Objective To explore the effectiveness of minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) for degenerative lumbar scoliosis stenosis by expandable tubular retractor. Methods Between April 2009 and October 2010, 39 patients with degenerative lumbar scoliosis stenosis were treated. Of 39 patients, 20 underwent MI-TLIF (group A) and 19 underwent open surgery (group B). There was no significant differences in gender, age, disease duration, range of lumbar degenerative scoliosis, Cobb angle, Oswestry disability index (ODI), and visual analogue scale (VAS) between 2 groups (P gt; 0.05). The operation time, intraoperative blood loss, postoperative independently turning over time, postoperative complication rate, Cobb angle, fusion rates, ODI score, and VAS score were compared between 2 groups. Results The operation time of group A was significantly longer than that of group B (P lt; 0.05), and the intraoperative blood loss of group A was significantly less than that of group B (P lt; 0.05); no significant difference was found in postoperative independently turning over time between 2 groups (t=1.869, P=0.069). The complication rate was 20.0% (4/20) in group A and 26.3% (5/19) in group B, showing no significant difference (χ2=0.219, P=0.640). All patients were followed up 2 years to 3 years and 6 months (mean, 2.9 years). At last follow-up, the fusion rate of bone graft was 92.9% (78/84) in group A and 95.2% (80/84) in group B, showing no significant difference (χ2=0.425, P=0.514). According to the Macnab standard for effectiveness evaluation, the results were excellent in 12 cases, good in 6 cases, fair in 1 case, and poor in 1 case, with an excellent and good rate of 90.0% in group A; the results were excellent in 12 cases, good in 5 cases, and fair in 2 cases, with an excellent and good rate of 89.5% in group B; there was no significant difference between 2 groups (Z= — 0.258, P=0.835). The postoperative VAS score, ODI score, and Cobb angle were significantly improved when compared with preoperative ones in 2 groups (P lt; 0.05); and there was no significant differences between 2 groups at 2 weeks after operation and last follow-up (P gt; 0.05). Conclusion MI-TLIF by expandable tubular retractor is an available clinical choice in treating degenerative lumbar scoliosis stenosis. It can obtain the same effectiveness as the open surgery.
Objective Degenerative lumbar scol iosis and spinal stenosis are more common in elderly patients. Because of many factors, treatment choices are more complex. To investigate the step treatment strategy of degenerative lumbarscol iosis and spinal stenosis. Methods Between January 2005 and December 2009, 117 patients with degenerative lumbar scol iosis and spinal stenosis were treated with step treatment methods, including conservative therapy (43 cases), posterior decompression alone (18 cases), posterior short segment fusion (1-2 segments, 41 cases), and posterior long segment fusion ( ≥ 3 segments, 15 cases). Step treatment options were made according to patient’s will, the medical compl ications, the degree of the symptoms of low back and lower extremity pain, the size of three-dimensional lumbar scol iosis kyphosis rotating deformity, lumbar spine stabil ity (lateral sl ip, degenerative spondylolysis), and the overall balance of the spine. The visual analogue scale (VAS) score of low back and lower extremity pain, Oswestry disabil ity index (ODI), lumbar lordosis angle, and scol iosis Cobb angle were measured and compared before and after treatments. Results Seventy-two cases were followed up more than 12 months, and there was no death or internal fixation failure in all patients. Of them, 19 patients underwent conservative treatment; the mean follow-up period was 19.3 months (range, 1-5 years); no symptom deterioration was observed; VAS score of low back and lower extremity and ODI were significantly decreased at last follow-up (P lt; 0.05); and lordosis angle was decreased and scol iosis Cobb angle was increased, but there was no significant difference (P gt; 0.05). Twelve cases underwentposterior decompression alone; the average follow-up was 36 months (range, 1-5 years); VAS score of lower extremity and ODI were significantly decreased at last follow-up (P lt; 0.05); and scol iosis Cobb angle was increased and lordosis angle was decreased, but there was no significant difference (P gt; 0.05). Thirty-one patients underwent posterior short segment fusion; the mean follow-up period was 21.3 months (range, 1-3 years); postoperative hematoma, poor wound heal ing, cerebrospinal fluid leakage, and superficial infection occurred in 1 case, respectively, and were cured after symptomatic treatment; VAS score of low back and lower extremity and ODI were significantly decreased (P lt; 0.05); and postoperative lumbar scol iosis Cobb angle and lordosis angle were significantly improved at last follow-up (P lt; 0.05). Ten patients underwent posterior long segment fusion; the mean follow-up period was 17.1 months (range, 1-3 years); postoperative symptoms worsened in 1 case and was cured after physical therapy and drug treatment for 3 months, and deep infection occurred in 1 case and was cured after debridement and continuous irrigation drainage; VAS score and ODI were significantly decreased (P lt; 0.05); and postoperative scol iosis Cobb angle and lordosis angle were improved significantly at last follow-up (P lt; 0.05). Conclusion The treatment of degenerative lumbar scol iosis and spinal stenosis should be individual and step. Surgery treatment should be rely on decompression while deformity correction subsidiary. Accurate judgment of the responsible segment of symptoms, scol iosis and lordosis can prevent the operation expansion and increase safety of surgery with active control bleeding.
ObjectiveTo explore the surgical indications,decompression and fusion method,and fusion level selection of degenerative lumbar scoliosis (DLS) and multi-segment lumbar spinal stenosis. MethodsBetween April 2000 and November 2011,46 cases of DLS and multi-segment lumbar spinal stenosis were treated with multi-level decompression by fenestration and crept enlargement plus internal fixation by interbody and posterior-lateral bone graft fusion (5 segments or above).Of 46 cases,25 were male and 21 were female,with a mean age of 70.2 years (range,65-81 years) and with a mean disease duration of 6.4 years (range,4 years and 6 months to 13 years).X-ray films showed that the lumbar Cobb angle was (26.7±10.0)°,and the lumbar lordotic angle was (20.3±8.8)°.The lumbar CT and MRI images showed three-segment stenosis in 24 cases,four-segment stenosis in 17 cases,and five-segment stenosis in 5 cases.A total of 165 stenosed segments included 12 L1,2,34 L2,3,43 L3,4,45 L4,5,and 31 L5 and S1.Visual analogue scale (VAS) score,Oswestry disability index (ODI),and Japanese Orthopedic Association (JOA) score (29 points) were employed to evaluate effectiveness. ResultsThirteen patients had leakage of cerebrospinal fluid during operation,and no infection was found after corresponding treatment; pulmonary infection and urinary system infection occurred in 4 and 2 patients respectively,who relieved after received antibiotic therapy; 8 patients with poor wound healing received dressing change,adequate drainage,debridement and suture.No death,paralysis,central nervous system infection,or other complication was observed in these patients.Forty-six cases were followed up 12-72 months (mean,36.2 months).Lumbago and backache and intermittent claudication of lower extremity were obviously improved.During follow-up,no screw incising,loosening and broken screws,or pseudarthrosis was noted under X-ray film and CT scanning.At last follow-up,the lumbar Cobb angle was reduced to (9.8±3.6)°,while the lumbar lordotic angle was increased to (34.1±9.4)°,which were significantly improved when compared with preoperative ones (t=16.935,P=0.000;t=15.233,P=0.000).At last follow-up,VAS,ODI,and JOA scores were 3.2±1.2,35.5%±14.0%,and 26.6±5.7 respectively,showing significant differences when compared with preoperative scores (8.0±2.2,60.8%±13.3%,and 12.9±3.4) (t=19.857,P=0.000;t=16.642,P=0.000;t=15.922,P=0.000). ConclusionMulti-segment decompression by fenestration and crept enlargement plus internal fixation by interbody and posterior-lateral bone graft fusion is helpful to relieve nerve compression symptoms,rebuild spinal balance,and improve the life quality of the patients.It is a very effective way to treat DLS and multi-segment lumbar spinal stenosis.
ObjectiveTo summarize and analyze the characteristics of L1-L4 vertebrae and hip bone mineral density (BMD) in patients with degenerative lumbar scoliosis under dual energy X-ray absorptiometry (DEXA). MethodsWe collected all the preoperative total spine frontal and lateral X-ray images and DEXA examination results of patients with degenerative lumbar scoliosis who were hospitalized in the Department of Orthopedic Surgery in West China Hospital between August 2013 and August 2014. SPSS 21.0 was used to analyze patients’ age, height and body weight; BMD of each vertebra of L1-L4 vertebrae and L1-L4 vertebrae as a whole, and the T score; BMD of left femoral neck, Ward triangle, greater trochanter, and femoral shaft, and the general BMD of femoral neck, and the T score. ResultsThirty-eight patients with an average age of (67.4±8.2) years were enrolled in this study. DEXA examination results showed that 23.7% (9/38) and 28.9% (11/38) of the patients were osteoporotic in the spine and the hip, respectively; the examination results of total lumbar vertebrae and total femoral neck bones were concordant in 60.5% (23/38) of the patients. For lumbar vertebrae, the BMD from high to low was listed as: L4 vertebra, L3 vertebra, total L1-L4 vertebrae, L2 vertebra, and L1 vertebra. The BMD of L4 vertebra was significantly higher than that of L1 vertebra, and the BMD of lumbar vertebrae from L1 to L4 in turn presented a step-like increasing trend. For hip bones, the BMD from high to low was listed as: femoral shaft, total femoral neck area, femoral neck, greater trochanter, and Ward triangle. The BMD of the femoral shaft was significantly higher than that of Ward triangle. In the whole DEXA examination, the BMD of total L1-L4 lumbar vertebrae and its T score were higher than the BMD of left femoral neck area and its T score, respectively. ConclusionsDegenerative changes of the lumbar spine may lead to misinterpretation of BMD measurements and cause underdiagnosis of osteoporosis with DEXA. Routine reporting of spine BMD at L1 can add valuable information for reassessment and monitoring. The BMD of hip is less affected by osteoarthritis, osteophytes than the lumbar spine, and thus, it will be more meaningful in diagnosing and monitoring of the disease.
ObjectiveTo completely establish a three-dimensional (3D) simulation model of degenerative lumbar scoliosis (DLS) with the whole lumbar segments, then to analyze the biomechanical changes of the scoliosis segments by finite element analysis.MethodsA case of DLS patient was selected with L1-5 segments of CT scanning data, which was imported into MIMICS 15, SolidWorks, Hyper-Mesh software to establish a 3D simulation model, and ANSYS 15 was used to analyze the model. At the same time, different material properties and boundary loading conditions were assigned to various structures to simulate the actual human body conditions.ResultsThe 3D model built a total of 856 154 units and 232 850 nodes, including the reconstruction of fine vertebral bodies, intervertebral disc tissue, structure of various ligaments and joint cartilages. Under the load and torque, the range of whole lumbar segments was decreased, in the stress distribution on the four discs: the L2/3 intervertebral disc stress value (3.320 MPa) > L 4/5 intervertebral disc stress value (0.783 MPa) > L 3/4 intervertebral disc stress value (0.551 MPa) > L 1/2 intervertebral disc stress value (0.462 MPa). The stress distribution of the vertebral body showed that, L5 vertebral stress (34.0 MPa) > L 4 (33.6 MPa) >L 3 (30.0 MPa) > L 1 (23.3 MPa) > L 2 (22.4 MPa).ConclusionThe range of motion of the six degrees of freedom of the lumbar spine in DLS is decreased, the local stress distribution of the lumbar spine is abnormal, and the abnormal stress changes of the apical vertebral body and the top intervertebral disc may be the biomechanical basis for the occurrence or progression of DLS.
ObjectiveTo explore the effectiveness of nano-hydroxyapatite/polyamide-66 (n-HA/PA66) Cage in interbody fusion for degenerative lumbar scoliosis.MethodsA retrospective analysis was designed and conducted for 43 patients, who underwent posterior decompression and n-HA/PA66 Cage interbody fusion with correction of deformity between January 2013 and June 2016. Eighteen cases were single-level fusion (single-level group) and 25 cases were double-level fusion (double-level group). There was no significant difference in gender, age, body mass index, direction of convex, degree of apical rotation, fusion level, the number of osteoporotic patients, pre-operative intervertebral height of fusion segments, coronal Cobb angle, visual analogue score (VAS), and modified Oswestry Disability Index (ODI) between 2 groups (P>0.05). The operation time, intraoperative blood loss, postoperative drainage, hospital stay, and complications of the operation were recorded. Modified ODI, VAS score, and MacNab criteria were adopted to assess clinical outcomes. Radiographic indexes, including intervertebral height of fusion segments, coronal Cobb angle, disc insertion depth, and the bone graft fusion rate, were also evaluated.ResultsThere was no significant difference in operation time, intraoperative blood loss, postoperative drainage, and hospital stay between 2 groups (P>0.05). All patients were followed up 18-62 months (mean, 30.9 months). Wound complications, postoperative delirium, and Cage retropulsion occurred in 4 cases (2 cases in single-level group, 2 cases in double-level group), 1 case of single-level group, and 1 case of double-level group, respectively. The intervertebral height of fusion segments after operation significantly improved compared with preoperative ones in both groups (P<0.05). At last follow-up, the intervertebral height in double-level group was superior to which in single-level group (P<0.05). The coronal Cobb angles after operation significantly improved compared with preoperative ones (P<0.05), and no significant difference was found between 2 groups at each time point (P>0.05). The disc insertion depth showed no significant difference between different time points after operation in 2 groups (P>0.05) and between 2 groups at each time point after operation (P>0.05). Bony fusion was obtained in all patients at last follow-up. The VAS score and modified ODI after operation in both groups were superior to those before operation (P<0.05). The VAS score in double-level group was higher than that in single-level group (P<0.05) at last follow-up, and no significant difference was found in VAS score and modified ODI between 2 groups at other time points (P>0.05). According to the MacNab criteria, the excellent and good rates at last follow-up were 94.4% and 84.0% in single-level group and double-level group, respectively.ConclusionThe n-HA/PA66 Cage can effectively restore and maintain the disc height of fusion segment, normal sequence, and biomechanical stability of the spine, and gain favorable effectivenss for degenerative lumbar scoliosis. And double-level fusion is superior to single-level fusion in maintaining disc height of fusion segment.
ObjectiveTo explore the risk factors of coronal imbalance after posterior long-level fixation and fusion for degenerative lumbar scoliosis.MethodsRetrospectivly analyzed the clinical records of 41 patients with degenerative lumbar scoliosis who had received posterior long-level fixation and fusion with selective transforaminal lumbar interbody fusion (TLIF) accompanied by Ponte osteotomy between August 2011 and July 2016. Patients were divided into imbalance group (group A, 11 cases) and balance group (group B, 30 cases) according to state of coronal imbalance measured at last follow-up. The radiographic parameters at preoperation and last follow-up were measured, and the variance of preoperative and last follow-up parameters were calculated. The radiographic parameters included coronal Cobb angle, coronal balance distance (CBD), apical vertebral translation (AVT), apical vertebral rotation (AVR), Cobb angle of lumbar sacral curve (LSC), and L5 tilt angle (L5TA). Univariate analysis was performed for the factors including gender, age, preoperative T value of bone mineral density, number of instrumented vertebra, upper and lower instrumented vertebra, segments of TLIF, decompression, and Ponte osteotomy, as well as the continuous variables of preoperative imaging parameters with significant difference were converted into two-category variables, obtained the influence factors of postoperative coronal imbalance. Multivariate logistic regression analysis was performed to verify the risk factors from the preliminary screened influence factors and the variance of imaging parameters with significant difference between the two groups.ResultsThe follow-up time of groups A and B was (3.76±1.02) years and (3.56±1.03) years respectively, there was no significant difference between the two groups (t=0.547, P=0.587). The coronal Cobb angle, AVT, LSC Cobb angle, and L5TA in group A were significantly higher than those in group B before operation (P<0.05), and all the imaging parameters in group A were significantly higher than those in group B at last follow-up (P<0.05). There was no significant difference between the two groups in parameters including the variance of coronal Cobb angle, AVT, and LSC Cobb angle before and after operation (P>0.05), and there were significant differences between the two groups in parameters including the variance of CBD, L5TA, and AVR (P<0.05). Univariate analysis showed that preoperative L5TA was the influencing factor of postoperative coronal imbalance (P<0.05). Multivariate logistic regression analysis showed that preoperative L5TA≥15° was an independent risk factor of postoperative coronal imbalance, and variance of pre- and post-operative AVR was a protective factor.ConclusionPreoperative L5TA≥15° is an independent risk factor for coronal imbalance in patients with degenerative lumbar scoliosis after posterior long-level fixation and fusion.