Scoliosis is a complex spinal three-dimensional malformation with complicated pathogenesis, often associated with complications as thoracic deformity and shoulder imbalance. Because the acquisition of specimen or animal models are difficult, the biomechanical study of scoliosis is limited. In recent years, along with the development of the computer technology, software and image, the technology of establishing a finite element model of human spine is maturing and it has been providing strong support for the research of pathogenesis of scoliosis, the design and application of brace, and the selection of surgical methods. The finite element model method is gradually becoming an important tool in the biomechanical study of scoliosis. Establishing a high quality finite element model is the basis of analysis and future study. However, the finite element modeling process can be complex and modeling methods are greatly varied. Choosing the appropriate modeling method according to research objectives has become researchers' primary task. In this paper, the author reviews the national and international literature in recent years and concludes the finite element modeling methods in scoliosis, including data acquisition, establishment of the geometric model, the material properties, parameters setting, the validity of the finite element model validation and so on.
Biomechanical Phenomena ; Computer Simulation ; Finite Element Analysis ; Humans ; Scoliosis ; physiopathology ; surgery ; Spine ; pathology

The study aimed to review the etiology of failed back surgery syndrome (FBSS) and to propose a treatment algorithm based on a systematic review of the current literature and individual experience. FBSS is a term that groups the conditions with recurring low back pain after spine surgery with or without a radicular component. Since the information on FBSS incidence is limited, data needs to be retrieved from old studies. It is generally accepted that its incidence ranges between 10% and 40% after lumbar laminectomy with or without fusion. Although the etiology of FBSS is not completely understood, it is possibly multifactorial, and the causative factors may be categorized into preoperative, operative, and postoperative factors. The evaluation of patients with FBSS symptoms should ideally initiate with reviewing the patients' clinical history (observing “red flags”), followed by a detailed clinical examination and imaging (whole-body X-ray, magnetic resonance imaging, and computed tomography). FBSS is a complex and difficult pathology, and its accurate diagnosis is of utmost importance. Its management should be multidisciplinary, and special attention should be provided to cases of recurrent disc herniation and postoperative spinal imbalance.
Diagnosis ; Failed Back Surgery Syndrome ; Humans ; Incidence ; Laminectomy ; Low Back Pain ; Magnetic Resonance Imaging ; Pathology ; Postural Balance ; Spine

The clinical effects of two different methods-high-viscosity cement percutaneous vertebroplasty (PVP) and low-viscosity cement percutaneous kyphoplasty (PKP) in the treatment of osteoporotic vertebral compression fractures (OVCFs) were investigated. From June 2010 to August 2013, 98 cases of OVCFs were included in our study. Forty-six patients underwent high-viscosity PVP and 52 patients underwent low-viscosity PKP. The occurrence of cement leakage was observed. Pain relief and functional activity were evaluated using the Visual Analog Scale (VAS) and Oswestry Disability Index (ODI), respectively. Restoration of the vertebral body height and angle of kyphosis were assessed by comparing preoperative and postoperative measurements of the anterior heights, middle heights and the kyphotic angle of the fractured vertebra. Nine out of the 54 vertebra bodies and 11 out of the 60 vertebra bodies were observed to have cement leakage in the high-viscosity PVP and low-viscosity PKP groups, respectively. The rate of cement leakage, correction of anterior vertebral height and kyphotic angles showed no significant differences between the two groups (P>0.05). Low-viscosity PKP had significant advantage in terms of the restoration of middle vertebral height as compared with the high-viscosity PVP (P<0.05). Both groups showed significant improvements in pain relief and functional capacity status after surgery (P<0.05). It was concluded that high-viscosity PVP and low-viscosity PKP have similar clinical effects in terms of the rate of cement leakage, restoration of the anterior vertebral body height, changes of kyphotic angles, functional activity, and pain relief. Low-viscosity PKP is better than high-viscosity PVP in restoring the height of the middle vertebra.
Administration, Cutaneous ; Aged ; Bone Cements ; chemistry ; therapeutic use ; Female ; Follow-Up Studies ; Fractures, Compression ; pathology ; rehabilitation ; surgery ; Humans ; Kyphoplasty ; instrumentation ; methods ; Male ; Middle Aged ; Osteoporosis ; pathology ; rehabilitation ; surgery ; Pain ; diagnosis ; physiopathology ; Pain Measurement ; Recovery of Function ; physiology ; Spinal Fractures ; pathology ; rehabilitation ; surgery ; Spine ; pathology ; surgery ; Treatment Outcome ; Viscosity ; Visual Analog Scale

OBJECTIVETo evaluate the therapeutic effects of conservative treatment of refracture in cemented vertebrae after percutaneous vertebroplasty for osteoporotic vertebral compression fractures in elderly patients.

METHODSBetween January, 2012 and August, 2014, a total of 324 elderly patients (381 vertebrae) received percutaneous vertebroplasty for osteoporotic vertebral compression fractures. Of these patients, 12 patients (14 vertebrae) complained of recurrence of back pain and were confirmed to have refracture in the cemented vertebrae by imaging examination. Seven of these 12 patients (9 vertebrae), who were all female with an average refracture time of 8±6.7 weeks (range 2-20 weeks), received conservative treatments with analgesics, osteoporosis medication, bracing and physical therapy, and their visual analogue scale (VAS) scores and Oswestry disability index (ODI) at 7 days and 1, 3 and 12 months after the treatment were measured.

RESULTSThe 7 patients were followed up for 21.3±11.2 months (range 13-29 months) after conservative treatments. Their VAS score and ODI decreased significantly over time after the treatment (P<0.05) and showed significant differences between the measurements at 7 days, 1 and 3 months (P<0.05) but not between 3 and 12 months (P>0.05). The average VAS score and ODI before treatments were 8.3±0.8 and (88.3±3.2)%, 3.1±1.2 and (56.3±7.7)% at 1 month, and 0.8±0.7 and (5.9±2.8)% at 3 months during the follow-up, respectively.No such complications as phlebothrombosis of the leg, decubitus, or hypostatic pneumonia occurred in these cases.

CONCLUSIONThough with a relatively low incidence rate, refracture in the cemented vertebrae is one of the important causes of recurrence of back pain following percutaneous vertebroplasty. Conservative treatment is effective in relieving pain and improving the spine function in such cases without obvious complications.

Aged ; Analgesics ; therapeutic use ; Back Pain ; therapy ; Bone Cements ; Female ; Fractures, Compression ; surgery ; therapy ; Humans ; Osteoporosis ; surgery ; therapy ; Pain Management ; Pain Measurement ; Recurrence ; Spinal Fractures ; surgery ; therapy ; Spine ; pathology ; Treatment Outcome ; Vertebroplasty

Efficacy and safety of bone cement augmentations for spinal pathologic fractures related to multiple myeloma, and usefulness of radionuclide studies for surgical decision were retrospectively evaluated. Forty eight vertebrae from 27 patients for bone cement augmentation procedures and 48 vertebrae from 29 patients for conservative treatment were enrolled. Clinical results using visual analogue scale (VAS) and Oswestry disability index (ODI), and radiologic results were assessed. For clinical decisions on treatment of spinal pathologic fracture, bone scan or single photon emission computed tomography was done for 20 patients who underwent surgery. Mean follow-up was 16.8 months. In terms of clinical results, immediate pain relief was superior in the operated group to that in the conservative group. ODI, maintenance of vertebral height and local kyphotic angle at the last follow-up were superior in the operated group in comparison to the conservative group. At one year follow-up, cumulative survival rate were 77.4% and 74.7% in the operated and conservative groups, respectively (log rank test> 0.05). Leakage of bone cement was noted at 10 treated vertebrae. Bone cement augmentations presented short-term pain relief for spinal pathologic fractures by myeloma with relative safety in highly selected patients, and radionuclide imaging studies were useful for the surgical decision on these procedures.
Aged ; Bone Cements/*therapeutic use ; Female ; Humans ; Male ; Middle Aged ; Multiple Myeloma/*pathology ; Pain Measurement ; Retrospective Studies ; Severity of Illness Index ; Spinal Fractures/*radionuclide imaging/*surgery ; Spine/radionuclide imaging/*surgery ; Treatment Outcome

BACKGROUND: Surgical treatment for metastatic spine disease has been becoming more prominent with the help of technological advances and a few favorable reports on the surgery. In cases of this peculiar condition, it is necessary to establish the role of surgery and analyze the factors affecting survival. METHODS: From January 2011 to April 2015, 119 patients were surgically treated for metastatic spine lesions. To reduce the bias along the heterogeneous cancers, the primary cancer was confined to either the lung (n = 25) or the liver (n = 18). Forty-three patients (male, 32; female, 11; mean age, 57.5 years) who had undergone palliative surgery were enrolled in this study. Posterior decompression and fusion was performed in 30 patients (P group), and anteroposterior (AP) reconstruction was performed in 13 patients (AP group) for palliative surgery. Pre- and postoperative (3 months) pain (visual analogue scale, VAS), performance status (Karnofsky performance score), neurologic status (American Spinal Injury Association [ASIA] grade), and spinal instability neoplastic score (SINS) were compared. The survival period and related hazard factors were also assessed by Kaplan-Meier and Cox regression analysis. RESULTS: Most patients experienced improvements in pain and performance status (12.3% +/- 17.2%) at 3 months postoperatively. In terms of neurologic recovery, 9 patients (20.9%) graded ASIA D experienced neurological improvement to ASIA E while the remainder was status quo. In an analysis according to operation type, there was no significant difference in patient demographics. At 12 months postoperatively, cumulative survival rates were 31.5% and 38.7% for the P group and the AP group, respectively (p > 0.05). Survival was not affected by the pre- and postoperative pain scale, Tokuhashi score, neurologic status, SINS, or operation type. Preoperative Karnofsky performance score (hazard ratio, 0.93; 95% confidence interval [CI], 0.89 to 0.96) and improvement of performance status after surgery (hazard ratio, 0.95; 95% CI, 0.92 to 0.97) significantly affected survival after operation. CONCLUSIONS: There was no significant difference in surgical outcomes and survival rates between posterior and AP surgery for metastatic lesions resulting from lung and hepatocellular cancer. Preoperative Karnofsky score and improvement of performance status had a significant impact on the survival rate following surgical treatment for these metastatic spine lesions.
Aged ; Back Pain ; *Decompression, Surgical/adverse effects/methods/mortality ; Female ; Humans ; Kaplan-Meier Estimate ; Liver Neoplasms/*pathology ; Lung Neoplasms/*pathology ; Male ; Middle Aged ; Pain, Intractable ; Palliative Care/*methods ; Prognosis ; Retrospective Studies ; *Spinal Fusion/adverse effects/methods/mortality ; *Spinal Neoplasms/mortality/surgery ; Spine/*surgery

BACKGROUND: Metastatic pathological fractures of the spine are a major problem for cancer patients; however, there is no consensus on treatment strategy. The purpose of this study was to evaluate various treatment options by analyzing their patterns for metastatic pathological fractures of the spine. METHODS: In this study, 54 patients (male:female = 36:18) who were diagnosed with metastatic pathological fractures of spine were recruited. Demographic data, origin of cancer, type of treatment, and results were obtained from electronic medical records. Treatment options were divided into radiotherapy (RT), vertebroplasty (VP) or kyphoplasty (KP), operation (OP), and other treatments. Treatment results were defined as aggravation, no response, fair response, good response, and unknown. The survival time after detection of pathologic fractures was analyzed with the Kaplan-Meier method. RESULTS: The mean age of the patients was 62.3 years. Hepatocellular carcinoma was the most common cancer of primary origin (n = 9), followed by multiple myeloma (n = 8). RT was the most common primary choice of treatment (n = 29, 53.7%), followed by OP (n = 13, 24.1%), and VP or KP (n = 10, 18.5%). Only 13 of 29 RT cases and 7 of 13 OP cases demonstrated a fair or good response. The mean survival time following detection of pathological spinal fractures was 11.1 months for 29 patients, who died during the study period. CONCLUSIONS: RT was the most common primary choice of treatment for metastatic pathological fractures of the spine. However, the response rate was suboptimal. Although OP should be considered for the relief of mechanical back pain or neurologic symptoms, care should be taken in determining the surgical indication. VP or KP could be considered for short-term control of localized pain, although the number of cases was too small to confirm the conclusion. It is difficult to determine the superiority of the treatment modalities, hence, a common guideline for the diagnosis and treatment of metastatic pathological fractures of the spine is required.
Carcinoma, Hepatocellular/mortality/pathology ; Female ; Humans ; Liver Neoplasms/mortality/pathology ; Male ; Middle Aged ; Multiple Myeloma/mortality/pathology ; Retrospective Studies ; Spinal Fractures/etiology/mortality/*radiotherapy/*surgery ; Spinal Neoplasms/*complications/secondary ; Spine ; Treatment Outcome

OBJECTIVE: To evaluate the curative effect of percutaneous vertebroplasty (PVP) for senile osteoporotic vertebral compressive fractures with posterior vertebral defect and spinal canal compromise.
 METHODS: A total of 50 patients with osteoporotic vertebral compressive fractures (50 vertebrae) underwent PVP from July, 2010 to October, 2013. Subsequent visual analogue scale (VAS) rating, analgesic utilization and mobility were recorded before and after the surgery.
 RESULTS: A total of 42 patients were followed up completely. The median VAS, analgesic administration score and patients' mobility score was significantly decreased at the 2nd hour, the 3rd day, the 1st month, the 3rd month, the 6th month and the 1st year after the surgery compared with those at the pre-operation (P<0.01). Five recurrence fractures were observed after PVP.
 CONCLUSION PVP is safe and effective and it is worthy for clinical popularization and application.
Fractures, Compression ; surgery ; Humans ; Osteoporotic Fractures ; surgery ; Pain Measurement ; Spinal Canal ; pathology ; Spinal Fractures ; surgery ; Spine ; pathology ; surgery ; Treatment Outcome ; Vertebroplasty

OBJECTIVE: We report magnetic resonance imaging (MRI) findings on focal anterior displacement of the thoracic spinal cord in asymptomatic patients without a spinal cord herniation or intradural mass. MATERIALS AND METHODS: We identified 12 patients (male:female = 6:6; mean age, 51.7; range, 15-83 years) between 2007 and 2011, with focal anterior displacement of the spinal cord and without evidence of an intradural mass or spinal cord herniation. Two radiologists retrospectively reviewed the MRI findings in consensus. RESULTS: An asymmetric spinal cord deformity with a focal dented appearance was seen on the posterior surface of the spinal cord in all patients, and it involved a length of 1 or 2 vertebral segments in the upper thoracic spine (thoracic vertebrae 1-6). Moreover, a focal widening of the posterior subarachnoid space was also observed in all cases. None of the patients had myelopathy symptoms, and they showed no focal T2-hyperintensity in the spinal cord with the exception of one patient. In addition, cerebrospinal fluid (CSF) flow artifacts were seen in the posterior subarachnoid space of the affected spinal cord level. Computed tomography myelography revealed preserved CSF flow in the two available patients. CONCLUSION: Focal anterior spinal cord indentation can be found in the upper thoracic level of asymptomatic patients without a spinal cord herniation or intradural mass.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Cerebrospinal Fluid/physiology ; Female ; Hernia/pathology ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Retrospective Studies ; Spinal Cord Diseases/pathology/*radiography/surgery ; Spine/pathology/radiography ; Thoracic Vertebrae/pathology/*radiography ; Tomography, X-Ray Computed ; Young Adult

OBJECTIVETo compare the therapeutic effects of debris spondylectomy, piecemeal spondylectomy, total en bloc spomdylectomy in treating lumbar metastatic tumors.

METHODSThe clinical data of 20 patients with lumbar metastatic tumors treated from January 2008 to October 2013 were retrospectively reviewed. There were 8 males and 12 females, aged from 35 to 65 years old with an average of (49.50 ± 9.97) years. All patients had single solitary metastases. Four cases were in L1,5 cases in L2,4 cases in L3,4 cases in L4, and 3 cases in L5. According to the type of Tomita, type II had in 4 cases, type III in 6 cases, type IV in 6 cases, type V in 4 cases. Tokuhashi score was 12.50 ± 1.97. All patients complained with back or leg pain, VAS score was 8.13 ± 0.85. Among patients, 7 cases were treated with debris spondylectomy (group A), 7 cases with piecemeal spondylectomy (group B), 6 cases with total en bloc spondylectomy (group C). Statistical analysis was used to compare the three groups with respect to surgical trauma (including operative time, transoperative bleeding, and intraoperative blood transfusion), clinical symptoms (by VAS score at 1 week after operation), surgical procedures conditions (by AP and lateral X-rays), and long-term results (by recurrence and death information).

RESULTSAll patients were followed up from 6 to 36 months with an average of (16.50 ± 7.88) months. Operative time for debris spondylectomy was (6.14 ± 0.68) h, intraoperative bleeding was (3 457.14 ± 399.40) ml, and intraoperative blood transfusion was (2 771.43 ± 423.14) ml. Operative time for piece-meal spondylectomy was (4.93 ± 0.61) h, intraoperative bleeding was (1 942.86 ± 378.51) ml, and intraoperative blood transfusion was (1 500.00 ± 336.65) ml. Operative time for total en bloc spondylectomy was(4.17 ± 0.67) h, intraoperative bleeding was (1 341.67 ± 361.13) ml, and intraoperative blood transfusion was (916.67 ± 321.66) ml. There was significant differences in operative time, intraoperative blood loss, and intraoperative blood transfusion between three groups (P < 0.05). In terms of these factors, total en bloc spondylectomy had the best outcome followed by piecemeal spondylectomy. All pains had released, VAS score decreased obviously at 1 week after operation (P < 0.05), and there was no significant differences between three groups (P > 0.05). Surgical effects were well with these methods according to the evaluation of AP and lateral X-rays . At final follow-up, group A had 4 recurrences (2 with breast cancer, 1 with prostate cancer,and 1 with thyroid cancer) and 3 deaths (2 with lung cancer and 1 with thyroid cancer); group B had 2 recurrences (1 with breast cancer and 1 with prostate cancer) and 3 deaths (1 with lung cancer, 1 with breast cancer and 1 with kidney cancer);group C had no recurrences and 2 deaths for lung cancer. There was significant differences in recurrence and death between three groups (P < 0.05). In terms of these factors, total en bloc spondylectomy had the best outcome in three methods.

CONCLUSIONThree kinds of operation method can relieve pain, improve nerve function, increase the spinal stability, control the local lesions, improve the patient's quality of life in treating lumbar metastatic tumors, but total en bloc spendylectomy, respect to operative time, transoperative bleeding, intraoperative blood transfusion, tumor recurrence and death is clearly superior to other two methods.

Adult ; Aged ; Blood Transfusion ; Female ; Humans ; Lumbar Vertebrae ; pathology ; Male ; Middle Aged ; Neoplasm Metastasis ; Operative Time ; Retrospective Studies ; Spinal Neoplasms ; pathology ; surgery ; Spine ; surgery