Objective To review the present clinical research situation of adjacent segment degeneration (ASD) after lumbar spinal fusion. Methods The recent literature concerning ASD in the concept, the incidence, the risk factors, and prevention was reviewed. Results The concept of ASD includes radiographic ASD and clinical ASD. The incidences of radiographic ASD and clinical ASD were 8%-100% and 5.2%-18.5%, respectively. The risk factors for ASD include both patient and surgical factors. Patient factors include age, gender, preoperative condition, and so on. Surgical factors include the length of the fusion, mode of fusion, internal fixator, sagittal balance, excessive distraction of disc space, and so on. It can prevent ASD to reduce the length of the fusion, to keep sagittal balance, and to use the non-fusion technology. Conclusion Many researches have proved that the incidence of ASD is increased after lumbar spinal fusion, and it can be reduced by the non-fusion technology. Non-fusion technology has obtained good short-term results. But the long-term results should be further observed because there are some complications.
ObjectiveTo observe the effect of stromal vascular fraction cells (SVFs) from rat fat tissue combined with sustained release of recombinant human bone morphogenetic protein-2 (rhBMP-2) in promoting the lumbar fusion in rat model.MethodsSVFs were harvested from subcutaneous fat of bilateral inguinal region of 4-month-old rat through the collagenase I digestion. The sustained release carrier was prepared via covalent bond of the rhBMP-2 and β-tricalcium phosphate (β-TCP) by the biominetic apatite coating process. The sustained release effect was measured by BCA method. Thirty-two rats were selected to establish the posterolateral lumbar fusion model and were divided into 4 groups, 8 rats each group. The decalcified bone matrix (DBX) scaffold+PBS, DBX scaffold+rhBMP-2/β-TCP sustained release carrier, DBX scaffold+SVFs, and DBX scaffold+rhBMP-2/β-TCP sustained release carrier+SVFs were implanted in groups A, B, C, and D respectively. X-ray films, manual spine palpation, and high-resolution micro-CT were used to evaluate spinal fusion at 8 weeks after operation; bone mineral density (BMD) and bone volume fraction were analyzed; the new bone formation was evaluated by HE staining and Masson’s trichrome staining, osteocalcin (OCN) was detected by immunohistochemical staining.ResultsThe cumulative release amount of rhBMP-2 was about 40% at 2 weeks, indicating sustained release effect of rhBMP-2; while the control group was almost released within 2 weeks. At 8 weeks, the combination of manual spine palpation, X-ray, and micro-CT evaluation showed that group D had the strongest bone formation (100%, 8/8), followed by group B (75%, 6/8), group C (37.5%, 3/8), and group A (12.5%, 1/8). Micro-CT analysis showed BMD and bone volume fraction were significantly higher in group D than groups A, B, and C (P<0.05), and in group B than groups A and C (P<0.05). HE staining, Masson’s trichrome staining, and immunohistochemistry staining for OCN staining exhibited a large number of cartilage cells with bone matrix deposition, and an active osteogenic process similar to the mineralization of long bones in group D. The bone formation of group B was weaker than that of group D, and there was no effective new bone formation in groups A and C.ConclusionThe combination of sustained release of rhBMP-2 and freshly SVFs can significantly promote spinal fusion in rat model, providing a theoretical basis for further clinical applications.
ObjectiveTo investigate the bone repair and regeneration abilities of biomimetic mineralized collagen bone graft material and autologous bone marrow in rabbit posterolateral spinal fusion model.MethodsTwenty-seven 20-week-old male New Zealand white rabbits were used to establish the posterolateral spinal fusion model of L5 and L6 segments by stripping the transverse process and exposing cancellous bone with electric burr. The rabbits were randomly divided into 3 groups, 9 in each group. Groups A, B, and C were implanted 1.5 mL autologous iliac bone, 1.5 mL (30 mm×10 mm×5 mm) biomimetic mineralized collagen bone graft material, and 1.5 mL (30 mm×10 mm×5 mm) biomimetic mineralized collagen bone graft material and autologous bone marrow in each bone defect. At 4, 8, and 12 weeks after operation, the apparent hardness of the bone grafting area was observed by manipulation method, in order to evaluate bone graft fusion effects. Three animals were sacrificed in each group at each time point, the vertebral body specimens were excised and the bone defect repair and fusion were observed by X-ray films, and three-dimensional CT examination was performed to evaluate whether new bone was formed in the body. HE staining was performed at each time point to observe the formation of new bone and the repair and fusion of bone defects.ResultsThe manipulation test showed that bone graft fusion was not found in all groups at 4 weeks after operation; 3 (50.0%), 2 (33.3%), and 4 (66.7%) of groups A, B, and C reached bone graft fusion at 8 weeks after operation; 5 (83.3%), 4 (66.7%), and 5 (83.3%) of groups A, B, and C reached bone graft fusion at 12 weeks after operation; the fusion rate of group C was similar to that of group A, and all higher than that of group B. X-ray film observation showed that the fusion rate of group C at 8 and 12 weeks after operation was higher than that of group B, which was similar to group A. Three-dimensional CT observation showed that the degree of bone fusion in group C was better than that in group B, which was close to group A. HE staining observation showed that large area of mature lamellar bone coverage appeared in the bone graft area of groups A, B, and C at 12 weeks after operation, the material was completely degraded, and the marginal boundary of the host bone disappeared and tightly combined.ConclusionBiomimetic mineralized collagen bone graft material mixed with autologous bone marrow has good osteoinduction and osteogenesis guidance. Compared with biomimetic mineralized collagen bone graft material, it has better and faster osteogenesis effect, which is close to autologous bone transplantation.
ObjectiveTo compare the effectiveness of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) with bilateral decompression via unilateral approach and bilateral decompression via bilateral approaches in the treatment of single-segment lumbar spinal stenosis.MethodsBetween February 2015 and January 2017, 70 cases of single-segment lumbar spinal stenosis were treated with MIS-TLIF. The bilateral decompression via unilateral approach (group U) was performed in 36 cases and bilateral decompression via bilateral approaches (group B) in 34 cases. There was no significant difference in age, gender, body mass index, disease duration, distribution of responsibility segments, preoperative visual analogue scale (VAS) score of low back pain and leg pain and Oswestry disability index (ODI) score (P>0.05). The operation time, intraoperative blood loss, hospitalization stay after operation, complications related to operation, incidence of asymptomatic lateral root symptoms, VAS scores of low back pain and leg pain, and ODI score before and after operation were compared between the two groups. X-ray film and CT scan at 12 months after operation were used to assessted the intervertebral bony fusion.ResultsThe operation time and intraoperative blood loss in group U were significantly less than those in group B (P<0.05). There was no significant difference in hospitalization stay after operation between the two groups (t=–0.311, P=0.757). During the operation, 1 case in group U and 2 cases in group B had dural tear. No screw placement related nerve injury or asymptomatic lateral root symptoms occurred after operation. The patients were followed up 24 to 38 months, with an average of 32.8 months in group U and 35.5 months in group B. The VAS scores of low back pain and leg pain at 2 days, 3, 6, and 12 months after operation were significantly lower than that before operation in the two groups (P<0.05), and there was no significant difference between the two groups (P>0.05). The ODI scores at 3, 6 and 12 months after operation were significantly lower than that before operation in the two groups (P<0.05), and there was no significant difference between the two groups (P>0.05). Radiographic examination showed interbody fusion at 12 months after operation in the two groups.ConclusionMIS-TLIF is safe and effective in the treatment of single-segment lumbar spinal stenosis with bilateral decompression via unilateral approach and bilateral decompression via bilateral approaches. Bilateral decompression via unilateral approach takes less operation time and has less intraoperative blood loss.
Objective To explore the application of robot-assisted pedicle screw fixation combined with total endoscopic decompression and interbody fusion in single segment lumbar decompression and fusion. Methods A total of 27 cases undergoing single segment lumbar decompression and fusion between August 2020 and May 2021 in the People’s Hospital of Deyang City were retrospectively collected. They were divided into group A and B according to their surgery method. The patients in group A underwent robot-assisted pedicle screw fixation combined with total endoscopic decompression and interbody fusion surgery, while the ones in group B underwent traditional posterior decompression and fusion. The operation time, amount of bleeding, Visual Analogue Scale (VAS) score and Oswestry Disability Index (ODI) score before operation and one month and three months after operation, and success rate of screw placement were compared. Results There were 12 patients in group A, 5 males and 7 females, aged (59.83±6.79) years, and 15 patients in group B, 6 males and 9 females, aged (53.73±14.87) years. The amount of intraoperative bleeding [(195.00±45.23) vs. (240.00±47.06) mL] and postoperative hospital stay [(5.92±1.56) vs. (8.33±3.62) d] in group A were less than those in group B (P<0.05), while the operation time [(185.80±52.13) vs. (160.70±21.37) min] and the success rate of screw placement [100.0% (48/48) vs. 96.7% (58/60)] had no statistical difference between the two groups (P>0.05). The VAS score and ODI score of the two groups decreased significantly over time (P<0.05), but there was no significant difference in VAS score between the two groups at the same time point before operation, one month after operation, or three months after operation (P>0.05). The ODI score of group A was better than that of group B one month after operation (P=0.010), but there was no significant difference between the two groups before operation or three months after operation (P>0.05). Conclusion Compared with traditional open surgery, the application of robot-assisted total endoscopic lumbar decompression and fusion technology in single segment lumbar fusion has good early clinical outcome, high success rate of screw placement, and small trauma, which is beneficial to early functional recovery and has the significance of further exploring its application prospect.