Objective To explore the feasibility and effectiveness of spinal pedicle screw internal fixation through endoscope-assisted posterior approach for the treatment of traumatic atlantoaxial instability. Methods Between September 2008 and September 2010, 44 patients with traumatic atlantoaxial instability received spinal pedicle screw internal fixation through endoscope-assisted posterior operation (micro-invasive surgical therapy group, n=22) or traditional surgical therapy (control group, n=22). There was no significant difference in gender, age, type of injury, disease duration, and preoperative Japanese Orthopedic Association (JOA) score between 2 groups (P gt; 0.05). The blood loss, operation time, length of the incision, improvement rate of JOA, and graft fusion rates were compared between 2 groups to assess the clinical outcomes. Results The blood loss, operation time, and length of the incision in the micro-invasive surgical therapy group were better than those in control group (P lt; 0.05). All incisions were primary healing. Of 88 pedicle screws, 7 pedicle screws penetrated into the interior walls of cervical transverse foramen in the micro-invasive surgical therapy group and 8 in the control group, but there was no syndrome of vertebral artery injury. All patients of the 2 groups were followed up 12 to 37 months (mean, 26 months). Bony fusion was achieved in all cases within 3 to 12 months (mean, 5.3 months). No loosening or breakage of screw occurred. At 6 months to 1 year after operation, the internal fixator was removed in 6 cases and the function of head and neck rotary movement were almost renewed. The JOA score was significantly improved at last follow-up when compared with preoperative score (P lt; 0.05), and no significant difference in JOA score and improvement rate between the 2 groups at last follow-up (P gt; 0.05). Conclusion The micro-invasive surgical therapy can acquire the same effectiveness to the traditional surgical therapy in immediate recovery of stability, high graft fusion rate, and less complication. Moreover, it can significantly reduce the operation time, blood loss, and soft tissue injury, so this approach may be an ideal way of internal fixation to treat traumatic atlantoaxial instability.
目的:探讨后路内固定治疗脊柱结核的必要性及适应证。方法:2002年1月~2008年12月采用后路器械固定、融合结合前路彻底病灶清除、植骨治疗脊柱结核17例。病变位于胸椎3例,胸腰段2例,腰椎4例,腰骶椎8例;累及2个节段7例,3个节段7例,4个节段3例;有3例伴窦道形成;9例伴不同程度的脊髓和(或)神经根受压症状;术前后凸成角10°~72°,平均31°。所有患者均一期手术。结果:术后随访6个月~5年,平均3.1年,术后切口均Ⅰ期愈合,后凸成角7°~58°,平均16°,椎间植骨平均在5个月融合,植骨融合率95.6%,优良率达89.6%,无一例复发。结论:后路器械固定结合前路彻底病灶清除、植骨治疗脊柱结核主要适用于多个节段受累、腰骶段及伴窦道者,利于恢复脊柱的稳定性、提高植骨融合率、纠正和预防后凸畸形。
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.
Objective To investigate the relationship between the volume of bone-graft and fusion efficacy in posterior lumbar interbody fusion and internal fixation of spondylolisthesis. Methods Between May 2004 and June 2007, 79 patients with spondylolisthesis were treated with posterior lumbar interbody fusion and internal fixation. The patients were randomly divided into 3 groups according to the volume of bone-graft for interbody fusion: group A (n=27), 5 bone granules/ cm3 on average; group B (n=26), 11 bone granules/cm3 on average; and group C (n=26), 25 bone granules/cm3 on average. There was no significant difference in gender, age, disease duration, affected segment, and the degree of vertebral slip among 3 groups (P gt; 0.05). The volume of bone-graft, the fusion rate, the loss of intervertebral height, and the incidence of internal fixation failure were compared among 3 groups. Results All cases were followed up 24-43 months (mean, 35 months). There were significant differences in volume of bone-graft among 3 groups (P lt; 0.05). There was no significant difference in total volume of bone-graft and Cage height among 3 groups (P gt; 0.05). The Oswestry disability index (ODI) and visual analogue scale (VAS) scores of low back pain and leg pain at last follow-up were significantly decreased when compared with preoperative scores in 3 groups (P lt; 0.05); but no significant difference was found among 3 groups (P gt; 0.05). The fusion rate was significantly higher in group B than in groups A and C, and in group A than in group C at 1 and 2 years after operation (P lt; 0.05). The change values of the intervertebral height were (2.2 ± 1.4), (0.8 ± 1.3), and (2.3 ± 1.6) mm respectively in groups A, B, and C; it was significantly lower in group B than in groups A and C (P lt; 0.05). The degree of vertebral slip at immediately after operation and last follow-up was significantly improved when compared with preoperative one in 3 groups (P lt; 0.05); the loss of vertebral slip in group B was significantly lower than that in groups A and C at last follow-up (P lt; 0.05). After operation, nail breaking occurred in 1 case (3.7%) of group C at 1 year, depinning in 1 case (3.8%) of group A at 2 years, and no nail breaking or depinning in group B. There was no significant difference in the incidence of internal fixation failure among 3 groups (χ2=3.950, P=0.604). Conclusion The application of bone-graft with middle volume (11 bone granules/cm3 on average) in internal fixation and posterior lumbar interbody fusion has a good imageology outcome, which can increase the fusion rate and decrease the loss of intervertebral height.
Objective To investigate the stability and the stress distributions of L3-5 fused with three different approaches (interbody, posterolateral and circumferential fusions) and to investigate degeneration of thesegment adjacent to the fused functional spinal unit. Methods A detailed L3-5 three-dimensional nonlinear finite element model of a normal man aged 32 was established and validated. Based on the model, the destabilized model, the interbody, posterolateral and circumferential fusions models of L4-5 were established. After the loadings were placed on all the models, we recorded the angular motions of the fused segment and the Von Mises stress of the adjacent intervertebral disc. Results The circumferential fusion was most stable than the others, and the interbody fusion was more stable than the posterolateral fusion. The maximal Von Mises stress of the adjacent L3,4 intervertebral disc in all the models was ranked descendingly as flexion,lateral bending,torsion and extension. For the three kinds of fusions, the stress increment of the L3,4 intervertebral disc was ranked ascendingly as interbody fusion,posterolateral fusion and circumferential fusion. Conclusion After destabilization of the L4,5 segment, the stability of the circumferential fusionis better than that of the others, particularly under the flexional or extensional loading. The stability of the interbody fusion is better than that of the posterolateral fusion, except for under the flexional loading. The feasibility of adjacent segment degeneration can be ranked descendingly as: circumferential fusion,posterolateral fusion and interbody fusion.
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 introduce operation skill of the spinal wedge osteotomy by posterior approach for correction of severe rigid scol iosis and to discuss the selection of the indications and the range of fusion and fixation. Methods Between July 1999 and January 2009, 23 patients with severe rigid scol iosis were treated with spinal wedge osteotomy by posterior approach, including 16 congenital scol iosis, 5 idiopathic scol iosis, and 2 neurofibromatosis scol iosis. There were 11 males and 12 females with a median age of 15 years (range, 8-29 years). Two patients had previous surgery history. The Cobb’s angles of scol iosis and kyphosis before operation were (85.39 ± 13.51)° and (56.78 ± 17.69)°, respectively. The mean spinal flexibil ity was 14.4% (range, 4.7%-22.5%). The trunk shift was (15.61 ± 4.89) mm. The preoperative CT or MRI showed bony septum in the canal in 2 patients. Results The mean operative time was 241 minutes and the mean blood loss was 1 452 mL. The average fused vertebrae were 10.7 segaments (range, 8-14 segaments). The follow-up ranged from 1 to 4 years with an average of 2 years and 6 months. The postoperative Cobb’s angle of scol iosis was (38.70 ± 6.51)°, the average correction rate was 54.7%. The postoperative Cobb’s angle of kyphosis was (27.78 ± 6.01)°, the average correction rate was 51.0%. The trunk shift was improved to (4.69 ± 1.87) mm, the increased height was 5.2 cm on average (range, 2.8-7.7 cm). The Cobb’s angle of scol iosis was (41.57 ± 6.80)° with an average 2.9° loss of correction at the final follow-up; the Cobb’s angle of kyphosis was (30.39 ± 5.94)° with an average 2.6° loss of correction at the final follow-up; the trunk shift was (4.78 ± 2.00) mm at the final follow-up. There were significant differences (P lt; 0.05) in the Cobb’s angles of scol iosis and kyphosis and the trunk shift between preoperation and postoperation, between preoperation and last follow-up. Four cases had pedicle fracture, 1 had L1 nerve root injury, 2 had superior mesenteric artery syndrome, 1 had exudates of incision, and 2 had temporary dysfunction of both lower extremity. Conclusion Spinal wedge osteotomy by posterior approach is a rel iable and safe surgical technique for correcting severe rigid scol iosis. With segmental pedical screw fixation, both the spinal balance and stabil ity can be restored.
Objective To evaluate the biomechanical characteristicsof titanium mesh with anterior plate fixation or ilium autograft in anterior cervical decompression.Methods Six fresh cervical spine specimens(C3-7) of young cadaver were used in the biomechanical test. After C5, C5,6 and C4-6 were given vertebrectomy,ilium autograft and titanium mesh with anterior plate fixation were performed. Their stabilities of flexion,bilateral axial rotation,the lateral bending and the extension were tested. Intact cervical spine specimens served as control group. Results Ilium autograft improved the stability of the unstable cervical vertebrae and decreased the flexion, the lateral bending or the extension, showing a significant difference when compared with control group(Plt;0.05). Whereas, axial rotational motion was decreased insignificantly(Pgt;0.05). Titanium meshwith anterior plate fixation improved the stability of the unstable spine and decreased the flexion,the bilateral axial rotation,the lateral bending or the extension, showing a significant difference when compared with control group(Plt;0.05). Conclusion The vertebrectomy and anterior cervical fusion by ilium autograft was the least stable construct of all modes tested,and the titanium mesh implantation is stabler than the intact cervical sample.
Objective To investigate the cl inical outcomes of lumbar spondylol isthesis associated with lumbar spinal stenosis through decompressive laminectomy, spondylol ithesis reduction system (SRS) internal fixation, single posteriolateralVigor Spacer threaded fusion cages and intertransverse process arthrodesis bone grafting. Methods From June 2002 to June 2006, 58 cases of lumbar spondylol isthesis were treated with decompressive laminectomy, fixed by SRS instrumentation, posterior installed with interbody Vigor Spacer Cage and bone grafted between intertransverse process arthrodesis. There were 47 males and 11 females, aged 32-66 years old (45.8 on average). The course of disease was 3 months to 7 years, with an medium course of 25 months. Accoding to the Meyerding standard, 38 cases were classified as degree I and 20 as degree II. Spondylol isthesis between L4 and L5 covered 21 cases and between L5 and S1 covered 37 cases. There were 44 cases of lumbar spondylol isthesis and 14 of degenerative lumbar spondylol isthesis. The intervertebral height was 1.5-10.5 mm with the average of 5.1 mm. Results All patients’ incisions obtained heal ing by first intension after operation. The operation time was 50-90 minutes with an average of 65 minutes. The blood loss was 200-500 mL with an average of 250 mL. The patients were followed up for 10-38 months with an average of 23.6 months. According to the Macrab criteria, 54 cases were excellent, 3 good, 1 fair and the choiceness rate was 98.3%. According to the Meyerding classification, 38 cases of degree I and 19 out of 20 cases of degree II obtained complete reduction, and the rate of complete reduction was 98.3%. There were 57 (98.3%) cases which fused well 3-6 months after operation. The intervertebral height resumed to 9.6-12.5 mm with an average of 11.6 mm, and no intervertebral height loss was found. Conclusion The treatment of lumbar spondylol isthesis with decompressive laminectomy, SRS internal fixation, single posteriorolateral Vigor Spacer threaded fusion cage and bone grafting has excellent cl inical results and stable reduction.