Back-forward bending CT in simulated surgical position to evaluate the remaining real angle and flexibility of thoracolumbar kyphosis secondary to old osteoporotic vertebral compression fracture / 中国修复重建外科杂志

OBJECTIVE@#To introduce a scout view scanning technique of back-forward bending CT (BFB-CT) in simulated surgical position for evaluating the remaining real angle and flexibility of thoracolumbar kyphosis secondary to old osteoporotic vertebral compression fracture.@*METHODS@#A total of 28 patients with thoracolumbar kyphosis secondary to old osteoporotic vertebral compression fracture who met the selection criteria between June 2018 and December 2021 were included in the study. There were 6 males and 22 females with an average age of 69.5 years (range, 56-92 years). The injured vertebra were located at T 10-L 2, including 11 cases of single thoracic fracture, 11 cases of single lumbar fracture, and 6 cases of multiple thoracolumbar fractures. The disease duration ranged from 3 weeks to 36 months, with a median of 5 months. All patients received examinations of BFB-CT and standing lateral full-spine X-ray (SLFSX). The thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), local kyphosis of injured vertebra (LKIV), lumbar lordosis (LL), and the sagittal vertical axis (SVA) were measured. Referring to the calculation method of scoliosis flexibility, the kyphosis flexibility of thoracic, thoracolumbar, and injured vertebra were calculated respectively. The sagittal parameters measured by the two methods were compared, and the correlation of the parameters measured by the two methods was analyzed by Pearson correlation.@*RESULTS@#Except LL ( P>0.05), TK, TLK, LKIV, and SVA measured by BFB-CT were significantly lower than those measured by SLFSX ( P<0.05). The flexibilities of thoracic, thoracolumbar, and injured vertebra were 34.1%±18.8%, 36.2%±13.8%, and 39.3%±18.6%, respectively. Correlation analysis showed that the sagittal parameters measured by the two methods were positively correlated ( P<0.001), and the correlation coefficients of TK, TLK, LKIV, and SVA were 0.900, 0.730, 0.700, and 0.680, respectively.@*CONCLUSION@#Thoracolumbar kyphosis secondary to old osteoporotic vertebral compression fracture shows an excellent flexibility and BFB-CT in simulated surgical position can obtain the remaining real angle which need to be corrected surgically.

Computer navigation-assisted surgical treatment with osteotomy for upper thoracic kyphosis / 中国组织工程研究

BACKGROUND: The biomechanical characteristics of kyphosis of the upper thoracic vertebra are unique. Decompression and internal fixation are relatively difficult. Previous relevant studies and case reports are few, and there is a lack of research on correction of kyphosis of the upper thoracic section with the assistance of computer navigation. OBJECTIVE: To explore the clinical effect of computer navigation-assisted surgical treatment of upper thoracic kyphosis by screws and osteotomy. METHODS: Totally 18 patients with kyphotic deformity of the spine (T1-T4) were admitted in Beijing Jishuitan Hospital from June 2011 to June 2018, including 11 males and 7 females, aged 12 to 59 years. They were all treated with computer-assisted surgical treatment with PSO osteotomy. Local Cobb angle of the upper thoracic kyphosis was determined during final follow-up. Cervical visual analogue scale, Nurick grades, EMS scores and satisfaction of the surgery were evaluated. This study was approved by the Ethics Committee of Beijing Jishuitan Hospital (approval No. 201709-23). RESULTS AND CONCLUSION: (1) A total of 18 patients were followed up for 6-90 months at an average time of (33. 73±35. 33) months. (2) The local Cobb angle of 18 patients at the last follow-up was significantly improved [(47. 32±9. 92)°, (24. 01 ±7. 64)°, P < 0. 001]. Cervical visual analogue scale score at the last follow-up was significantly lower than that before surgery (3. 64±2. 16, 0. 73±1. 01, P< 0. 001). Nurick score at the last follow-up was significantly lower than that before surgery (2. 91 ±0. 94, 0. 82±1. 47, P < 0. 001). EMS score at the last follow-up was significantly higher than that before surgery (14. 45±0. 93), 17. 09±1. 45, P< 0. 001). (3) Surgical satisfaction was excellent (n=16) or good (n=2). (4) At the last follow-up, 18 patients had no adverse reactions related to implants, and the wound healed well without screw loosening. (5) The results showed that reasonable osteotomy correction with computer-assisted surgery and PSO osteotomy could effectively treat kyphosis of upper thoracic segment.

Correction of kyphotic deformity due to neglected fracture dislocation thoracolumbar spine with posterior vertebral column resection

Kyphotic deformity is serious problem for sagittal spinal balance and resulting back pain, neurologic impairment, and also cosmetic problem. Post traumatic kyphotic deformity most common occur following unstable spine. A circumferential approach with anterior release via discectomies and corpectomies, followed by posterior instrumentation and fusion has been the standard of care. This is a case of progressive post traumatic kyphotic deformity due to fracture dislocation which was performed laminectomy without posterior instrumentation and succesfully corrected with single step posterior vertebral column resection.

Posterior-Only Approach with Pedicle Screws for the Correction of Scheuermann's Kyphosis

STUDY DESIGN: Retrospective study (level of evidence: level 3). PURPOSE: The purpose of this study was to evaluate the clinical and radiological results of the posterior-only approach with pedicle screws for the treatment of Scheuermann's kyphosis (SK). OVERVIEW OF LITERATURE: The correction of SK with instrumentation can be performed using posterior-only or combined anterior-posterior procedures. With the use of all-pedicle screw constructs in spine surgery, the posterior-only approach has become a popular option for the definitive treatment of SK. In a nationwide study involving 2,796 patients, a trend toward posterior-only fusion with lower complication rates was reported. METHODS: We retrospectively reviewed the data of patients who underwent posterior-only correction for SK between January 2005 and May 2013. Patients with a definite diagnosis of SK who fulfilled the minimum follow-up criterion of 24 months were included. The thoracic kyphosis (T5–T12), lumbar lordosis (L1–S1), and thoracolumbar junction (T10–L2) angles were measured from preoperative, postoperative, and last control radiographs. Sagittal balance, thoracic length, thoracic diameter, Voutsinas index and the sacral slope, pelvic tilt, proximal junction kyphosis, and distal junction kyphosis angles were also measured. RESULTS: Forty-five patients underwent surgery for the treatment of SK between 2005 and 2013. After applying the exclusion criteria, 20 patients (18 males and 2 females) with a mean age of 19 years were included. The mean thoracic kyphosis angle was 79.8 degrees preoperatively, 44.6 degrees postoperatively, and 44.9 degrees at the last control. There were statistically significant differences between preoperative and postoperative values in the thoracic kyphosis and lumbar lordosis angles, thoracic length, thoracic diameter, and Voutsinas index (p<0.05). CONCLUSIONS: The clinical and radiological results of the current study suggest that posterior-only fusion is an efficient technique for the treatment of SK.

What Effects Does Necrotic Area of Contrast-Enhanced MRI in Osteoporotic Vertebral Fracture Have on Further Compression and Clinical Outcome?

OBJECTIVE: The objective of this study was to analyze the correlation between further compression and necrotic area in osteoporotic vertebral fracture (OVF) patients with contrast-enhanced magnetic resonance imaging (CEMRI). In addition, we investigated the radiological and clinical outcome according to the range of the necrotic area. METHODS: Between 2012 and 2014, the study subjects were 82 OVF patients who did not undergo vertebroplasty or surgical treatment. The fracture areas examined on CEMRI at admission were defined as edematous if enhancement was seen and as necrotic if no enhancement was seen. The correlation between further compression and the necrotic and edematous areas of CEMRI, age, and bone mineral density was examined. Also, necrotic areas were classified into those with less than 25% (non-necrosis group) and those with more than 25% (necrosis group) according to the percentages of the entire vertebral body. For both groups, further compression and the changes in wedge and kyphotic angles were examined at admission and at 1 week, 3 months, and 6 months after admission, while the clinical outcomes were compared using the visual analog scale (VAS) and Eastern Cooperative Oncology Group (ECOG) performance status grade. RESULTS: Further compression was 14.78±11.11% at 1 month and 21.75±14.43% at 6 months. There was a very strong correlation between the necrotic lesion of CEMRI and further compression (r=0.690, p<0.001). The compression of the necrosis group was 33.52±12.96%, which was higher than that of the non-necrosis group, 14.96±10.34% (p<0.005). Also, there was a statistically significantly higher number of intervertebral cleft development and surgical treatments being performed in the necrosis group than in the non-necrosis group (p<0.005). Moreover, there was a statistical difference in the decrease in the height of the vertebral body, and an increase was observed in the kyphotic change of wedge angle progression. There was also a difference in the VAS and ECOG performance scales. CONCLUSION: The necrotic area of CEMRI in OVF had a strong correlation with further compression over time. In addition, with increasing necrosis, intervertebral clefts occurred more frequently, which induced kyphotic changes and resulted in poor clinical outcomes. Therefore, identifying necrotic areas by performing CEMRI on OVF patients would be helpful in determining their prognosis and treatment course.

Kyphotic Deformity after Spinal Fusion in a Patient with Diffuse Idiopathic Skeletal Hyperostosis: A Case Report

STUDY DESIGN: Case report. OBJECTIVES: To report a case of progressive kyphotic deformity after spinal fusion in a patient with diffuse idiopathic skeletal hyperostosis (DISH). SUMMARY OF LITERATURE REVIEW: DISH is characterized by spinal and peripheral enthesopathy, and is a completely different disease from ankylosing spondylitis (AS). Though DISH can be associated with thoracic kyphosis, no reports have described a progressive thoracolumbar kyphotic deformity after spinal fusion surgery in a DISH patient. MATERIALS AND METHODS: A 47-year-old male presented with pain in the thoracolumbar region. After excluding the possibility of AS and confirming the diagnosis of DISH, we performed spinal fusion for the treatment of a T11-T12 flexion-distraction injury. The kyphotic deformity was found to be aggravated after the first operation, and we then performed corrective osteotomy and additional spinal fusion. Results: The kyphotic deformity of the patient was corrected after the second operation. RESULTS: The kyphotic deformity of the patient was corrected after the second operation. CONCLUSIONS: In DISH patients in whom AS must be excluded in the differential diagnosis, a kyphotic deformity can become aggravated despite spinal fusion surgery, so regular and continuous follow-up is required.

Delayed Vertebral Collapse in Osteoporotic Vertebral Compression Fractures: Risk Factors and Treatment Strategies

STUDY DESIGN: Literature review. OBJECTIVES: To review the complications of osteoporotic vertebral compression fractures (OCFs) with regard to risk factors and treatment strategies. SUMMARY OF LITERATURE REVIEW: Understanding the complications and treatment methods of OCFs is important given their increasing prevalence. MATERIALS AND METHODS: Review of the literature. RESULTS: The complications of OCFs include kyphotic deformity due to a delayed collapse of the vertebral body and neurologic deficits. The pathophysiologic mechanism of these complications has not been established; however, the most accepted theory is posttraumatic avascular necrosis of the vertebral body. The risk factors for these complications include fracture at the thoracolumbar junction, systemic usage of steroids, severe osteoporosis, and radiological intravertebral vacuum cleft. Most of these complications require surgical treatment, the indications for which include progressing axial back pain, pseudarthrosis, kyphotic deformity, and neurologic deficits. Surgical approaches for treating the complications of OCFs include anterior, posterior, and combined anterior-posterior approaches. Osteotomies should be done when deformity correction is needed. The decision among these various surgical methods should be made considering patient factors and the surgeon's ability to achieve the best outcomes with solid fusion. CONCLUSIONS: complications of OCFs include kyphotic deformity due to delayed collapse of the vertebral body and neurologic deficits. Most of these complications require surgical treatment, in which achieving solid fusion at the fracture site is the ultimate goal. Patient-related factors and the surgeon's ability should be considered prior to making decisions regarding surgery.

The application of self-made adjustable wedge plate in radiotherapy positioning / 中华放射医学与防护杂志

Objective To investigate the repeatability of precise radiotherapy placement of self-made adjustable angle wedge plate,negative pressure vacuum pad and conmon soft pillow,corresponding to 3 groups.The study is demonstrated with a thermoplastic membrane immobilization technology in kyphotic deformity patients with head and neck cancer (including primary and secondary),respectively.Methods From Jun 2014 to Apr 2016,48 cases of severe head and neck cancer patients received radiotherapy humpback who were randomly divided into 3 groups.Combined with thermoplastic head and neck shoulder film position fixation,the right foot direction at the end of the skull styloid process layer center was set as a reference point.On the left foot at the end of the direction of styloid process layer center,localization of the origin of the coordinate system in patients around the head and foot,dorsoventrally (x,y,z) analysis of the direction change of position measurement was performed.Results There was no significant difference between the adjustable angle wedge plate and negative pressure vacuum pad groups of the coordinate system (P ＞ 0.05).Compared with common soft pillow group,three dimensional positioning errors and three dimensional coordinate system transfer errors of the adjustable angle wedge plate and negative pressure vacuum pad groups were statistically significantly different (t =-6.99 to-2.69,-5.13 to-2.71,P＜0.05).Conclusions The self-made adjustable angle wedge plate has good repeatability,saves time and money,is simple and durable on precise radiotherapy positioning of kyphotic deformity patients with head and neck cancer.

Bone cement distribution patterns of osteoporotic vertebral fractures with intravertebral clefts after vertebroplasty / 中国组织工程研究

10.3969/j.issn.2095-4344.2013.26.006

The Correlation between Insertion Depth of Prodisc-C Artificial Disc and Postoperative Kyphotic Deformity: Clinical Importance of Insertion Depth of Artificial Disc

OBJECTIVE: This study was designed to investigate the correlation between insertion depth of artificial disc and postoperative kyphotic deformity after Prodisc-C total disc replacement surgery, and the range of artificial disc insertion depth which is effective in preventing postoperative whole cervical or segmental kyphotic deformity. METHODS: A retrospective radiological analysis was performed in 50 patients who had undergone single level total disc replacement surgery. Records were reviewed to obtain demographic data. Preoperative and postoperative radiographs were assessed to determine C2-7 Cobb's angle and segmental angle and to investigate postoperative kyphotic deformity. A formula was introduced to calculate insertion depth of Prodisc-C artificial disc. Statistical analysis was performed to search the correlation between insertion depth of Prodisc-C artificial disc and postoperative kyphotic deformity, and to estimate insertion depth of Prodisc-C artificial disc to prevent postoperative kyphotic deformity. RESULTS: In this study no significant statistical correlation was observed between insertion depth of Prodisc-C artificial disc and postoperative kyphotic deformity regarding C2-7 Cobb's angle. Statistical correlation between insertion depth of Prodisc-C artificial disc and postoperative kyphotic deformity was observed regarding segmental angle (p<0.05). It failed to estimate proper insertion depth of Prodisc-C artificial disc effective in preventing postoperative kyphotic deformity. CONCLUSION: Postoperative segmental kyphotic deformity is associated with insertion depth of Prodisc-C artificial disc. Anterior located artificial disc leads to lordotic segmental angle and posterior located artificial disc leads to kyphotic segmental angle postoperatively. But C2-7 Cobb's angle is not affected by artificial disc location after the surgery.

Predictive Risk Factors for Refracture after Percutaneous Vertebroplasty

OBJECTIVE: To identify risk factors for developing a vertebral refracture after percutaneous vertebroplasty. METHOD: A retrospective analysis of 60 patients who had undergone percutaneous vertebroplasty between January 2008 and April 2010 was conducted. All patients were observed for a 1 year follow-up period, and fracture was defined when it was both clinically reported and radiographically confirmed. Twenty-seven patients with a refractured vertebra and 33 patients without a refracture were included. Of the 60 patients, 20 presented with a refracture from a cemented vertebra, whereas the remaining 40 patients did not. Clinical, imaging and procedure-related factors for each group were analyzed by the Fisher's exact, chi-square, and the Mann-Whitney U-tests. RESULTS: Local kyphotic angle and sagittal index were significant as a result of researching various risk factors related to vertebral refracture (p<0.001, p<0.001, respectively) and refracture from a cemented vertebra itself (p=0.004, p<0.001, respectively). Other factors were not significant. CONCLUSION: Patients who had a high preoperative local kyphotic angle and a high sagittal index required a close follow-up and attention.

Measurement of Vertebral Compression and Kyphosis in the Thoracolumbar and Lumbar Fractures

STUDY DESIGN: A retrospective radiologic study. OBJECTIVES: We wanted to compare the compression ratio and kyphosis of thoracolumbar and lumbar fractures according to the radiologic measuring methods and we wanted to analyze their relationship with the stability of fracture. SUMMARY OF THE LITERATURE REVIEW: There are several methods for measuring the compression ratio and kyphotic angle in thoracolumbar fractures, but no definitive measurements and no different values according to the stability have been established. MATERIALS AND METHODS: From July 2002 to August 2008, the plain films, CT, MRI and medical records of thoracolumbar and lumbar fracture were reviewed. The compression ratio and kyphotic angle were calculated by several different formulas with using the lateral view of the plain X-ray film, the sagittal reconstruction image of CT and the sagittal image of MRI and the results were compared. Each subject was classified according to both McAfee's classification and the TLISS classification. RESULTS: Two hundred forty eight vertebral bodies of 205 thoracolumbar fracture patients were analyzed. The compression ratio according to formula 1, which was calculated as 1-anterior vertebral height/posterior vertebral height, was significantly correlated with Cobb's angle and the local kyphotic angle. There was no significant difference between the Cobb's angle calculated using the lateral X-ray and that using the sagittal view of CT; however, it was significantly less using the sagittal MRI view. The unstable fractures according to McAfee's classification showed a significantly higher compression ratio and kyphotic angle compared to those of the stable fractures. CONCLUSIONS: The compression ratio formula 1 was most significantly correlated with the kyphotic deformity. The unstable fractures showed a mean compression ratio higher than 30%, a mean Cobb's angle of 15degrees and local kyphotic angle of 18degrees. The sagittally reconstructed CT was a useful measuring method for the evaluation of kyphotic deformity, and it was more accurate than that of the plain film.

Chance Fracture Secondary to a Healed Kyphotic Compression Osteoporotic Fracture

Chance fracture is an unstable vertebral fracture, which usually results from a high velocity injury. An elderly lady with a previously healed osteoporotic fracture of the T12 and L1 vertebra which resulted in a severe kyphotic deformity subsequently sustained a Chance fracture of the adjacent L2 vertebrae after a minor fall. The previously fracture left her with a deformity which resulted in significant sagittal imbalance therefore predisposing her to this fracture. This case highlights the importance of aggressive treatment of osteoporotic fractures in order to prevent significant sagittal imbalance from resultant (i.e. kyphotic) deformity.

The Effect of Vertebral Wedge Angle to the Change of Kyphotic Angle by the Posterior Instrumentation Method in Thoracolumbar Spine Fracture / 대한척추외과학회지

STUDY DESIGN: Retrospective study OBJECTIVES: To examine the effect of transpedicular screw fixation on fractured vertebrae about the vertebral wedge angle (VWA) after posterior instrumentation of the thoracolumbar fracture, determine the effect of reduced VWA on the change in the Kyphotic angle (KA), and minimize loss of reduction of KA. SUMMARY OF THE LITERATURE REVIEW: Maintenance of the KA of a thoracolumbar fracture after surgery is important for the radiologic and functional outcome. MATERIALS AND METHODS: Forty patients, who had undergone posterior instrumentation in a thoracolumbar fracture between February 2006 and February 2008 and followed-up for more than one year, were enrolled in this study. The patients were divided into two groups according to transpedicular screw fixation (Group A) or not (Group B) including fractured vertebrae. The evaluation was performed by measuring the changes in the KA and VWA taken after the injury, immediate after surgery and 1 year after surgery. RESULTS: There was correlation between groups A (transpedicular screw fixation on fractured vertebrae) and B (no transpedicular screw fixation on the fractured vertebrae) regarding the correction of the VWA and the loss of correction KA, (p<0.05). CONCLUSIONS: Reduction of the VWA is an important factor for preventing reduction loss of the KA, and transpedicular screw fixation including fractured vertebrae would help reduce the VWA. Therefore, the operator must pay attention to the increase in VWA to maintain the KA through short segment transpedicular screw fixation including fractured vertebrae.

Treatment of Thoracolumbar Vertebrate Fracture by Transpedicular Morselized Bone Grafting in Vertebrae for Spinal Fusion and Pedicle Screw Fixation / 华中科技大学学报（医学）（英德文版）

To enhance the fusion of graft bone in thoracolumbar vertebrae and minimize the postoperative loss of correction, short-segment pedicle screw fixation was reinforced with posterior moselizee bone grafting in vertebrae for spinal fusion in patients with thoracrolumbar vertebrate fractures. Seventy patients with thoracrolumbar vertebrate fractures were treated by short-segment pedicle screw fixation and were randomly divided into two groups. Fractures in group A (n=20) were reinforced with posterior morselized bone grafting in vertebrae for spinal fusion, while patients group B (n=50) did not receive the morselized bone grafting for bone fusion. The two groups were compared in terms of kyphotic deformity, anterior vertebral height, instrument failure and neurological functions after the treatment. Frankel grading system was used for the evaluation of neurological evaluation and Denis scoring scale was employed for pain assessment. The results showed that the kyphosis correction was achieved in both group A and group B (group A: 6.4 degree; group B: 5.4 degree)/At the end of follow-up, kyphosis correction was maintained in group A but lost in group B (P=0.0001). Postoperatively, greater anterior height was achieved in group A than in group B (P<0.01). During follow-up study, anterior vertebral height was maintained only in Group A (P<0.001). Both group A and group B showed good Denis pain scores (P1 and P2) but group A outdid group B in terms of control of severe and constant pain (P4 and P5). By Frankel criteria, the changes in neurological functions in group A was better than those of group B (P<0.001). It is concluded that reinforcement of short-segment pedicle fixation with morselized bone grafting for the treatment of patients with thoracolumbar vertebrae fracture could achieve and maintain kyphosis correction, and it may also increase and maintain anterior vertebral height. Morselized bone grafting in vertebrae offers immediate spinal stability in patients with thoracolumbar vertebrate fractures, decreases the instrument failure and provides better postoperative pain control than without the morselized bone grafting.

The Factors that Affect the Deformity Correction of Vertebral Body during Kyphoplasty of Osteoporotic Vertebral Compression Fracture

PURPOSE: To study which factors affect the deformity correction of vertebral body during kyphoplasty procedure. MATERIALS AND METHODS: 25 osteoporotic vertebral compression fractures were treated with balloon kyphoplasty from October 2006 to May 2007. Lateral radiographs were taken at 5 different stages with preoperative lateral decubitus position, after placing the patient in prone position on an operation table, after inflating balloon, after deflation and removal of the balloon, after inserting the cement. Then we analyzed the compression ratios and kyphotic angles of the vertebral bodies in each stage. RESULTS: Placing the patient in prone position showed significant postural reduction in kyphotic angle and restorement of the anterior and middle body height. The inflation of the balloon demonstrated significant reduction of kyphotic angle and restorement of the anterior and middle body height. After the deflation, anterior and middle body height has decreased significantly. After the deflation, the kyphotic angle and the anterior and middle body heights were not restored signigicantly compared with those of initial prone position. CONCLUSION: Vertebral height and kyphotic angle were partially recovered by inflating the balloon, but the correction was lost after deflating the balloon. Statistically, the body deformity was not restored significantly after deflating the balloon compared with that of intraoperative prone position. Therefore, we concluded that, in kyphoplasty of osteoporotic compression fractures, the postural reduction is the most important factor in deformity correction of fractured vertebral bodies.

Post-Laminectomy Kyphosis in Patients with Cervical Ossification of the Posterior Longitudinal Ligament: Does It Cause Neurological Deterioration?

OBJECTIVE: Total laminectomy (TL) is an effective surgical technique for the treatment of cervical ossification of the posterior longitudinal ligament (OPLL) along multiple levels. However, kyphosis and probable neurological deterioration have been frequently reported after laminectomy. We analyzed the changes in the cervical curvature after TL and subsequent changes in neurological status. METHODS: We retrospectively reviewed the records of 14 patients who underwent TL for the treatment of cervical OPLL between Jan. 1998 and Dec. 2003. TL was selected according to the previously determined criteria. The curvature of the cervical spine was visualized on a lateral cervical spine X-ray and measured using Ishihara's Curvature Index (CI) before the operation and at the last follow-up examination. Perioperative neurological status was estimated using the modified Japanese Orthopedic Association score and the Improvement Rate (IR) at the same time as the images were evaluated. RESULTS: The mean age of the patients was 57 years, the male/female ratio was 10:4, and the mean follow-up period was 41 months. The mean number of OPLL was 4.9, and the mean number of operated levels was also 4.9. The CI decreased after TL (p=0.002), which was indicative of a kyphotic change. However, this kyphotic change showed no correlation with the length of the follow-up period, number of operated levels and preoperative CI. Neurological examination at the last follow-up showed an improved neurological status in all patients (p=0.001). There was no neurological deterioration in any case during the follow-up period. Moreover, there was no correlation between IR and the degree of kyphotic change. Postoperative complications, such as C5 radiculopathy and epidural bleeding, resolved spontaneously without neurological sequelae. CONCLUSION: Kyphotic change was observed in all but one patient who underwent TL for the treatment of cervical OPLL. However, we did not find any contributing factors to kyphosis or evidence of postoperative neurological deterioration.

Clinical Efficacy of Implant Removal after Posterior Spinal Arthrodesis with Pedicle Screw Fixation for the Thoracolumbar Burst Fractures / 대한정형외과학회잡지

PURPOSE: To evaluate the clinical efficacy of implant removal by analyzing the radiological changes after posterior spinal stabilization in patients with thoracolumbar burst fractures. MATERIALS AND METHODS: Fifty-eight patients, who received surgical treatment after a thoracolumbar burst fracture with at least a two year follow-up, were enrolled in this study. An evaluation of the clinical results was based on the VAS score to examine degree of pain and discomfort. The evaluation of the radiological results was performed by measuring the changes in the kyphotic angle of the fractured vertebral bodies and the severity of the collapse of the anterior vertebral height taken after the injury, after fusion and after metal removal on the plain lateral radiograph. RESULTS: The VAS score on pain and discomfort after removing the implants showed a significant decrease from 6.5 to 3.2 and from 5.6 to 2.8, respectively. Overall, the kyphotic angle after removing the implants increased by 3.7 degrees, whereas the anterior height of the fractured vertebral body after removing the implant decreased by 1.5% in correction. CONCLUSION: The removal of implants after posterior arthrodesis in thoracolumbar burst fractures can be performed effectively to relieve the pain and restore flexibility but can result in the progression of kyphosis. However careful consideration should be made before removing an implant in cases of severe initial damage.

Comparison of Uniportal and Biportal Vertebroplasty in Bone Cement Distribution and Leakage

PURPOSE: To evaluate the differences of radiological outcomes of uniportal and biportal vertebroplasty in the point of bone cement distribution and leakage. MATERIALS AND METHODS: A retrospective study reviewing the period between May 2002 and January 2006 investigated 100 vertebrae which underwent vertebroplasty and followed for more than three months by uniportal approach (55 vertebrae, group 1) and biportal approach (45 vertebrae, group 2). The operative time, the amount of bone cement injected, anterior vertebral height restoration, kyphotic angle, bone cement distribution, and bone cement leakage were evaluated. RESULTS: The amount of injected bone cement of group 1 (3.9 cc) was statistically smaller than that of group 2 (5.1 cc) (p=0.016). There were no significant differences in the operative time, anterior vertebral height restoration, kyphotic angle in both groups. The rate of bone cement distribution over 8 zones was significantly higher in group 2 than in group 1 (p=0.014). However, the rate of bone cement distribution over 7 zones and the rate of bone cement distributed on whole anterior vertebral body were not significantly different in both groups. The cement leakage was not also significantly different in both groups. CONCLUSION: Although the amount of injected bone cement was smaller in uniportal vertebroplasty, the radiological results and cement leakage were similar to biportal vertebroplasty. These findings suggest that uniportal vertebroplasty can be the operative options in osteoporotic vertebral fracture.

Kyphotic Angle Measurement Accuracy for Vertebral Osteoporotic Compression Fracture: Reliable Method for Kyphotic Angle Measurement

OBJECTIVE: Having a reliable and reproducible measurement technique to measure the sagittal contour in vertebral fractures is paramount to clinical decision making. This study is designed to determine the most reliable measurement technique in osteoporotic vertebral compression fracture. METHODS: Fifteen lateral radiographs of thoracic and lumbar fractures were selected and measured on two separate occasions by three spine surgeons using six different measurement techniques (Centroid, Harrison Posterior Tangent Methods and 4 different types of modified Cobb method). The radiograph quality was assessed and the center beam location was determined. Statistical analysis including ANOVA for repeated measures was carried out using the SAS software (v 8.0). RESULTS: The inter and intraobserver variance of the Cobb method 4 and Harrison posterior tangent method were significantly lower than the other four methods. The intraobserver correlation coefficients were the most consistent using the Cobb method 4 (0.982), which was followed by the Harrison posterior tangent (0.953) and Cobb methods 1 (0.874). The intraobserver agreement (% of repeated measures within 5 degrees of the original measurement) ranged from 42% to 98% for each technique for all three observers, with the Cobb method 4 showing the best agreement (97.8%) followed by the Harrison posterior tangentmethod (93.7%). CONCLUSION: The Cobb method-4 and Harrison posterior tangent methods, when applied to measuring the kyphosis, are reliable and have a similar small error range. The Cobb method 4 shows the best overall reliability. However, the centroid method and Cobb method using a fractured endplate do not produce an accurate result due to inter and intraobserver differences in determining the baseline.