Biomechanical characterization and in vitro mechanical injury of elderly human femoral head cartilage: comparison to adult bovine humeral head cartilage.

OBJECTIVES: In vitro mechanical injury of articular cartilage is useful to identify events associated with development of post-traumatic osteoarthritis (OA). To date, many in vitro injury models have used animal cartilage despite the greater clinical relevance of human cartilage. We aimed to characterize a new in vitro injury model using elderly human femoral head cartilage and compare its behavior to that of an existing model with adult bovine humeral head cartilage. DESIGN: Mechanical properties of human and bovine cartilage disks were characterized by elastic modulus and hydraulic permeability in radially confined axial compression, and by Young's modulus, Poisson's ratio, and direction-dependent radial strain in unconfined compression. Biochemical composition was assessed in terms of tissue water, solid, and glycosaminoglycan (GAG) contents. Responses to mechanical injury were assessed by observation of macroscopic superficial tissue cracks and histological measurements of cell viability following single injurious ramp loads at 7 or 70%/s strain rate to 3 or 14 MPa peak stress. RESULTS: Confined compression moduli and Young's moduli were greater in elderly human femoral cartilage vs adult bovine humeral cartilage whereas hydraulic permeability was less. Radial deformations of axially compressed explant disks were more anisotropic (direction-dependent) for the human cartilage. In both cartilage sources, tissue cracking and associated cell death during injurious loading was common for 14 MPa peak stress at both strain rates. CONCLUSION: Despite differences in mechanical properties, acute damage induced by injurious loading was similar in both elderly human femoral cartilage and adult bovine humeral cartilage, supporting the clinical relevance of animal-based cartilage injury models. However, inherent structural differences such as cell density may influence subsequent cell-mediated responses to injurious loading and affect the development of OA.

Direct MR arthrography of the shoulder under axial traction: Feasibility study to evaluate the superior labrum-biceps tendon complex and articular cartilage.

PURPOSE: To assess the value of adding axial traction to direct MR arthrography of the shoulder, in terms of subacromial and glenohumeral joint space widths, and coverage of the superior labrum-biceps tendon complex and articular cartilage by contrast material. MATERIALS AND METHODS: Twenty-one patients investigated by direct MR arthrography of the shoulder were prospectively included. Studies were performed with a 3 Tesla (T) unit and included a three-dimensional isotropic fat-suppressed T1-weighted gradient-recalled echo sequence, without and with axial traction (4 kg). Two radiologists independently measured the width of the subacromial, superior, and inferior glenohumeral joint spaces. They subsequently rated the amount of contrast material around the superior labrum-biceps tendon complex and between glenohumeral cartilage surfaces, using a three-point scale: 0 = no, 1 = partial, 2 = full. RESULTS: Under traction, the subacromial (Δ = 2.0 mm, P = 0.0003), superior (Δ = 0.7 mm, P = 0.0001) and inferior (Δ = 1.4 mm, P = 0.0006) glenohumeral joint space widths were all significantly increased, and both readers noted significantly more contrast material around the superior labrum-biceps tendon complex (P = 0.014), and between the superior (P = 0.001) and inferior (P = 0.025) glenohumeral cartilage surfaces. CONCLUSION: Direct MR arthrography of the shoulder under axial traction increases subacromial and glenohumeral joint space widths, and prompts better coverage of the superior labrum-biceps tendon complex and articular cartilage by contrast material. J. Magn. Reson. Imaging 2013;37:1228-1233. © 2012 Wiley Periodicals, Inc.

Revisiting spatial distribution and biochemical composition of calcium-containing crystals in human osteoarthritic articular cartilage.

INTRODUCTION: Calcium-containing (CaC) crystals, including basic calcium phosphate (BCP) and calcium pyrophosphate dihydrate (CPP), are associated with destructive forms of osteoarthritis (OA). We assessed their distribution and biochemical and morphologic features in human knee OA cartilage. METHODS: We prospectively included 20 patients who underwent total knee replacement (TKR) for primary OA. CaC crystal characterization and identification involved Fourier-transform infra-red spectrometry and scanning electron microscopy of 8 to 10 cartilage zones of each knee, including medial and lateral femoral condyles and tibial plateaux and the intercondyle zone. Differential expression of genes involved in the mineralization process between cartilage with and without calcification was assessed in samples from 8 different patients by RT-PCR. Immunohistochemistry and histology studies were performed in 6 different patients. RESULTS: Mean (SEM) age and body mass index of patients at the time of TKR was 74.6 (1.7) years and 28.1 (1.6) kg/m², respectively. Preoperative X-rays showed joint calcifications (chondrocalcinosis) in 4 cases only. The medial femoro-tibial compartment was the most severely affected in all cases, and mean (SEM) Kellgren-Lawrence score was 3.8 (0.1). All 20 OA cartilages showed CaC crystals. The mineral content represented 7.7% (8.1%) of the cartilage weight. All patients showed BCP crystals, which were associated with CPP crystals for 8 joints. CaC crystals were present in all knee joint compartments and in a mean of 4.6 (1.7) of the 8 studied areas. Crystal content was similar between superficial and deep layers and between medial and femoral compartments. BCP samples showed spherical structures, typical of biological apatite, and CPP samples showed rod-shaped or cubic structures. The expression of several genes involved in mineralization, including human homolog of progressive ankylosis, plasma-cell-membrane glycoprotein 1 and tissue-nonspecific alkaline phosphatase, was upregulated in OA chondrocytes isolated from CaC crystal-containing cartilages. CONCLUSIONS: CaC crystal deposition is a widespread phenomenon in human OA articular cartilage involving the entire knee cartilage including macroscopically normal and less weight-bearing zones. Cartilage calcification is associated with altered expression of genes involved in the mineralisation process.

Direct magnetic resonance arthrography of the wrist with axial traction: A feasibility study to assess joint cartilage.

PURPOSE: To assess the impact of axial traction during acquisition of direct magnetic resonance (MR) arthrography of the wrist with regard to joint space width and amount of contrast material between the opposing cartilage surfaces. MATERIALS AND METHODS: Fifteen consecutive patients (12 male, mean age 38.1 years) were included in this Institutional Review Board-approved prospective study. Three-compartment wrist MR arthrographies were performed between October and December 2009 on a 3 T unit using a fat-suppressed T1-weighted isotropic high-resolution volumetric interpolated breathhold examination (VIBE) sequence in the coronal plane, with and without axial traction (3 kg). Two radiologists measured radiocarpal (radioscaphoid, radiolunate) and midcarpal (lunocapitate, hamatolunate) joint space widths, with and without traction, and assessed the amount of contrast material between the opposing cartilage surfaces using a three-point scale: 0 = absence, 1 = partial, 2 = complete. RESULTS: With traction, joint space width increased significantly at the radioscaphoid (Delta = 0.78 mm, P < 0.01), radiolunate (Delta = 0.18 mm, P < 0.01), and lunocapitate (Delta = 0.45 mm, P < 0.01) spaces, and both observers detected significantly more contrast material between the cartilage surfaces. At the hamatolunate space, the differences in joint space width (Delta = 0.14 mm, P = 0.54) and amount of contrast material were not significant. CONCLUSION: Direct wrist MR arthrography with axial traction of 3 kg increases joint space width at the radiocarpal and lunocapitate spaces, and prompts better coverage of the articular cartilage by the contrast material. J. Magn. Reson. Imaging 2011;. (c) 2011 Wiley-Liss, Inc.

Intra-articular osteoid osteoma of the knee: clinical and therapeutical particularities

The intra-articular osteoid osteoma (10-13% of the cases) is often difficult to identify. They present frequent atypical clinical signs and radiological images that eventually lead to inadequate treatment. For example, it has been observed that this pathology leads to inappropriate arthroscopies (up to 40%). Meniscal tear and then osteochondritis were initially suspected on a patient with an intra-articular osteoid osteoma at the tibia level. For the treatment, any damage of the cartilage has to be avoided. Thermoablation with radiofrequency is the treatment of choice

Octacalcium Phosphate (OCP) Crystals Induce Synovial Inflammation and Cartilage

Introduction: The presence of intra-articular basic calcium phosphate (BCP) crystals, including OCP, carbonated-apatite, hydroxyapatite and tricalcium phosphate crystals, is associated with severe osteoarthritis and destructive arthropathies such as Milwaukee shoulder. Although BCP crystals displayed, in vitro, mitogenic, anabolic and catabolic responses, their intra-articular effect was never assessed.Objective: To determine the effects of OCP crystals in joints in vivo.Methods: OCP crystals (200 ug in 20 ml PBS) were injected into the right knee joint (the contra-lateral knee joint injected with 20 ul of PBS serving as a control) of wild-type mice treated or not by the IL1R antagonist Anakinra or mice deficient for the inflammasome proteins ASC and NALP3. 4 days and 17 days after crystal injection, mice were sacrificed and knee joints dissected. Histological scoring for synovial inflammation and characterisation of macrophages, neutrophils and T cells were performed. Technetium (Tc) uptake was measured at 6h, 1 and 4 days after OCP injection. Cartilage degradation was evaluated by Safranin O staining and VDIPEN immunohistochemistry. Intra-articular localisation of injected OCP crystals was evidenced by Von Kossa staining.Results: The intra-articular localisation of injected OCP crystals was evidenced by Von Kossa staining performed on non-decalcified samples embedded in methyl-metacrylate. Injection of OCP crystals into knee joints led at day 4 to an inflammatory response with intense macrophage staining and also some neutrophil recruitment in the synovial membrane. This synovitis was not accompanied by increased Tc uptake into the knee joint, Tc uptake being similar in OCP crystal injected knee or control knee at all time points investigated (6h, 1 day, 4 days). The histological modifications persisted over 17 days, with an additional fibrosis evidenced at this later time-point. The OCP crystal-induced synovitis was totally IL-1a and IL-1 independent as shown by the absence of inhibitory effects of anakinra injected into wild-type mice. Accordingly, OCP crystal-induced synovitis was similar in ASC-/- and NALP3-/- mice as no alterations of inflammation were demonstrated between these mice groups. Concerning cartilage matrix degradation, OCP crystals induced a strong breakdown of proteoglycans 4 and 17 days after injection, as measured by loss of red staining from Safranin O-stained sections of cartilage surfaces. In addition, we also measured advanced cartilage matrix destruction mediated by MMPs, as evidenced by VDIPEN staining of cartilage. OCP-mediated cartilage degradation was similar in all experimental conditions tested (WT+Anakinra, or ASC or NALP3 deficient mice).Conclusion: These data indicate in vivo that the intra-articular presence of OCP crystals is associated with cartilage destruction along with synovial inflammation. This is an interesting and new model of destructive arthropathy related to BCP crystals which will allow to assess new therapies in this disease.

Anatomical distribution of areas of preserved cartilage in advanced femorotibial osteoarthritis using CT arthrography (Part 1).

OBJECTIVE: To determine subregions of normal and abnormal cartilage in advanced stages of femorotibial osteoarthritis (OA) by mapping the entire femorotibial joint in a cohort of pre-total knee replacement (TKR) OA knees. DESIGN: We defined an areal subdivision of the femorotibial articular cartilage surface on CT arthrography (CTA), allowing the division of the femorotibial articular surface into multiple (up to n = 204 per knee) subregions and the comparison of the same areas between different knees. Two readers independently classified each cartilage area as normal, abnormal or non-assessable in 41 consecutive pre-TKR OA knees. RESULTS: A total of 6447 cartilage areas (from 41 knees) were considered assessable by both readers. The average proportion of preserved cartilage was lower in the medial femorotibial joint than in the lateral femorotibial joint for both readers (32.0/69.8% and 33.9/68.5% (medial/lateral) for reader 1 and 2 respectively, all P < 0.001). High frequencies of normal cartilage were observed at the posterior aspect of the medial condyle (up to 89%), and the anterior aspect of the lateral femorotibial compartment (up to 100%). The posterior aspect of the medial condyle was the area that most frequently exhibited preserved cartilage in the medial femorotibial joint, contrasting with the high frequency of cartilage lesions in the rest of that compartment. CONCLUSIONS: Cartilage at the posterior aspect of the medial condyle, and at the anterior aspect of the lateral femorotibial compartment, may be frequently preserved in advanced grades of OA.

Arthro-IRM directe en traction axiale: technique et intérêt [Technique and value of direct MR arthrography applying articular distraction]

Direct MR arthrography has a better diagnostic accuracy than MR imaging alone. However, contrast material is not always homogeneously distributed in the articular space. Lesions of cartilage surfaces or intra-articular soft tissues can thus be misdiagnosed. Concomitant application of axial traction during MR arthrography leads to articular distraction. This enables better distribution of contrast material in the joint and better delineation of intra-articular structures. Therefore, this technique improves detection of cartilage lesions. Moreover, the axial stress applied on articular structures may reveal lesions invisible on MR images without traction. Based on our clinical experience, we believe that this relatively unknown technique is promising and should be further developed.

Bucket-handle tear of the triangular fibrocartilage complex : case report of a complex peripheral injury with separation of the distal radioulnar ligaments from the articular disc.

Palmer previously proposed a classification system of triangular fibrocartilage complex (TFCC) injuries that proved to be useful in directing clinical management. However, dorsal peripheral tears (variants of class 1C) were not described and have rarely been reported in the literature since. We herewith present a rare case of bucket-handle tear of the TFCC. To our knowledge, this is the first case demonstrating partial separation of both the palmar and dorsal distal radioulnar ligaments (DRULs) from the articular disc. The particular wrist magnetic resonance (MR) arthrographic findings of this unusual complex peripheral TFCC tear (a variant of both class 1B and 1C) were nicely appreciated upon sagittal reformatted images.

Arthroskopie bei Hüftdysplasie [Arthroscopy in hip dysplasia]

[The causal treatment of a residual hip dysplasia consists of an acetabular reorientation osteotomy, the results of which, however, strongly depend on concomitant intra-articular lesions. The most important prognostic factor is the cartilage status. However, tears in the labrum and the ligament of the head of the femur may also be responsible for symptoms. Hip arthroscopy is a valuable tool for a precise diagnosis and simultaneous treatment of these lesions. However, as yet no results supporting this treatment algorithm have been published.]

Usefulness of intra-articular bupivacain and lidocain adjunction in MR or CT arthrography: a prospective study in 148 patients.

PURPOSE: To evaluate the influence of shorter- and longer-acting intra-articular anaesthetics on post-arthrographic pain. MATERIALS AND METHODS: 154 consecutive patients investigated by MR or CT arthrographies were randomly assigned to one of the following groups: 1--intra-articular contrast injection only; 2--lidocain 1% adjunction; or 3--bupivacain 0.25% adjunction. Pain was assessed before injection, at 15 min, 4 h, 1 day and 1 week after injection by visual analogue scale (VAS). RESULTS: At 15 min, early mean pain score increased by 0.96, 0.24 and 0 in groups 1, 2 and 3, respectively. Differences between groups 1 & 3 and 1 & 2 were statistically significant (p=0.003 and 0.03, respectively), but not between groups 2 & 3 (p=0.54). Delayed mean pain score increase was maximal at 4 h, reaching 1.60, 1.22 and 0.29 in groups 1, 2 and 3, respectively. Differences between groups 1 & 2 and 2 & 3 were statistically significant (p=0.002 and 0.02, respectively), but not between groups 1 & 2 (p=0.46). At 24 h and 1 week, the interaction of local anaesthetics with increase in pain score was no longer significant. Results were independent of age, gender and baseline VAS. CONCLUSION: Intra-articular anaesthesia may significantly reduce post-arthrographic pain. Bupivacain seems to be more effective than lidocain to reduce both early and delayed pain.