The effect of inclination angle on the strength of vertical mattress configuration for meniscus repair.

PURPOSE: Vertical mattress configuration is the strongest of all other configurations and the repairing devices of meniscus repair. The purpose was whether increasing the inclination angle between two strands of the vertical mattress configuration by increasing the amount of meniscus tissue captured would enhance the initial strength of the construction. METHODS: A 2-cm long anteroposterior vertical longitudinal incision was created in two groups of bovine medial menisci. In the first group, the distance between the two vertical suture strands and the vertical horizontal sutures on the capsular side of the meniscal lesion was 2 mm (Group 1). In the second group, the distance was 5 mm (Group 2). The following repair specimens underwent cyclic loading prior to loading the failure testing. The endpoints included ultimate failure load (N), stiffness (N/mm) and cyclic displacement (mm) after the 100 cycles and the mode of failure. RESULTS: Group 1 (2 mm) (90.7 (±19.9) N) had lower ultimate load than Group 2 (5 mm) (120.8 (±24.5)) (P < 0.05). Stiffness and displacements during the cycling were not different between the groups (n.s.). All specimens failed by suture rupture. CONCLUSION: Increased inclination angle with increased distance between the two vertical suture strands on the capsular side of the meniscal lesion resulted in higher failure load compared to control group with lower inclination angle and distance on the capsular side.

Biocompatibility of MG-63 cells on collagen, poly-L-lactic acid, hydroxyapatite scaffolds with different parameters.

PURPOSE: In this study, osteoblast-like MG-63 cells were cultured on 3 different scaffold types composed of (a) collagen + poly-L-lactic acid (PLLA), (b) collagen + hydroxyapatite (HA; 30ºC) or (c) collagen + hydroxyapatite (HA; 37ºC) and produced with different porosities. METHODS: Biomechanical properties of the scaffolds were characterized by tensile strength measurements. Properties of the cell-seeded scaffolds were evaluated with scanning electron microscopy (SEM). Cell adhesion and proliferation capacities were evaluated. Alkaline phosphatase (ALP) levels in media were measured. Transmission electron microscopy (TEM) and histological analyses were used to assess morphological characteristics. RESULTS: Our results showed that collagen-based PLLA and HA scaffolds have good cell biocompatibility. MTT test showed that the scaffolds exhibited no cytotoxicity. According to the force and displacement data, collagen + HA at 37ºC showed the highest mechanical strength and displacement. CONCLUSION: The results suggest that collagen-based PLLA and HA scaffolds might improve osteoblastic growth in vitro and have biomaterial integration potential in possible therapeutic approaches for future clinical studies.