ObjectiveTo explore the effect of silk fibroin/poly(L-lactic acid-co-e-caprolactone) [SF/P(LLA-CL)] nanofibrous scaffold on tendon-bone healing of rabbits.MethodsSF/P(LLA-CL) nanofibrous scaffold was fabricated by electrospinning methods. The morphology of the scaffold was observed by scanning electron microscope (SEM). Pre-osteoblasts MC3T3-E1 cells were seeded on the scaffold and cultured for 1, 3, and 5 days. Cell adhesion and proliferation were also observed by SEM. Meanwhile, twenty-four New Zealand white rabbits were randomly divided into the autogenous tendon group (control group) and the autogenous tendon wrapped with SF/P(LLA-CL) scaffold group (experimental group), with twelve rabbits in each group. An extra-articular model was established, the effect was evaluated by histological examination and mechanical testing.ResultsThe morphology of SF/P(LLA-CL) nanofibrous scaffold was random, with a diameter of (219.4±66.5) nm. SEM showed that the MC3T3-E1 cells seeded on the scaffold were in the normal shape, growing well, and proliferating with time course. The results of histological examination showed that inflammatory cells infltrated into the graft-host bone interface at 6 weeks after operation in both groups. Besides, the width of interface showed no significant difference between groups. At 12 weeks after operation, protruding new bone tissue could be observed at the interface in the experimental group, while scar tissue but no new bone tissue could be seen at the interface in the control group. Mechanical testing showed that there was no significant difference in the failure load and the stiffness between groups at 6 weeks after operation (P>0.05). The failure load and the stiffness in the experimental group were significantly higher than those in the control group at 12 weeks after operation (P<0.05).ConclusionThe SF/P(LLA-CL) nanofibrous scaffold has good cell biocompatibility and can effectively promote tendon-bone healing, thus providing new method for modifying graft for ACL reconstruction in the clinical practice.
Objective To make further exploration of the structure characteristics of anterolateral ligament (ALL) and provide clinical reference for diagnosis and treatment of ALL injury, especially for ALL reconstruction through anatomical study of ALL in a Chinese population. Methods Sixteen cadaveric knees, including 8 left knees and 8 right knees with sex ratio of 1∶1 and a mean age of 73.5 years (range, 57-84 years), were dissected to reveal the ALL through a standard approach. A qualitative and a quantitative characterizations of the ALL were performed. Results ALL was seen in 75.0% of the specimens, originating on the lateral femoral epicondyle, proximal and posterior to the lateral collateral ligament (LCL). It coursed on LCL or was parallel to LCL, anterodistally to its anterolateral tibial attachment approximately midway between the center of the Gerdy’s tubercle and the lateral margin of the fibular head. A strong connection was observed between the middle part of the ALL and the periphery of the meniscal body of the lateral meniscus. The distance between the center of the insertion and Gerdy’s tubercle was (23.9±3.3) mm; and the distance between the center of the insertion and the lateral margin of the fibular head was (23.8±4.0) mm. The ALL length at 0° and 60° flexion and neutral knee rotation were (44.8±5.1) mm and (47.8±5.5) mm respectively (t=14.071, P=0.000), and the ligament had its great extend at 60° of knee flexion and internal rotation. Furthermore, the ALL length at 0° and 60° flexion of males were both significantly higher than those of females (t=2.920, P=0.015; t=2.806, P=0.019), while other measurements differences were significant between males and females (P>0.05). Conclusion ALL is an independent and a non-isometric ligament located in the anterolateral area to the knee, of which the length is different between males and females. ALL plays a role in rotational stability of the knee, and should be put much emphasis in clinical practice.
ObjectiveTo review the advances in utilizing paracrine effect of stem cells in knee osteoarthritis (OA) treatment.MethodsThe researches in applying stem cells derived conditioned medium, extracellular matrix, exosomes, and microvesicles in knee OA treatment and cartilage repair were reviewed and analyzed.ResultsThe satisfying outcomes of using different products of stem cells paracrine effect in knee OA condition as well as cartilage defect is revealed in studies in vitro and in vivo. The mechanism including suppressing the intraarticular inflammation, the apoptosis of chondrocytes, and the degradation of cartilage matrix, while enhancing the synthesis of cartilage matrix, the differentiation of in-situ stem cells into chondrocytes and the migration to the affected area. The effectiveness can be further improved supplemented with the tissue engineering methods or gene modification.ConclusionCompared with the traditional stem cell therapy, applying the products from paracrine effect of stem cells in knee OA treatment is more economical and safer, presenting great potential in clinical practice.