Objective To investigate the effects of intermittent negative pressure on the mRNA expression of osteoprotegerin (OPG) and osteoprotegerin l igand (OPGL) in human BMSCs cultured in vitro. Methods BMSCs were isolated from adult marrow donated by 2 hip osteoarthritis patients with prosthetic replacement in January 2008 and cultured in vitro. The third passage cells were divided into experimental group and control group. The experimental group was induced by negative pressure intermittently for 2 weeks (pressure: 50 kPa, 30 minutes each time, twice per day) and the control groupwas routinely cultured. After 2 weeks of culture, cell morphology was observed by inverted phase contrast microscope, and the mRNA expressions of OPG and OPGL in BMSCs were analyzed by real-time PCR. Results The cell prol iferation speed of the experimental group was slower than that of the control group. The cell morph changed from shuttle to megagon with some prominences in experimental group and the cell morph kept shuttle in the control. The mRNA expression of OPG in experimental group increased significantly (P lt; 0.01) and the mRNA expression of OPGL in experimental group decreased significantly compared with control group (P lt; 0.01) 2 weeks later. Conclusion Intermittent negative pressure is capable of promoting the expression of OPG, while inhibiting the expression of OPGL in human BMSCs.
Objective To study the feasibility of virtual intercondylar notchplasty by applying MRI two-dimensional (2D) images to reconstruct three-dimensional (3D) images and measure the size of intercondylar notch. Methods Thirty healthy volunteers who had no knee joint disease and surgery history were selected. There were 15 females and 15 males with an age range of 20-30 years, weight range of 45-74 kg, and height range of 150-185 cm. They were divided into male group and female group, and the knees of each group were divided into 2 subgroups (the left group and right group). MRI scan of the left and right knees was performed, and the 2D images of MRI were imported into Mimics10.01 medical image control system for 3D reconstruction. The related anatomical data as follows were measured from the 3D digital model and analyzed by statistical software: notch width (NW), condylar width (CW), and notch width index (NWI). Then the 3D knee images of patients with anterior cruciate ligament (ACL) injury were collected between January and March 2010, and 4 patients with narrow intercondylar notch (NWI≤0.2) were selected for reconstructing the 3D model of the knee and simulating the intercondylar notch plasty. Then, the volume of osteotomy in 3D model was calculated and applied in the ACL reconstruction surgery, and whether the graft had impingement with intercondylar notch or not was evaluated. Results There were significant differences in NW and CW between male group and female group (P≤lt;≤0.05), but no significant difference was found in the NWI (P≤gt;≤0.05). And there was no significant difference in NW, CW, and NWI between the left and right knees both in male group and female group (P≤gt;≤0.05). After ACL reconstruction and intercondylar notchplasty, the shape of intercondylar notch became normal (NWI≤gt;≤0.22), no impingement occurred between the graft and intercondylar notch under arthroscopy within 3-month follow-up. Conclusion The shape of intercondylar notch of 3D model based on MRI 2D images is similar to the real intercondylar notch. NWI is one of important indexes which can reflect the narrow level of intercondylar notch. The virtual intercondylar notchplasty may provide preoperative plan and guidence for ACL reconstruction operation to avoid the impingement between graft and intercondylar notch after surgery.
Objective To investigate the influence on matrix metalloproteinases (MMP) 3, 9, and 13 levels of human articular cartilage cells after blocking stromal cell derived factor 1 (SDF-1)/ chemokine receptor 4 (CXCR4) signaling pathway withAMD3100 and to define the function mechanism of AMD3100. Methods A total of 144 cartilage blocks from 12 osteoarthritis (OA) patients undergoing total knee arthroplasty (OA cartilage group) and 144 normal cartilage blocks (Mankin score of 0 or 1) from 12 patients undergoing traumatic amputation (normal cartilage group). OA cartilage group was further divided into subgroups A1, B1, and C1, and normal cartilage group into subgroups A2, B2, and C2. The cartilage tissues were cultured in DMEM solution containing 100 ng/mL SDF-1 and 1 000 nmol/L AMD3100 in subgroup A, 100 ng/mL SDF-1 and 1 000 nmol/L MAB310 in subgroup B, and 100 ng/mL SDF-1 in subgroup C, respectively. The levels of MMP-3, 9, and 13 were measured by ELISA; the expressions of MMP-3, 9, and 13mRNA were tested by RT-PCR. Results ELISA and RT-PCR results showed that the levels of MMP-3, 9, and 13 and the expressions of MMP-3, 9, and 13 mRNA were significantly lower in subgroup A than in subgroups B and C at the same time points (P lt; 0.05); the levels of MMP-3, 9, and 13 and the expressions of MMP-3, 9, and 13 mRNA were significantly higher in OA cartilage group than in normal cartilage group at the same time points (P lt; 0.05). Conclusion SDF-1 could induce overexpression and release of MMP-3, 9, and 13 in the articular cartilage through the SDF-1/CXCR4 signaling pathway; AMD3100 could reduce the mRNA expressions and secretion of MMP-3, 9, and 13 in OA cartilage by blocking the SDF-1/CXCR4 signaling pathway; but AMD3100 could not make the secretion of MMP-3, 9, and 13 return to normal levels in OA cartilage.
Objective To discuss the authenticity of reconstructing the anterior cruciate l igament (ACL) threedimensional digital model of normal adult knee joint by use of MRI. Methods The double knee joint specimens were selected from 20 fresh normal adult corpses and double knee joint of 20 normal adult volunteers, and were scanned with MRI; continuous image data of level thick 1.0 mm were acquired, and then these data were imported into Mimics 10.01 software for three-dimensional reconstruction; and full three-dimensional digital models were built, including the corpse specimens (corpsemodel group) and normal adult (normal model group). The relevance anatomy index of ACL were measured with easuring tool of Mimics 10.01 software, and double knee joint specimens of 20 fresh normal adult corpses were dissected, and the relevance data were measured (corpse specimens group). Results There was no significant difference in all indexes between corpse model group and corpse specimen group (P gt; 0.05), and between corpse model group and normal model group (P gt; 0.05). Conclusion The image data gathered by MRI could reconstruct the ACL three-dimensional digital model of normal adult knee joint, which has authenticity.