efforts and multiple clinical trials aimed at discovering efficacious disease-modifying osteoarthritis (OA) drugs (DMOAD), we still do not have a drug that shows convincing scientific evidence to be approved as an effective DMOAD. It has been suggested these DMOAD clinical trials were in part unsuccessful since eligibility criteria and imaging-based outcome evaluation were solely based on conventional radiography. The OA research community has been aware of the limitations of conventional radiography being used as a primary imaging modality for eligibility and efficacy assessment in DMOAD trials. An imaging modality for DMOAD trials should be able to depict soft tissue and osseous pathologies that are relevant to OA disease progression and clinical manifestations of OA. Magnetic resonance imaging (MRI) fulfills these criteria and advances in technology and increasing knowledge regarding imaging outcomes likely should play a more prominent role in DMOAD clinical trials. In this perspective article, we will describe MRI-based tools and analytic methods that can be applied to DMOAD clinical trials with a particular emphasis on knee OA. MRI should be the modality of choice for eligibility screening and outcome assessment. Optimal MRI pulse sequences must be chosen to visualize specific features of OA.

How to effectively utilize imaging in disease-modifying treatments for osteoarthritis clinical trials: the radiologist's perspective

Introduction: One of the reasons for failures of disease-modifying osteoarthritis drug clinical trials has been the radiography-based definition of structural eligibility criteria. Imaging, particularly MRI, has a critical role in planning and conducting clinical trials of osteoarthritis.Areas covered: A literature search was performed using keywords including 'osteoarthritis,' 'knee,' 'MRI,' 'intra-articular injection,' 'semiquantitative scoring,' 'clinical trial,' and other specific terms where relevant. The core concepts of using MRI in osteoarthritis clinical trials are explained focusing on knee osteoarthritis, including its role in determining patient eligibility and inclusion/exclusion criteria as well as outcome measures from the expert musculoskeletal radiologist's perspective. A brief overview of statistical analyses that should be deployed in clinical trials utilizing semiquantitative MRI analyses is discussed.Expert opinion: In order to increase chances to detect measurable efficacy effects, investigators should consider utilizing MRI from screening to outcome assessment. Recognition of several phenotypes of osteoarthritis helps in participant stratification and will lead to more targeted clinical trials. Inclusion and exclusion criteria need to be defined using not only radiography but also MRI. Correct intra-articular injection of investigational compounds is critically important if intra-articular drug delivery is required, and such procedure should be performed and documented using appropriate imaging guidance.

The Effect of Synthetic Osteoconductive Bone Graft Material for Augmentation of Internally Fixed Unstable Trochanteric Fractures

This study aimed to evaluate whether the augmentation of CaP into the femoral head around the lag screw results in superior clinical and radiological outcomes of treatment of unstable trochanteric fractures using an intramedullary (IM) implant. Fifty-six consecutive patients with unstable trochanteric fractures who had been surgically treated with IM devices between 2014 and 2016 were prospectively reviewed and randomly divided into two groups based on the use of CaP degradable cements: 28 patients were assigned to the CaP group, while the other 28 patients were assigned to the control group (no use of CaP). Clinical evaluations and radiological analyses were conducted during a minimum of 2-year follow-up. No significant differences in the mean visual analogue scale for the hip pain scores and modified Harris Hip Scores were found between the CaP group and the controls at postoperative 2 months and 2 years. However, earlier walker ambulation was possible in the CaP group (10 ± 9 days) compared to the control group (13 ± 12 days) (P = 0.02). In radiological analysis, the CaP group showed significantly lower difference between tip-apex distance measured immediately after surgery and that measured at one-year follow-up compared to the control group (P = 0.012). No screw cut-out occurred in the CaP group, while one patient in the control group was reoperated for screw cut-out. The CaP augmentation into the femoral head around lag screw can reduce lag screw penetration, prevent screw cut-out beyond the femoral head, and facilitate early ambulation in elderly patients with unstable trochanteric fractures.

Understanding Magnetic Resonance Imaging of Knee Cartilage Repair: A Focus on Clinical Relevance

The aims of this review article are (a) to describe the principles of morphologic and compositional magnetic resonance imaging (MRI) techniques relevant for the imaging of knee cartilage repair surgery and their application to longitudinal studies and (b) to illustrate the clinical relevance of pre- and postsurgical MRI with correlation to intraoperative images. First, MRI sequences that can be applied for imaging of cartilage repair tissue in the knee are described, focusing on comparison of 2D and 3D fast spin echo and gradient recalled echo sequences. Imaging features of cartilage repair tissue are then discussed, including conventional (morphologic) MRI and compositional MRI techniques. More specifically, imaging techniques for specific cartilage repair surgery techniques as described above, as well as MRI-based semiquantitative scoring systems for the knee cartilage repair tissue-MR Observation of Cartilage Repair Tissue and Cartilage Repair OA Knee Score-are explained. Then, currently available surgical techniques are reviewed, including marrow stimulation, osteochondral autograft, osteochondral allograft, particulate cartilage allograft, autologous chondrocyte implantation, and others. Finally, ongoing research efforts and future direction of cartilage repair tissue imaging are discussed.

The effect of intra-articular glucocorticosteroids and exercise on symptoms and bone marrow lesions in knee osteoarthritis: a secondary analysis of results from a randomized controlled trial

OBJECTIVE

To evaluate if the relative volume of bone marrow lesions (BMLs) changed in patients with knee osteoarthritis (OA) during a therapeutic study.

DESIGN

This study is a sub-study to a larger clinical trial which compared the clinical effects of intra-articular corticosteroid injection in knee OA to placebo injection, both given prior to exercise therapy. Clinical assessment using the Knee injury and Osteoarthritis Outcome Score (KOOS) and magnetic resonance imaging (MRI) examinations with BML assessments were performed at baseline and follow-up after 14 weeks and 26 weeks, respectively. The BML volume was determined using a computer assisted method focusing on participants with valid baseline and follow-up MRI examinations. Any changes in BML and KOOS were analyzed and investigated for associations.

RESULTS

Fifty participants received steroid and placebo injection, respectively, of which 41 and 45 had complete MRI examinations at week 14, and 36 and 33 at week 26, respectively. All participants received 12 weeks of exercise. A significant change in relative BML volume was observed between the corticosteroid group and the placebo group after 14 weeks [-1.1% vs 2.7%; between-group difference, 3.8% (95% CI 0.5-7.0)] but not after 26 weeks [0.8% vs 1.6%; between-group difference, 0.8% (95% CI -2.8 to 4.4)]. No significant association was found between changes in relative BML volume and KOOS.

CONCLUSIONS

Despite the statistically significant difference in BML volume at 14 weeks after corticosteroid injection and 12 weeks exercise therapy compared to placebo injection and exercise, there is very little evidence on a relationship between corticosteroids and BML volume.

EU CLINICAL TRIALS REGISTER

EudraCT number: 2012-002607-18.

Imaging in Osteoarthritis

With technologic advances and the availability of sophisticated computer software and analytical strategies, imaging plays an increasingly important role in understanding the disease process of osteoarthritis (OA). Radiography has limitations in that it can visualize only limited features of OA, such as osteophytes and joint space narrowing, but remains the most commonly used modality for establishing an imaging-based diagnosis of OA. This article describes the roles and limitations of different imaging modalities and discusses the optimum imaging protocol, imaging diagnostic criteria of OA, differential diagnoses, and what the referring physician needs to know.

Assessment of subchondral bone marrow lesions in knee osteoarthritis by MRI: a comparison of fluid sensitive and contrast enhanced sequences

Background

Bone marrow lesions (BMLs) in knee osteoarthritis (OA) can be assessed using fluid sensitive and contrast enhanced sequences. The association between BMLs and symptoms has been investigated in several studies but only using fluid sensitive sequences. Our aims were to assess BMLs by contrast enhanced MRI sequences in comparison with a fluid sensitive STIR sequence using two different segmentation methods and to analyze the association between the MR findings and disability and pain.

Methods

Twenty-two patients (mean age 61 years, range 41–79 years) with medial femoro-tibial knee OA obtained MRI and filled out a WOMAC questionnaire at baseline and follow-up (median interval of 334 days). STIR, dynamic contrast enhanced-MRI (DCE-MRI) and fat saturated T1 post-contrast (T1 CE FS) MRI sequences were obtained. All STIR and T1 CE FS sequences were assessed independently by two readers for STIR-BMLs and contrast enhancing areas of BMLs (CEA-BMLs) using manual segmentation and computer assisted segmentation, and the measurements were compared. DCE-MRIs were assessed for the relative distribution of voxels with an inflammatory enhancement pattern, N_voxel, in the bone marrow. All findings were compared to WOMAC scores, including pain and overall symptoms, and changes from baseline to follow-up were analyzed.

Results

The average volume of CEA-BML was smaller than the STIR-BML volume by manual segmentation. The opposite was found for computer assisted segmentation where the average CEA-BML volume was larger than the STIR-BML volume. The contradictory finding by computer assisted segmentation was partly caused by a number of outliers with an apparent generally increased signal intensity in the anterior parts of the femoral condyle and tibial plateau causing an overestimation of the CEA-BML volume.

Both CEA-BML, STIR-BML and N_voxel were significantly correlated with symptoms and to a similar degree. A significant reduction in total WOMAC score was seen at follow-up, but no significant changes were observed for either CEA-BML, STIR-BML or N_voxel.

Conclusions

Neither the degree nor the volume of contrast enhancement in BMLs seems to add any clinical information compared to BMLs visualized by fluid sensitive sequences. Manual segmentation may be needed to obtain valid CEA-BML measurements.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-016-1336-9) contains supplementary material, which is available to authorized users.

Three-dimensional turbo spin-echo magnetic resonance imaging (MRI) and semiquantitative assessment of knee osteoarthritis: comparison with two-dimensional routine MRI

PURPOSE

The aim of this study was to evaluate three-dimensional (3D) turbo spin-echo (TSE) magnetic resonance imaging (MRI) for semiquantitative assessment of knee OA.

MATERIALS AND METHOD

Twenty subjects fulfilling the American College of Rheumatology clinical criteria of knee OA underwent both two-dimensional (2D) and 3D MRIs on the same day. The 2D MRI protocol included triplanar fat-suppressed (FS) intermediate-weighted (Iw) TSE. For the 3D TSE technique, a sagittal FS Iw sequence was acquired and triplanar reformations were constructed. 2D and 3D MRIs were read separately by two radiologists using the Whole-Organ Magnetic Resonance Imaging Score (WORMS) system. Agreement was determined using weighted kappa statistics and percentage of overall agreement. The diagnostic performance of WORMS readings using 3D TSE MRI to detect the presence or absence of features was assessed using readings from 2D TSE images as a reference.

RESULTS

Agreement for the scored features ranged between 0.62 (osteophytes (OS)) and 0.94 (meniscal extrusion). The sensitivity of WORMS readings using the 3D TSE technique ranged between 80% (periarticular cysts) and 100% (several features), the specificity ranged between 62.3% (OS) and 100% (several features), and accuracy ranged between 77.2% (OS) and 99.3% (subchondral cysts).

CONCLUSIONS

Semiquantitative assessment of knee OA can be reliably performed using 3D TSE MRI, showing substantial to almost perfect agreement and high accuracy when compared to routine 2D TSE MRI. 3D TSE MRI also takes less time, which is important for large OA studies.

Magnetic resonance imaging of subchondral bone marrow lesions in association with osteoarthritis

OBJECTIVES

This nonsystematic literature review provides an overview of magnetic resonance imaging (MRI) of subchondral bone marrow lesions (BMLs) in association with osteoarthritis (OA), with particular attention to the selection of MRI sequences and semiquantitative scoring systems, characteristic morphology, and differential diagnosis. Histologic basis, natural history, and clinical significance are also briefly discussed.

METHODS

PubMed was searched for articles published up to 2011, using the keywords bone marrow lesion, osteoarthritis, magnetic resonance imaging, bone marrow edema, histology, pain, and subchondral.

RESULTS

BMLs in association with OA correspond to fibrosis, necrosis, edema, and bleeding of fatty marrow as well as abnormal trabeculae on histopathology. Lesions may fluctuate in size within a short time and are associated with the progression of articular cartilage loss and fluctuation of pain in knee OA. The characteristic subchondral edema-like signal intensity of BMLs should be assessed using T2-weighted, proton density-weighted, intermediate-weighted fat-suppressed fast spin echo or short tau inversion recovery. Several semiquantitative scoring systems are available to characterize and grade the severity of BMLs. Quantitative approaches have also been introduced. Differential diagnoses of degenerative BMLs include a variety of traumatic or nontraumatic pathologies that may appear similar to OA-related BMLs on MRI.

CONCLUSIONS

Subchondral BMLs are a common imaging feature of OA with clinical significance and typical signal alteration patterns, which can be assessed and graded by semiquantitative scoring systems using sensitive MRI sequences.

Osteoarthritis year 2011 in review: imaging in OA--a radiologists' perspective

With major technological advances and application of magnetic resonance imaging (MRI) to large longitudinal osteoarthritis (OA) studies the role of imaging has become increasingly important for OA research over the last years. Currently, radiography, MRI and ultrasound are the most established imaging tools applied in a research setting. MRI assessment of OA features can be morphologic, compositional and can be applied in non-loaded and loaded conditions. Morphologic assessment includes semiquantitative and quantitative analyses. Novel semiquantitative scoring methods for knee, hip and hand OA using MRI were introduced. A series of key reports were published this year, reviewing the importance of radiography and MRI as a research tool. Although radiography is insensitive for the detection of OA-related structural pathology when compared to MRI, it still has been widely used for subject inclusion in observational and interventional studies due also to a straight forward disease definition that was established more than 50 years ago. In an attempt to generate an MRI-based definition of structural disease, a Delphi exercise was performed to develop a testable MRI definition of structural OA. This presentation reviews publications related to imaging of OA, published in English between September 2010 and October 2011, excluding animal studies or in vitro data. This is not a systematic or comprehensive review and the selection of papers included is based on the expert opinions of the presenter, from a musculoskeletal radiologist's perspective.