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<p><b>BACKGROUND</b>Recent studies have demonstrated that the Lenke system is relatively efficient and consistent in classifying scoliosis curves. Basically, fusion should include the main curve and the structural minor curve. The criteria for defining the structural minor curve were established to help guide these decision-making process. The present study was designed to investigate predictors of the structural curve, and see whether it was possible to prevent the formation of the structural curve by interfering with influencing factors to decrease the fusion level.</p><p><b>METHODS</b>Age, gender, Cobb angle, Perdriolle rotation, Risser sign and the number of vertebrae included in the curve, brace treatment, and curve location were recorded in 145 idiopathic scoliosis patients from July 2001 to January 2007. The patients were divided into two groups: structural and non-structural groups. Demographics and baseline characteristics were compared between the two groups as an initial screen. Logistic regression was used to analyze factors affecting the minor curve to become the structural curve.</p><p><b>RESULTS</b>Compared with the non-structural group, the structural group had a higher Cobb angle ((51.34 ± 13.61)° vs. (34.20 ± 7.21)°, P < 0.001), bending angle ((33.94 ± 9.92)° vs. (8.46 ± 5.56)°, P < 0.001) and curve rotation ((23.25 ± 12.86)° vs. (14.21 ± 8.55)°, P < 0.001), and lower flexibility ((33.48 ± 12.53)% vs. (75.50 ± 15.52)%, P < 0.001). There was no significant difference in other parameters between the two groups. The results of the Logistic regression analysis showed that the Cobb angle (OR: 9.921, P < 0.001) and curve location (OR: 4.119, P = 0.016) were significant predictors of structural curve in adolescent idiopathic scoliosis. Every 10° change of Cobb angle increased the possibility of turning the minor curve into the structural curve by 10-fold. And thoracic curve showed, on the average, the possibility of becoming the structural curve about 4-fold more often than did the thoracolumbar/lumbar curve.</p><p><b>CONCLUSIONS</b>Curve severity and curve location affect the minor curve's structural features in adolescent idiopathic scoliosis.</p>
Subject(s)
Adolescent , Female , Humans , Male , Logistic Models , Lumbar Vertebrae , Pathology , Scoliosis , Pathology , Thoracic Vertebrae , PathologyABSTRACT
ObjectiveTo analyze the disc working zone of intervertebral foramens (ⅣF) for percutaneous posterolateral approach to the lumbar disc with dissection and measurement of adult cadaveric spine speciments.MethodsTwenty-five lumbar IVFs of cadaveric spines(age:45-65 years; body height:150-176 cm) were studied.The heights of the intervertebral space at the most posterior margin (h) and the angles between the nerve root and the plane of the disc (β) at the sagittal plane and the distance from the nerve root to posterolateral margin of disc(d) were measured.The distances from nerve root to the lateral edge of articular process at the plane of the inferior endplate of the upper vertebra (a1) and the plane of the superior endplate of the vertebra below(a2) were measured.We also measured the distance between the nerve root and the dura at two planes of the vertebra endplate(b1,b2) after removing the lamina and articular processes.ResultsThe disc in the ⅣF is contained in the trapezoid shaped zone at the sagittal plane or the coronal plane.The parameters of two trapezoids are displayed:h is (7.0±1.1) mm; β is 77.6°±8.4°; d is (3.4±2.3)mm; a1 is (9.4±2.2) mm; a2 is (10.8±4.6) mm; b1 is (9.9±2.7) mm; and b2 is (17.7±2.1) mm.All values increase as the level goes down except the value of β,which decreases.ConclusionThe disc working zone of ⅣF is a complicated three-dimensional structure changed from the Kambin's triangle,which could be simulated by construction of two trapezoid on sagittal and coronal planes.The anatomic study of the structure is able to help the clinical transforaminal managements of the lumbar disc.For example,the dimension of working cannula could be figured out by the height of the intervertebral space.The angle of the needle inserted is affected by the distance from nerve root to the disc in this structure.
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ObjectiveTo compare the clinical results between minimally invasive transforaminal lumbar(mini-TLIF) and posterior open surgery in treatment of lumbar spondylolisthesis.MethodsFrom March 2008 to August 2010,a total of 49 cases with lumbar spondylolisthesis underwent surgical intervention were retrospectively analyzed,including 23 cases with mini-TLIF and 26 with open surgery.Operation time,intra-operative bleeding,and radiation exposure times were recorded.Pre- and postoperative back pain was assessed by visual analogue scale(VAS),and lumbar function was evaluated by Oswestry disability index (ODI).The clinical results were assessed by Macnab criterion,and the pre and postoperative radiologic parameters were compared.ResultsThe mean follow-up time was 11 months(ranged,9-22).Both groups got good clinical results and satisfactory radiologic parameters.The group of mini-TLIF was superior to the group of open surgery in intra-operative bleeding,VAS of the second day postoperatively and the willingness of reoperation(P＜0.05).The ODI in the patients with open surgery were decreased from 31.2％±8.2％ to 16.1％±6.8％ corresponding to the pre-oporation and the final follow-up.The ODI in the patients with mini-TLIF were decreased from 34.4％±11.7％ to 15.3％±4.3％ corresponding to the pre-operation and the final follow-up.There is no significant difference of the change of ODI between two groups (t=0.673,P=0.412).The group of mini-TLIF need more operation time and were exposed to more X-ray when compared to the open surgery group(P＜0.05).ConclusionMini-TLIF and open surgery can both get satisfactory clinical outcomes in treatment of lumbar spondylolisthesis.Mini-TLIF was superior to open surgery in intra-operative bleeding and VAS of the second day postoperatively,but it needs more operation time and radiation exposure.
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<p><b>BACKGROUND</b>Trans-sacral axial L5/S1 interbody fusion (AxiaLIF), a novel surgical procedure, recently adopted in clinical practice, has excellent clinical outcomes. However, there is inadequate data on the feasibility of the approach in all adult patients and the optimal surgical approach is currently unclear; therefore, further studies are required. In order to enhance the surgical approach for AxiaLIF, prospective anatomical imaging optimization is necessary. The objective of this study was to investigate the ability of magnetic resonance imaging (MRI) to achieve an optimal procedural setting.</p><p><b>METHODS</b>The subjects (n=40) underwent lumbosacral MRI examination. The median sagittal MRI images were analyzed and four measurement markers were defined as follows: the center of the L5/S1 disc (A), the anterior margin of the S1/2 disc space (B), the sacrococcygeal junction (C), and the coccygeal tip (D). The measurement markers were connected to each other to produce five lines (AB, AC, AD, BC, and BD), as reference lines for surgical approaches. The distance between each reference line and the anterior and posterior margins of the L5 and S1 vertebral bodies was measured to determine the safety of the respective approaches.</p><p><b>RESULTS</b>In all patients, Lines AB and AC satisfied the imaging safety criteria. Line AB would result in a significant deviation from the median and was determined to be unsuitable for AxiaLIF. Line AD satisfied the imaging safety criteria in 39 patients. However, the anal proximity of the puncture point proved to be limiting. For lines BC and BD, the imaging safety criteria were satisfied in 70% and 45% of patients, respectively.</p><p><b>CONCLUSIONS</b>The AxiaLIF procedure is a safe technique for insertion of fusion implants in all subjects. Line AC is a favorable reference line for surgical approach and safe for all subjects, while line BC is not suitable for all subjects.</p>
Subject(s)
Adult , Aged , Aged, 80 and over , Humans , Male , Middle Aged , Fractures, Bone , General Surgery , Magnetic Resonance Imaging , Methods , Sacrum , General Surgery , Spinal Fusion , Methods , Treatment OutcomeABSTRACT
<p><b>BACKGROUND</b>Previous clinical and basic research of axial lumbar interbody fusion (AxiaLIF) all focused on the L5/S1. However, there is no data on the feasibility of this approach for the fusion of both L4/5 and L5/S1. This study aimed to explore whether transsacral axial interbody fusion is a candidate for the fusion of both L4/5 and L5/S1.</p><p><b>METHODS</b>The subjects (n = 40) underwent lumbosacral magnetic resonance imaging (MRI). The median sagittal MRI images were analyzed and five measurement markers were defined as follows: the center of the L4/5 disc (A), the center of the L5/S1 disc (B), the anterior margin of the S1/2 space (C), the sacrococcygeal junction (D), and the coccygeal tip (E). The measurement markers were connected each other to produce nine lines (AB, AC, AD, AE, BC, BD, BE, CD and CE) as the reference lines for surgical approaches. The distance between each reference line and the anterior and posterior margins of the L4, L5 and S1 vertebral bodies were measured to determine the safety of the respective approaches.</p><p><b>RESULTS</b>Twenty subjects were capable of finding one reference line to fuse both L4/5 and L5/S1 via transsacral axial interbody fusion approach. The surgical approach reference line was AE or CE line. In the other 20 subjects, it was failed to find a reference line which met the safety criteria for fusing both L4/5 and L5/S1.</p><p><b>CONCLUSIONS</b>About half of subjects were capable of finding a suitable AxiaLIF reference line to fuse both L4/5 and L5/S1. In some subjects, it was difficult to find a suitable AxiaLIF reference line to fuse both L4/5 and L5/S1.</p>
Subject(s)
Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Magnetic Resonance Imaging , Minimally Invasive Surgical Procedures , Methods , Spinal Fusion , MethodsABSTRACT
<p><b>OBJECTIVE</b>To investigate the clinical results of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for lumbar spinal stenosis with lumbar instability.</p><p><b>METHODS</b>Retrospective study was done on 42 cases of lumbar spinal stenosis with lumbar instability treated with bilateral decompression via unilateral approach and MIS-TLIF through an expandable tubular retractor from March 2010 to January 2011. There were 18 males and 24 females, and mean age was 61.7 years (rang, 48 - 79 years). The level of surgery was L(3-4) in 4 patients, L(4-5) in 26 patients, and L(5)-S(1) in 12 patients. All patients had symptoms of intermittent claudication. And 24 patients had symptoms of lower extremity pain and numbness in one side, and 18 patients had same symptoms in both legs. Operation time, intra-operative bleeding, postoperative hospital stay and complications were recorded. Visual analogue scale (VAS) scores for low back pain and leg pain were recorded before and after surgery. Oswestry disability index (ODI) scores were also recorded before and after surgery. The Bridwell criterion was used for evaluating the interbody fusion, and the MacNab criterion was used for assessment after surgery.</p><p><b>RESULTS</b>The mean operative time was 150.4 minutes (range, 120 - 170 minutes), and mean blood loss was 147.1 ml (range, 50 - 400 ml). The hospitalization time after surgery was 5 - 18 d, an average of 8.8 d. All cases were followed-up for 6 - 14 months (average 11 months). VAS score of low back pain before surgery was 7.3 ± 1.0, and were 2.9 ± 0.8 and 2.0 ± 0.8 at three months after surgery and the last follow-up respectively. VAS score of leg pain before surgery was 7.9 ± 0.7, and were 2.0 ± 0.5 and 1.0 ± 0.7 at three months after surgery and the last follow-up respectively. ODI score was 75% ± 6% before surgery, were 16% ± 6% and 12% ± 5% at three months after surgery and the last follow-up respectively. VAS and ODI scores showed statistically significant improvements (t = 3.110 - 56.323, P < 0.01). There were 40 cases were grade I and II, according to the Bridwell criteria. The clinical results were excellent in 16 cases, good in 22 cases and fair in 4 cases to the MacNab criteria at the final follow-up.</p><p><b>CONCLUSIONS</b>MIS-TLIF is an ideal surgical method for single segment lumbar spinal stenosis with lumbar instability, but close attention should be paid to specific patients, surgeons and hospitals.</p>
Subject(s)
Aged , Female , Humans , Male , Middle Aged , Follow-Up Studies , Lumbar Vertebrae , General Surgery , Minimally Invasive Surgical Procedures , Retrospective Studies , Spinal Diseases , General Surgery , Spinal Fusion , Methods , Spinal Stenosis , General SurgeryABSTRACT
<p><b>OBJECTIVE</b>To evaluate clinical outcomes of a group of adolescent idiopathic scoliosis (AIS) patients undergoing posterior pedicle screw-only instrumentations.</p><p><b>METHODS</b>Between April 2002 and July 2006, 121 AIS patients (93 female and 28 male, average age at operation was 15.5 years which ranged from 10 to 20 years) received posterior pedicle screw-only instrumentation and fusion. All the patients were evaluated by the various-parameters measured in X-ray films before and after surgery, including Cobb angle on coronal plane, Cobb angle on sagittal plane, clavicle angle and shoulder height difference, lowest instrumented vertebrae (LIV) angulation, proximal junction kyphotic angle, the distances of central sacral vertical line (CSVL) to the LIV, to the apical vertebra and to the C(7) plumb line respectively. Complications were followed.</p><p><b>RESULTS</b>An average of (11.0 + or - 1.5) levels was fused. An average coronal correction of proximal thoracic curve was 41.8%, of thoracic curve was 70.8%, of thoracolumbar/lumbar curves was 74.0%. No significant change was found in sagittal alignment. Shoulder balance and apex vertebral to central sacral line were restored well. There were no pseudoarthroses and loss of correction during the follow-ups. One adding-on, 4 proximal thoracic decompensation and 15 proximal junction kyphosis were found during the follow-ups.</p><p><b>CONCLUSION</b>Posterior pedicle screw-only instrumentation and fusion has excellent radiographic and clinical results with minimal complications in the surgical treatment of AIS.</p>
Subject(s)
Adolescent , Child , Female , Humans , Male , Young Adult , Bone Screws , Follow-Up Studies , Retrospective Studies , Scoliosis , General Surgery , Spinal Fusion , Methods , Treatment OutcomeABSTRACT
<p><b>BACKGROUND</b>This study was to investigate the safety of two types of commercially available lumbar artificial discs (CHARITE and PRODISC-L) during a magnetic resonance imaging (MRI) procedure in a 1.5-Tesla MR system, and to evaluate the size of metal artifacts on the MR image for different sequences.</p><p><b>METHODS</b>A 1.5-Tesla clinical MR imaging system was used. The degree of deflection of the endplates of two artificial discs was evaluated by an angle-measurement instrument at the portals of the MRI scanner. The heating effect of the radio frequency (RF) magnetic field was evaluated by using "worst-case" imaging sequences on a human cadaver implanted with an artificial lumbar disc at the L5/S1 intervertebral disc location. The temperatures of the tissue adjacent to the implant, and of the L4/L5 intervertebral disc (used as a control) were measured, respectively, using a digital probe thermometer before and after the MRI scan sequence. A rectangular water phantom was designed to evaluate the metal artifacts of these two artificial discs under different MR imaging sequences.</p><p><b>RESULTS</b>The maximal deflection angle of the endplate of the implants under a static MR field was 7.5 and 6.0 degrees, for the CHARITE and PRODISC-L, respectively. The difference between temperature rise of tissue adjacent to the two types of artificial discs and the temperature rise of the L4/L5 control location was 0.4 and 0.6 degrees C, respectively. The size of metal artifacts on images of TSE (T1/T2 -weighted), STIR and Turbo Dark Fluid sequences were relatively less than those of TSE fat saturation, Flash and SE (T1-weighted) sequences.</p><p><b>CONCLUSIONS</b>The CHARITE and the PRODISC-L artificial disc do not present an additional hazard or risk to a patient undergoing an MRI procedure using a scanner operating with a static magnetic field of 1.5 T or lower. Image artifacts from the implants may present problems if the anatomical region of interest is in or near the area where these implants are located (e.g., vertebral canal at affected segment).</p>
Subject(s)
Humans , Equipment Safety , Evaluation Studies as Topic , Intervertebral Disc , Pathology , General Surgery , Intervertebral Disc Displacement , Pathology , General Surgery , Lumbar Vertebrae , Pathology , General Surgery , Magnetic Resonance Imaging , Methods , Metals , Prostheses and ImplantsABSTRACT
Objective: To discuss the influence of posterior thoracic and lumbar titanium internal fixation system on magnetic resonance image (MRI). Methods: Twelve patients who received thoracic-lumbar posterior titanium internal fixation system were subjected to MRI scanning. The artifact characteristics of titanium internal fixator and its influence on the spinal canal structure were analyzed. Results: The artifact size was 2-3 times that of the internal fixator. The details in the spinal canal and spinal cord were clearly displayed on the sagittal T1 and T2 weighted images and axial T1 weighted image. The link rod had small artifact and had influence on the images of adjacent lamina and facet, but had little influence on the observations after operation. The pedicle screw in the right position had considerable artifact, which influenced the images of lateral spinal canal, foramina, nerve root, and posterolateral herniated disc. Conclusion: Turbo spin echo sequence should be chosen for MRI scanning in patients implanted with posterior thoracic and lumbar titanium internal fixation system, with the echo time minimized. When reading the MRI images, the influence of titanium fixation system on the postoperative MRI should be considered in order to obtain the correct information of the patients.
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Objective: To find out the pathomechanism of low back and leg pain related to intervertebral disc. Methods: The nucleus pulposus of coccygeal vertebral was transplanted to the cavum epidurale of rats to establish the non-compressive model with transplanted nucleus pulposus. The evoke potentials and morphology of nerve roots were observed. Results: Even without mechanical compression, rats transplanted with nucleus pulposus resulted in significant harm to evoked potential and morphology of cauda equina. Conclusion: The biomechanical and/or immunologic inflammatory effect of nucleus pulposus can result in nerve roots injury and is an important factor in the pathogenesis of low back and leg pain.
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Objective: To find out the pathomechanism of low back and leg pain related to intervertebral disc. Methods: The nucleus pulposus of coccygeal vertebral was transplanted to the cavum epidurale of rats to establish the non-compressive model with transplanted nucleus pulposus. The evoke potentials and morphology of nerve roots were observed. Results: Even without mechanical compression, rats transplanted with nucleus pulposus resulted in significant harm to evoked potential and morphology of cauda equina. Conclusion: The biomechanical and/or immunologic inflammatory effect of nucleus pulposus can result in nerve roots injury and is an important factor in the pathogenesis of low back and leg pain.
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Objective To investigate the management and outcome of cerebrospinal fluid leakage(CSFL)complicating anterior cervical surgery.Methods1052patients were performed anterior cervical surgery between October1997and October2002.Of 1052cases,926cases were of cervical spondylotic myelopathy(CSM),and126of ossification of posterior longitudinal ligament (OPLL).11patients suffered from cerebrospinal fluid leakage during operation.There were8males and3females aging from46to72years(average,58years).In the group of CSM,there were2cases of CSFL(0.22%)occurred in resection of osteophyte of the posterior vertebral edge,who were serious CSM of C 4,5 and C 5,6 with severe anterior compression by osseous mass to spinal cord showed on MRI.In the group of OPLL,there were9cases of CSFL(7.14%)occurred in resection of the ossified posterior longitudinal ligament accompanied with severe spinal canal stenosis and anterior compression to spinal cord on radiological imagings,4of them were con-tinuous OPLL from C 2 to C 6 combined with herniation of cervical disc,3segmental,and2mixed.Results The defect area of spinal dura were(0.6～2.0)cm?(1.0～1.5)cm.The cerebrospinal fluid was blocked with fascia and absorbable gelatin sponge during the operation.If CSFL was persistent more than3days after oper-ation,expectant treatment was performed.After the operation,no CSFL occurred in8of 11patients,and the other3cases with postoperative CSFL were cured5,14and17days by dressing change,blocking the wound with gelatin sponge,and suturing of the wound respectively.All patients were followed up for 10to62months(mean,26months).No cerebrospinal fluid cyst and infection occurred.There were no significant negative effects of CSFL on the recovery of neuromuscular function.Conclusion CSFL following cervical anterior surgery can be cured by blocking up leakage of spinal dura during operation,however,conventional conservative treatment including of dressing change,antibiotics administration,horizontal position with low pillow are necessary after operation.