Molecular Characterization and Differentiation of Mesenchymal Progenitor Cells from Human Rheumatoid Arthritis Cartilage.

The presence of mesenchymal progenitor cells (MPCs) in rheumatoid arthritis (RA) articular cartilage is sparsely investigated largely owing to the persistent pathogenic disease condition and lack of specific biomarkers. Considering the recent advancements for potential cell-based therapies in immunomodulatory diseases, such as RA, this in vitro study was aimed at investigating the cellular, molecular, and differentiation characteristics of human RA cartilage-derived MPCs. Articular cartilage fragments from RA patients were obtained for the isolation of MPCs and characterization of their cellular and biological properties, cytogenetic stability, pluripotency, and plasticity. Established MPCs were phenotypically identified using a panel of markers, and their differentiation ability into mesenchymal lineages was assessed by cytochemical staining and the expression of molecular markers. MPCs displayed a heterogenous population of cells with characteristic features of multipotent stem cells. Cells had higher viability, proliferative rate, and colony-forming ability. Further, MPCs showed the expression of pluripotency markers, cytogenetic stability, and minimal replicative senescence. In addition, MPCs differentiated into osteocytes, adipocytes, and chondrocytes, and modulated the expression of each lineage-specific gene markers. The results demonstrated the availability of a viable pool of MPCs residing in RA cartilage, which could serve as an ideal cell source for reinstating native homotypic cartilage.

Repair tissue quality after arthroscopic autologous collagen-induced chondrogenesis (ACIC) assessed via T2* mapping.

OBJECTIVE: A novel single-stage approach using arthroscopic microdrilling and atelocollagen/fibrin-gel application is employed for cartilage repair of the knee. The purpose of our study was to investigate the morphological and biochemical MRI outcome after this technique. MATERIALS AND METHODS: A retrospective case series of ten patients (mean age 45 years) with symptomatic chondral defects in the knee who were treated arthroscopically with microdrilling and atelocollagen application was analyzed. All defects were ICRS grade III or IV and the sizes were 2-8 cm(2) intra-operatively. All patients underwent morphological MRI and T2-star mapping at 1.5 T at 1-year follow-up. The magnetic resonance observation of cartilage repair tissue (MOCART) score was assessed. T2* relaxation time values of repair tissue and a healthy native cartilage area was assessed by means of region of interest analysis on the T2* maps. RESULTS: The mean MOCART score at 1-year follow-up was 71.7 ± 21.0 ranging from 25 to 95. The mean T2* relaxation times were 30.6 ± 11.3 ms and 28.8 ± 6.8 ms for the repair tissue and surrounding native cartilage, respectively. The T2* ratio between the repair tissue and native cartilage was 105% ± 30%, indicating repair tissue properties similar to native cartilage. CONCLUSIONS: An arthroscopic single-stage procedure using microdrilling in combination with atelocollagen gel and fibrin-glue can provide satisfactory MRI results at 1-year follow-up, with good cartilage defect filling. The T2* values in the repair tissue achieved similar values compared to normal hyaline cartilage.

Long-term follow-up of a hydroxyapatite ceramic-coated threaded cup: an analysis of survival and fixation at up to 15 years.

We evaluated the survival of 112 consecutive JRI hydroxyapatite ceramic-coated threaded acetabular components (JRI Ltd, London, UK). Follow-up was for a minimum of 13 years (range, 13-15 years). Patients were assessed clinically and radiographically using the Merle d'Aubigné and Postel scoring systems and the De Lee and Charnley zones. Cup angle, migration, and signs of radiolucency were used to assess loosening. The criteria for failure were revision or impending revision due to pain and septic or aseptic loosening. The mean results of the Merle d'Aubigné and Postel score for pain, motion, and ability to walk were 2.2/2.7/2.2 preoperatively and 5.6/4.3/5.1 postoperatively. There was 100% endosteal bone formation in De Lee and Charnley zones 1 and 3 and 87% in zone 2. No reactive lines were seen in any zone in any cup. There were no cases of migration, change in cup angle, or revision for loosening. Our survival was 99% at 13 years (95% confidence interval, 96-100).