Jean-Emile Dubuc

Multidetector spiral CT arthrography of the shoulder. Clinical applications and limits, with MR arthrography and arthroscopic correlations

Although MR imaging and MR arthrography are the first choice modalities for shoulder imaging, CT arthrography (CTA) may be used successfully to address many clinical questions. The advent of submillimeter multiple detector CT technology and subsequent excellent three-plane resolution has considerably increased the quality of CTA examinations and has propelled this technique to the forefront in a growing number of indications. The combined use of iodinated contrast material for fluoroscopic confirmation of the articular position of the needle before injection of gadolinium chelates for MR arthrography offers the unique opportunity to compare CTA and MRA findings in carefully selected cases. This paper illustrates capabilities and limits of CTA for the study of rotator cuff tears, shoulder instability, cartilage lesions, anatomical variants and abnormalities of the glenoid labrum, with correlations to MR arthrography and surgical findings.

Gene expression pattern of cells from inflamed and normal areas of osteoarthritis synovial membrane

To compare the gene expression patterns of synovial cells from inflamed or normal/reactive areas of synovial membrane obtained from the same patient with osteoarthritis (OA).

Gene expression pattern of synovial cells from inflammatory and normal areas of osteoarthritis synovial membrane.

To compare the gene expression patterns of synovial cells from inflamed or normal/reactive areas of synovial membrane obtained from the same patient with osteoarthritis (OA).

Fibulin 3 peptides Fib3-1 and Fib3-2 are potential biomarkers of osteoarthritis.

OBJECTIVE This study was undertaken to identify new biomarkers of osteoarthritis (OA) by proteomics analysis and to develop specific immunoassays to detect and quantify them. METHODS Proteomics analysis was performed in urine samples from 10 women (mean±SD age 76.0±5.0 years) undergoing knee replacement surgery due to severe OA and 5 healthy women (mean±SD age 25.6±2.6 years). Protein content was analyzed by 2-dimensional differential gel electrophoresis. Protein spots that exhibited an OA:control abundance ratio of ≥1.5 were identified by mass spectrometry. Specific enzyme-linked immunosorbent assays were developed and validated in serum obtained from 236 healthy subjects ages 20-64 years and from 76 patients with severe radiologic knee OA (mean±SD age 68.8±11.9 years). Immunohistochemical analysis was performed on articular cartilage from tibial plateaus. RESULTS Thirteen proteins within spots that were significantly modified between groups were identified. Two peptides of fibulin 3, named Fib3-1 and Fib3-2, were of particular interest. Two antisera directed against these peptides were used to develop immunoassays. Compared with age-matched healthy subjects, median levels of serum Fib3-1 and Fib3-2 were elevated in OA patients (54.6 pM versus 85.1 pM [P<0.0001] and 144.4 pM versus 191.4 pM [P<0.0001], respectively). Using area under the receiver operating characteristic curve analysis, we demonstrated that Fib3-1 and Fib3-2 levels discriminate between OA and normal populations. Immunostaining revealed the presence of Fib3-1 and Fib3-2 in chondrocytes and in the extracellular matrix of the superficial layer of the fibrillated cartilage. CONCLUSION Our findings indicate that Fib3-1 and Fib3-2 are potential biochemical markers for the diagnosis of OA.

One-year follow-up of Coll2-1, Coll2-1NO2 and myeloperoxydase serum levels in osteoarthritis patients after hip or knee replacement

Objectives: To determine Coll2-1, Coll2-1NO2 and myeloperoxydase (MPO) levels in serum of patients with knee or hip osteoarthritis (OA) before the surgery, 3 months and 1 year after knee or hip replacement. Methods: Coll2-1, Coll2-1NO2 and MPO were measured in 103 patients with isolated symptomatic knee or hip OA candidates for joint replacement. Sera were taken the day before surgery, 3 months and 1 year after hip or knee replacement. Coll2-1 and Coll2-1NO2 immunohistochemistry was performed on biopsies removed from cartilage lesions. Results: Immunostainings revealed the extensive presence of Coll2-1 and Coll2-1NO2 in the superficial layer of fibrillated cartilage and around some chondrocytes clusters. Three months after joint replacement, Coll2-1 and MPO serum levels were decreased and even reached the reference value for Coll2-1. By contrast, Coll2-1NO2 levels remained elevated. At 1-year follow-up, Coll2-1 levels remained at the reference value, MPO levels were similar to those measured at 3 months, and Coll2-1NO2 levels were unchanged and comparable to the pre-surgery values. However, in patients with pre-surgery values above the median (more than 0.42 nM), Coll2-1NO2 levels significantly and progressively decreased post-operatively, but tended towards an increase in patients with pre-surgery Coll2-1NO2 values below the median. Conclusions: The normalisation of Coll2-1 levels 3 months after surgery indicates that Coll2-1 is a disease-specific marker that is sensitive to the structural changes occurring in a single joint. Furthermore, the immunohistochemical findings are consistent with the concept that the major source of serum Coll2-1 is the damaged articular cartilage. Finally, serum MPO levels decreased after joint replacement indicating that neutrophil activation occurs in OA joints, even in the late stage of the disease.

Characterization of synovial angiogenesis in osteoarthritis patients and its modulation by chondroitin sulfate

IntroductionThis work aimed at comparing the production of inflammatory and pro- and anti-angiogenic factors by normal/reactive (N/R) or inflammatory (I) areas of the osteoarthritic synovial membrane. The effects of interleukin (IL)-1β and chondroitin sulfate (CS) on the expression of pro- and anti-angiogenic factors by synovial fibroblasts cells (SFC) were also studied.MethodsBiopsies from N/R or from I areas of osteoarthritic synovial membrane were collected at the time of surgery. The inflammatory status of the synovial membrane was characterized by the surgeon according to macroscopic criteria, including the synovial vascularization, the villi formation and the hypertrophic aspect of the tissue. We assessed the expression of CD45, von Willebrand factor and vascular endothelial growth factor (VEGF) antigen by immunohistochemistry in both N/R and I biopsies. The production of IL-6, -8, VEGF and thrombospondin (TSP)-1 by N/R or I synovial cells was quantified by ELISA. SFC were cultured in the absence or in the presence of IL-1β (1 ng/ml) and with or without CS (10, 50, 200 μg/ml). Gene expression of pro-angiogenic factors (VEGF, basic fibroblast growth factor (bFGF), nerve growth factor (NGF), matrix metalloproteinase (MMP)-2 and angiopoietin (ang)-1) and anti-angiogenic factors (vascular endothelial growth inhibitor (VEGI), TSP-1 and -2) were determined by real time RT-PCR. Production of VEGI and TSP-1 was also estimated by ELISA.ResultsImmunohistochemistry showed the increase of lymphocyte infiltration, vascular density and VEGF expression in I compared to N/R synovial biopsies. Synovial cells from I areas produced more IL-6, IL-8 and VEGF but less TSP-1 than cells isolated from N/R synovial biopsies. The expression of pro-angiogenic factors by SFC was stimulated by IL-1β. A time dependent regulation of the expression of anti-angiogenic factor genes was observed. IL-1β stimulated the expression of anti-angiogenic factor genes but inhibited it after 24 h. CS reversed the inhibitory effect of IL-1β on anti-angiogenic factors, VEGI and TSP-1.ConclusionsWe demonstrated that synovial biopsies from I areas expressed a pro-angiogenic phenotype. IL-1β induced an imbalance between pro- and anti-angiogenic factors in SFC and CS tended to normalize this IL-1β-induced imbalance, providing a new possible mechanism of action of this drug.

Evaluation of Rotator Cuff Tendon Tears: Comparison of Multidetector CT Arthrography and 1.5-T MR Arthrography

PURPOSE To compare the diagnostic performance of multidetector computed tomographic (CT) arthrography and 1.5-T magnetic resonance (MR) arthrography in the evaluation of rotator cuff lesions, with arthroscopic correlation. MATERIALS AND METHODS This study was approved by the institutional ethical committee, and informed consent was obtained from all patients. CT and MR arthrographic images prospectively obtained in 56 consecutive patients, following the same arthrographic procedure, were independently evaluated by two radiologists. Arthroscopy, performed within 1 month of the imaging, was used as the reference standard. Sensitivity and specificity of CT and MR arthrography were compared by using the McNemar test. Interobserver and intertechnique agreement for detecting rotator cuff lesions were measured and compared with κ and Z statistics. The Bland-Altman method was used to determine interobserver and intertechnique agreement for measuring tendon tears. For grading fatty infiltration of rotator cuff muscles, κ and Z statistics were used. RESULTS There was no statistically significant difference in sensitivity and specificity between CT arthrography and MR arthrography in depiction of rotator cuff lesions. The respective sensitivity and specificity of CT arthrography were 92% and 93%-97% for the supraspinatus, 100% and 77%-79% for the infraspinatus, 75%-88% and 85%-90% for the subscapularis, and 55%-65% and 100% for the biceps tendon. The respective sensitivity and specificity of MR arthrography were 96% and 83%-93% for the supraspinatus, 88%-100% and 81%-83% for the infraspinatus, 75%-88% and 90%-100% for the subscapularis, and 65%-85% and 100% for the biceps tendon. Interobserver agreement was substantial to almost perfect (κ = 0.744-0.964 for CT arthrography; κ = 0.641-0.893 for MR arthrography), and intertechnique agreement was almost perfect (κ > 0.819). CT and MR arthrography both yielded moderate interobserver and intertechnique agreement for measuring rotator cuff tears and grading muscle fatty infiltration. CONCLUSION Data suggest that CT and MR arthrography have similar diagnostic performance for the evaluation of rotator cuff tendon tears.

Reconstruction du coude par allogreffe massive ostéo-articulaire totale : échec précoce par instabilité

Total elbow allografts were implanted for the treatment of trauma-induced bone defects in three patients between 1986 and 1990. Six allografts were implanted and finally explanted. The longest follow-up for an implanted allograft was five years. Allografts had to be removed because of nonunion in one patient and gross instability in the others. A constrained elbow prosthesis was implanted in all three patients. This short series illustrates mid-term failure to be expected with total elbow allografts, mainly due to instability. Accordingly, we no longer recommend the use of total elbow allografts alone as a salvage procedure for bony defects. If an allograft is needed, it should be implanted with a prosthesis.Resume Trois patients ont eu une reconstruction du coude par allogreffe massive de coude entre 1986 et 1990. Il s’agissait de coudes ballants d’origine post-traumatique. Toutes les allogreffes ont ete retirees, soit pour pseudarthrose dans un cas, soit pour instabilite chez les autres. La plus longue duree d’implantation a ete de 5 ans. Toutes les reconstructions se sont terminees par une prothese de coude dont la mise en place n’a pas pose de probleme particulier. Cette experience est un echec et signifie pour nous que toute reconstruction d’articulation par une allogreffe osteo-articulaire complete doit etre abandonnee. Si une allogreffe doit etre implantee au niveau du coude, elle doit l’etre avec une prothese.

Chitosan Enriched Three-Dimensional Matrix Reduces Inflammatory and Catabolic Mediators Production by Human Chondrocytes

This in vitro study investigated the metabolism of human osteoarthritic (OA) chondrocytes encapsulated in a spherical matrix enriched of chitosan. Human OA chondrocytes were encapsulated and cultured for 28 days either in chitosan-alginate beads or in alginate beads. The beads were formed by slowly passing dropwise either the chitosan 0.6%–alginate 1.2% or the alginate 1.2% solution through a syringe into a 102 mM CaCl2 solution. Beads were analyzed histologically after 28 days. Interleukin (IL)-6 and -8, prostaglandin (PG) E2, matrix metalloproteinases (MMPs), hyaluronan and aggrecan were quantified directly in the culture supernatant by specific ELISA and nitric oxide (NO) by using a colorimetric method based on the Griess reaction. Hematoxylin and eosin staining showed that chitosan was homogeneously distributed through the matrix and was in direct contact with chondrocytes. The production of IL-6, IL-8 and MMP-3 by chondrocytes significantly decreased in chitosan-alginate beads compared to alginate beads. PGE2 and NO decreased also significantly but only during the first three days of culture. Hyaluronan and aggrecan production tended to increase in chitosan-alginate beads after 28 days of culture. Chitosan-alginate beads reduced the production of inflammatory and catabolic mediators by OA chondrocytes and tended to stimulate the synthesis of cartilage matrix components. These particular effects indicate that chitosan-alginate beads are an interesting scaffold for chondrocytes encapsulation before transplantation to repair cartilage defects.

Intra-articular myxofibrosarcoma of the hip in a 10-year-old child

We report a case of intra-articular myxofibrosarcoma with acetabular involvement observed in a 10-year-old boy. Myxofibrosarcoma is a frequent soft tissue sarcoma usually observed in elderly subjects. It is extremely rare in children and has not been reported previously before the age of 22 years. Myxofibrosarcoma is a specific type of soft tissue tumor. Discussion continues concerning its relation with the myxoid variant of malignant fibrous histiocytoma. The myxoid matrix harbors fibroblastic cells with a curvilinear vessel configuration. Prognosis is good after complete resection and careful surveillance. Local recurrence may occur generally with progression of the tumor stage and risk of later metastasis. This is the first report of an intra-articular localization. We discuss the therapeutic options.