Objective To review the current development in meniscus tissue engineering. Methods Recent literature concerning the development of the meniscus tissue engineering was extensively reviewed and summarized. Results Recent researches mainly focus on: selection of seed cells and research of their potential of differentiation into chondrocytes; selection of scaffold materials and research of their mechanical properties; cytokines and their mechanisms of action. Conclusion Many achievements have been made in meniscus tissue engineering. Most important topics in future research include: finding seed cells that are adapted to physiological process, are easy to culture, and have higher chondrogenic differentiation ability; looking for necessary cytokines and their mechanisms of action; finding scaffold meterials with b morphological plasticity, no antigenicity, good degradability, and mechanical property close to normal meniscus.
Objective To compare the effectiveness of arthroscopic screw and suture fixations in treatment of anterior cruciate ligament tibial eminence avulsion fractures. Methods Between January 2002 and January 2009, 43 patients with freshanterior cruciate ligament tibial eminence avulsion fracture were treated, which were rated as types II and III according to Meyers- McKeever-Zaricznyj classification. Fractures were fixed with either screw (screw group, n=21) or nonabsorbable suture (suture group, n=22). There was no significant difference in sex, age, disease duration, and fracture type between 2 groups (P gt; 0.05). The range of motion (ROM) and Lysholm score were compared between 2 groups, and the knee stabil ity was evaluated based on the Lachman test and KT-2000 measurement. Results The operation time was 48-60 minutes (mean, 51.6 minutes) in the screw group, and 55-68 minutes (mean, 63.2 minutes) in the suture group, showing significant difference (t=4.645, P=0.032). Incisions healed by first intention and no compl ication occurred in 2 groups. All patients were followed up (5.7 ± 0.6) years in the screw group and (5.3 ± 0.5) years in the suture group. The fracture healed completely in both groups; the heal ing time was (3.3 ± 0.6) months in the screw group and (3.2 ± 0.4) months in the suture group, showing significant difference (t=3.723, P=0.019). Between the screw group and the suture group, no significant difference was found in ROM [(128.6 ± 10.1)° vs. (130.2 ± 14.1)°, P gt; 0.05] and Lysholm score (94.6 ± 14.5 vs. 95.1 ± 17.2, P gt; 0.05). The stabil ities based on KT-2000 measurement were also similar between 2 groups at last follow-up [(0.9 ± 0.3) mm vs. (1.0 ± 0.4) mm, P gt; 0.05]. Lachman test of 2 groups were negative. Conclusion Boththe screw and nonabsorbable suture fixation techniques for anterior cruciate l igament tibial eminence avulsion fracture (type II or III) have good results in terms of functional outcome and stabil ity. However, some patients show flexion contractures of 5° or 10°.
Objective To investigate the feasibility of rabbit synovial-derived mesenchymal stem cells (SMSCs) differentiating into fibrocartilage cells by the recombinant adenovirus vector mediated by bone morphogenetic protein 2/7 (BMP-2/7) genes in vitro. Methods SMSCs were isolated and purified from 3-month-old New Zealand white rabbits [male or female, weighing (2.1 ± 0.3) kg]; the morphology was observed; the cells were identified with immunocytological fluorescent staining, flow cytometry, and cell cycles. The adipogenic, osteogenic, and chondrogenic differentiations were detected. The recombinant plasmid of pAdTrack-BMP-2-internal ribosome entry site (IRES)-BMP-7 was constructed and then was used to infect SMSCs. The cell DNA content and the oncogenicity were tested to determine the safety. Then infected SMSCs were cultured in incomplete chondrogenic medium in vitro. Chondrogenic differentiation of infected SMSCs was detected by RT-PCR, immunofluorescent staining, and toluidine blue staining. Results SMSCs expressed surface markers of stem cells, and had multi-directional potential. The transfection efficiency of SMSCs infected by recombinant plasmid of pAdTrack-BMP-2-IRES-BMP-7 was about 70%. The safety results showed that infected SMSCs had normal double time, normal chromosome number, and normal DNA content and had no oncogenicity. At 21 days after cultured in incomplete chondrocyte medium, RT-PCR results showed SMSCs had increased expressions of collegan type I and collegan type II, particularly collegan type II; the expressions of RhoA and Sox-9 increased obviously. Immunofluorescent staining and toluidine blue staining showed differentiation of SMSCs into fibrocartilage cells. Conclusion It is safe to use pAdTrack-BMP-2-IRES-BMP-7 for infecting SMSCs. SMSCs infected by pAdTrack-BMP-2-IRES-BMP-7 can differentiate into fibrocartilage cells spontaneously in vitro.