[Current therapy status and research progress of cartilage defects of knees].

To demonstrate the current strategies for treating cartilage defects of knees and the related research. Published papers about cartilage defects were searched and reviewed. The current strategies for the treatment were summarized. Based on the research of our study and others, the conclusion how to treat cartilage defects was made. The current ways for treating cartilage defects include micro-fractures, chondrocytes transplantation, mosaicplasty and tissue engineering; Research on functional magnetic resonance imaging in the early diagnosis of cartilage defects, cartilage degeneration is gradually increasing. There is still no effective treatment of cartilage defects and tissue engineering has brought new hopes for the treatment of cartilage defects , functional magnetic resonance imaging has some significance in early diagnosis of cartilage defects, cartilage degeneration.

Preparation and characterization of bone marrow mesenchymal stem cell-derived extracellular matrix scaffolds.

The aim of this study was to assess the feasibility of creating extracellular matrix (ECM) scaffolds from mesenchymal stem cells. Bone marrow mesenchymal stem cell (BMSC)-derived ECM (BMSC-dECM) scaffolds were fabricated by lyophilization after crosslinking, without using a decellularization process. Acellular porcine chondrocyte-derived ECM (AC-dECM) scaffolds were used as a control. The surface morphology, internal structure, water uptake ratio, mechanical properties, and biocompatibility of the scaffolds, as well as the in vitro behavior of cells grown on the scaffolds were examined and compared between the two scaffold types. For the BMSC-dECM scaffolds, the average pore size was 304.4 ± 108.2 µm, average porosity was 93.3% ± 4.5%, average compressive modulus was 6.8 ± 1.5 kPa, and average water uptake ratio exceeded 20. The BMSC-dECM scaffolds supported the in vitro attachment and proliferation of cells, with these aspects likely being comparable to those of the AC-dECM scaffolds. The findings of this preliminary study highlight the potential utility of BMSC-derived ECM scaffolds for future cartilage tissue-engineering applications.

Evaluation of transtibial double-bundle posterior cruciate ligament reconstruction using a single-sling method with a tibialis anterior allograft.

BACKGROUND: The authors devised a double-bundle posterior cruciate ligament reconstruction technique in combination with a single-sling method. However, the double-bundle technique needs more simplicity and a decreased possibility of failure. HYPOTHESIS: A novel surgical technique of transtibial double-bundle posterior cruciate ligament reconstruction using a single-sling method with a tibialis anterior allograft, previously introduced, produces satisfactory results. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Twenty-one patients who underwent double-bundle transtibial isolated posterior cruciate ligament reconstruction using a single-sling method between July 2003 and September 2007 were enrolled in this study. The exclusion criteria applied were (1) a multiligamentous injury, (2) posterior cruciate ligament reconstruction previously performed using another technique, and (3) the presence of any additional injury capable of affecting knee stability. The Lysholm and International Knee Documentation Committee (IKDC) knee scales were used for the clinical outcome evaluation. Stability was evaluated using a KT-2000 arthrometer. The evaluation was performed by comparing preoperative and last follow-up results. RESULTS: Nineteen men and 2 women were enrolled, with a mean follow-up of 49.2 months (range, 25-73 months). The mean Lysholm score was 53 ± 5.3 (range, 34-68) preoperatively and improved to 83.5 ± 13 (range, 61-97) at the last follow-up after surgery (P < .001). The IKDC score also improved from preoperative (0 A, 0 B, 7 C, 14 D) to final follow-up (8 A, 9 B, 3 C, 1 D; P < .001). Mean side-to-side difference in posterior translation, measured using the KT-2000 arthrometer, was 13.5 ± 1.2 mm preoperatively and 3.4 ± 0.8 mm at last follow-up evaluations (mean 51.7 months postoperatively). CONCLUSION: After follow-up for longer than 24 months, the transtibial double-bundle posterior cruciate ligament reconstruction with a single sling was found to produce satisfactory clinical and stability results, which indicates that the described technique should be viewed as a viable alternative.

Design of antiangiogenic hypoxic cell radiosensitizers: 2-nitroimidazoles containing a 2-aminomethylene-4-cyclopentene-1,3-dione moiety.

We designed chiral 2-nitroimidazole derivatives containing a 2-aminomethylene-4-cyclopentene-1,3-dione moiety as antiangiogenic hypoxic cell radiosensitizers. Based on results of molecular orbital calculations, the 2-aminomethylene-4-cyclopentene-1,3-dione moiety is expected to show high electrophilicity comparable to that of the 2-methylene-4-cyclopentene-1,3-dione moiety included in TX-1123 and tyrphostin AG17. We evaluated the antiangiogenic and radiosensitizing effects of the new compounds, along with other biological properties including their activities as hypoxic cytotoxicities and protein tyrosine kinase (PTK) inhibitory activities. Among the compounds tested, 5 (TX-2036) proved to be the strongest antiangiogenic hypoxic cell radiosensitizer. All the other chiral 2-nitroimidazole derivatives having 2-aminomethylene-4-cyclopentene-1,3-dione moiety tested were also antiangiogenic hypoxic cell radiosensitizers. The PTK inhibitory activity of 5 (TX-2036) showed this to be a promising and potent EGFR kinase inhibitor, having an IC(50) value of lower than 2microM. This compound also was an Flt-1 kinase inhibitor having an IC(50) value of lower than 20microM. Our results show that these chiral 2-nitroimidazole derivatives that contain the 2-aminomethylene-4-cyclopentene-1,3-dione moiety as a potent antiangiogenic pharmacophoric descriptor are promising lead candidates for the development of antiangiogenic hypoxic cell radiosensitizers.

Posterior cruciate ligament reconstruction with a single-sling technique using a tibialis anterior tendon allograft.

Reconstruction of the posterior cruciate ligament (PCL) has been performed in various ways. Recent biomechanical tests revealed that a double-bundle graft with a 2-tunnel technique is more likely to restore normal knee stability throughout the full range of knee motion. Several techniques using double-bundle grafts have been implemented for PCL reconstruction; however, each technique has its own advantages and disadvantages. To provide a simplified surgical technique and minimize its inherent complications, the purpose of this study was to introduce a novel technique of arthroscopic PCL reconstruction using an allogeneic tibialis anterior tendon and forming a single sling.

Surgical treatment for distal clavicle fracture associated with coracoclavicular ligament rupture using a cannulated screw fixation technique.

BACKGROUND: A clavicle fracture is a common traumatic injury. However, the high percentage of distal clavicle fractures associated with a rupture of the coracoclavicular (CC) ligament can result in delayed union or nonunion. There is no standard treatment for a clavicle fracture. This report introduces a method for treating distal clavicle fractures associated with a ruptured CC ligament using a cannulated screw. METHODS: Seventeen patients suffering from a clavicle fracture caused by a rupture of the CC ligament were treated with a closed reduction and a cannulated screw fixation technique. Twelve patients were male and five were female and the average age was 30.5 years (range, 8-64 years). The patients were assessed using a clinical and radiologic evaluation as well as by the University of California at Los Angeles (UCLA) shoulder rating scale for 12 to 16 months after surgery. RESULTS: After confirming the formation of a callus, the implants were routinely removed approximately 8 weeks after surgery in all patients except for one. In this patient, the implant was removed 16 weeks after surgery as a result of a loosened screw, which caused displacement at the fracture site. During the final follow-up, the fracture site displayed nonunion and a partially limited range of motion (ROM). The shoulder function of the other 16 patients was restored to the preinjury level after 4 approximately 6 months of treatment. In one patient, heterotopic ossification was observed along the CC ligament without any functional deficit. All but one patient showed good results according to the UCLA scale. CONCLUSIONS: The cannulated screw fixation technique can maintain the rigid fixation of fracture fragments and allow an early return to work and sport activities. Therefore, the cannulated screw fixation technique is expected to be a useful method for treating distal clavicle fractures associated with a coracoclavicular ligament rupture.

Angiogenesis inhibitor TX-1898: syntheses of the enantiomers of sterically diverse haloacetylcarbamoyl-2-nitroimidazole hypoxic cell radiosensitizers.

(R)- and (S)-Epichlorohydrins were used to prepare the enantiomers of sterically diverse haloacetylcarbamoyl-2-nitroimidazoles that function as hypoxic cell radiosensitizers. The synthetic design allowed for introduction of a side chain of varying bulk that permitted an examination of the steric effects on enantio-discrimination in biological assay systems. The single stereocenter also connected the two pharmacophores--a 2-nitroimidazole moiety critical to hypoxic cell radiosensitization, and a haloacetylcarbamoyl group to function as an anti-angiogenesis pharmacophore. In the chick embryo chorioallantoic membrane (CAM) assay, the R-enantiomers possessing the bulky p-tert-butylphenyl group showed higher anti-angiogenic activity than the corresponding S-enantiomers, while there were no differences in the activity between the enantiomers containing the less bulky methyl and tert-butyl groups. Among the compounds we report, R-p-tert-butylphenyl-bromoacetylcarbamoyl-2-nitroimidazole, TX-1898, was found to be the most promising candidate for further development of as anti-angiogenic hypoxic cell radiosensitizer.