Weishi Li

Peking University Third Hospital, Peping, Beijing, China

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Publications (29)57.91 Total impact


  • No preview · Article · Aug 2015 · Neurosurgery
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    ABSTRACT: To study the risk factors for deep surgical site infection after posterior thoracic and lumbar surgery. The medical data of the patients with deep surgical site infection after posterior thoracic and lumbar surgery from January 2008 to December 2013 were reviewed.For each case patient, 3 non-infected controls were randomly selected from the same database of all patients who underwent posterior thoracic and lumbar surgery.Patients who had diagnosis of spinal fractures, infection, tuberculosis, and tumor were excluded. The microbiology and related factors were collected and analyzed. T-test, χ(2) test and Logistic analysis were used to analyze the data, respectively. Ninety-nine cases were identified (infection group), 57 men and 42 women, average 54.5 years old, average body mass index 26.4 kg/m(2). Fifty-five (55.6%) patients were identified with organisms, and the most common identified organism was Staphylococcus Aureus. Compared with the cases in the control group (44.4 g/L), the cases in the infection group (43.1 g/L) had a significant low albumin preoperatively (P=0.001). Multivariate Logistic analysis showed that obesity (OR=2.102, 95% CI = 1.259 - 3.508), diabetes (OR = 1.926, 95% CI = 1.041 - 3.563), number of surgical levels ≥3 (OR = 1.985, 95% CI = 1.130 - 3.486) were risk factors for this complication (P < 0.05). For deep surgical site infection after posterior thoracic and lumbar surgery, obesity, diabetes, preoperative low albumin and number of surgical levels ≥3 are risk factors.
    No preview · Article · May 2015 · Zhonghua wai ke za zhi [Chinese journal of surgery]
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    ABSTRACT: To summarize the clinical characteristics of severe lumbar dysplastic spondylolisthesis, and to investigate the effectiveness of the posterior surgery including decompression, partial reduction with instrumentations and interbody fusion. Twelve patients of severe lumbar dysplastic spondylolisthesis treated between March 2007 and February 2012 were studied retrospectively. Twelve patients include 10 female and 2 male patients with an average age of 10.7 years (9-17 years). All of their spondylolisthetic level was L5 vertebrae. None of them were effective after regular conservative treatment. Eleven of 12 patients were treated surgically through a posterior decompression and instrumented reduction. One case was treated by L5 vertebrectomy and reduction of L4 onto sacrum. Their levels of instrumentations were L4-S1 in 8 patients and L5-S1 in 4 patients. All of 12 patients were fused via interbody fusion. The visual analog scale(VAS), Oswestry disability index (ODI), Japanese Orthopaedic Association(JOA) score, slip angle, percentage slip, lumbar lordosis, sagittal balance were used as outcome measures. All of these patients were followed up regularly with an average follow-up of 32 months (6-64 months). Five of these 12 patients suffered postoperative nerve root impairment, including impairment of unilateral and bilateral L5 nerve roots. At the latest follow-up, only 1 case was still suffering from the weakness of unilateral peroneal long and short muscles, the other 4 patients recovered totally. The degree of their spondylolisthesis was reduced II degrees or more, and their slip angles decreased from 35.6 degree preoperatively to 9.8 degree postoperatively. The VAS, ODI , JOA, lumbar lordosis and sagittal balance were improved postoperatively. No instrumentation loosening or rupture was found. In patients with severe lumbar dysplastic spondylolisthesis, isolated posterior decompression, reduction with internal fixation may lead to a satisfactory clinical outcomes. Surgical reduction is helpful to improve the interbody contact area, thus possibly improve the fusion rate. At the same time, reduction may reduce or correct the lumbar-sacral kyphosis, recover the normal lumbar lordosis and normal sagittal alignment with an excellent cosmetic result. The incidence of the postoperative nerve impairment is high because of the stretching of L5 nerve roots secondary to the reduction, but most of the patients with postoperative nerve impairment may recover gradually.
    No preview · Article · Nov 2014 · Zhonghua wai ke za zhi [Chinese journal of surgery]
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    ABSTRACT: Scheuermann's disease (SD) is a spinal disorder and includes both a classic form and an atypical form. Interestingly, its existence among the general population as well as the disc disease patients is common. One of our previous studies showed that about 18% of the hospital staff members meet the SD criteria. On the other hand, another study has demonstrated that 95.2% of the symptomatic thoracolumbar disc herniation (STLDH) patients meet the SD criteria, which suggests that STLDH is very likely a special form of SD. The purpose of this study was to discriminate the factors contributing to the development of STLDH by comparing STLDH patients with the healthy SD-like hospital staff members. This is a retrospective study including 33 STLDH patients who met the SD criteria and 30 SD-like hospital staff members. The STLDH group was chosen from a group of patients who underwent surgery after a diagnosis of STLDH (T10/11-L1/2) at our hospital between June 2007 and June 2010. SD-like hospital staff members were chosen from a database created in 2007, which contained a lumbar MR and low back pain (LBP) questionnaire of 188 hospital staff members. The demographic and radiologic characteristics were compared between groups. There was no statistical difference in sex, age, and height between the two groups. The STLDH patients had higher body weight, boby mass index, and thoracolumbar kyphotic angle than SD-like hospital staff members. In addition, STLDH patients had more levels of Schmorl's nodes (3.5±1.7 vs. 2.0±1.9, t = 3.364, P = 0.001) and irregular endplateson (4.0±1.9 vs. 2.7±1.9, t = 2.667, P = 0.010) compared to the SD-like hospital staff members. Higher body weight, higher body mass index, larger thoracolumbar kyphosis, and more Schmorl's nodes and irregular endplates on MR may be associated with the development of STLDH in "SD-like people."
    Full-text · Article · Nov 2014 · Chinese medical journal

  • No preview · Article · Aug 2014 · The Spine Journal
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    ABSTRACT: Study Design. A clinical study.Objective. To measure the changes in pulmonary function and thoracic volume associated with surgical correction of kyphotic deformities.Summary of Background Data. No prior study has focused on the pulmonary function and thoracic cavity volume before and after corrective surgery for kyphosis.Methods. Thirty-four patients with kyphosis underwent posterior deformity correction with instrumented fusion. Preoperative and postoperative pulmonary function was measured, and pulmonary function grade was evaluated as mild, significant, or severe. The change in preoperative to postoperative pulmonary function was analyzed, using six comparative sub-groupings of patients based on: age, severity of kyphosis, location of kyphosis apex, length of follow up time after surgery, degree of kyphosis correction, and number of segments fused. A second group of nineteen patients also underwent posterior surgical correction of kyphosis, which had thoracic volume measured preoperatively and postoperatively with CT scanning.Results. All of the pulmonary impairments were found to be restrictive. After surgery, most of the patients had improvement of the pulmonary function. Before surgery, the pulmonary function differences were found to be significant, both based on severity of preoperative kyphosis (less than 60 degrees vs. more than 60 degrees), and based on the location of the kyphosis apex (above T10 vs. below T10). Younger patients (below 35 years old) were more likely to exhibit statistically significant improvements in pulmonary function after surgery. However, thoracic volume was not significantly related to pulmonary function parameters. After surgery, average thoracic volume had no significant change.Conclusion. The major pulmonary impairment caused by kyphosis was found to be restrictive. Patients with kyphosis angle≥60° or with kyphosis apex above T10 had more severe pulmonary dysfunction. Patient age was significantly related to change in pulmonary function after surgery. However, the average thoracic volume had no significant change after surgery.
    No preview · Article · Jul 2014 · Spine
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    ABSTRACT: To analyze the clinical characteristics of focal kyphosis in upper thoracic spine, and observe the outcome of the posterior corrective surgical procedures. Thirteen patients of focal kyphosis were treated with posterior surgical procedures in our medical center. The kyphosis apex was above T6 in all cases. The surgical procedures performed in this study included pedicle subtraction osteotomy (PSO) in six cases and vertebral column resection (VCR) in seven cases. For each case, the kyphosis angle, curvature of lower thoracic spine, lumbar lordosis angle, cervical lordosis angle, pelvic parameters, and the sagittal plane balance of the spine were compared before and after surgery. Neurological function change was assessed based on Frankel grading system and oswestry disability index (ODI). The average follow-up time of this study was 28.3 months. The average kyphosis angle was reduced from 73.5A(0) before surgery to 32.7A(0) immediately after surgery, and remained at 33.5A(0) at follow-up. The average ODI improved from 22.5 before surgery to 15.5 at follow-up. The neurological function improved after surgery in eight cases. There were two cases of transient neurological deficiency in the lower extremities after VCR procedure, who eventually recovered under postoperative care. One case had recurrent kyphosis due to implant failure after VCR procedure, and recovered after the revision surgery. Although high risk needs to be warned, the corrective surgery for focal kyphosis in upper thoracic spine still can achieve satisfactory results. Given the comparative surgical results yet less complications, PSO seems to be a preferable procedure over VCR for kyphosis at this region.
    No preview · Article · Jun 2014 · European Spine Journal
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    ABSTRACT: Methods: This retrospective cohort study included 188 staff members from a single hospital. Participants' lumbar MR images and self-administered questionnaires concerning demographic information, LBP status, consequences, and functional limitations were collected. Participants were classified into 2 groups according to whether lumbar MR images met SD diagnostic criteria, and LBP status, consequences, and functional limitation were compared. Follow-up interviews were conducted after 6 years to compare LBP progression.
    Full-text · Article · Jun 2014 · Spine
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    ABSTRACT: Background: For young patients, the surgical method for lumbar disc herniation remains controversial. The aim of this study was to prospectively determine the short-term clinical outcome after surgery for young patients with lumbar disc herniation. Methods: In this prospective comparative study between April 2010 and August 2011, a total of 80 patients underwent primary surgery at a single level for lumbar disc herniation. The patients were divided into two groups: decompression alone and decompression with instrumented fusion. An independent examiner clinically evaluated the patients at preoperation and at 1, 3, 6, and 12 months after surgery. The patients filled out the instruments for back and leg pain using a Visual Analog Scale (VAS), Oswestry Low Back Pain Disability Questionnaire (ODI), and Japanese Orthopaedic Association (JOA) scores. The differences between the two groups were analyzed. Results: The mean age of all the patients at the time of surgery was 33.7 years. Of the 80 patients, 38 patients underwent decompression alone and 42 patients underwent posterior lumbar interbody fusion. Increasing complexity of surgery was associated with a longer surgery time, greater blood loss, and a longer hospital stay after surgery. Both methods of surgery independently improved outcomes compared with baseline status based on VAS, ODI, and JOA scores (P < 0.05), and no significant differences were found between the two groups at most of the measuring points in time, although patients with decompression alone had a higher JOA score (P = 0.016) and higher JOA recovery rate (P = 0.010) at the 3-month follow-up. Conclusions: The short-term results of our study showed that both methods of surgery obtained effective clinical outcomes, but decompression alone had some advantages (shorter surgery time, less blood loss, shorter hospital stay, and lower cost) compared with decompression with instrumented fusion. Young patients with decompression alone could achieve great physical function earlier.
    No preview · Article · Jun 2014 · Chinese medical journal
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    ABSTRACT: Study design:: Retrospective review. Objective:: To examine the epidemiological characteristics and causes of spinal cord compression in thoracic spinal stenosis (TSS). Summary of background data:: As the thoracic spinal canal is relatively narrow and the thoracic cord has a poor blood supply, severe neurological symptoms may develop if TSS is not treated promptly. However, as it is rare, TSS is less often studied and its clinical features are often not recognized. Methods:: Between 2005 and 2012, 427 patients diagnosed with TSS underwent surgery in our department. The male to female ratio was 1.4:1. The mean age was 53 years. The most reported symptom was motor deficit in the lower extremities (347 cases, 81%), followed by sensory deficit in the lower limbs (271 cases, 64%). Falls were the most common trigger of acute symptoms (29 cases, 7%). Preoperative imaging results of each case were reviewed to summarize the causes and site of cord compression, and co-existing spinal diseases. Results:: The most reported compressive factor was ossification of the ligamentum flavum (OLF) which implicated in 309 cases, followed by thoracic disc herniation (TDH) and ossification of the posterior longitudinal ligament (OPLL). The most common site of OLF and TDH was T9-L1 (56% and 89%, respectively), while OPLL was mainly found at T1-8 (90%). Forty-seven patients (11%) had co-existing lumbar spinal disease and 64 (15%) had cervical disease. Conclusions:: Onset of TSS was generally insidious but may be triggered acutely by apparently trivial events. Myelopathy mainly affected the lower limbs. The most common cause was OLF in the lower thoracic spine. Cervical or lumbar spinal disease was often also evident; therefore, comprehensive clinical assessment is needed to avoid delays in diagnosis and treatment.
    No preview · Article · May 2014 · Journal of Spinal Disorders & Techniques
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    ABSTRACT: Traumatic fractures of the spine are most common at the thoracolumbar junction and can be a source of great disability. To review the most current information regarding the pathophysiology, injury pattern, treatment options, and outcomes. Literature review. Relevant articles, textbook chapters, and abstracts covering thoracolumbar spine fractures with and without neurologic deficit from 1960 to the present were reviewed. The thoracolumbar spine represents a unique system from a skeletal as well as neurological standpoint. The rigid rib-bearing thoracic spine articulates with the more mobile lumbar spine at the thoracolumbar junction (T10 - L2), the site of most fractures. A complete examination includes a careful neurologic examination of both motor and sensory systems. CT scans best describe bony detail while MRI is most efficient at describing soft tissues and neurological structures. The most recent classification system is that of the new Thoracolumbar Injury Classification and Severity Score. The different fracture types include compression fractures, burst fractures - both stable and unstable -, flexion-distraction injuries and fracture dislocations. Their treatment, both operative and non-operative depends on the degree of bony compromise, neurological involvement, and the integrity of the posterior ligamentous complex. Minimally invasive approaches to the care of thoracolumbar injuries have become more popular, thus, the evidence regarding their efficacy is presented. Finally, the treatment of osteoporotic fractures of the thoracolumbar spine is reviewed, including vertebroplasty and kyphoplasty, their risks and controversies, and senile burst fractures, as well. Thoracolumbar spine fractures remain a significant source of potential morbidity. Advances in treatment have minimized the invasiveness of our surgery and in certain stable situations, eliminated it all together.
    No preview · Article · Jan 2014 · The spine journal: official journal of the North American Spine Society
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    ABSTRACT: There have been several surgical approaches used in the treatment of thoracolumbar disc herniation (TLDH) from T10/11 to L1/2. However, central calcified TLDH cases are still challenging to spine surgeons. The anterior transthoracic approaches and lateral/posterolateral approaches are all essentially performed from one side; thus, the compressive lesion and the dura matter on the other side of the spinal canal are not clearly visualized, predisposing the procedure to incomplete decompression or inadvertent cord manipulation. Moreover, a number of these approaches are technically demanding and require entry into the chest. The purpose of this study was to introduce a new surgical procedure-circumspinal decompression and fusion through a posterior midline incision-for the treatment of central calcified TLDH and to evaluate its surgical outcome. In this study, 22 patients (15 males and 7 females; mean age 49 years) with central calcified TLDH underwent this procedure between April 2008 and April 2011. Altogether, 26 discs were excised, with two discs at T10/11, eight discs at T11/12, nine discs at T12/L1 and seven discs at L1/2. Of these patients, 16 returned for final follow-up, with a mean follow-up period of 41 months (range 24-57 months). Clinical outcomes, including operative time, blood loss, perioperative complications, post-operative time of hospitalization, neurological status improvement, extent of decompression, back pain, local spinal curvature and fusion, were investigated. The patients' neurological status was evaluated by a modified Japanese Orthopedic Association scoring system of 11 points. Fusion and the extent of decompression were evaluated by reconstruction CT at final follow-up. The mean operative time was 185 min, the mean blood loss was 896 ml and the mean post-operative hospitalization time was 8 days. Four patients suffered perioperative complications, but only two were related to dura violation and none involved the respiratory system. All of the 16 patients who returned for the final follow-up showed improvement, and evidence of improvement was found in five of the other six patients who did not return for final follow-up through telephone interview or earlier follow-up evaluations. Complete decompression was achieved in 12 of the 16 patients who returned for final follow-up. In the 16 patients who returned for final follow-up, back pain was significantly reduced and local spinal curvature remained unaltered. In addition, based on reconstruction CT images, solid fusion was observed in 15 of the 16 patients who returned for final follow-up. The circumspinal decompression and fusion through a posterior midline incision procedure can be used to treat central calcified TLDH patients with neurological deficits. This method's greatest advantage is that it is a highly effective and safe procedure for decompression. Although it is a major and destructive procedure, spinal stability was well maintained in most of the cases. In this era when minimally invasive spine surgeries like thoracoscopy have been in an upward trajectory, spine surgeons still should be made aware of this procedure.
    Full-text · Article · Oct 2013 · European Spine Journal
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    ABSTRACT: Study Design. Retrospective and radiological analysis of spino-pelvic sagittal alignment in Chinese patients with thoracic and thoracolumbar kyphosis.Objective. To determine the impact of thoracic and thoracolumbar kyphosis on pelvic sagittal morphology and the mechanisms of adjusting trunk sagittal balance.Summary of Background Data. Previous studies have reported the normative values of pelvic sagittal parameters and classification of normal patterns of sagittal curvature, but no study has analyzed the impact of thoracic and thoracolumbar kyphosis on pelvic sagittal morphology and the mechanisms of maintaining the sagittal balance.Methods. Whole spine and standing lateral radiographs of 49 Chinese patients with thoracic and thoracolumbar kyphosis were taken before surgery, immediately after surgery and in the final follow-up. The pelvic and spinal parameters were measured and the correlations of all parameters were analyzed. A descriptive analysis characterizing these parameters and a multivariate analysis were performed.Results. The patients had a mean age of 30.3 years, while the mean age at which the patients developed kyphosis was 7.1 years. Preoperative pelvic incidence was significantly less than that of normal subjects, and there was no difference in the preoperative, in the immediate postoperative and in the final follow-up radiographs. The magnitude of kyphosis and the levels involved were independent factors of pelvic incidence. Pelvis anteversion and lumbar hyperlordosis were the mechanisms of adjusting the trunk sagittal balance. Although kyphosis and sagittal imbalance was corrected by surgery, pelvic sagittal morphology remained unchanged.Conclusion. Thoracic and thoracolumbar angular kyphosis occurring during the growth period will lead to abnormal pelvic morphology. Greater the kyphotic angle and lower the kyphotic levels, greater impact it will have on the pelvic morphology during skeletal maturation. The mechanisms of adjusting the trunk sagittal balance include not only pelvis anteverting, but also lumbar hyperlordosis. The latter serves as the main mechanism once skeletal maturation has been established. After skeletal maturation, surgery can reestablish the spinal sagittal balance but not the pelvis morphology.
    No preview · Article · Mar 2013 · Spine
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    ABSTRACT: Purpose The purpose of this study is to review our operative experience of congenital kyphosis or kyphoscoliosis undergoing either pedicle subtraction osteotomy (PSO) or posterior vertebral column resection (pVCR) according to certain criteria we have established. Methods From December 2003 to 2009, 23 consecutive patients of congenital kyphosis or kyphoscoliosis were treated by means of PSO or pVCR procedure in a single institution. The average preoperative kyphosis angle was 74.3º. The C7 plumb line was 12.6 mm posterior to the posterior–superior corner of S1 on average, showing negative imbalance. In the 11 cases who had accompanied scoliosis, the average preoperative scoliosis angle was 42.6º. The average Oswestry Deficiency Index (ODI) for back pain was 14.6 before surgery. Eleven patients had compromise of neurological functions. Results After PSO or pVCR procedure, the average kyphosis angle decreased to 20.0º, and the accompanied scoliosis also decreased to 15.8º. The average follow-up time after surgery was 34.3 months. At the last follow-up, the average kyphosis corrective rate was 73.7 %, and the average scoliosis corrective rate was 61.7 %. The negative imbalance improved, with the C7 plumb line being 1.5 mm posterior to the posterior–superior corner of S1 on average. After surgery, the average ODI for back pain had 40.6 % improvement, and most patients who had neurological symptoms before surgery had varying degrees of relief. The total satisfactory rate to corrective surgery was 91.3 %. No permanent neurological damage was observed. Conclusions If selected appropriately, both PSO and pVCR procedures can achieve compatible and satisfactory correction results in the surgical treatment of congenital kyphosis or kyphoscoliosis.
    No preview · Article · Aug 2012 · European Spine Journal
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    ABSTRACT: Milling operations in spinal surgery demand much experience and skill for the surgeon to perform the procedure safely. A 3D navigation method is introduced aiming at providing a monitoring system with enhanced safety and minimal intraoperative interaction. An automatic registration method is presented to establish the 3D-3D transformation between the preoperative CT images and a common reference system in the surgical space, and an intensity-based similarity metric adapted for the multi-planar configuration is introduced in the registration procedure. A critical region is defined for real-time monitoring in order to prevent penetration of the lamina and avoid violation of nerve structures. The contour of the spinal canal is reconstructed as the critical region, and different levels of warning limits are defined. During the milling procedure, the position of the surgical instrument relative to the critical region is provided with augmented display and audio warnings. Timely alarm is provided for surgeons to prevent surgical failure when the mill approaches the critical region. Our validation experiment shows that real-time 3D navigation and monitoring is advantageous for improving the safety of the milling operation.
    No preview · Article · Apr 2012 · Computer methods and programs in biomedicine
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    ABSTRACT: STUDY DESIGN:: A clinical retrospective study. OBJECTIVE:: To analyze the complications and relevant management of the correction procedure for focal kyphosis. SUMMARY OF BACKGROUND DATA:: The treatment of focal kyphosis is a difficult problem in spine surgery. The potential complications of surgery should be considered cautiously and managed positively. METHODS:: Eighty-one patients with focal kyphosis were treated by posterior osteotomy and correction. The etiology was posttraumatic in 31 cases, healed tuberculosis in 31 cases, congenital in 17 cases, and iatrogenic in 2 cases. The surgical procedures were pedicle subtraction osteotomy in 19 cases, posterior osteotomy with anterior opening-posterior closing correction in 23 cases, and posterior vertebral column resection with dual axial rotation correction in 39 cases. The intraoperative and postoperative complications were summarized, and the corresponding management was described in detail. RESULTS:: The average follow-up time was 31 months. Among patients who underwent pedicle subtraction osteotomy, the intraoperative and postoperative complications included 3 cases of dural tear and 1 case of wound infection. For posterior osteotomy with anterior opening-posterior closing correction, the complications included 4 cases of dural tear, 1 case of wound infection, and 1 case of instrumentation loosening and recurrence of kyphosis . For posterior vertebral column resection with dual axial rotation correction, the complications included 3 cases of dural tear, 5 cases of nerve root injury, 1 case of titanium mesh loosening, 1 case of osteotomy segment migration, 2 cases of transient neurological compromise, and 1 case of instrumentation loosening and kyphosis recurrence. All the complications were treated positively and pertinently. CONCLUSIONS:: During the posterior osteotomy and correction of focal kyphosis, the risk of surgery increases along with the more severe deformity and the more complicated surgical procedure. However, most complications do not significantly affect the outcome if treated appropriately.
    No preview · Article · Feb 2012 · Journal of spinal disorders & techniques
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    ABSTRACT: The object of this study was to compare the clinical and radiographic outcomes of 36 patients with posttuberculosis kyphosis who underwent one of two types of osteotomy. Each patient underwent single-stage correction via a posterior surgical approach. A modified pedicle subtraction osteotomy (mPSO) was performed when the kyphotic deformity was less than 70° (7 cases), whereas a posterior vertebral column resection (VCR) was performed when the kyphotic deformity exceeded 70° (29 cases). Full-length standing radiographs were obtained before surgery and at follow-up visits. These images were used to measure the kyphosis angle; sagittal alignment of the lumbar, thoracic, and cervical regions; and sagittal balance of the spine. Back pain was rated using the visual analog scale (VAS), and neurological function was classified based on the American Spinal Injury Association (ASIA) grading system. Each patient's overall satisfaction with surgical treatment was measured with the Patient Satisfaction Index. For purposes of comparison, patients were studied in 2 groups based on the region of their kyphotic apex. Half of the cohort had apical kyphosis in the lower thoracic spine or thoracolumbar junction (TL group). Using both radiographic and clinical assessments, the authors compared this group with the other half of the patients who had apical kyphosis in the upper to mid thoracic spine (MT group). The cohort included 15 males and 21 females, with an average age of 34 years at the time of surgery. The minimum follow-up was 24 months, and the mean follow-up was 31 months. Following surgery, kyphosis across the treated segments was reduced by an average of 60°. Lumbar lordosis also improved by an average of 24°, and thoracic kyphosis improved by an average of 20°. Both back pain and neurological function improved after surgical treatment. There was a 67% improvement in VAS scores, and 13 of the 36 patients had improvement in their ASIA grade. The 2 surgical procedures used for deformity correction (mPSO and VCR) demonstrated comparable radiographic and clinical results. Note, however, that differences were found in both radiographic and clinical outcomes in comparing patients who had lower thoracic or thoracolumbar (TL group) versus upper to midthoracic (MT group) apical kyphosis. Posterior tubercular kyphosis can be effectively improved through corrective surgery, and deformity correction can be accompanied by improvement in clinical symptoms. When appropriately selected, both the mPSO and the VCR can be expected to yield satisfactory reduction of post-tuberculosis kyphotic deformities. Differences in radiographic and clinical outcomes should be anticipated, however, when treating such deformities in different regions of the spine.
    No preview · Article · Jan 2012 · Journal of neurosurgery. Spine
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    ABSTRACT: OBJECTIVES:: To analyze the clinical characteristics and surgical results of posttraumatic kyphosis of the thoracolumbar segment. METHODS:: Thirty-four patients with posttraumatic kyphosis of the thoracolumbar segment underwent posterior osteotomy, kyphosis correction, and fixation at our hospital. The kyphosis apex was from T10 to L2. There were 15 male and 19 female patients. The mean age was 48.9 years. Full-spine standing radiographs were obtained before surgery, after surgery, and at follow-up. The sagittal spine balance status was evaluated, and the kyphotic angle, the lumbar lordotic angle, and the thoracic kyphotic angle were measured. The Frankel grading system for neurological functions and the Visual Analogue Scale for back pain were evaluated before surgery and at follow-up. The Oswestry Disability Index was applied for assessment of life quality and surgical results of patients. The Patient Satisfied Index (PSI) was also used for determination of surgical results. Patients were grouped according to the extent of kyphotic angle and the surgical technique. The difference in kyphosis correction and back pain between groups was observed before and after surgery. Relief from neurological symptoms was also observed. RESULTS:: The average kyphotic angle was 48.5 degrees, the average lumbar lordotic angle was 57.9 degrees, and the average thoracic kyphotic angle was 11.4 degrees before surgery. The sagittal spine balance was well maintained in 14 cases, and negative imbalance and positive imbalance were seen in 13 cases and 7 cases, respectively. There was significant difference in back pain between patients in the abnormal and normal groups of the lumbar lordotic angle. The average follow-up time after surgery was 32.1 months. The average kyphotic angle correction rate was 90.4% after surgery and 87.2% at follow-up. The average Oswestry Disability Index was 50.4% before surgery, which improved to 29.4% at follow-up, with an improvement rate of 41.5%. The Patient Satisfied Index result showed a total satisfactory rate of 94.1%. There were 16 cases of neurological deficit before surgery; 8 of them achieved various degrees of improvement after surgery. CONCLUSIONS:: Surgical correction of posttraumatic kyphosis of the thoracolumbar segment can show good radiologic and clinical results with the appropriate procedure according to the extent of the kyphosis angle. Some patients with neurological deficit are still worthy of surgical treatment.
    No preview · Article · Sep 2011 · Journal of spinal disorders & techniques
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    ABSTRACT: Controlled laboratory study. To evaluate the effect of lumbar degenerative disc diseases (DDDs) on motion of the facet joints during functional weight-bearing activities. It has been suggested that DDD adversely affects the biomechanical behavior of the facet joints. Altered facet joint motion, in turn, has been thought to associate with various types of lumbar spine pathology including facet degeneration, neural impingement, and DDD progression. However, to date, no data have been reported on the motion patterns of the lumbar facet joint in DDD patients. Ten symptomatic patients of DDD at L4-S1 were studied. Each participant underwent magnetic resonance images to obtain three-dimensional models of the lumbar vertebrae (L2-S1) and dual fluoroscopic imaging during three characteristic trunk motions: left-right torsion, left-right bending, and flexion-extension. In vivo positions of the vertebrae were reproduced by matching the three-dimensional models of the vertebrae to their outlines on the fluoroscopic images. The kinematics of the facet joints and the ranges of motion (ROMs) were compared with a group of healthy participants reported in a previous study. In facet joints of the DDD patients, there was no predominant axis of rotation and no difference in ROMs was found between the different levels. During left-right torsion, the ROMs were similar between the DDD patients and the healthy participants. During left-right bending, the rotation around mediolateral axis at L4-L5, in the DDD patients, was significantly larger than that of the healthy participants. During flexion-extension, the rotations around anterioposterior axis at L4-L5 and around craniocaudal axis at the adjacent level (L3-L4), in the DDD patients, were also significantly larger, whereas the rotation around mediolateral axis at both L2-L3 and L3-L4 levels in the DDD patients were significantly smaller than those of the healthy participants. DDD alters the ROMs of the facet joints. The rotations can increase significantly not only at the DDD levels but also at their adjacent levels when compared to those of the healthy participants. The increase in rotations did not occur around the primary rotation axis of the torso motion but around the coupled axes. This hypermobility in coupled rotations might imply a biomechanical mechanism related to DDD.
    No preview · Article · May 2011 · Spine
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    ABSTRACT: Case-control study. To evaluate the effect of lumbar degenerative disc disease (DDD) on the disc deformation at the adjacent level and at the level one above the adjacent level during end ranges of lumbar motion. It has been reported that in patients with DDD, the intervertebral discs adjacent to the diseased levels have a greater tendency to degenerate. Although altered biomechanics have been suggested to be the causative factors, few data have been reported on the deformation characteristics of the adjacent discs in patients with DDD. Ten symptomatic patients with discogenic low back pain between L4 and S1 and with healthy discs at the cephalic segments were involved. Eight healthy subjects recruited in our previous studies were used as a reference comparison. The In Vivo kinematics of L3-L4 (the cephalic adjacent level to the degenerated discs) and L2-L3 (the level one above the adjacent level) lumbar discs of both groups were obtained using a combined magnetic resonance imaging and dual fluoroscopic imaging technique at functional postures. Deformation characteristics, in terms of areas of minimal deformation (defined as less than 5%), deformations at the center of the discs, and maximum tensile and shear deformations, were compared between the two groups at the two disc levels. In the patients with DDD, there were significantly smaller areas of minimal disc deformation at L3-L4 and L2-L3 than the healthy subjects (18% compared with 45% of the total disc area, on average). Both L2-L3 and L3-L4 discs underwent larger tensile and shear deformations in all postures than the healthy subjects. The maximum tensile deformations were higher by up to 23% (of the local disc height in standing) and the maximum shear deformations were higher by approximately 25% to 40% (of the local disc height in standing) compared with those of the healthy subjects. Both the discs of the adjacent level and the level one above experienced higher tensile and shear deformations during end ranges of lumbar motion in the patients with DDD before surgical treatments when compared with the healthy subjects. The larger disc deformations at the cephalic segments were otherwise not detectable using conventional magnetic resonance imaging techniques. Future studies should investigate the effect of surgical treatments, such as fusion or disc replacement, on the biomechanics of the adjacent segments during end ranges of lumbar motion.
    Preview · Article · Apr 2011 · Spine

Publication Stats

164 Citations
57.91 Total Impact Points

Institutions

  • 2003-2015
    • Peking University Third Hospital
      Peping, Beijing, China
  • 2011-2014
    • Massachusetts General Hospital
      • Bioengineering Laboratory
      Boston, Massachusetts, United States
    • Harvard University
      Cambridge, Massachusetts, United States
  • 2011-2012
    • Peking University
      Peping, Beijing, China
  • 2009
    • Boston College, USA
      Boston, Massachusetts, United States