Objective To explore the osteogenic potential of cervical intervertebral disc fibroblasts in vitro, to investigate the regulatory factors of recombinant human bone morphogenetic protein 2(rhBMP-2) and tumor necrosis factor α(TNF-α) on osteogenic phenotype of fibroblasts and to discuss the condition that facilitates osteogenesis of fibroblasts. Methods Theannulus fibroblasts cell lines of experiment goats were established in vitro and the biologicspecificity was found. According to different medias, 4 groups were included in this experiment: control group, TNF-α group ( 50 U/ml TNF-α), rhBMP-2 group (0.1 μg/ml rhBMP-2) and TNF-α+rhBMP-2 group (50 U/ml TNF-α+0.1 μg/ml rhBMP-2). Thefibroblasts were incubated in the media for about 3 weeks,and then the markers for osteogenic features were investigated by biochemistry, histochemistry observations. Results rhBMP-2 and TNF-α had no effect on the proliferation of fibroblasts from the experiment goats. rhBMP-2 or TNF-α could stimulate fibroblasts to secrete alkaline phosphatase and collagen type Ⅰ. The combined use of rhBMP-2 and TNF-α or the single use of rhBMP-2 could make fibroblasts to secrete osteocalin and the morphological changes of the fibroblasts were very obvious. Histochemical study of the nodules with specific new bone labeler(Alizarin red S) revealed positive reaction, denoting that the nodules produced by the fibroblasts werebone tissues. There was statistically significant difference(Plt;0.05) inALP activity between 3 experimental groups and control group and in secretion of osteocalcin between rhBMP-2 group, TNF-α+rhBMP-2 group and control group. Conclusion The results point out clearly that rhBMP-2 can induce theosteogenic potential of annulus fibroblasts in vitro.
The lumbar intervertebral disc exhibits a complex physiological structure with interactions between various segments, and its components are extremely complex. The material properties of different components in the lumbar intervertebral disc, especially the water content (undergoing dynamic change as influenced by age, degeneration, mechanical loading, and proteoglycan content) - critically determine its mechanical properties. When the lumbar intervertebral disc is under continuous pressure, water seeps out, and after the pressure is removed, water re-infiltrates. This dynamic fluid exchange process directly affects the mechanical properties of the lumbar intervertebral disc, while previous isotropic modeling methods have been unable to accurately reflect such solid-liquid phase behaviors. To explore the load-bearing mechanism of the lumbar intervertebral disc and establish a more realistic mechanical model of the lumbar intervertebral disc, this study developed a solid-liquid biphasic, fiber-reinforced finite element model. This model was used to simulate the four movements of the human lumbar spine in daily life, namely flexion, extension, axial rotation, and lateral bending. The fluid pressure, effective solid stress, and liquid pressure-bearing ratio of the annulus fibrosus and nucleus pulposus of different lumbar intervertebral discs were compared and analyzed under the movements. Under all the movements, the fluid pressure distribution was closer to the nucleus pulposus, while the effective solid stress distribution was more concentrated in the outer annulus fibrosus. In terms of fluid pressure, the maximum fluid pressure of the lumbar intervertebral disc during lateral bending was 1.95 MPa, significantly higher than the maximum fluid pressure under other movements. Meanwhile, the maximum effective solid stress of the lumbar intervertebral disc during flexion was 2.43 MPa, markedly higher than the maximum effective solid stress under other movements. Overall, the liquid pressure-bearing ratio under axial rotation was smaller than that under other movements. Based on the solid-liquid biphasic modeling method, this study more accurately revealed the dominant role of the liquid phase in the daily load-bearing process of the lumbar intervertebral disc and the solid-phase mechanical mechanism of the annulus fibrosus load-bearing, and more effectively predicted the solid-liquid phase co-load-bearing mechanism of the lumbar intervertebral disc in daily life.
Degenerative disc disease is a prevalent chronic disease that orthopaedic surgeons currently face as a difficulty. Tissue engineering represents the most promising possible therapeutic strategy for disc repair and regeneration. Surgery is the primary treatment for degenerative disc disease, but there are still inherent limits in practical practice. Electrospinning technique is a method for manufacturing nanoscale fibers with varied mechanical properties, porosity, and orientation, which can imitate the structural qualities and mechanical properties of natural intervertebral discs. Therefore, electrospinning materials can be utilized for disc regeneration and replacement. This article reviews recent advancements in disc tissue engineering and electrostatically spun nanomaterials typically utilized for the fabrication of disc scaffolds, as well as present and future techniques that may enhance the performance of electrostatically spun fibers.
OBJECTIVE To observe the effects of sodium hyaluronate on nerve root adhesion after operation of lumbar disc protrusion (LDP). METHODS From April 1996 to June 2001, 152 cases with LDP were performed the removal of nucleus pulposus under endoscope. After operation, 2 ml of sodium hyaluronate were injected. The clinical results were evaluated by clinical symptom, straight leg raising test, patient’s satisfaction degree and back pain. RESULTS All the patients were followed for 1 month to 3 years. The average angle of straight leg raising test increased from 26 degree preoperatively to 62 degree postoperatively. The patient’s pain were markedly relieved. Patient’s satisfactory degree were 86.8%. CONCLUSION The injection of sodium hyaluronate after operation of LDP has effect on preventing postoperative nerve root adhesion.
Objective To evaluate the cl inical results of posterior microendoscopic foraminotomy in the treament of cervical radiculopathy and cervical intervertebral disc protrusion. Methods From February 2004 to June 2007, 24 cases of cervical radiculopathy received posterior microendoscopic foraminotomy. There were 16 males and 8 females, aging 42-68 years (59 years on average), including 16 cases of cervical radiculopathy and 8 cases of cervical intervertebral disc protrusion.The course of disease was 6-15 months. The affected intervertebral discs were C4, 5 in 8 cases, C5, 6 in 12 cases, and C6, 7 in 4 cases. The radiological examinations showed that 8 protrusions included 6 soft tissue protusions and 2 rigid tissue protusions, and that cervical radiculopathy were caused by yellow l igament hypertrophy, Luschka’s joint hyperplasia, and abnormal position of facet joint. According to Japanese Orthopedic Association (JOA), the score before operation was (12.60 ± 1.52) points. Results The operation time was 90 to 120 minutes (100 minutes on average), the bleeding during operation was 100 to 150 mL (120 mL on average). Nerve root pain were rel ieved completely in 19 cases and were rel ieved partly in 4 cases. One case of calcified nucleus pulposus had neurological traction injury and recovered completely after 3 months. All cases were followed up 24-36 months (28 months on average). The radiological examinations after operation showed the intervertebral disc site was decompressed completely and the height of intervertebral disc and the cervical segmental al ignment were normal. At 24 months postoperatively, the JOA score was (16.10 ± 0.29) points, showing significant difference when compared with that of preoperation (P lt; 0.01). Conclusion The posterior microendoscopic foraminotomy can get to the operation site with miniincision, decrease tissue damage during operation, and avoid narrow intervertebral space, so it has satisfactory cl inical results.
Objective To investigate the feasibility oftissue engineered intervertebral disc for regeneration of discs. Methods A three-dimensional porous poly(L-lactic-co-glycolic acid) (PLGA) scaffold was fabricated by temperature induced phase separation method. Human fetal disc cells were isolated and cultured in vitro. The disc cells labeledwith a PKH-26 fluorescent dye were seeded into a threedimensional porous scaffold. The proliferation of disc cells with PKH-26 fluorescent labels was assessed by using MTT uptake, laser fluorescence microscopy and SEM. Results Human fetal disc cells displayed a polygonal shape in primary monolayer culture. A regular arrangement and microtubules orientationstructure scaffold with 50-300 μm in diameter was fabricated by thermal-induced phase separation technique. MTT uptake and fluorescent microscopy examination indicated that the seeded disc cells were viable and showed proliferation activity within a porous scaffold. Conclusion The above findings support potential applications of tissue engineered disc in treatment of disc degenerative diseases.
ObjectiveTo analyze the relationship between the bone mineral density (BMD) and lumbar intervertebral disc degeneration in rhesus macaques by using T1ρ-MRI.
MethodsTwenty female rhesus macaques at the age of 10.9 years on average (rang, 4-20 years) were selected. The lumbar intervertebral discs were classified by Pfirrmann grading system and the T1ρ relaxation time (T1ρ value) was examined by using MRI (Philips 1.5 Tesla), and then BMD values of the L4,5 vertebrae and femoral ward's triangle were detected by using Osteocore dual energy X-ray absorptiometry. Finally, the relationship of T1ρ value of the lumbar intervertebral discs and Pfirrmann grading with age, weight, BMD of lumbar vertebrae and femoral ward's triangle was analyzed.
ResultsThe BMD values of lumbar vertebrae and femoral ward's triangle were (0.64±0.17) g/cm2 and (0.67±0.19) g/cm2 respectively, showing no significant difference (t=2.893, P=0.128). According to Pfirrmann grading system, there were 7 cases of grade I, 8 cases of grade Ⅱ, and 5 cases of grade Ⅲ at L4,5 intervertebral discs. The T1ρ value of the lumbar intervertebral disc was (104.08±18.65) ms; the T1ρ values of grades I, Ⅱ, and Ⅲ were (121.31±13.44), (104.73±15.01), and (77.41±11.87) ms, respectively. There was a negative correlation between T1ρ value and the age and the BMD of lumbar vertebrae and femoral ward's triangle. There was a positive correlation between Pfirrmann grading and the variables as listed above. Significant negative linear correlation was also observed between T1ρ value and Pfirrmann grading.
ConclusionThe T1ρ value is a reliable index when quantifying lumbar intervertebral disc degeneration, and there is a significant positive correlation between BMD and lumbar intervertebral disc degeneration in rhesus macaques.
Objective To compare the clinical effects of treating prolapse of the cervical intervertebral disc by the Solis cage fusion, the titanium cage fusion or the autogenous iliac crest graft combined with the titanium plate fixation. Methods Sixty-four patients with prolapse of the cervical intervertebral discadmitted to hospital from February 2002 to May 2005 were retrospectively analyzed. In Group A, 20 patients (15 males and 5 females, aged 38.76 years, 30 intervertebral spaces) were treated with the Solis cage fusion, and the preoperative JOAscores were 9-16, averaged 11.4; in Group B, 21 patients (15 males and 6 females,aged 37-78 years, 23 intervertebral spaces) were treated with the titanium cagefusion, and the preoperative JOA scores were 8-13, averaged 10.1; in Group C, 23 patients (18 males and 5 females, aged 32-76 years, 28 intervertebral spaces)were treated with the autogenous iliac crest graft combined with the titanium plate fixation, and the preoperative JOA scores were 9-14, averaged 10.6. The comparative analysis was made among the 3 groups in the following aspects: X-ray exposure time, time working on the iliac bone, operation time, hemorrhage amount，complication incidence after operation, cervical vertebral fusion rate, symptom relief rate, and recovery rate of the JOA score. Results According to the follow-upfor 2-15 months averaged 12 months, the time working on the iliac bone was longer in Group C than in Groups A and B (11.5±2.4 vs 4.1±1.7 minand 4.2±1.9 min, P＜0.05); the operation time was longer in Group C than in Groups A and B (98.3±14.7 min vs 55.5±10.3 min and 56.8±12.6 min, P＜0.05); and the X-ray exposure time was longer in Group C than in Groups A and B (7.8±1.8 min vs 4.3±1.2 min and 4.2±1.3 min, P＜0.05). Also, the hemorrhage amount in Group C was much greater than in Groups A and B (145.8±19.3 ml vs 65.8±10.2 ml and 67.2±12.3 ml,P＜0.05). The postoperative complication rate was lower in Groups A and Bthan in Group C (P＜0.05). There was a significant difference in the complication rate in the cervical region between Group A (5.0%±1.8%) and Group B (14.3%±2.6%,Plt;0.05）. The fusion rate in Groups A and B was 100% 3-4 monthsafteroperation, and there was no difference when compared with that in Group C. The recovery rates of the JOA scores in the three groups were 81.9%±3.2%，78.9%±7.3%, and 76.3%±9.4%, respectively, and there was no significant difference among the three groups. Conclusion The Solis cage fusion has a better therapeutic effect in treating prolapse of the cervical intervertebral disc than the titanium cage fusion and the autogenous iliac crest graft combined with the titanium plate fixation. The Solis cage fusion also makes the operation easier, with a more rapid recovery rate and fewer postoperative complications in the patient.
ObjectiveTo observe the efficacy and safety of the posterior fusion dynamic system (Dynesys) on lumbar intervertebral disc.
MethodsBetween April 2010 and April 2012, 30 patients diagnosed lumbar disc herniation in our department were included in the study. The Dynesys was performed on these patients. Follow-up lasted for 6 to 12 months. We used visual analogue scale (VAS) and Oswestry disability index (ODI) to evaluate the efficacy and safety of the system at the time points of the day before surgery, 1 week, 3 months and 6 months after surgery. Paired-samples t-test was used in the data analysis.
ResultsThe VAS score 1 day before surgery was 7.9±0.9; 1 week after surgery, VAS was 2.1±0.8 (t=49.395, P<0.001); 3 months after surgery, VAS was 1.6±0.4 (t=88.304, P<0.001); 6 months after surgery, VAS was 1.4±0.3 (t=93.721, P<0.001). ODI 1 day before surgery was (74.0±6.0)%; 1 week after surgery, ODI was (19.6±2.5)% (t=82.006, P<0.001); 3 months after surgery, ODI was (16.3±1.2)% (t=88.344, P<0.001); 6 months after surgery, ODI was (14.5±1.8)% (t=90.113, P<0.001). All the patients were given X ray review 1 week, 3 months, and 6 months after surgery. No screw loosening or breakage was detected.
ConclusionThe combination of Dynesys and decompression surgery has been proved to be effective and safe in the short term. Dynesys reserves the mobility of pathological lumbar, ensures the stability of the posterior spine and corrects lumbar instability.
Objective
To develop a modified short time inversion recovery (STIR) sequence grading system for lumbar intervertebral disc degeneration based on MRI STIR sequences, and to test the validity and reproducibility of this grading system.
Methods
A modified 8-level grading system for lumbar intervertebral disc degeneration based on routine sagittal STIR sequences and modified Pfirrmann grading system was developed. Between April 2011 and February 2012, 60 patients with different degrees of lumbar intervertebral disc degeneration were selected as objects of study, including 32 males and 28 females with an average of 50 years (range, 17-85 years). T2 weighted and STIR sequence images were obtained from the lumbar discs of L1, 2-L5, S1 of each object (total, 300 discs). All examinations were analyzed independently by 3 observers and a consensus readout was performed after all data collected. The validity and reproducibility were analyzed by calculating consistent rate and Kappa value.
Results
According to the grading system, there were 0 grade 1, 83 (27.7%) grade 2, 87 (29.0%) grade 3, 66 (22.0%) grade 4, 31 (10.3%) grade 5, 15 (5.0%) grade 6, 12 (4.0%) grade 7, and 6 (2.0%) grade 8. Intra-observer consistency was b (Kappa value range, 0.822-0.952), and inter-observer consistency was high to b (Kappa value range, 0.749-0.843). According to the consensus analysis, the total consistent rate was 82.7%-92.7% (mean, 85.6%). A difference of one grade occurred in 13.9% and a difference of two or more grades in 0.5% of all the cases.
Conclusion Disc degeneration can be graded by using modified STIR sequence grading system, which can improve the accuracy of grading different degrees of lumbar intervertebral disc degeneration.
