Strong adhesiveness of a new biodegradable hydrogel glue, LYDEX, for use on articular cartilage.

AIM: Until recently, only fibrin glue has been available for clinical usage to repair articular cartilage, although its adhesiveness is not strong enough for use with articular cartilage, and it is derived from human blood and thus carries the risk of contamination. Recently, LYDEX, a new biodegradable hydrogel glue, has come onto the market. The purpose of this study was to evaluate the adhesive strength and cytotoxicity of LYDEX when used on articular cartilage. MATERIALS AND METHODS: The differing adhesive strengths of collagen membrane and articular cartilage with LYDEX versus with fibrin glue were measured using a tensile tester. In addition, the cytotoxicity of LYDEX in vitro was evaluated. The cytotoxicity of LYDEX for the articular cartilage of rats was evaluated histopathologically. RESULTS: The adhesive strength of LYDEX was significantly stronger than that of fibrin glue, giving values about 3.8 times higher. LYDEX has no discernible effect on normal articular cartilage. CONCLUSIONS: Our study is the first to assess the usefulness and safety of LYDEX for use on articular cartilage.

Treatment of cartilage defects by subchondral drilling combined with covering with atelocollagen membrane induces osteogenesis in a rat model.

BACKGROUND: The coverage of the atelocollagen membrane at the chondral defect after subchondral drilling might improve the beneficial effects for cartilage repair because of the prevention of scattering and accumulation of cells and growth factors from bone marrow within the chondral defect. On the other hand, it might block cells and factors derived from the synovium or cause high pressure in the chondral defect, resulting in prevention of cells and growth factors gushing out from the bone marrow, which leads to disadvantages for cartilage repair. METHOD: We tested this hypothesis in a 2-mm-diameter chondral defect created in the articular cartilage of the patellar groove in a rat models. Defects were left untreated, or were drilled or drilled and covered with an atelocollagen membrane; healing was evaluated by histology and gene expression analysis using real-time polymerase chain reaction and immunohistochemistry. RESULTS: Membrane coverage induced bone tissue ingrowth into the punched chondral defect. At 1 week, expression of TGFß, Sox9, Runx2, osteocalcin, Col1a1, and Col2a1 in the drilling group was significantly higher than in the covering group. At 4 weeks, expressions of TGFß, Runx2, and Col1a1 were all significantly higher in the drilling group, while Sox9, osteocalcin, and Col2a1 were significantly higher in the covering group. Immunohistochemistry demonstrated Sox9, osteocalcin, and type II collagen on the bony reparative tissue in the covering group. CONCLUSIONS: These results suggest that the atelocollagen membrane coverage resulted in inhibition of cartilage repair.

Augmentation technique for anterior cruciate ligament injury.

The augmentation technique for anterior cruciate ligament (ACL) injury has started to receive the attention of orthopedic surgeons because preservation of the ACL remnant may be beneficial in terms of proprioception, biomechanical functions, and vascularization of the graft. This article describes the current indications and surgical techniques of ACL augmentation for patients with continuity of ACL remnant between the tibia and either the femur or posterior cruciate ligament (PCL).

Characteristic shape of the lateral femoral condyle in patients with osteochondritis dissecans accompanied by a discoid lateral meniscus.

BACKGROUND: There are various indirect signs of a discoid lateral meniscus in radiographs, for example lateral joint space widening, hypoplasia of the LFC, etc. There has, however, been no previous report of the characteristic shape of the lateral femoral condyle (LFC) in patients with osteochondritis dissecans (OCD) accompanied by a discoid lateral meniscus. The purpose of this study was to evaluate the characteristic shape of the LFC in patients with OCD accompanied by a discoid lateral meniscus, and sex differences associated with the shape of the LFC in those patients. METHODS: This study included 29 males (31 knees) and 29 females (32 knees) of average age 17.7 years. There were 15 knees in 15 patients that were accompanied by OCD of the LFC (9 males, 9 knees; 6 females, 6 knees; average age 14.9 years; OCD group). There were 48 knees in 43 patients that were not accompanied by OCD of the LFC (20 males, 22 knees; 23 females, 26 knees; average age 17.6 years; non-OCD group). Standardized Rosenberg view radiographs of the knee were obtained for all patients. We evaluated the shape of LFC using the Rosenberg view and measured the condylar prominence ratio of the medial and lateral condyles adjacent to the intercondylar notch, in accordance with Ha's procedure. RESULTS: The OCD group had a significantly larger prominence ratio than the non-OCD group. The prominence ratio for males was significantly larger than that for females. CONCLUSION: We clearly demonstrated that the prominence ratio in the OCD group was significantly larger than that in the non-OCD group, indicating that the shape of the LFC and OCD in the LFC may be associated with the development of these lesions.

New hamstring fixation technique for medial collateral ligament or posterolateral corner reconstruction using the mosaicplasty system.

In this study, we describe a new hamstring fixation technique with a bone graft using the Mosaicplasty system for the reconstruction of the medial collateral ligament (MCL) or posterolateral corner (PLC) of the knee. In this technique, a cylindrical bone plug (6.5 mm in diameter, 15 mm in length) is harvested from the anatomical femoral attachment of the MCL or popliteal tendon using the Mosaicplasty system. After placing the autologous semitendinosus or gracilis tendon as a graft in the created bone socket, the bone plug is replaced over the graft. The graft is secured with a spike staple after appropriate tension is applied to the graft. This fixation technique can provide rigid and less invasive fixation, because the distance between the fixation sites can be shorter than that in the Endobutton technique. Compared to fixation with only a staple with no bone graft, the bone graft may enhance tendon to bone healing.