Objective To study the time effect of the gene expression of recombinant adeno-associated virus (rAAV) vector co-expressing human vascular endothel ial growth factor 165 (hVEGF165) and human bone morphogenetic protein 7 (hBMP-7) genes so as to lay a theoretical foundation for gene therapy of osteonecrosis. Methods The best multipl icity of infection (MOI) of BMSCs transfected with rAAV was detected by fluorescent cell counting. The 3rd generation rabbit bone mesenchymal stem cells (BMSCs) were transfected with rAAV-hVEGF165-internal ribosome entry site (IRES)-hBMP-7 (experimental group) and green fluorescent protein (GFP) labeled rAAV-IRES-GFP (control group), respectively. The expression of GFP was observed by inverted fluorescent microscope. The expressions of hVEGF165 and hBMP-7 were assessed by RT-PCR assay and Western blot assay in vitro. The transfected cells in 2 groups were prepared into suspension with 5 × 106 cells/mL, and injected into the rabbit thigh muscles of experimental group 1 (n=9) and control group 1 (n=9), respectively. The muscle injected with rAAV-IRES-GFP was sl iced by frozen section method and the expression of GFP protein was observed by inverted fluorescent microscope. The expressions of hVEGF165 and hBMP-7 were assessed by Western blot assay and ELISA assay in vivo. Results The best MOI of BMSCs transfected with rAAV was 5 × 104 v.g/cell. In vitro, the expressions of GFP, hVEGF165, and hBMP-7 genes started at 1 day after transfection, the expressions obviously increased at 14 days after transfection, and the expression maintained the b level at 28 days after transfection. In vivo, the expressions of GFP, hVEGF165, and hBMP-7 genes could be detected at 2 weeks after injection, and b expressions were shown at 6 to 8 weeks after injection. The values of hVEGF165 and hBMP-7 were (248.67 ± 75.58) pg/mL and (4.80 ± 0.61) ng/mL respectively in experimental group 1, and were (32.28 ± 8.42) pg/mL and (0.64 ± 0.42) ng/mL respectively in control group 1; showing significant differences between 2 groups (P lt; 0.05). Conclusion The rAAV-hVEGF165-IRES-hBMP-7 has efficient gene expression ability.
Objective To investigate the expression levels of osteoprotegerin (OPG) and receptor activator of NF-κB l igand (RANKL) mRNAs in bone tissues of the femoral head of the patients suffering glucocorticoid-induced osteonecrosisof the femoral head (ONFH), and to discuss the relationship between OPG/RANKL and ONFH. Methods Between March2007 and March 2008, bone tissues of the femoral head were collected as the experimental material from 35 patients suffering ONFH (experimental group) and from 21 patients suffering fracture of femoral neck (control group). The ratio of men to women in both groups was 4 ∶ 3, whose age was 41-70 years old (55.34 on average in the experimental group and 55.33 on average in the control group). The experimental group received over 3 weeks’ glucocorticoid treatment or more than 1 week’ s high-dose glucocorticoid treatment in recent 2 years, while the control group never received more than 1 week’s hormone treatment. In the two groups, the microstructure of bone tissues of the femoral head was detected by HE staining and the bone tissue total RNA was extracted, and then the expression levels of OPG mRNA and RANKL mRNA were examined by realtime quantitative PCR (RTQ-PCR) for each sample. Results HE staining: bone trabeculae and bone units were replaced by interrupted bone fragments, which were surrounded by many inflammatory granulation tissues and few osteocytes were seen in bone lacunae in the experimental group. In the control group, bone trabeculae and bone units were made by complete lamellar bones which surrounded blood vessels and osteocytes were seen in lacunae. RTQ-PCR testing: in the experimental group, OPG mRNA and RANKL mRNA were 1.35 ± 0.42 and 4.36 ± 1.35, respectively, while in the control group they were 1.78 ± 0.63 and 3.49 ± 1.02, respectively. The expression level of OPG mRNA in the experimental group was significantly lower than that in the control group, and the expression level of RANKL mRNA of the former was significantly higher than the latter. The OPG mRNA/ RANKL mRNA ratio in the xperiment group (0.34 ± 0.16) was significantly lower than that in the control group (0.54 ± 0.20), and there was significant difference (P lt; 0.05). Conclusion The glucocorticoid-induced ONFH may be related to the expression levels of OPG mRNA/RANKL mRNA in bone tissues.
Objective To explore the significance of osteocyte apoptosis in steroidinduced osteonecrosis of the femoral head. Methods SixtyNew Zealand rabbits were divided into experimental group and control group(n=30). The experimental group was given 10 ml/kg of horse serum intravenously 2 times at 2 weeks intervals and an intraperitoneal injection of 45 ml/kg·d of methylprednisolone acetate for 3 days；the control group was given equal isotonic Na chloride. Osteocyteapoptosis was observe by means of TUNEL. Results The number of apoptosis in the experimental group(112.33‰±26.12‰) was significantly higher than that in the control(47.01‰±22.95‰) (Plt;0.01)in the 4th week. With time, osteocytes apoptosis progressively increased. In the 6thand 8th weeks, the percentage of empty osteocyte lacunae in the experimental group (17.23%±3.44%, 28.56%±3.45%) was significantly higher than that in the control group (11.29%±2.89%,11.26%±2.75%，Ｐlt;0.05). The transmission electron microscope showed that the characteristics of osteocyte apoptosisincluded intact nuclear membrane,comdensed chromatin and increased electron dense. Conclusion Osteocytes apoptosis may play a key role in the process of steroidinduced early osteonecrosis of the femoral head.
Objective To compare the clinical effect of reamed and nonreamed intramedullary interlocking nails on treating open tibial fractures. Methods From February 2002 to February 2004, 92 cases of open tibial fractures (86 patients) were treated with intramedullary interlocking nails. Of the 86 patients, 65 were male and 21 were female. Their age ranged from 18 to 68 years (36.5 on average). Of the 92 cases, 54 were in the reamed group and 38 in the nonreamed group. Patients moved with the support of crutch after their wounds were healed. Results All patients were followed up regularly for 6 to 24months. Infection rate in the reamed group and nonreamed group was 20.3% and 5.3% respectively, and there was significant difference between them (Ｐlt;0.05). The averagehealing time of the fractures was 22.5 weeks in reamed group and 19 weeks in nonreamed group, and there was no significant difference between them (Ｐ＞0.05). Delayed unions occurred in 8 cases and 3 cases in reamed group and nonreamed group respectively. Conclusion Compared with reamed group, nonreamed intramedullary interlocking nails have lowerinfection rate and fewer delayed unions and ununions.
Objective To investigate the effect difference between the Solis fixation fusion and the titanium plate fixation by the cervical anterior approach after decompression and bone graft implantation. Methods Of the 104 patients with cervical disease from September 2001 to March 2004, 36 were treated with the Solis implantation after decompression by the cervical anterior approach, and 68 were treated with the titanium plate fixation after decompression and bone graft implantation. The recovery of the neurological function in all the patients were assessed with the JOA Scoring at 6 weeks,3,6,12,24 and 36 months. The fragment fusion and its stability as well as the changes in the intervertebral height were assessed with X-ray examination. Results According to the JOA Scoring, the excellent and good outcomes accounted for 94.4% in the Solis group and 94.1% in the titanium plate group. In allthe patients, the fragment fusion was achieved in 3 months. The change in the Cobb angle of the fused fragment was less than 5° at the flexionextension posture, 3.6±0.8° in the Solis group, 2.4±0.7° in the titanium plate group. There was significant differences between the two groups(P＜0.05). The intervertebral height of the operation fragment in the Solis group increased 1.6±0.7mm, which was higher than that in the titanium plate group(P＜0.05). Conclusion Clinical effects of the two internalfixation operations are good; however, the Solis fixation has more advantages because of its simpler performance,less trauma, and fewer complications.
Objective To determine whether the number of distal locking bolts have an impact on the biomechanical feature of locking intramedullary nails. Methods Twenty locking nails tested were divided into two groups randomly. One distal locking screw was used in first group (single bolt group); and two were used in the other group (double bolts group). After being fixed in the model, compressive and torsional strength of the interlocking nail were measured in each group. Results The average maximum strength of double bolts group and single bolt group was 2 160 N and 1 880 N respectively in compression tests(P＜0.05). In torsion tests, the average maximum torsional moment of double bolts group and single bolt group was 55.8 Nm and 55.5 Nm respectively(P＞0.05), the average maximum torsional angle indouble bolts group and single bolt group was 58.3° and 58.0° respectively(P＞0.05). Conclusion Single distal bolt used in interlocking nail system can meet clinical request, though the whole biomechanical behavior isnot better than that of double bolts. One distal bolt is enough for the stable fracture types and double bolts should be used in the serious fracture types.
Objective To study the effect of olfactory ensheathingcells(OECs) transplantation on protecting spinal cord and neurons after peripheral nerve injury. Methods Fifty-five SD rats were randomly divided into blank group (n=5), experimental group (n=25) and control group (n=25). The right sciatic nerves of all the rats were transected. The proximal end was embedded in muscle and treated with OECs (experimental group) and DMEM (control group). No treatment was given to the blank group. The rats were sacrificed 1, 2, 3, 7, and 14 days after the transplantation, the related neurons were observed with histological and TUNEL methods. Results After sciatic nerves were transected, death of neurons occurred in spinal cord and ganglion. One, 2, 3 days after treatment, the neuron survival rate in experimental group was 98.4％±6.5%，97.6％±6.5%，95.2％±6.7% respectively. The neuron survival rate in control group was 97.8％±6.7%，97.4％±6.4%，94.3％±6.8% 1, 2, and 3 days after treatment respectively. There was no significant difference between experimental group and control group. Seven and 14 days after treatment, the neuron survival rate in experimental group was 92.4％±8.9%，87.7％±9.4% respectively. The neuron survival rate in control group was 87.4％±8.6%，83.4％±8.5% 7 and 14 days after treatment respectively. There was significant difference between experimental group and control group. On 1st and 2nd day, no apoptosis was seen in spinal cord anterior horn of the rats in both experimental group and control group. On 3rd, 7th, and 14th day, the apoptosis index of spinal cord anterior horn motoneuron in experimental rats were lower（1.2±0.8，1.4±0.6，4.1±1.3） than that in the control group（2.1±1.1，3.1±1.1，6.1±1.8）（Plt;0.05）. One, 2, and 3 days after the operation, no ganglion neurons apoptosis was observed in all rats. On 7th day the apoptosis index of ganglion neurons in experimental group（2.10±0.32）were lower than thatin control group （4.40±0.56）（Plt;0.05）. On 14th day there was no significant difference in the apoptosis index of ganglion neurons between experimental group （4.30±1.80）and control group（6.70±2.50）(P＜0.05). Conclusion Apoptosis of neurons occur after peripheral nerve injury in spinal cord and ganglion. OECs transplantation is effective in preventing apoptosis.
BJECTIVE: To discuss the clinical effect and the application of AF device fixation system and PROSPACE interbody fusion cage on treating lumbar spondylolisthesis. METHODS: Twenty-one cases of lumbar spondylolisthesis treated by operation from 1999 to 2002 were analyzed retrospectively (13 males and 8 females, 25-66 years old averaging 42 years). We had thorough decompression on the part of nerve compression and had replacement and fixation of the slippage vertebral body with the AF transpedicular screw/rod system so that the normal spine physiological curvature could be recovered, and then performed the posterolateral interbody fusion with implanting the PROSPACE filled with autograft bones. RESULTS: All the patients were followed up for 3 months to 3 years with an average of 15 months. The preoperation symptoms improved in 20 cases (95.2%). CONCLUSION: The combination of AF device fixation system and PROSPACE interbody fusion cage can relieve effectively nerve compression, recover the normal spinal physiological curvature, maintain the height of interbody and promote the nerve fusion. It is reliable and effective in the treatment of spondylolisthesis.
Objective To compare and evaluate the capability of pure autogenous bone and the enhanced autogenous bone combined with bone morphogenetic protein in bone repair of femoral head. Methods Eighteen femoral heads of 9 dogs weredrilled by trephine, 4 mm in diameter, followed by respective implantations of autogenous bone grafting (group B) and of the enhanced autogenous bone composite, combined with bone morphogenetic protein (group C), with the selfrepair of bone defect as the control (group A). Three, six, nine weeks after the operation, radiological examination, computerized tomography, light and electronic microscopes were performed to investigate the bone healing of the defect in the femoral head. Results In group A, it could be observed that there washematoma organization and delayed woven bone formation in the 3rd week after operation, and therewas little replacement of woven bone by bone trabecula in the 9th week; in group B, the autogenous bone implanted were dead in the 3rd week and maintained in situ in the 9th week; in group C, active new bone formation, either endochondral or intramembranous ossification, was found in the 3rd week and entire repair of the bone defect by bone trabecula in the 9th week after operation. Conclusion The enhanced autogenous bone combined with bone morphogenetic protein could promote reconstruction of the bone defect in femoral head, superior to pure autogenous bone which could provide a framework for the new bone formation.
Objective To compare the difference in the inclination and anteversion angles of the acetabular cup measured by intraoperative robot-assisted total hip arthroplasty (THA) and postoperative X-ray films and CT imaging. MethodsThe clinical data of 54 patients (54 hips) who underwent robot-assisted THA between May 2020 and December 2020 were retrospectively analyzed. Among them, there were 26 males (26 hips) and 28 females (28 hips), with an average age of 58.4 years (range, 39-71 years). The body mass index was 19.2-29.3 kg/m2, with an average of 25.2 kg/m2. All the patients had their first THA, including 31 cases of osteonecrosis of the femoral head, 12 cases of hip arthritis, 8 cases of femoral neck fracture, and 3 cases of developmental dysplasia of the hip. The anteversion and inclination angles of the acetabular cup were obtained through the surgical data in the robot host system. All patients underwent X-ray and CT scan examination within 2-7 days after operation to obtain the postoperative anteversion and inclination angles of the acetabular cup. According to the concept of “Lewinnek safe zone”, the proportion of acetabular in the safe zone intra- and post-operation were compared. ResultsThe operation time was 57.8-89.2 minutes, with an average of 68.3 minutes; the intraoperative blood loss was 125.0-450.0 mL, with an average of 204.8 mL. No adverse events such as dislocation of hip joint and infection occurred during hospitalization. The anteversion angle of acetabular cup was (40.8±0.6)° during operation and (41.2±2.8)° after operation, with no significant difference (t=1.026, P=0.307). The anteversion angle of acetabular cup measured during operation was (17.6±1.4)°, which was significantly smaller than that measured after operation (23.4±3.8)°(t=10.520, P=0.000). According to “Lewinnek safe zone”, 54 hips (100%) were in the safety zone during operation, and 16 hips were out of the safety zone, 38 hips were in the safty zone after operation, the ratio of the hips in the safty zone was 70.4%, showing a significant difference (χ2=18.783, P=0.000). ConclusionRobot-assisted THA can obtain accurate placement of the acetabular cup, but there is a large deviation between the anteversion angle of the acetabular cup in the lateral position during operation and the supine position after operation. Further study is needed to define the intraoperative placement position of the acetabular cup.