Objective To find a new culture system to induce proliferation and osteodifferentiation of marrow stromal cells (MSCs) in vitro for bone tissueeng ineering． Methods There were four groups in this experiment to study effects of Passage 3 osteoblasts derived from the rat cranium and the osteogenic inductor (1 nmol/L dexamethasone，10 mmol/L beta-glycero-phosphate，50 μg/ml retin oic acid) on growth of MSCs isolated from the rat femur and the tibia． MSCs were cultured in the DMEM medium (the c ontrol group) and in the osteoinductive culture medium (the inductor group)；fur thermore, MSCs were co-cultured with the osteoblasts in the DMEM medium (the osteoblast group) and in the osteoinductive culture medium (the combined treatment group)．The cells in the four groups were counted every 2 days for 8 days and alkaline phosphatase (ALP) activity of MSCs at 10 days of cultivation was measured．The MRNA expression of osteocalcin (OC) of MSCs at 2 weeks was assayed with the reverse transcript polymase chain reaction (RT-PCR)． Results There were more cells in the osteoblast group than in the control group(31.73±3.31×104 V S. 24.33±3.04×104, Plt;0.05), but there were fewer cells in the inductor gro up(16.23±2.44×104, Plt;0.05). There was no significant difference in th e cell number between the combined treatment group (21.54±2.29×104) and th e control group（Pgt;0.05）．The ALP activity was higher in the combined trea tment group （2.01±0.56 U）than in the control group (1.27±0.43 U), in the inductor group（1.27±0.43 U）, and in the osteoblast group （0.77±0.19 U）.The osteocalcin mRNA was expressed in the three treat ment groups but was not expressed in the control group. The significantly higher leve l of the osteocalcin mRNA was expressed in the inductor group（0.783±0.094）and in the combined treatment group（0.814±0.071）than in the osteoblast group（0.302±0.026） (Plt;0.05). Conclusion The combined use of t he osteoblast and the inductor can induce marrow stromal cells. Their combined u se does not affect the normal proliferation but can obviously promote the osteodifferentiation of marrow stromal cells. This combined use can become a new culture system of the seed cells for bone tissue engineering．
Objective To review the influencing factors of medial patellofemoral ligament (MPFL) reconstruction for patellar dislocation. Methods The literature of MPFL reconstruction for patellar dislocation at home and abroad in recent years were summarized and analyzed. Results The influencing factors such as the location of the femoral insertion point, the tension and the fixed angle of the grafts, the dysplasia of the femoral trochlear before operation, the abnormal tuberositas tibiae-trochlear groove value, the high position of the patellar, and the tilting angle of the patellar, are all the factors affecting the effectiveness of MPLF reconstruction. Conclusion During MPFL reconstruction, the surgical techniques and elimination of other factors that caused patellar instability need to be focused in order to reduce the complications and operation failure.
Objective To summarize the molecular biological research progress of non-coding RNAs modulating osteoarthritis (OA), and provide a reference basis for biological study and clinical treatment of OA. Methods Recent domestic and foreign related literature about the regulation of OA pathological process by non-coding RNAs was widely reviewed. Results Non-coding RNAs can be divided into three types based on the length of RNA. A lot of non-coding RNAs participating in OA pathological process are screened out by high throughput sequencing technology and microarray technology, and it is verified that these non-coding RNAs involve in the regulation of OA by RT-PCR. The mechanism of OA mediated target is clarified by knocking-down and overexpressing of the most prominent expressed non-coding RNAs in OA. There are the complicated gene expressed network topology in non-coding RNAs, and between non-coding RNAs and coding RNAs. It provides a basis for clearing the effect of gene structure and function, and finding the definite therapeutic target of OA. Conclusion There is preliminary study on molecular biological mechanism of non-coding RNAs mediating OA, but the key structure or sequence of non-coding RNAs, formation and interaction of effecting composite structure about mediating OA are unknown, and it needs further study.
ObjectiveTo investigate the heterotopic osteogenesis of tissue engineered bone using the co-culture system of vascular endothelial cells (VECs) and adipose-derived stem cells (ADSCs) as seed cells.MethodsThe partially deproteinized biological bone (PDPBB) was prepared by fibronectin combined with partially deproteinized bone (PDPB). The ADSCs of 18-week-old Sprague Dawley (SD) rats and VECs of cord blood of full-term pregnant SD rats were isolated and cultured. Three kinds of tissue engineered bone were constructed in vitro: PDPBB+VECs (group A), PDPBB+ADSCs (group B), PDPBB+co-cultured cells (VECs∶ADSCs was 1∶1, group C), and PDPBB was used as control group (group D). Scanning electron microscopy was performed at 10 days after cell transplantation to observe cell adhesion on scaffolds. Forty-eight 18-week-old SD rats were randomly divided into groups A, B, C, and D, with 12 rats in each group. Four kinds of scaffolds, A, B, C, and D, were implanted into the femoral muscle bags of rats in corresponding groups. The animals were killed at 2, 4, 8, and 12 weeks after operation for gross observation, HE staining and Masson staining histological observation, and the amount of bone collagen was measured quantitatively by Masson staining section.ResultsScanning electron microscopy showed that the pores were interconnected in PDPB materials, and a large number of lamellar protein crystals on the surface of PDPBB modified by fibronection were loosely attached to the surface of the scaffold. After 10 days of co-culture PDPBB and cells, a large number of cells attached to PDPBB and piled up with each other to form cell clusters in group C. Polygonal cells and spindle cells were mixed and distributed, and some cells grew along bone trabeculae to form cell layers. Gross observation showed that the granulation tissue began to grow into the material pore at 2 weeks after operation. In group C, a large number of white cartilage-like substances were gradually produced on the surface of the material after 4 weeks, and the surface of the material was uneven. At 12 weeks, the amount of blood vessels on the surface of group A increased, and the material showed consolidation; there was a little white cartilage-like material on the surface of group B, but the pore size of the material did not decrease significantly; in group D, the pore size of the material did not decrease significantly. Histological observation showed that there was no significant difference in the amount of bone collagen between groups at 2 weeks after operation (F=2.551, P=0.088); at 4, 8, and 12 weeks after operation, the amount of bone collagen in group C was significantly higher than that in other 3 groups, and that in group B was higher than that in group D (P<0.05); there was no significant difference between group A and groups B, D (P>0.05).ConclusionThe ability of heterotopic osteogenesis of tissue engineered bone constructed by co-culture VECs and ADSCs was the strongest.
Objective To establish a three-dimensional finite element analysis model of the knee joint in fresh frozen cadavers, to verify the validity of the model and to simulate the stress distribution characteristics of the patellofemoral joint after combined proximal and distal knee extension rearrangement surgery for recurrent patellar dislocation. Methods One male and one female fresh frozen cadavers (4 knees in total), using voluntary body donations, were used to measure the maximum pressure on the patellofemoral articular surface at each passive flexion angle (0°, 30°, 60°, 90°, 120°) of the normal knee joint and the model after combined proximal and distal knee extension rearrangement surgery for recurrent patellar dislocation with tibial tuberosity-trochlear groove distance (TT-TG) value >2.00 cm using pressure-sensitive paper, respectively. Then, the 2 freshly frozen cadavers were used to construct three-dimensional finite element models of normal knee joints and postoperative knee joints, and the maximum pressure on the patellofemoral articular surface was measured at various passive flexion angles. The maximum pressure was compared with the measurement results of the pressure-sensitive paper to verify the validity of the three-dimensional finite element model. In addition, the maximum pressure on the patellofemoral joint surface measured by three-dimensional finite element was compared between the normal knee joint and the postoperative knee joint at various passive flexion angles, so as to obtain an effective three-dimensional finite element model for the simulation study of the stress distribution characteristics of the patellofemoral joint after combined proximal and distal knee extension rearrangement surgery for recurrent patellar dislocation. ResultsThe maximum pressure on the patellofemoral joint surface measured by pressure-sensitive paper and three-dimensional finite element measurements were similar at all passive flexion angles in the normal knee joint, with a difference of −0.08-0.06 MPa; the maximum pressure on the patellofemoral joint surface measured by pressure-sensitive paper and three-dimensional finite element measurements were also similar at all passive flexion angles in the knee after combined proximal and distal knee extension rearrangement surgery, with a difference of −0.04-0.09 MPa. The maximum pressure on the patellofemoral joint surface measured by three-dimensional finite elements were also similar between the normal knee joint and the knee joint after combined proximal and distal knee extension rearrangement surgery at all passive flexion angles, with a difference of −0.50-−0.03 MPa. ConclusionThe three-dimensional finite element model of the normal knee joint and the knee joint after combined proximal and distal knee extension rearrangement surgery can accurately and effectively quantify the change in the maximum pressure on the patellofemoral joint surface; for recurrent patellar dislocations with TT-TG value>2.00 cm, the combined proximal and distal knee extension rearrangement surgery can achieve a maximum pressure of the patellofemoral joint surface similar to that of the normal knee joint.
ObjectiveTo investigate the short-term effectiveness of total knee arthroplasty (TKA) assisted by three-dimensional (3D) printing osteotomy navigation template.MethodsA retrospective study was performed on 60 patients with osteoarthritis bewteen January 2016 and June 2017. Thirty cases underwent TKA assisted by 3D printing osteotomy navigation template (3D printing group) and 30 cases underwent the conventional TKA (conventional TKA group). There was no significant difference in gender, age, body mass index, surgical side, and disease duration between 2 groups (P>0.05). The operation time, the pre- and post-operative hemoglobin values, the amount of drainage, the Hospital for Special Surgery (HSS) score and Knee Society Score (KSS) of knee joint before operation and at 3 months after operation were observed. And 6 freedom degrees of knee (the varus and valgus angle, the internal and external rotation angle, the antero-posterior displacement, the proximal-distal displacement, the flexion and extension angle, and the internal and external displacement) before operation and at 3 months after operation were recorded by Opti-Knee (the knee 3D motion analysis system). The values of 2 groups were compared with 30 healthy adults (<60 years).ResultsThe operation time was shorter in 3D printing group than that in conventional TKA group (t=5.833, P=0.000). The hemoglobin values at 1 and 3 days after operation were higher in 3D printing group than those in conventional TKA group (P<0.05). The amount of drainage was less in 3D printing group than that in conventional TKA group (t=5.468, P=0.000). All patients were followed up 6-9 months (mean, 7.3 months). There was no significant difference in pre- and post-operative HSS score and KSS clinical score between 2 groups (P>0.05). There was no significant difference in preoperative KSS function score between 2 groups (P>0.05), but the KSS function score of 3D printing group at 3 months after operation was higher than that of conventional TKA group (P<0.05). Before operation, the varus and valgus angle, the internal and external rotation angle, the antero-posterior displacement, the proximal-distal displacement of 3D printing group and conventional TKA group were larger than that of the healthy adults (P<0.05); there was no significant difference in the flexion and extension angle and the internal and external displacement between 2 groups and healthy adults (P>0.05). At 3 months after operation, compared with healthy adults, the varus and valgus angle of conventional TKA group was increased, the flexion and extension angle of conventional TKA group was decreased (P<0.05); the proximal-distal displacement and the internal and external displacement of 2 groups were decreased (P<0.05); there was no significant difference in other freedom degrees between groups (P>0.05). No sign of prosthesis loosening was observed by X-ray examination.ConclusionCompared with the traditional TKA, TKA assisted by the 3D printing osteotomy navigation template had such advantages as shorter operation time, less postoperative blood loss, and well postoperative recovery.
Objective To explore the mid-term effectiveness of combined knee extensor mechanism realignment with bone anchor for recurrent patella dislocation. Methods Between August 2017 and May 2019, 21 patients with recurrent patella dislocation underwent combined knee extensor mechanism realigament with bone anchor and followed up more than 3 years. There were 8 males and 13 females with an average age of 19.4 years (range, 13-26 years). All 21 patients had a history of recurrent patellar dislocation for 2-5 times (median, 3 times), and the disease duration was 1-16 years (mean, 5 years). The preoperative Lysholm score was 67.5±6.3 and the Kujula score was 64.1±7.0. The defect of meniscus, anterior and posterior cruciate ligaments, and medial and lateral collateral ligaments were excluded by MRI examination; CT examination showed that the tibial tuberosity-trochlear groove distance was 2.05-2.56 cm, with an average of 2.16 cm; X-ray examination showed that lower limb force line was abnormal. The effectiveness were evaluated by Lysholm score and Kujula score before operation and at 3 years after operation, and Insall evaluation standard at 3 years after operation. Results All the incisions healed by first intention, and there was no surgical complication such as lower extremity deep vein thrombosis, incision infection, and nerve injury. All 21 patients were followed up 3.0-3.5 years, with an average of 3.2 years. Anteroposterior and lateral X-ray films of the knee joint at 3 years after operation showed that the position of the patella was normal, and the axial X-ray films of the patella (30°, 60°, 90°) showed that the patellofemoral joint had a good relationship. During the follow-up, there was no anchor drop or fracture, no obvious pseudarthrosis formation, and no epiphyseal injury in the minor patients. The Lysholm score was 91.5±7.1 and the Kujula score was 88.1±7.6 at 3 years after operation, which were significantly improved when compared with those before operation (t=11.57, P=0.00; t=12.78, P=0.00). According to the Insall evaluation criteria, 12 cases were excellent, 4 cases were good, 4 cases were fair, and 1 case was poor, with an excellent and good rate of 76.2%. ConclusionCombined knee extensor mechanism realignment with bone anchor is a simple and reliable way to treat the recurrent patella dislocation, with a satisfactory mid-term effectiveness and less complications; however, its long-term effectiveness needs further follow-up.