Study of human chondrocyte redifferntiation capacity in three-dimensional hydrogel culture

Articular cartilage tissue defects cannot be repaired by the proliferation of resident chondrocytes. Autologous chondrocyte transplantation [ACT] is a relatively new therapeutic approach to cover full thickness articular cartilage defects by in vitro grown chondrocytes from the joint of a patient. Therefore, we investigated the differentiation capability of human chondrocytes maintained in alginate culture. The cartilage specimens obtained from 50 patients who underwent total knee and hip operations at the teaching hospital of Isfahan University of Medical Sciences, Isfahan Iran. Isolated primary chondrocytes were first grown in monolayer cultures for 1 to 6 passages [each passage lasting about 3 days]. At each passage, monolayer cells seeded in alginate culture and investigated morphologically and immuno-cytologically for expression of cartilage-specific markers [collagen type II and cartilage-specific proteoglycans]. The chondrocytes from monolayer passages PI to P4 introduced in alginate cultures regained a chondrocyte phenotype. Cells were interconnected by typical gap junctions and after few days, they produced a cartilage-specific extracellular matrix [collagen type II and cartilage-specific proteoglycans]. In contrast, cells from monolayer passages P5 and P6 did not redifferentiate to chondrocytes in the alginate cultures. Chondrocyte culture was established for the first time in Iran. The alginate culture conditions promote the redifferentiation of dedifferentiated chondrocytes that have still a chondrogenic potential. This procedure opens up a promising approach to produce sufficient numbers of differentiated chondrocytes for ACT. Indeed, in some patients the harvested cells were used immediately and successfully for transplantation

Combined anterolateral posterolateral rotary instability: Is posterolateral complex reconstruction necessary?

The treatment of combined anterolateral posterolateral rotary instability has been done by correcting knee alignment, anterior cruciate ligament [ACL] reconstruction plus repair or reconstruction of the posterolateral complex. Because of the technical difficulties encountered in these operations and the need for more than two stages, and considering the controversy among the role of posterolateral complex [PLC] in valgus knees, this study was designed to observe the results of treating this instability by ACL-reconstruction alone, after correction of varus, without reconstruction of the posterolateral complex or further extra-articular manipulation. This was a clinical trial performed on 29 patients [29 knees] with combined anterolateral posterolateral rotary in stability. Subjective and objective instability signs were recorded. Arthroscopy was then performed and a valgus osteotomy was done to correct alignment. Then in a second stage, an ACL-reconstruction was carried out. Results, after a mean of 23 months follow-up, were compared to the conditions before surgery. Fisher exact test, X2 and Wilcoxon tests were used to analyze the data. P<0.05 was considered to be meaningful. Pain was relieved in more than half and locking was improved in all of the patients. Giving way of the knee was diminished from 79.3% to 6.9%. Special instability tests showed a significant improvement after surgery [P<0.001]. Most of the patients returned to the preinjury level of work or sports. Based on the results of this study, ACL-reconstruction alone, after correction of varus, can be sufficient to address this combined knee instability without farther procedures on extra-articular structures and posterolateral complex, thus avoiding unnecessary complications and longer rehabilitation

Access to chondrocyte culture, with alginate, in Iran

In this study, chondrocyte culture was established for the first time in Iran, and calcium alginate was used for longer culture of chondrocyte in vitro. The study was programmed in order to be used for future human chondrocyte transplantation. The cartilage specimen obtained from 50 patients who underwent total knee and hip operations in Isfahan University of Medical Sciences. Cartilage specimens were used for monolayer as well as suspension culture in alginate beads. Approximately 12 +/- 1 millions cells were harvested from the 3[RD] passage. The cells were round with large euchromatic nucleus and several nucleoli and small vacuoles. The cells derived from passages 1 to 4, which were grown up then, in alginate beads, showed higher staining with alcian blue. The harvested cells in some patients were immediately and successfully used for autologus transplantation. This later work will be reported separately