Comparative in vivo forefoot kinematics of Homo sapiens and Pan paniscus

The human metatarsophalangeal joints play a key role in weight transmission and propulsion during bipedal gait, but at present, the identification of when a habitual, human-like metatarsi-fulcrimating mechanism first appeared in the fossil record is debated. Part of this debate can be attributed to the absence of certain detailed quantitative data distinguishing human and great ape forefoot form and function.The aim of this study is to quantitatively test previous observations that human metatarsophalangeal joints exhibit greater amounts of dorsal excursion (i.e., dorsiflexion) than those of Pan at the terminal stance phase of terrestrial locomotion. Video recordings were made in order to measure sagittal excursions of the medial metatarsophalangeal joints in habitually shod/unshod adult humans and adult bonobos (Pan paniscus). Results indicate that the human first and second metatarsophalangeal joints usually dorsiflex more than those of bonobos. When timing of maximum excursion of the first metatarsophalangeal joint is coupled with existing plantar pressure data, the unique role of the human forefoot as a key site of leverage and weight transmission is highlighted. These results support hypotheses that significant joint functional differences between great apes and humans during gait underlie taxonomic distinctions in trabecular bone architecture of the forefoot.     

Antibodies against PM/Scl-75 and PM/Scl-100 are independent markers for different subsets of systemic sclerosis patients

Introduction

The aim of this study was to investigate the magnetic resonance imaging (MRI) features of bone disease in the arthritis mutilans (AM) form of psoriatic arthritis (PsA).

Methods

Twenty-eight patients with erosive PsA were enrolled (median disease duration of 14 years). Using x-rays of both hands and feet, 11 patients were classified as AM and 17 as non-AM (erosive psoriatic arthritis without bone lysis)by two observers. MRI scans (1.5T) of the dominant hand (wrist and fingers scanned separately) were obtained using standard contrast-enhanced T1-weighted and fat-saturated T2-weighted sequences. Scans were scored separately by two readers for bone erosion, oedema and proliferation using a PsA MRI scoring system. X-rays were scored for erosions and joint space narrowing.

Results

On MRI, 1013 bones were scored by both readers. Reliability for scoring erosions and bone oedema was high (intraclass correlation coefficients = 0.80 and 0.77 respectively) but only fair for bone proliferation (intraclass correlation coefficient = 0.42). MRI erosion scores were higher in AM patients (53.0 versus 15.0, p = 0.004) as were bone oedema and proliferation scores (14.7 versus 10.0, p = 0.056 and 3.6 versus 0.7, p = 0.003 respectively). MRI bone oedema scores correlated with MRI erosion scores and X-ray erosion and joint space narrowing scores (r = 0.65, p = 0.0002 for all) but not the disease activity score 28-C reactive protein (DAS_28CRP) or pain scores.

Conclusions

In this patient group with PsA, MRI bone oedema, erosion and proliferation were all more severe in the AM-form. Bone oedema scores did not correlate with disease activity measures but were closely associated with X-ray joint damage scores. These results suggest that MRI bone oedema may be a pre-erosive feature and that bone damage may not be coupled with joint inflammation in PsA.     

类风湿性关节炎活动性病变MRI征象及其与FIB、FDP、D-D的相关性研究

摘要 目的：探讨类风湿性关节炎（RA）活动性病变磁共振成像（MRI）征象及其与纤维蛋白原（FIB）、纤维蛋白(原)降解产物（FDP）、D-二聚体（D-D）的相关性研究。方法：选取2020年1月-2021年2月期间我院诊治的61例RA患者,根据28个关节疾病活动指数（DAS28）评分将其分为活动组（35例）和稳定组（26例）。对比两组MRI征象,血清FIB、FDP、D-D水平。采用Spearman相关性分析RA活动期患者MRI各征象间的相关性及MRI各征象与血清FIB、FDP、D-D水平间的相关性。结果：活动组滑膜增厚或滑膜炎、骨髓水肿、软骨及骨侵蚀、腱鞘炎或周围软组织受累、关节腔积液征象人数占比均高于稳定组（P＜0.05）。活动组患者血清FIB、FDP、D-D水平均高于稳定组（P＜0.05）。Spearman相关性分析结果显示,RA活动期患者滑膜增厚或滑膜炎征象与骨髓水肿、软骨及骨侵蚀、关节腔积液征象均呈正相关（P＜0.05）,骨髓水肿征象与软骨及骨侵蚀征象呈正相关（P＜0.05）;RA活动期患者滑膜增厚或滑膜炎、骨髓水肿、关节腔积液征象与血清FIB、FDP、D-D水平均呈正相关（P＜0.05）,软骨及骨侵蚀征象与FIB呈正相关（P＜0.05）。结论：MRI征象可清晰显示RA患者的滑膜、骨质、关节腔及周围肌腱、软组织等异常改变,且MRI征象之间具有相关性,可在一定程度上反映RA的病理改变;血清FIB、FDP、D-D的检测有助于反映RA活动情况;MRI征象与血清FIB、FDP、D-D水平间具有相关性,二者联合应用有助于进一步评估RA活动情况。     

Monitoring cartilage loss in the hands and wrists in rheumatoid arthritis with magnetic resonance imaging in a multi-center clinical trial: IMPRESS (NCT00425932)

Introduction

Magnetic resonance imaging (MRI) is increasingly being used in clinical trials of rheumatoid arthritis (RA) because of its superiority over x-ray radiography (XR) in detecting and monitoring change in bone erosion, osteitis and synovitis. However, in contrast to XR, the MRI scoring method that was used in most clinical trials did not include cartilage loss. This limitation has been an obstacle to accepting MRI as a potential alternative to XR in clinical trials. Cross-sectional studies have shown MRI to be sensitive for cartilage loss in the hands and wrist; although, longitudinal sensitivity to change has not yet been confirmed. In this study we examined the ability of MRI to monitor change in cartilage loss in patients with RA in a multi-site clinical trial setting.

Methods

Thirty-one active RA patients from a clinical trial (IMPRESS) who were randomized equally into treatment with either rituximab + methotrexate or placebo + methotrexate had MRI of the dominant hand/wrist at baseline, 12 weeks and 24 weeks at 3 clinical sites in the US. Twenty-seven of these patients also had XR of both hands/wrists and both feet at baseline and 24 weeks. One radiologist scored all XR images using the van der Heijde-modified Sharp method blinded to visit order. The same radiologist scored MR images for cartilage loss using a previously validated 9-point scale, and bone erosion using the Outcome Measures in Rheumatology Clinical Trials (OMERACT) RA MRI Score (RAMRIS) blinded to visit order and XR scores. Data from the two treatment arms were pooled for this analysis.

Results

Mean MRI cartilage score increased at 12 and 24 weeks, and reached statistical significance at 24 weeks. XR total Sharp score, XR erosion score and XR joint-space narrowing (JSN) score all increased at 24 weeks, but only XR total Sharp score increased significantly.

Conclusions

To our knowledge, this is the first publication of a study demonstrating MRI''s ability to monitor cartilage loss in a multi-site clinical trial. Combined with MRI''s established performance in monitoring bone erosions in RA, these findings suggest that MRI may offer a superior alternative to XR in multi-site clinical trials of RA.     

Are bone erosions detected by magnetic resonance imaging and ultrasonography true erosions? A comparison with computed tomography in rheumatoid arthritis metacarpophalangeal joints

The objective of the study was, with multidetector computed tomography (CT) as the reference method, to determine whether bone erosions in rheumatoid arthritis (RA) metacarpophalangeal (MCP) joints detected with magnetic resonance imaging (MRI) and ultrasonography (US), but not with radiography, represent true erosive changes. We included 17 RA patients with at least one, previously detected, radiographically invisible MCP joint MRI erosion, and four healthy control individuals. They all underwent CT, MRI, US and radiography of the 2nd to 5th MCP joints of one hand on the same day. Each imaging modality was evaluated for the presence of bone erosions in each MCP joint quadrant. In total, 336 quadrants were examined. The sensitivity, specificity and accuracy, respectively, for detecting bone erosions (with CT as the reference method) were 19%, 100% and 81% for radiography; 68%, 96% and 89% for MRI; and 42%, 91% and 80% for US. When the 16 quadrants with radiographic erosions were excluded from the analysis, similar values for MRI (65%, 96% and 90%) and US (30%, 92% and 80%) were obtained. CT and MRI detected at least one erosion in all patients but none in control individuals. US detected at least one erosion in 15 patients, however, erosion-like changes were seen on US in all control individuals. Nine patients had no erosions on radiography. In conclusion, with CT as the reference method, MRI and US exhibited high specificities (96% and 91%, respectively) in detecting bone erosions in RA MCP joints, even in the radiographically non-erosive joints (96% and 92%). The moderate sensitivities indicate that even more erosions than are seen on MRI and, particularly, US are present. Radiography exhibited high specificity (100%) but low sensitivity (19%). The present study strongly indicates that bone erosions, detected with MRI and US in RA patients, represent a loss of calcified tissue with cortical destruction, and therefore can be considered true bone erosions.     

Bone marrow edema and osteitis in rheumatoid arthritis: the imaging perspective

Magnetic resonance imaging bone marrow edema is an imaging feature that has been described in many conditions, including osteomyelitis, overuse syndromes, avascular necrosis, trauma, and inflammatory arthritides. In rheumatoid arthritis (RA), bone edema has special significance as it has been shown to be a common and widespread lesion that is often apparent at the hands and wrists but has also been described elsewhere, including the feet. It may occur in early or late disease and has been shown in several large cohort studies to have major negative implications for prognosis. It is the strongest predictor of erosive progression yet to be identified and characteristically occurs in those patients with the most aggressive and potentially disabling disease. In patients with undifferentiated arthritis, bone edema also predicts progression to criteria-positive RA, both independently and to a greater extent when combined with anti-cyclic citrullinated peptide status or rheumatoid factor positivity. Its histological correlate in the late stages of RA has been shown to be osteitis, in which the bone marrow beneath the joint is invaded by an inflammatory and vascular lymphoplasmacytic infiltrate. This lies adjacent to trabecular bone, where increased numbers of osteoclasts have been observed within resorption lacunae, suggesting a mechanistic link between inflammation and erosive bone damage. This could lead to erosion both of the overlying cortex, leading to classic radiographic rheumatoid erosions, and of local trabecular bone, possibly contributing to periarticular osteopenia and cyst formation. In addition to synovitis, osteitis is now regarded as a major rheumatoid lesion that is responsive to therapeutic intervention.     

Prognostic potential of precise molecular diagnosis of Autosomal Recessive Osteopetrosis with respect to the outcome of bone marrow transplantation

Hematopoietic stem cell transplantation (HSCT) is often the only practical approach to fatal genetic defects. One of the first pathologies which HSCT was applied to was Autosomal Recessive Osteopetrosis (ARO), a rare genetic bone disease in which a deficit in bone resorption by osteoclasts leads to increased bone density and secondary defects. The disease is often lethal early in life unless treated with HSCT. In utero transplantation (IUT) of the oc/oc mouse, reproducing the clinical features of a subset of ARO, has demonstrated that the quality of life and the survival of transplanted animals are greatly improved, suggesting that a similar protocol could be applied to humans. However, recently the dissection of the molecular bases of the disease has shown that ARO is genetically heterogeneous and has revealed the presence of subsets of patients which do not benefit from HSCT. This observation highlights the importance of molecular diagnosing ARO to identify and establish the proper therapies for a better prognosis. In particular, on the basis of experimental results in murine models, efforts should be undertaken to develop approaches such as IUT and new pharmacological strategies.     

TEP/TDM au fluorure (18F) de sodium pour la détection des métastases osseuses du cancer de la prostate. Description de l’étude Fluprostic de comparaison de la TEP/TDM au fluorure (18F) de sodium à l’IRM corps entier dans cette indication

Fluorodeoxyglucose (¹⁸F) or FDG, the radioactive glucose analogue which is the reference radiopharmaceutical in oncologic PET, is not well suited for the detection of prostate cancer metastases the glucose metabolism of which is usually only slightly enhanced. Fluoride (¹⁸F) accumulates into the cortical bone, rapidly and intensely in reaction to a bony metastasis. In 2008, it has been granted a marketing authorisation in France, including imaging bone metastasis of prostate cancer. We report original clinical cases to illustrate its diagnostic performance. Whole-body MRI is developing and can also detect bone metastases. Recently diffusion-weighted MRI (DWI) has been proposed to increase the detection rate of metastases of the axial skeleton, which are largely predominant in prostate cancer. Using either hybrid PET/CT or MRI requires mobilising equipments, which are less available and more expensive than the gamma-cameras for classical bone scintigraphy, in the aim to achieve superior diagnostic performance. A clinical study protocol (STIC) has just been accepted for public funding. It aims to assess the impact on patient management of the discovery of the first macroscopic bony metastasis and the efficacy of diagnostic strategies including those innovations, individually and in association. In case of prostate cancer with a high risk of metastasis, but without any proven bone metastasis and no typical pattern on bone scintigraphy, fluoride (¹⁸F) PET/CT will be performed as well as whole-body MRI. Histopathology and/or data of a 6-month follow-up will be the standard of truth to evaluate the adequacy of impact on patient management and the benefit / cost ratio of those examinations. With this prospective national study, we hope to demonstrate in the real world a clinical role for this radiopharmaceutical, which was proposed several decades ago, but benefits from a renewed interest thanks to the development of PET/CT imaging.     

Comparative forefoot trabecular bone architecture in extant hominids

The appearance of a forefoot push-off mechanism in the hominin lineage has been difficult to identify, partially because researchers disagree over the use of the external skeletal morphology to differentiate metatarsophalangeal joint functional differences in extant great apes and humans. In this study, we approach the problem by quantifying properties of internal bone architecture that may reflect different loading patterns in metatarsophalangeal joints in humans and great apes. High-resolution x-ray computed tomography data were collected for first and second metatarsal heads of Homo sapiens (n = 26), Pan paniscus (n = 17), Pan troglodytes (n = 19), Gorilla gorilla (n = 16), and Pongo pygmaeus (n = 20). Trabecular bone fabric structure was analyzed in three regions of each metatarsal head. While bone volume fraction did not significantly differentiate human and great ape trabecular bone structure, human metatarsal heads generally show significantly more anisotropic trabecular bone architectures, especially in the dorsal regions compared to the corresponding areas of the great ape metatarsal heads. The differences in anisotropy between humans and great apes support the hypothesis that trabecular architecture in the dorsal regions of the human metatarsals are indicative of a forefoot habitually used for propulsion during gait. This study provides a potential route for predicting forefoot function and gait in fossil hominins from metatarsal head trabecular bone architecture.     

Can erosions on MRI of the sacroiliac joints be reliably detected in patients with ankylosing spondylitis? - A cross-sectional study

Introduction

Erosions of the sacroiliac joints (SIJ) on pelvic radiographs of patients with ankylosing spondylitis (AS) are an important feature of the modified New York classification criteria. However, radiographic SIJ erosions are often difficult to identify. Recent studies have shown that erosions can be detected also on magnetic resonance imaging (MRI) of the SIJ early in the disease course before they can be seen on radiography. The goals of this study were to assess the reproducibility of erosion and related features, namely, extended erosion (EE) and backfill (BF) of excavated erosion, in the SIJ using a standardized MRI methodology.

Methods

Four readers independently assessed T1-weighted and short tau inversion recovery sequence (STIR) images of the SIJ from 30 AS patients and 30 controls (15 patients with non-specific back pain and 15 healthy volunteers) ≤45 years old. Erosions, EE, and BF were recorded according to standardized definitions. Reproducibility was assessed by percentage concordance among six possible reader pairs, kappa statistics (erosion as binary variable) and intraclass correlation coefficient (ICC) (erosion as sum score) for all readers jointly.

Results

SIJ erosions were detected in all AS patients and six controls by ≥2 readers. The median number of SIJ quadrants affected by erosion recorded by four readers in 30 AS patients was 8.6 in the iliac and 2.1 in the sacral joint portion (P < 0.0001). For all 60 subjects and for all four readers, the kappa value for erosion was 0.72, 0.73 for EE, and 0.63 for BF. ICC for erosion was 0.79, 0.72 for EE, and 0.55 for BF, respectively. For comparison, the kappa and ICC values for bone marrow edema were 0.61 and 0.93, respectively.

Conclusions

Erosions can be detected on MRI to a comparable degree of reliability as bone marrow edema despite the significant heterogeneity of their appearance on MRI.     

Proteomics‐based discovery of biomarkers for paediatric acute lymphoblastic leukaemia: challenges and opportunities

There are important breakthroughs in the treatment of paediatric acute lymphoblastic leukaemia (ALL) since 1950, by which the prognosis of the child majority suffered from ALL has been improved. However, there are urgent needs to have disease‐specific biomarkers to monitor the therapeutic efficacy and predict the patient prognosis. The present study overviewed proteomics‐based research on paediatric ALL to discuss important advances to combat cancer cells and search novel and real protein biomarkers of resistance or sensitivity to drugs which target the signalling networks. We highlighted the importance and significance of a proper phospho‐quantitative design and strategy for paediatric ALL between relapse and remission, when human body fluids from cerebrospinal, peripheral blood, or bone‐marrow were applied. The present article also assessed the schedule for the analysis of body fluids from patients at different states, importance of proteomics‐based tools to discover ALL‐specific and sensitive biomarkers, to stimulate paediatric ALL research via proteomics to ‘build’ the reference map of the signalling networks from leukemic cells at relapse, and to monitor significant clinical therapies for ALL‐relapse.     

Human bone disorders: Pathological role and diagnostic potential of matrix metalloproteinases

Bone undergoes continuous remodeling under physiological and pathological conditions. Failure of the regulation of this process leads to several disorders involving bone erosion. This series of events is mainly based on the action of proteinases, particularly matrix metalloproteinases (MMPs). MMPs have been recently suggested as potential bone resorption markers which could be added to the commonly used ones, in order to predict outcome of disease processes and healing, and to monitor disease response to treatment. As for classical biochemical bone markers, MMPs are far from being applied in primary clinical diagnosis, but they could be promising in some cases for disease prognosis. MMPs as bone remodeling biomarkers could provide information that boosts our understanding of the prognosis, disease activity and pathogenesis of bone disorders. Clarifying the MMPs’ role in bone remodeling and healing could potentially help predict disease progression and the effects of direct specific therapy.     

Anti-Arthritic Effect of Chebulanin on Collagen-Induced Arthritis in Mice

Rheumatoid arthritis is a chronic degenerative autoimmune disease characterized by persistent inflammation of synovial membranes, which leads to cartilage destruction and bone erosion. To date, there are no effective therapies to slow the progress of this degenerative condition. Here, we evaluate the anti-arthritic effect of chebulanin, an abundant anti-inflammatory agent isolated from Terminalia chebula, in collagen induced arthritis in DBA/1 mice by intragastric administration. Arthritic severity was scored by performing histopathological evaluation of the joints and measuring the expression of inflammatory cytokines and relative enzymes by immunohistochemical staining. In parallel, bone destruction and erosion were confirmed by micro-CT. Our data revealed that chebulanin significantly improved the severity of arthritis. Specifically, the histopathological characteristics of the tissues were improved and expression of TNF-α, IL-6, MMP-3 and COX-2 in the paws and joints of the treated mice decreased in a dose-dependent manner compared with control mice. Furthermore, micro-CT analysis revealed that chebulanin induced a dose-dependent reduction in cartilage destruction and bone erosion. Taken together, our findings suggest that chebulanin suppresses the expression of inflammatory mediators and prevents cartilage destruction and bone erosion in mice. Therefore, chebulanin is a strong therapeutic alternative for the treatment of RA.     

Detection of bone erosions in rheumatoid arthritis wrist joints with magnetic resonance imaging, computed tomography and radiography

Background

The objectives of the present study were, with multidetector computed tomography (CT) as the reference method, to determine the performance of magnetic resonance imaging (MRI) and radiography for the detection of bone erosions in rheumatoid arthritis wrist bones, and to test whether measuring volumes of erosions on CT and MRI is reproducible and correlated to semiquantitative assessments (scores) of erosions on CT, MRI and radiography.

Methods

Seventeen patients with rheumatoid arthritis and four healthy control individuals underwent CT, MRI and radiography of one wrist, performed on the same day. CT was performed on a Philips Mx8000IDT unit (voxel size 0.4 mm × 0.4 mm × 1 mm) and MRI was performed on a Philips Panorama 0.6T unit (voxel size 0.4 mm × 0.4 mm × 0.4 mm). Images were evaluated separately for erosions in all wrist bones and were scored according to the principles of the Outcome Measures in Rheumatology Rheumatoid Arthritis MRI Scoring System (CT and MRI) and the Sharp/van der Heijde (radiographs) scoring methods. Measurements of erosion volumes of all erosions were performed twice with a 1-week interval.

Results

With CT as the reference method, the overall sensitivity, specificity and accuracy (concordance) of MRI for detecting erosions were 61%, 93% and 77%, respectively, while the respective values were 24%, 99% and 63% for radiography. The intramodality agreements when measuring erosion volumes were high for both CT and MRI (Spearman correlation coefficients 0.92 and 0.90 (both P < 0.01), respectively). Correlations between volumes and scores of individual erosions were 0.96 for CT and 0.99 for MRI, while they were 0.83 (CT) and 0.80 (MRI) for persons' total erosion volume and total score (all P < 0.01).

Conclusion

With CT as the reference method, MRI showed moderate sensitivity and good specificity and accuracy for detection of erosions in rheumatoid arthritis and healthy wrist bones, while radiography showed very low sensitivity. The tested volumetric method was highly reproducible and correlated to scores of erosions.     

Observations on tooth development and implantation in the upper pharyngeal jaws in Astatotilapia elegans (Teleostei,Cichlidae)

Prominent stages in the development of teeth, associated with the upper pharyngeal jaws in early postembryonic stages of the mouth brooding cichlid A statotilapia elegans were studied on semithin sections in relation to changes in the underlying endoskeletal parts and to the formation of the dentigerous bone. Because the pattern of tooth implantation on infrapharyngobranchial III-IV is constant, at least in early postembryonic stages, it is possible to trace the life history of a given tooth by tracing its homologue throughout the ontogenetic series. A probable causal relationship exists between tooth development and erosion of the underlying cartilage. Fully developed, though unerupted teeth, differentiate annular bone of attachment, which, depending on its position, is formed either outside the cartilage or within the previously induced erosion cavities. Attachment bone of adjacent teeth fuses to build up the dentigerous bone, which, as a result, may be situated within the area previously occupied by cartilage. As soon as the tooth has built up its bone of attachment, it may erupt. The collagenous matrix between tooth and attachment bone persists and gives rise to the movable connection between both. Differentiation of teeth on infrapharyngobranchial III-IV, together with enlargement of the dentigerous bone, proceeds from the lateral and the rostral border, where new germs constantly form. The appearance of new germs on infrapharyngobranchial II is more unpredictable.     

Repair of bone defect of the lateral forefoot by double segment triangular fibula flap with vascular pedicle: A case report

Objective: To expound the clinical effect of a new operation by transplanting double segment triangular fibula flap with vascular pedicle to repair the forefoot with lateral bone defect, and to study how to improve the operation method in the following stage. Methods: The inclusion criteria: More than 2 phalangeal and metatarsal bones defects of the lateral forefoot, widespread skin and soft tissue defects on pelma and dorsal foot, and destruction of the anterior aspect of foot arch, which seriously affects the foot function. There was one case of clinical application in November 2014. The repairing method is as followed: the harvested vascularized free fibula was cut into 2 segments and then they were folded into a right angle. According to selected control points on the residual metatarsals, an optimal stereo triangular net was constructed. Meanwhile, according to flow-through mode, the free anterolateral thigh flap was incorporated to repair the forefoot and foot arch. Results: Postoperative bone flaps all survived. After a 17-month following up, it was found that the grafted fibular healed well, shape of the foot was good, weight-bearing walking was practical, a slight limp and discomfort with plantar pain existed, sensory recovery reached S3 level and functional recovery of weight-bearing walking by forefoot reached W3 level, comprehensive evaluation was good, and there were wear scar and ulcer on the plantar flap during long-time walking for patients, such results were excellent according to foot function scoring criteria. Conclusion: In this operation the grafted fibula was fold into a triangle according to actual need, which though not completely restores the tridimensional structure of the longitudinal, transverse arches of the lateral foot makes weight-bearing walking possible, besides, its appearance and function is satisfactory. Such an operation has overcome the shortage of non-tridimensional structure of the transverse arch etc. in traditional operations and it should be an ideal operation in repairing serious defects on the lateral forefoot through further improvement.     

Evaluating joint-space narrowing and cartilage loss in rheumatoid arthritis by using MRI

Introduction

Magnetic resonance imaging (MRI) has been shown to be superior to radiography (XR) for assessing synovitis, osteitis, and bone erosion in rheumatoid arthritis (RA), particularly in clinical trials. However, relatively little has been reported on the ability of MRI to evaluate articular cartilage loss, or joint-space narrowing (JSN), in the hands and wrists. In a previous study, we adapted the nine-point Genant-modified Sharp XR-JSN score for use with MRI (MRI-JSN). In this study, we compare MRI-JSN with XR-JSN by using images from two multicenter clinical trials.

Methods

Baseline XR and 1.5-Tesla MR images of one hand and wrist from each of 47 subjects with RA enrolled in one of two multicenter clinical trials were evaluated by using the XR-JSN and MRI-JSN methods by a single radiologist experienced in the two methods. Radiographs and MR images were read independently on different occasions.

Results

In total, 575 of 611 joints were compared (one metacarpophalangeal joint of the thumb and 35 proximal interphalangeal joints were outside the MRI field of view and could not be assessed). The 22 (47%) subjects showed JSN with both XR and MRI, and 25 (53%) subjects showed no JSN with either method. No subject showed JSN with only one or the other method. MRI showed high agreement with XR (intraclass correlation coefficient = 0.83). Sensitivity of MRI for JSN, by using XR as the gold standard, was 0.94; specificity was 0.91; accuracy was 0.91; positive predictive value was 0.64; and negative predictive value was 0.99.

Conclusions

This validation exercise suggests that MRI JSN scoring may offer a viable alternative to XR JSN scoring in multicenter clinical trials of RA. However, the relative longitudinal sensitivity of MRI to change and the ability to discriminate therapeutic effect on JSN were not evaluated in this study.     

Fish bone‐derived cell lines: an alternative in vitro cell system to study bone biology

Human bone diseases represent a major health problem worldwide and effective therapies have still to be developed. Despite numerous studies using mammalian systems, cellular and molecular processes governing bone and cartilage homeostasis in vertebrates are still not fully understood. Recently, fish have emerged as a suitable model and a promising alternative to the classical mammalian systems to study vertebrate development, in particular skeletogenesis. To complement in vivo developmental studies and identify signalling pathways involved in development processes, fish cell lines have been developed, in particular bone‐derived cells. This work intends to review what is presently known about fish bone‐derived cell lines, focusing on their relevance for bone biology studies.     

Biomechanical factors and physical examination findings in osteoarthritis of the knee: associations with tissue abnormalities assessed by conventional radiography and high-resolution 3.0 Tesla magnetic resonance imaging

Introduction

We aimed to explore the associations between knee osteoarthritis (OA)-related tissue abnormalities assessed by conventional radiography (CR) and by high-resolution 3.0 Tesla magnetic resonance imaging (MRI), as well as biomechanical factors and findings from physical examination in patients with knee OA.

Methods

This was an explorative cross-sectional study of 105 patients with knee OA. Index knees were imaged using CR and MRI. Multiple features from CR and MRI (cartilage, osteophytes, bone marrow lesions, effusion and synovitis) were related to biomechanical factors (quadriceps and hamstrings muscle strength, proprioceptive accuracy and varus-valgus laxity) and physical examination findings (bony tenderness, crepitus, bony enlargement and palpable warmth), using multivariable regression analyses.

Results

Quadriceps weakness was associated with cartilage integrity, effusion, synovitis (all detected by MRI) and CR-detected joint space narrowing. Knee joint laxity was associated with MRI-detected cartilage integrity, CR-detected joint space narrowing and osteophyte formation. Multiple tissue abnormalities including cartilage integrity, osteophytes and effusion, but only those detected by MRI, were found to be associated with physical examination findings such as crepitus.

Conclusion

We observed clinically relevant findings, including a significant association between quadriceps weakness and both effusion and synovitis, detected by MRI. Inflammation was detected in over one-third of the participants, emphasizing the inflammatory component of OA and a possible important role for anti-inflammatory therapies in knee OA. In general, OA-related tissue abnormalities of the knee, even those detected by MRI, were found to be discordant with biomechanical and physical examination features.