Objective To evaluate the application of artificial lamina of multi-amino-acid copolymer (MAACP)/nano-hydroxyapatite (n-HA) in prevention of epidural adhesion and compression of scar tissue after posterior cervical laminectomy. Methods Fifteen 2-year-old male goats [weighing, (30 ± 2) kg] were randomly divided into experimental group (n=9) and control group (n=6). In the experimental group, C4 laminectomy was performed, followed by MAACP/n-HA artificial lamina implantations; in the control group, only C4 laminectomy was performed. At 4, 12, and 24 weeks after operation, 2, 2, and 5 goats in the experimental group and 2, 2, and 2 goats in the control group were selected for observation of wound infection, artificial laminar fragmentation and displacement, and its shape; Rydell’s degree of adhesion criteria was used to evaluate the adhesion degree between 2 groups. X-ray and CT images were observed; at 24 weeks after operation, CT scan was used to measure the spinal canal area and the sagittal diameter of C3, C4, and C5 vertebrea, 2 normal goats served as normal group; and MRI was used to assess adhesion and compression of scar tissue on the dura and the nerve root. Then goats were sacrificed and histological observation was carried out. Results After operation, the wound healed well; no toxicity or elimination reaction was observed. According to Rydell’s degree of adhesion criteria, adhesion in the experimental group was significantly slighter than that in the control group (Z= — 2.52, P=0.00). X-ray and CT scan showed that no dislocation of artificial lamina occurred, new cervical bone formed in the defect, and bony spinal canal was rebuilt in the experimental group. Defects of C4 vertebral plate and spinous process were observed in the control group. At 24 weeks, the spinal canal area and sagittal diameter of C4 in the experimental group and normal group were significantly larger than those in the control group (P lt; 0.05), but no significant difference was found between experimental group and normal group (P gt; 0.05). MRI showed cerebrospinal fluid signal was unobstructed and no soft tissue projected into the spinal canal in the experimental group; scar tissue projected into the spinal canal and the dura were compressed by scar tissue in the control group. HE staining and Masson trichrome staining showed that artificial lamina had no obvious degradation with high integrity, some new bone formed at interface between the artificial material and bone in the experimental group; fibrous tissue grew into defect in the control group. Conclusion The MAACP/n-HA artificial lamina could maintaine good biomechanical properties for a long time in vivo and could effectively prevent the epidural scar from growing in the lamina defect area.
ObjectiveTo compare the clinical and radiographic outcomes between laminoplasty and laminectomy compression and fusion with internal fixation to treat cervical spondylotic myelopathy. MethodsBetween September 2006 and September 2009, 143 cases of multilevel cervical myelopathy (the affected segments were more than 3) were treated by laminoplasty in 87 cases (group A) and by laminectomy decompression and fusion with lateral mass screw fixation in 56 cases (group B). There was no significant difference in gender, age, disease duration, pathological type, and affected segments between 2 groups (P gt; 0.05). The operation time, intraoperative blood loss, improvement of neurological function [Japanese Orthopaedic Association (JOA) 17 score], and the incidences of complications were observed; the cervical curvature index (CCI), range of motion (ROM), and symptoms of neck and shoulder pain [visual analogue scale (VAS) and neck disability index (NDI) scores] were recorded and compared. ResultsThere was no significant difference in operation time and intraoperative blood loss between 2 groups (P gt; 0.05). All patients were followed up 18-30 months (mean, 24 months). C5 nerve root palsy occurred in 4 cases (4.60%) of group A and in 5 cases (8.93%) of group B, showing no significant difference (χ2=0.475, P=0.482). No complication of deep infection, pseudarthrosis, or screw loosening occurred. No closure of opened laminae was observed in group A; and no screw extrusion, breakage, or nerve injury was observed in group B. At last follow-up, neck axial symptoms appeared in 35 cases (40.23%) of group A and in 11 cases (19.64%) of group B, showing significant difference (χ2=6.612, P=0.009). No significant difference was found in JOA score, CCI, ROM, or VAS scores between 2 groups at preoperation (P gt; 0.05); the JOA score, ROM, and VAS scores of groups A and B and CCI of group A at last follow-up were significantly improved when compared with preoperative ones (P lt; 0.05). No significant difference was found in the JOA score, improvement rate, and VAS score between 2 groups (P gt; 0.05); however, significant differences were found in ROM and CCI between 2 groups (P lt; 0.05). There were significant differences (P lt; 0.05) in pain intensity, lifting, work, reaction, driving, and total score between 2 groups at last follow-up. ConclusionLaminectomy decompression and fusion with internal fixation can effectively relieve pain, but it will greatly reduce the ROM; laminoplasty has less complications and satisfactory outcome. The two methods have similar effectiveness in the improvement of neurological function.
Objective To evaluate the short-term effectiveness of local laminectomy and interlaminar lumbar instrumented fusion (ILIF) through a small incision for lumbar spinal stenosis. Methods Between November 2009 and January 2011, 16 patients with lumbar spinal stenosis were treated by local laminectomy and ILIF through a small incision. Therewere 7 males and 9 females with an average age of 52.8 years (range, 49-67 years). Sixteen patients had lumbar degenerative stenosis with an average disease duration of 4 years and 7 months (range, 2 years-9 years and 4 months). Four cases complicated by lateral recessus stenosis, 3 by lumbar disc herniation. Involved segments included L3, 4 in 2 cases, L4, 5 in 4 cases, L5, S1 in 4 cases, L3, 4 and L4, 5 (double segments) in 2 cases, L4, 5 and L5, S1 (double segments) in 4 cases. The effectiveness was evaluated with the pre- and post-operative Visual Analogue Scale (VAS) scores, Oswestry Disabil ity Index (ODI). The cross-sectional areas of spinal canal were measured by CT scanning and were compared between pre- and post-operation. Results The average operative time was 47 minutes (range, 35-80 minutes); the average blood loss was 145 mL (range, 120-350 mL); and the average hospital ization days were 7.8 days (range, 4-15 days). Cerebrospinal fluid leakage occurred in 1 case, and healing of incisions by first intention was achieved in the others. The patients were followed up 12-22 months (mean, 14.8 months). CT scanning showed interspinous fusion in 14 cases and possible fusion in 2 cases after operation, with an average fusion time of 4.6 months(range, 3-10 months). The postoperative VAS score, ODI, and cross-sectional area were significantly improved when compared with preoperative values (P lt; 0.05). Conclusion The ILIF can promote fusion between spinous processes, provide spine stabil ization, and protect the spinal cord. The procedure has small incision, simple method of fixation and fusion.
Objective To study the clinical effects of artificial vertebral laminae of the biomimetic nano-hydroxyapatite/polyamide 66 (n-HA/PA66) composites in prevention of the scar formation in lumbar spinal canal and the reconstruction of posterior vertebral laminae structure. Methods From January 2003 to December 2005, 23 patients were treated with artificialvertebral laminae of the biomimetic n-HA/PA66 composites. There were 16 males and 7 females, aging from 48 to 76 years with an average of 59 years. Of 23 cases,11 cases had spinal stenosis, 7 cases had spinal stenosis with spondylolysis, 3 cases had lumbar disk herniation and 2 cases had spinal tumor. Twenty cases of vertebral laminae were reconstructed by 1 artificial vertebral laminae and 3 cases by 2.The affected locations were C5,6,L1 and L2 in 1 case respectively; L4,5 in 5 cases; L4-S1 in 9 cases; and L5, S1 in 6 cases. Results First intension was achieved in 22 cases and infection occured in 1 case.In the period of follow-up for all cases lasted from 5 to 24 months,the postoperative CT showed that the nHA/PA66 artificial vertebral laminae enlarged the spinal canal. MRI showed little scar formation and adhesion in the lumbar spinal canal. CT showed illdefined boundary between artificial vertebral laminae and recipient vertebral laminae. No neural symptoms occured in all cases except onebecause of stretch injury of nerve root in operation. Also no rejection reaction was observed. Conclusion The artificial vertebral laminae of the biomimetic nHA/PA66 composites can effectively prevent the compression to the nerve root and dural sac from the scar and restore the vertebral laminae.
Objective To explore effective substances and methods for prevention of peridural adhesion. Methods Laminectomy was performed on the 5th lumbar segment in 64 rabbits, which were equally divided into 4 groups. The duramater (12 mm×6 mm) was exposed. The exposed duramater was left uncovered in Group A; the exposed dura mater was covered with sodium hyaluronate jel (high molecular weight, 1 ml) in Group B; the lamina repair was performed with the autologous spinous process in Group C; the lamina repair was performed with the sodium hyaluronate jel filling and the autologous spinousprocess in Group D. The specimens were observed grossly and histologically at 2, 4, 6 and 8 weeks postoperatively. The computed imaging analysis on the epidural adhesion was also performed at 6 weeks postoperatively. Results ①The gross anatomical evaluation: Severe peridural adhesion was formed in Group A, less adhesion formed in Groups B and C, but no obvious adhesion formed in Group D. ②The area percentage of the epidural scar: The area percentage ofthe epidural scar was 15.89%±1.88% and 13.94%±1.89% in Groups C and D respectively, which were significantly lower than those in Groups A and B (22.66%±2.89% and 20.70%±2.82%,Plt;0.05). ③The density of epidural scar: Thedensity of the epidural scars were 42.03%±7.36% and 36.50%±9.08% in Groups B and D, which were significantly lower than those in Groups A and C (63.73%±6.06% and 52.11%±4.10%，Plt;0.05). Conclusion The high molecular weight sodium hyaluronate jel filling combined with the lamina repair using the autologous spinous process has the best preventive effect on the peridural adhesion after laminectomy.
Objective To determine the ability of the polyactic acid glue (PLA-G) in preventing epidural adhesion after laminectomy. Methods Each of the 24 randomly selected rats was done laminectomyof L2 and L5. The PLA-G, which would change from liquid to solid when meets with serum, was used in the epidural site of L5 to become a half-solid membrane(the experimental group, EG). The PLA-G was not used in the same site of L2(the control group, CG) .The gross anatomical, histological, and microscopical evaluation were made 2，4，6，8，10 and 12 weeks after operation; electron microscope observation was also made on two rats 4 weeks after operation(both EG and CG). Results Obvious epidural space was observed between dura mater and scar tissue(ST), but no cells in the epidural space were observed inEG 2 weeks after operation. Corps of the red cells between dura mater and ST and proliferation of fibroblast cell(FB) were observed in CG 2 weeks after operation. Some remaining glue shiver in the epidural space with lightly increasing fibroblast and smooth dura mater were observed in EG 4 weeks after operation. However, fragile scar conglutinated with dura mater diffusely and more FB were observed in CG. From the 6th week to the 12th week, a potential interspace between scar and dura mater was observed and PLA glue was absorbed completely in EG. However, tougher scar, which was very difficult to dissect from dura mater and surrounding tissues, was observed. According to the fibroblast ultrastructure observation, bigger nucleus and more plentiful rough endoplasmic reticulum were observed in CG. Conclusion The PLA-G can effectively reduce the epidural scar and adhesion in animal experiment.
In order to find an ideal biological material to prevent peridural adhesion following laminectomy, 30 rabbits were used as animal model, in each of which 2 defects with a size of 1 cm x 0.5 cm were made following laminectomy of L3, L5 spine. One of the defects was covered extradurally with chitosan, gelatin foam or PLA membrane respectively, while the other defect was exposed as control. All of these animals were sacrificed on the 2nd, 4th, 6th, 8th and 10th week after operation, and the extradural fibrosis and adhesion of every animal were evaluated by gross observation and histological examinations. It was revealed that in the chitosan and PLA membrane groups, the extradural tissue was smooth without thickening and there was no fibrous proliferation or adhesion in the epidural cavity, and that in the chitosan group, the growth of fibroblast was restrained but the growth of the epithelial cells was promoted significantly, thus, wound healing was rapid. In the control group and gelatin foam group, obvious extradural fibrosis and adhesion were observed and the extradural space had almost disappeared. Therefore, it was concluded that the biodegradable PLA membrane and chitosan were both an ideal material in the prevention of postoperative epidural adhesion.
Objective To investigate the technique and effectiveness of modified laminoplasty for lumbar spinal stenosis (LSS) and to explore the application value of modified laminoplasty in maintaining the stability of the spine by comparing with the conventional laminectomy. Methods Fifty-six patients with LSS were included between June 2012 and July 2013, and they were divided into 2 groups: 27 patients underwent modified laminoplasty in group A, and 29 patients received conventional laminectomy in group B. There was no significant difference in sex, age, disease duration, narrow segment, visual analogue scale (VAS) score of low back pain and leg pain, Japanese Orthopaedic Association (JOA) score, and walking tolerance between 2 groups (P > 0.05). The postoperative VAS score of low back pain and leg pain, JOA score, walking tolerance, X-ray film, and CT were used to evaluate the clinical results. Results Dural tear occurred in 2 cases of group A and 1 case of group B and were repaired during operation. All incisions primarily healed without infection. The patients were followed up 24-31 months (mean, 24.7 months) in group A, and 24-37 months (mean, 26.2 months) in group B. The bone healing time was 6-12 months (mean, 9 months) in group A. CT showed healing at the junction of spinous process and vertebral plate in group A at 12 months after operation; new scar in varying degre es was observed in group B. At last follow-up, lumbar spondylolisthesis and instability occurred in 4 and 2 cases of group B respectively, and received re-operation. The change value of slip distance was (0.27±0.23) mm in group A and was (0.83±1.22) mm in group B, showing significant difference (t=-2.405, P=0.023). The postoperative JOA score, VAS score, and walking tolerance were significantly improved when compared with preoperative ones in 2 groups (P < 0.05). At last follow-up, group A was better than group B in VAS score of low back pain (P < 0.05), but no significant difference was found in the other indexes between 2 groups (P > 0.05). Conclusion The modified laminoplasty is better than the conventional laminectomy in relieving low back pain and maintaining the stability of the lumbar spine.