Objective To summarize the anatomic features of the posterior septum of the knee joint and its application in posterior trans-septal portal for arthroscopic surgery. Methods The literature related to posterior septum of the knee joint and arthroscopic surgery was extensively reviewed and analyzed. Results The posterior septum of the knee joint has more mechanoreceptors and blood vessels in the upper part, which are close to arteria popliteal at the tibial plateau level; the posterior compartment is divided into wider posteromedial and narrower posterolateral compartments. A safe arthroscopic trans-septal portal is established, in the knee flexion of 90°, in a lateral-to-medial direction, and with an inserting location below the middle of posterior septum. Conclusion The establishment method of posterior trans-septal portal is not uniform and all the features of posterior septum should be considered to decrease the complications.
Objective To measure the included angle between tibia anatomical axis and anterior cortex, and to define the relative position of them in order to give direction in placement of tibia extra-medullary alignment bar during total knee arthroplasty. Methods A total of 100 healthy volunteers were included (49 left knees and 51 right knees). There were 52 males and 48 females, aged 20-86 years with an average age of 45.2 years (20-35 years in 29 cases, 35-50 years in 32 cases, and over 50 years in 39 cases). The tibiofibular lateral X-ray films were taken to measure the included angle between tibia anatomical axis and anterior cortex with AutoCAD2004 system. The samples were grouped according to gender, age, and side. Results The included angles between tibia anatomical axis and anterior cortex ranged from 3.007 to 3.021° with an average of 3.001°; the angles were (2.965 ± 0.361)° in male and (3.041 ± 0.311)° in female; the angles were (2.996 ± 0.332)° in the left knee and (3.006 ± 0.347)° in the right knee; and the angles were (2.918 ± 0.346)° in 20-35 years age group, (3.060 ± 0.330)° in 35-50 years age group, and (3.014 ± 0.336)° in over 50 years age group. No significant difference was found in the included angle between tibia anatomical axis and anterior cortex between male and female, among different ages, and between left and right knees (P gt; 0.05). Conclusion The included angle between tibia anatomical axis and anterior cortex is about 3°, so tibia extra-medullary alignment bar should be placed at the angle of 3° with anterior cortex during total knee arthroplasty.
ObjectiveTo investigate the role of osteopontin (OPN) on the expressions of matrix metalloproteinase 13 (MMP-13) mRNA and protein in human knee osteoarthritic chondrocytes and to find the optimal time and concentration for OPN treatment. MethodsChondrocytes were isolated from articular cartilage tissues of patients with primary osteoarthritis (OA) and cultured using one step digestive treatment with collagenase typeⅡ. The chondrocytes were then identified using immunohistochemistry of collagen typeⅡ. The first generation of chondrocytes were stimulated with OPN at a concentration of 1μg/mL for 0, 24, 48, and 72 hours, and with OPN at the concentrations of 0, 0.5, 1, 2, and 4μg/mL for 48 hours. The levels of MMP-13 mRNA and protein expressions were measured with real-time fluorescent quantitative PCR and Western blot. ResultsThe immunohistochemical staining showed that first generation of chondrocytes expressed collagen typeⅡ. Both MMP-13 mRNA and protein expression levels in OA chondrocytes increased significantly in the presence of OPN (1μg/ mL) and peaked at 48 hours after incubation, showing significant difference between different time points (P < 0.05). The MMP-13 mRNA expression level in OA chondrocytes at the OPN concentration of 1μg/mL was significantly higher than those at the other concentrations (P < 0.05), and the MMP-13 protein expression level at the OPN concentration of 1μg/mL was significantly higher than that at 0μg/mL (P < 0.05). MMP-13 protein expression level at the OPN concentrations of 0.5, 2, and 4μg/mL were significantly higher than that at 0μg/mL (P < 0.05). ConclusionOPN induces up-regulation of MMP-13 mRNA and protein expressions in human knee osteoarthritic chondrocytes in time-and dose-dependent manners. The optimal time and concentration for OPN treatment are 48 hours and 1μg/mL, respectively.