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1.  Bone Cement Augmentation of Short Segment Fixation for Unstable Burst Fracture in Severe Osteoporosis 
The purpose of this study was to determine the efficacy of short segment fixation following postural reduction for the re-expansion and stabilization of unstable burst fractures in patients with osteoporosis.
Twenty patients underwent short segment fixation following postural reduction using a soft roll at the involved vertebra in cases of severely collapsed vertebrae of more than half their original height. All patients had unstable burst fracture with canal compromise, but their motor power was intact. The surgical procedure included postural reduction for 2 days and bone cement-augmented pedicle screw fixations at one level above, one level below and the fractured level itself. Imaging and clinical findings, including the level of the vertebra involved, vertebral height restoration, injected cement volume, local kyphosis, clinical outcome and complications were analyzed.
The mean follow-up period was 15 months. The mean pain score (visual analogue scale) prior to surgery was 8.1, which decreased to 2.8 at 7 days after surgery. The kyphotic angle improved significantly from 21.6±5.8° before surgery to 5.2±3.7° after surgery. The fraction of the height of the vertebra increased from 35% and 40% to 70% in the anterior and middle portion. There were no signs of hardware pull-out, cement leakage into the spinal canal or aggravation of kyphotic deformities.
In the management of unstable burst fracture in patients with severe osteoporosis, short segment pedicle screw fixation with bone cement augmentation following postural reduction can be used to reduce the total levels of pedicle screw fixation and to correct kyphotic deformities.
PMCID: PMC2588283  PMID: 19096650
Unstable burst fracture; Osteoporosis; Short segment fixation
2.  Short Segment Fixation for Thoracolumbar Burst Fracture Accompanying Osteopenia : A Comparative Study 
The purpose of this study was to compare the results of three types of short segment screw fixation for thoracolumbar burst fracture accompanying osteopenia.
The records of 70 patients who underwent short segment screw fixation for a thoracolumbar burst fracture accompanying osteopenia (-2.5< mean T score by bone mineral densitometry <-1.0) from January 2005 to January 2008 were reviewed. Patients were divided into three groups based on whether or not bone fusion and bone cement augmentation procedure 1) Group I (n=26) : short segment fixation with posterolateral bone fusion; 2) Group II (n=23) : bone cement augmented short segment fixation with posterolateral bone fusion; 3) Group III (n=21) : bone cement augmented, short segment percutaneous screw fixation without bone fusion. Clinical outcomes were assessed using a visual analogue scale and modified MacNab's criteria. Radiological findings, including kyphotic angle and vertebral height, and procedure-related complications, such as screw loosening or pull-out, were analyzed.
No significant difference in radiographic or clinical outcomes was noted between patients managed using the three different techniques at last follow up. However, Group I showed more correction loss of kyphotic deformities and vertebral height loss at final follow-up, and Group I had higher screw loosening and implant failure rates than Group II or III.
Bone cement augmented procedure can be an efficient and safe surgical techniques in terms of achieving better outcomes with minimal complications for thoracolumbar burst fracture accompanying osteopenia.
PMCID: PMC3579078  PMID: 23440679
Burst fracture; Osteopenia; Fusion
3.  Short Segment Screw Fixation without Fusion for Unstable Thoracolumbar and Lumbar Burst Fracture : A Prospective Study on Selective Consecutive Patients 
The purpose of this prospective study was to evaluate the efficacy and safety of screw fixation without bone fusion for unstable thoracolumbar and lumbar burst fracture.
Nine patients younger than 40 years underwent screw fixation without bone fusion, following postural reduction using a soft roll at the involved vertebra, in cases of burst fracture. Their motor power was intact in spite of severe canal compromise. The surgical procedure included postural reduction for 3 days and screw fixations at one level above, one level below and at the fractured level itself. The patients underwent removal of implants 12 months after the initial operation, due to possibility of implant failure. Imaging and clinical findings, including canal encroachment, vertebral height, clinical outcome, and complications were analyzed.
Prior to surgery, the mean pain score (visual analogue scale) was 8.2, which decreased to 2.2 at 12 months after screw fixation. None of the patients complained of worsening of pain during 6 months after implant removal. All patients were graded as having excellent or good outcomes at 6 months after implant removal. The proportion of canal compromise at the fractured level improved from 55% to 35% at 12 months after surgery. The mean preoperative vertebral height loss was 45.3%, which improved to 20.6% at 6 months after implant removal. There were no neurological deficits related to neural injury. The improved vertebral height and canal compromise were maintained at 6 months after implant removal.
Short segment pedicle screw fixation, including fractured level itself, without bone fusion following postural reduction can be an effective and safe operative technique in the management of selected young patients suffering from unstable burst fracture.
PMCID: PMC3377876  PMID: 22737299
Screw fixation; Burst fracture; Bone fusion
4.  Implant Removal after Percutaneous Short Segment Fixation for Thoracolumbar Burst Fracture : Does It Preserve Motion? 
The purpose of this study was to evaluate the efficacy of implant removal of percutaneous short segment fixation after vertebral fracture consolidation in terms of motion preservation.
Between May 2007 and January 2011, 44 patients underwent percutaneous short segment screw fixation due to a thoracolumbar burst fracture. Sixteen of these patients, who underwent implant removal 12 months after screw fixation, were enrolled in this study. Motor power was intact in all patients, despite significant vertebral height loss and canal compromise. The patients were divided into two groups by degree of osteoporosis : Group A (n=8), the non-osteoporotic group, and Group B (n=8), the osteoporotic group. Imaging and clinical findings including vertebral height loss, kyphotic angle, range of motion (ROM), and complications were analyzed.
Significant pain relief was achieved in both groups at final follow-up versus preoperative values. In terms of vertebral height loss, both groups showed significant improvement at 12 months after screw fixation and restored vertebral height was maintained to final follow-up in spite of some correction loss. ROM (measured using Cobb's method) in flexion and extension in Group A was 10.5° (19.5/9.0°) at last follow-up, and in Group B was 10.2° (18.8/8.6°) at last follow-up. Both groups showed marked improvement in ROM as compared with the screw fixation state, which was considered motionless.
Removal of percutaneous implants after vertebral fracture consolidation can be an effective treatment to preserve motion regardless of osteoporosis for thoracolumbar burst fractures.
PMCID: PMC3958576  PMID: 24653799
Fusion; Percutaneous; Removal
5.  Clinical application of the paraspinal erector approach for spinal canal decompression in upper lumber burst fractures 
Percutaneous pedicle screw fixation is commonly used for upper lumber burst fractures. The direct decompression remains challenging with this minimally invasive surgery. The objective was to evaluate a novel paraspinal erector approach for effective and direct decompression in patients with canal compromise and neurologic deficit.
Patients (n = 21) with neurological deficiency and Denis B type upper lumbar burst fracture were enrolled in the study, including 14 cases in the L1 and 7 cases in the L2. The patients underwent removal of bone fragments from the spinal canal through intervertebral foramen followed by short-segment fixation. Evaluations included surgery-related, such as duration of surgery and blood loss, and 12-month follow-up, such as the kyphotic angle, the height ratio of the anterior edge of the vertebra, the ratio of sagittal canal compromise, visual analog scale (VAS), Oswestry Disability Index (ODI), and Frankel scores.
All patients achieved direct spinal canal decompression using the paraspinal erector approach followed by percutaneous pedicle screw fixation. The mean operation time (SD) was 173 (23) min, and the mean (SD) blood loss was 301 (104) ml. Significant improvement was noted in the kyphotic angle, 26.2 ± 8.7 prior to operation versus 9.1 ± 4.7 at 12 months after operation (p <0.05); the height ratio of the anterior edge of the injured vertebra, 60 ± 16% versus 84 ± 9% (p <0.05); and the ratio of sagittal canal compromise, 46.5 ± 11.4% versus 4.3 ± 3.6% (p <0.05). Significant improvements in VAS (7.3 ± 1.2 vs. 1.9 ± 0.7, p <0.05), ODI (86.7 ± 5.8 vs. 16.7 ± 5.1, p <0.05), and Frankel scores were also noted.
The paraspinal erector approach was effective for direct spinal canal decompression with minimal injury in the paraspinal muscles or spine. Significant improvements in spinal function and prognostics were achieved after the percutaneous pedicle screw fixation.
PMCID: PMC4240844  PMID: 25387608
Erector spinae; Direct spinal canal decompression; Minimally invasive spine surgery; Surgical approach; Upper lumber burst fractures
6.  Treatment of acute thoracolumbar burst fractures with kyphoplasty and short pedicle screw fixation: Transpedicular intracorporeal grafting with calcium phosphate: A prospective study 
Indian Journal of Orthopaedics  2007;41(4):354-361.
In the surgical treatment of thoracolumbar fractures, the major problem after posterior correction and transpedicular instrumentation is failure to support the anterior spinal column, leading to loss of correction and instrumentation failure with associated complaints. We conducted this prospective study to evaluate the outcome of the treatment of acute thoracolumbar burst fractures by transpedicular balloon kyphoplasty, grafting with calcium phosphate cement and short pedicle screw fixation plus fusion.
Materials and Methods:
Twenty-three consecutive patients of thoracolumbar (T9 to L4) burst fracture with or without neurologic deficit with an average age of 43 years, were included in this prospective study. Twenty-one from the 23 patients had single burst fracture while the remaining two patients had a burst fracture and additionally an adjacent A1-type fracture. On admission six (26%) out of 23 patients had neurological deficit (five incomplete, one complete). Bilateral transpedicular balloon kyphoplasty with liquid calcium phosphate to reduce segmental kyphosis and restore vertebral body height and short (three vertebrae) pedicle screw instrumentation with posterolateral fusion was performed. Gardner kyphosis angle, anterior and posterior vertebral body height ratio and spinal canal encroachment were calculated pre- to postoperatively.
All 23 patients were operated within two days after admission and were followed for at least 12 months after index surgery. Operating time and blood loss averaged 45 min and 60 cc respectively. The five patients with incomplete neurological lesions improved by at least one ASIA grade, while no neurological deterioration was observed in any case. The VAS and SF-36 (Role physical and Bodily pain domains) were significantly improved postoperatively. Overall sagittal alignment was improved from an average preoperative 16° to one degree kyphosis at final followup observation. The anterior vertebral body height ratio improved from 0.6 preoperatively to 0.9 (P<0.001) postoperatively, while posterior vertebral body height improved from 0.95 to 1 (P<0.01). Spinal canal encroachment was reduced from an average 32% preoperatively to 20% postoperatively. Cement leakage was observed in four cases (three anterior to vertebral body and one into the disc without sequalae). In the last CT evaluation, there was a continuity between calcium phosphate and cancellous vertebral body bone. Posterolateral radiological fusion was achieved within six months after index operation. There was no instrumentation failure or measurable loss of sagittal curve and vertebral height correction in any group of patients.
Balloon kyphoplasty with calcium phosphate cement secured with posterior short fixation in the thoracolumbar spine provided excellent immediate reduction of posttraumatic segmental kyphosis and significant spinal canal clearance and restored vertebral body height in the fracture level.
PMCID: PMC2989509  PMID: 21139791
Balloon kyphoplasty; calcium phosphate; neurological deficit; pedicle screw; short internal fixation; thoracolumbar vertebral fracture; transpedicular grafting
7.  Radiological study on disc degeneration of thoracolumbar burst fractures treated by percutaneous pedicle screw fixation 
European Spine Journal  2012;22(3):489-494.
To examine disc degeneration at levels adjacent and next adjacent to the fractured vertebra and to analyses, if the disc degeneration is determined by the endplate fracture.
Summary of background data
Thoracolumbar burst fracture is one of the most common spinal injuries. The diagnostic (clinical and imaging) approach and treatment of a fractured vertebra is well established; however, some controversy remains. The associated disc degeneration is less well known after 9–12 months of the short segment pedicle screw fixations. There is a major controversy whether spinal trauma with vertebral endplate fractures can result in posttraumatic disc degeneration. No study to date, however, has assessed disc degeneration of the AO type A3 thoracolumbar fractures without neurologic deficits after pedicle screw fixations.
Twenty-six patients with single-level AO type A3 thoracolumbar fractures and no neurological deficit were treated by using postural reduction and short segment percutaneous pedicle screw fixation. No laminectomy and fusion were performed. Implants were removed 9–12 months after the first operation. The thoracolumbar magnetic resonance imaging (MRI) was used to assess disc degeneration at levels adjacent and next adjacent to the fractured vertebra before the first operation and after the second operation in a retrospective study.
After the instrumentation removal, new disc degeneration was usually found at level adjacent to the cranial endplate of fractured vertebra by MRI examination in 24 patients. The average Pfirrmann grade of degenerative discs adjacent to the cranial fractured endplates deteriorated from 2.1 pre-operatively to 3.4 after the second operation. No change of disc degeneration was seen at the caudal disc space adjacent to the fractured vertebra and the levels next adjacent to the fractured vertebra. The discs next adjacent to the fractured vertebra were showed to be relatively normal without changes of degeneration during the study period.
Disc degeneration usually occurs at level adjacent to the fractured endplate of thoracolumbar burst fractures. Endplate fracture is strongly associated with disc degeneration. No correlation between fixation level and disc degeneration is seen in this study.
PMCID: PMC3585651  PMID: 22890568
Disc degeneration; Thoracolumbar fracture; Endplate; Pedicle screw fixation; Minimally invasive surgery
8.  Short segment screw fixation without fusion in treatment for unstable thoracolumbar burst fracture 
This study aims to evaluate clinical efficacy of short segment pedicle screw fixation without bone fusion for unstable thoracolumbar burst fracture. Nineteen patients younger than 40 years old with unstable thoracolumbar burst fractures were included. The surgical procedure included postural reduction for 3 days and screw fixations at one level above, one level below and at the fractured level itself. The implants were removed 12 months after initial operation. Imaging and clinical findings were analyzed at preoperative, 12 months after surgery, just before implant removal, and at six months after implant removal. Results indicated that difference was statistically significant between preoperative period or postoperative 1 year follow-up, just before implant removal and 6 months after implant removal (P < 0.05). Results at postoperative 1 year follow-up, just before implant removal and 6 months after implant removal were better than preoperative period. There were no significant complications or neurological deterioration after screws insert and removal in any patient. The rate of clinical outcome with excellent and good was 94.7%. In conclusion, short segment pedicle screw fixation without bone fusion can be an effective and safe operative srategytechnique in the management of young patients suffering from unstable burst fracture.
PMCID: PMC4307537  PMID: 25664090
Pedicle screw fixation; short segment; burst fracture; bone fusion
9.  Balloon Kyphoplasty 
Executive Summary
To review the evidence on the effectiveness and cost-effectiveness of balloon kyphoplasty for the treatment of vertebral compression fractures (VCFs).
Clinical Need
Vertebral compression fractures are one of the most common types of osteoporotic fractures. They can lead to chronic pain and spinal deformity. They are caused when the vertebral body (the thick block of bone at the front of each vertebra) is too weak to support the loads of activities of daily living. Spinal deformity due to a collapsed vertebral body can substantially affect the quality of life of elderly people, who are especially at risk for osteoporotic fractures due to decreasing bone mass with age. A population-based study across 12 European centres recently found that VCFs have a negative impact on health-related quality of life. Complications associated with VCFs are pulmonary dysfunction, eating disorders, loss of independence, and mental status change due to pain and the use of medications. Osteoporotic VCFs also are associated with a higher rate of death.
VCFs affect an estimated 25% of women over age 50 years and 40% of women over age 80 years. Only about 30% of these fractures are diagnosed in clinical practice. A Canadian multicentre osteoporosis study reported on the prevalence of vertebral deformity in Canada in people over 50 years of age. To define the limit of normality, they plotted a normal distribution, including mean and standard deviations (SDs) derived from a reference population without any deformity. They reported a prevalence rate of 23.5% in women and a rate of 21.5% in men, using 3 SDs from the mean as the limit of normality. When they used 4 SDs, the prevalence was 9.3% and 7.3%, respectively. They also found the prevalence of vertebral deformity increased with age. For people older than 80 years of age, the prevalence for women and men was 45% and 36%, respectively, using 3 SDs as the limit of normality.
About 85% of VCFs are due to primary osteoporosis. Secondary osteoporosis and neoplasms account for the remaining 15%. A VCF is operationally defined as a reduction in vertebral body height of at least 20% from the initial measurement. It is considered mild if the reduction in height is between 20% and 25%; moderate, if it is between 25% and 40%; and severs, if it is more than 40%. The most frequently fractured locations are the third-lower part of the thorax and the superior lumbar levels. The cervical vertebrae and the upper third of the thorax are rarely involved.
Traditionally, bed rest, medication, and bracing are used to treat painful VCFs. However, anti-inflammatory and narcotic medications are often poorly tolerated by the elderly and may harm the gastrointestinal tract. Bed rest and inactivity may accelerate bone loss, and bracing may restrict diaphragmatic movement. Furthermore, medical treatment does not treat the fracture in a way that ameliorates the pain and spinal deformity.
Over the past decade, the injection of bone cement through the skin into a fractured vertebral body has been used to treat VCFs. The goal of cement injection is to reduce pain by stabilizing the fracture. The secondary indication of these procedures is management of painful vertebral fractures caused by benign or malignant neoplasms (e.g., hemangioma, multiple myeloma, and metastatic cancer).
The Technology
Balloon kyphoplasty is a modified vertebroplasty technique. It is a minimally invasive procedure that aims to relieve pain, restore vertebral height, and correct kyphosis. During this procedure, an inflatable bone tamp is inserted into the collapsed vertebral body. Once inflated, the balloon elevates the end plates and thereby restores the height of the vertebral body. The balloon is deflated and removed, and the space is filled with bone cement. Creating a space in the vertebral body enables the application of more viscous cement and at a much lower pressure than is needed for vertebroplasty. This may result in less cement leakage and fewer complications. Balloons typically are inserted bilaterally, into each fractured vertebral body. Kyphoplasty usually is done under general anesthesia in about 1.5 hours. Patients typically are observed for only a few hours after the surgery, but some may require an overnight hospital stay.
Health Canada has licensed KyphX Xpander Inflatable Bone Tamp (Kyphon Inc., Sunnyvale, CA), for kyphoplasty in patients with VCFs. KyphX is the only commercially available device for percutaneous kyphoplasty. The KyphX kit uses a series of bone filler device tubes. Each bone filler device must be loaded manually with cement. The cement is injected into the cavity by pressing an inner stylet.
In the United States, the Food and Drug Administration cleared the KyphX Inflatable Bone Tamp for marketing in July 1998. CE (Conformité European) marketing was obtained in February 2000 for the reduction of fracture and/or creation of a void in cancellous bone.
Review Strategy
The aim of this literature review was to evaluate the safety and effectiveness of balloon kyphoplasty in the treatment of painful VCFs.
INAHTA, Cochrane CCTR (formerly Cochrane Controlled Trials Register), and DSR were searched for health technology assessment reports. In addition, MEDLINE, EMBASE, and MEDLINE In-Process & Other Non-Indexed Citations were searched from January 1, 2000 to September 21, 2004. The search was limited to English-language articles and human studies.
The positive end points selected for this assessment were as follows:
Reduction in pain scores
Reduction in vertebral height loss
Reduction in kyphotic (Cobb) angle
Improvement in quality of life scores
The search did not yield any health technology assessments on balloon kyphoplasty. The search yielded 152 citations, including those for review articles. No randomized controlled trials (RCTs) on balloon kyphoplasty were identified. All of the published studies were either prospective cohort studies or retrospective studies with no controls. Eleven studies (all case series) met the inclusion criteria. There was also a comparative study published in German that had been translated into English.
Summary of Findings
The results of the 1 comparative study (level 3a evidence) that was included in this review showed that, compared with conservative medical care, balloon kyphoplasty significantly improved patient outcomes.
Patients who had balloon kyphoplasty reported a significant reduction in pain that was maintained throughout follow-up (6 months), whereas pain scores did not change in the control group. Patients in the balloon kyphoplasty group did not need pain medication after 3 days. In the control group, about one-half of the patients needed more pain medication in the first 4 weeks after the procedure. After 6 weeks, 82% of the patients in the control group were still taking pain medication regularly.
Adjacent fractures were more frequent in the control group than in the balloon kyphoplasty group.
The case series reported on several important clinical outcomes.
Pain: Four studies on osteoporosis patients and 1 study on patients with multiple myeloma/primary cancers used the Visual Analogue Scale (VAS) to measure pain before and after balloon kyphoplasty. All of these studies reported that patients had significantly less pain after the procedure. This was maintained during follow-up. Two other studies on patients with osteoporosis also used the VAS to measure pain and found a significant improvement in pain scores; however, they did not provide follow-up data.
Vertebral body height: All 5 studies that assessed vertebral body height in patients with osteoporosis reported a significant improvement in vertebral body height after balloon kyphoplasty. One study had 1-year follow-up data for 26 patients. Vertebral body height was significantly better at 6 months and 1 year for both the anterior and midline measurements.
Two studies reported that vertebral body height was restored significantly after balloon kyphoplasty for patients with multiple myeloma or metastatic disease. In another study, the researchers reported complete height restoration in 9% of patients, a mean 56% height restoration in 60% of patients, and no appreciable height restoration in 31% of the patients who received balloon kyphoplasty.
Kyphosis correction: Four studies that assessed Cobb angle before and after balloon kyphoplasty in patients with osteoporosis found a significant reduction in degree of kyphosis after the procedure. In these studies, the differences between preoperative and postoperative Cobb angles were 3.4°, 7°, 8.8°, and 9.9°.
Only 1 study investigated kyphosis correction in patients with multiple myeloma or metastatic disease. The authors reported a significant improvement (5.2°) in local kyphosis.
Quality of life: Four studies used the Short Form 36 (SF-36) Health Survey Questionnaire to measure the quality of life in patients with osteoporosis after they had balloon kyphoplasty. A significant improvement in most of the domains of the SF-36 (bodily pain, social functioning, vitality, physical functioning, mental health, and role functioning) was observed in 2 studies. One study found that general health declined, although not significantly, and another found that role emotional declined.
Both studies that used the Oswestry Disability Index found that patients had a better quality of life after balloon kyphoplasty. In one study, this improvement was statistically significant. In another study, researchers found that quality of life after kyphoplasty improved significantly, as measured with the Roland-Morris Disability Questionnaire. Yet another study used a quality of life questionnaire and found that 62% of the patients that had balloon kyphoplasty had returned to normal activities, whereas 2 patients had reduced mobility.
To measure quality of life in patients with multiple myeloma or metastatic disease, one group of researchers used the SF-36 and found significantly better scores on bodily pain, physical functioning, vitality, and social functioning after kyphoplasty. However, the scores for general health, mental health, role physical, and role emotional had not improved. A study that used the Oswestry Disability Index reported that patients’ scores were better postoperatively and at 3 months follow-up.
These were the main findings on complications in patients with osteoporosis:
The bone cement leaked in 37 (6%) of 620 treated fractures.
There were no reports of neurological deficits.
There were no reports of pulmonary embolism due to cement leakage.
There were 6 cases of cardiovascular events in 362 patients:
3 (0.8%) patients had myocardial infarction.
3 (0.8%) patients had cardiac arrhythmias.
There was 1 (0.27%) case of pulmonary embolism due to deep venous thrombosis.
There were 20 (8.4%) cases of new fractures in 238 patients.
For patients with multiple myeloma or metastatic disease, these were the main findings:
The bone cement leaked in 12 (9.6%) of 125 procedures.
There were no reports of neurological deficits.
Economic Analysis
Balloon kyphoplasty requires anesthesia. Standard vertebroplasty requires sedation and an analgesic. Based on these considerations, the professional fees (Cdn) for each procedure is shown in Table 1.
Professional Fees for Standard Vertebroplasty and Balloon Kyphoplasty
Balloon kyphoplasty has a sizable device cost add-on of $3,578 (the device cost per case) that standard vertebroplasty does not have. Therefore, the up-front cost (i.e., physician’s fees and device costs) is $187 for standard vertebroplasty and $3,812 for balloon kyphoplasty. (All costs are in Canadian currency.)
There are also “downstream costs” of the procedures, based on the different adverse outcomes associated with each. This includes the risk of developing new fractures (21% for vertebroplasty vs. 8.4% for balloon kyphoplasty), neurological complications (3.9% for vertebroplasty vs. 0% for balloon kyphoplasty), pulmonary embolism (0.1% for vertebroplasty vs. 0% for balloon kyphoplasty), and cement leakage (26.5% for vertebroplasty vs. 6.0% for balloon kyphoplasty). Accounting for these risks, and the base costs to treat each of these complications, the expected downstream costs are estimated at less than $500 per case. Therefore, the expected total direct medical cost per patient is about $700 for standard vertebroplasty and $4,300 for balloon kyphoplasty.
Kyphon, the manufacturer of the inflatable bone tamps has stated that the predicted Canadian incidence of osteoporosis in 2005 is about 29,000. The predicted incidence of cancer-related vertebral fractures in 2005 is 6,731. Based on Ontario having about 38% of the Canadian population, the incidence in the province is likely to be about 11,000 for osteoporosis and 2,500 for cancer-related vertebral fractures. This means there could be as many as 13,500 procedures per year in Ontario; however, this is highly unlikely because most of the cancer-related fractures likely would be treated with medication. Given a $3,600 incremental direct medical cost associated with balloon kyphoplasty, the budget impact of adopting this technology could be as high as $48.6 million per year; however, based on data from the Provider Services Branch, about 120 standard vertebroplasties are done in Ontario annually. Given these current utilization patterns, the budget impact is likely to be in the range of $430,000 per year. This is because of the sizable device cost add-on of $3,578 (per case) for balloon kyphoplasty that standard vertebroplasty does not have.
Policy Considerations
Other treatments for osteoporotic VCFs are medical management and open surgery. In cases without neurological involvement, the medical treatment of osteoporotic VCFs comprises bed rest, orthotic management, and pain medication. However, these treatments are not free of side effects. Bed rest over time can result in more bone and muscle loss, and can speed the deterioration of the underlying condition. Medication can lead to altered mood or mental status. Surgery in these patients has been limited because of its inherent risks and invasiveness, and the poor quality of osteoporotic bones. However, it may be indicated in patients with neurological deficits.
Neither of these vertebral augmentation procedures eliminates the need for aggressive treatment of osteoporosis. Osteoporotic VCFs are often under-diagnosed and under-treated. A survey of physicians in Ontario (1) who treated elderly patients living in long-term care homes found that although these physicians were aware of the rates of osteoporosis in these patients, 45% did not routinely assess them for osteoporosis, and 26% did not routinely treat them for osteoporosis.
Management of the underlying condition that weakens the vertebral bodies should be part of the treatment plan. All patients with osteoporosis should be in a medical therapy program to treat the underlying condition, and the referring health care provider should monitor the clinical progress of the patient.
The main complication associated with vertebroplasty and balloon kyphoplasty is cement leakage (extravertebral or vascular). This may result in more patient morbidity, longer hospitalizations, the need for open surgery, and the use of pain medications, all of which have related costs. Extravertebral cement leakage can cause neurological complications, like spinal cord compression, nerve root compression, and radiculopathy. In some cases, surgery is required to remove the cement and release the nerve. The rate of cement leakage is much lower after balloon kyphoplasty than after vertebroplasty. Furthermore, the neurological complications seen with vertebroplasty have not seen in the studies of balloon kyphoplasty. Rarely, cement leakage into the venous system will cause a pulmonary embolism. Finally, compared with vertebroplasty, the rate of new fractures is lower after balloon kyphoplasty.
Diffusion – International, National, Provincial
In Canada, balloon kyphoplasty has not yet been funded in any of the provinces. The first balloon kyphoplasty performed in Canada was in July 2004 in Ontario.
In the United States, the technology is considered by some states as medically reasonable and necessary for the treatment of painful vertebral body compression fractures.
There is level 4 evidence that balloon kyphoplasty to treat pain associated with VCFs due to osteoporosis is as effective as vertebroplasty at relieving pain. Furthermore, the evidence suggests that it restores the height of the affected vertebra. It also results in lower fracture rates in other vertebrae compared with vertebroplasty, and in fewer neurological complications due to cement leakage compared with vertebroplasty. Balloon kyphoplasty is a reasonable alternative to vertebroplasty, although it must be reiterated that this conclusion is based on evidence from level 4 studies.
Balloon kyphoplasty should be restricted to facilities that have sufficient volumes to develop and maintain the expertise required to maximize good quality outcomes. Therefore, consideration should be given to limiting the number of facilities in the province that can do balloon kyphoplasty.
PMCID: PMC3387743  PMID: 23074451
10.  Transpedicular hydroxyapatite grafting with indirect reduction for thoracolumbar burst fractures with neurological deficit: A prospective study 
Indian Journal of Orthopaedics  2007;41(4):368-373.
The major problem after posterior correction and instrumentation in the treatment of thoracolumbar burst fractures is failure to support the anterior spinal column leading to loss of correction of kyphosis and hardware breakage. We conducted a prospective consecutive series to evaluate the outcome of the management of acute thoracolumbar burst fractures by transpedicular hydroxyapatite (HA) grafting following indirect reduction and pedicle screw fixation.
Materials and Methods:
Eighteen consecutive patients who had thoracolumbar burst fractures and associated incomplete neurological deficit were operatively treated within four days of admission. Following indirect reduction and pedicle screw fixation, transpedicular intracorporeal HA grafting to the fractured vertebrae was performed. Mean operative time was 125 min and mean blood loss was 150 ml. Their implants were removed within one year and were prospectively followed for at least two years.
The neurological function of all 18 patients improved by at least one ASIA grade, with nine (50%) patients demonstrating complete neurological recovery. Sagittal alignment was improved from a mean preoperative kyphosis of 17°to −2°(lordosis) by operation, but was found to have slightly deteriorated to 1° at final followup observation. The CT images demonstrated a mean spinal canal narrowing preoperatively, immediate postoperative and at final followup of 60%, 22% and 11%, respectively. There were no instances of hardware failure. No patient reported severe pain or needed daily dosages of analgesics at the final followup. The two-year postoperative MRI demonstrated an increase of one grade in disc degeneration (n = 17) at the disc above and in 11 patients below the fractured vertebra. At the final followup, flexion-extension radiographs revealed that a median range of motion was 4, 6 and 34 degrees at the cranial segment of the fractured vertebra, caudal segment and L1-S1, respectively. Bone formation by osteoconduction in HA granules was unclear, but final radiographs showed healed fractures.
Posterior indirect reduction, transpedicular HA grafting and pedicle screw fixation could prevent the development of kyphosis and should lead to reliable neurological improvement in patients with incomplete neurological deficit. This technique does not require fusion to a segment, thereby preserves thoracolumbar motion.
PMCID: PMC2989521  PMID: 21139793
Pedicle screw fixation; thoracolumbar burst fracture; transpedicular hydroxyapatite grafting
11.  Pullout strength of pedicle screws with cement augmentation in severe osteoporosis: A comparative study between cannulated screws with cement injection and solid screws with cement pre-filling 
Pedicle screws with PMMA cement augmentation have been shown to significantly improve the fixation strength in a severely osteoporotic spine. However, the efficacy of screw fixation for different cement augmentation techniques, namely solid screws with retrograde cement pre-filling versus cannulated screws with cement injection through perforation, remains unknown. This study aimed to determine the difference in pullout strength between conical and cylindrical screws based on the aforementioned cement augmentation techniques. The potential loss of fixation upon partial screw removal after screw insertion was also examined.
The Taguchi method with an L8 array was employed to determine the significance of design factors. Conical and cylindrical pedicle screws with solid or cannulated designs were installed using two different screw augmentation techniques: solid screws with retrograde cement pre-filling and cannulated screws with cement injection through perforation. Uniform synthetic bones (test block) simulating severe osteoporosis were used to provide a platform for each screw design and cement augmentation technique. Pedicle screws at full insertion and after a 360-degree back-out from full insertion were then tested for axial pullout failure using a mechanical testing machine.
The results revealed the following 1) Regardless of the screw outer geometry (conical or cylindrical), solid screws with retrograde cement pre-filling exhibited significantly higher pullout strength than did cannulated screws with cement injection through perforation (p = 0.0129 for conical screws; p = 0.005 for cylindrical screws). 2) For a given cement augmentation technique (screws without cement augmentation, cannulated screws with cement injection or solid screws with cement pre-filling), no significant difference in pullout strength was found between conical and cylindrical screws (p >0.05). 3) Cement infiltration into the open cell of the test block led to the formation of a cement/bone composite structure. Observations of the failed specimens indicated that failure occurred at the composite/bone interface, whereas the composite remained well bonded to the screws. This result implies that the screw/composite interfacial strength was much higher than the composite/bone interfacial strength. 4) The back-out of the screw by 360 degrees from full insertion did not decrease the pullout strength in any of the studied cases. 5) Generally, larger standard deviations were found for the screw back-out cases, implying that the results of full insertion cases are more repeatable than those of the back-out cases.
Solid screws with retrograde cement pre-filling offer improved initial fixation strength when compared to that of cannulated screws with cement injection through perforation for both the conically and cylindrically shaped screw. Our results also suggest that the fixation screws can be backed out by 360 degrees for intra-operative adjustment without the loss of fixation strength.
PMCID: PMC3224375  PMID: 21284883
12.  Treatment of unstable thoracolumbar junction burst fractures with short- or long-segment posterior fixation in magerl type a fractures 
European Spine Journal  2007;16(8):1145-1155.
The treatment of thoracolumbar fractures remains controversial. A review of the literature showed that short-segment posterior fixation (SSPF) alone led to a high incidence of implant failure and correction loss. The aim of this retrospective study was to compare the outcomes of the SS- and long-segment posterior fixation (LSPF) in unstable thoracolumbar junction burst fractures (T12–L2) in Magerl Type A fractures. The patients were divided into two groups according to the number of instrumented levels. Group I included 32 patients treated by SSPF (four screws: one level above and below the fracture), and Group II included 31 patients treated by LSPF (eight screws: two levels above and below the fracture). Clinical outcomes and radiological parameters (sagittal index, SI; and canal compromise, CC) were compared according to demographic features, localizations, load-sharing classification (LSC) and Magerl subgroups, statistically. The fractures with more than 10° correction loss at sagittal plane were analyzed in each group. The groups were similar with regard to age, gender, LSC, SI, and CC preoperatively. The mean follow-ups were similar for both groups, 36 and 33 months, respectively. In Group II, the correction values of SI, and CC were more significant than in Group I. More than 10° correction loss occurred in six of the 32 fractures in Group I and in two of the 31 patients in Group II. SSPF was found inadequate in patients with high load sharing scores. Although radiological outcomes (SI and CC remodeling) were better in Group II for all fracture types and localizations, the clinical outcomes (according to Denis functional scores) were similar except Magerl type A33 fractures. We recommend that, especially in patients, who need more mobility, with LSC point 7 or less with Magerl Type A31 and A32 fractures (LSC point 6 or less in Magerl Type A3.3) without neurological deficit, SSPF achieves adequate fixation, without implant failure and correction loss. In Magerl Type A33 fractures with LSC point 7 or more (LSC points 8–9 in Magerl Type A31 and A32) without severe neurologic deficit, LSPF is more beneficial.
PMCID: PMC2200786  PMID: 17252216
Thoracolumbar fracture; Classification; Spinal instrumentation; Short/long
13.  Two levels above and one level below pedicle screw fixation for the treatment of unstable thoracolumbar fracture with partial or intact neurology 
Treatment of unstable thoracolumbar fractures is controversial regarding short or long segment pedicle screw fixation. Although long level fixation is better, it can decrease one motion segment distally, thus increasing load to lower discs.
We retrospectively analyzed 31 unstable thoracolumbar fractures with partial or intact neurology. All patients were operated with posterior approach using pedicle screws fixed two levels above and one level below the fracture vertebra. No laminectomy, discectomy or decompression procedure was done. Posterior fusion was achieved in all. Post operative and at final follow-up radiological evaluation was done by measuring the correction and maintenance of kyphotic angle at thoracolumbar junction. Complications were also reported including implant failure.
Average follow-up was 34 months. All patients had full recovery at final follow-up. Average kyphosis was improved from 26.7° to 4.1° postoperatively and to 6.3° at final follow-up. And mean pain scale was improved from 7.5 to 3.9 postoperatively and to 1.6 at final follow-up, All patients resumed their activity within six months. Only 4 (12%) complications were noted including only one hardware failure.
Two levels above and one level below pedicle screw fixation in unstable thoracolumbar burst fracture is useful to prevent progressive kyphosis and preserves one motion segment distally.
PMCID: PMC2724433  PMID: 19635134
14.  Trans-iliosacral plating for vertically unstable fractures of sacral spine associated with spinopelvic dissociation: A cadaveric study 
Indian Journal of Orthopaedics  2012;46(3):274-278.
The treatment algorithm for sacral fracture associated with vertical shear pelvic fracture has not emerged. Our aim was to study a new approach of fixation for comminuted and vertically unstable fracture pattern with spinopelvic dissociation to overcome inconsistent outcome and avoid complications associated with fixations. We propose fixation with well-contoured thick reconstruction plate spreading across sacrum from one iliac bone to another with fixation points in iliac wing, sacral ala and sacral pedicle on either side. Present biomechanical study tests the four fixation pattern to compare their stiffness to vertical compressive forces.
Materials and Methods:
Dissection was performed on human cadavers through posterior midline paraspinal approach elevating erector spinae from insertion with two flaps. Feasibility of surgical exposure and placement of contoured plate for fixation was evaluated. Ten age and sex matched computed tomography scans of pelvis with both hips were obtained. Reconstructions were performed with advantage windows 4.2 (GE Light Speed QX/I, General Electric, Milwaukee, WI, USA). Using the annotation tools, direct digital CT measurement (0.6 mm increments) of three linear parameters was carried out. Readings were recorded at S2 sacral level. Pelvic CT scans were extensively studied for entry point, trajectory and estimated length for screw placement in S2 pedicle, sacral ala and iliac wing. Readings were recorded for desired angulation of screw in iliac wing ala of sacrum and sacral pedicle with respect to midline. The readings were analyzed by the values of mean and standard deviation. Biomechanical efficacy of fixation methods was studied separately on synthetic bone. Four fixation patterns given below were tested to compare their stiffness to vertical compressive forces: 1) Single S1 iliosacral screw (7.5 mm cancellous screw), 2) Two S1 and S2 iliosacral screws, 3) Isolated trans-iliosacral plate, 4) Trans-iliosacral plate + single S1 iliosacral screw.
Statistical Analysis:
Mean of desired angulation for inserting screws and percentage of displacement on biomechanical testing was evaluated.
Mean angulations for inserting sacral pedicel were 12.3° (SD 2.7°) convergent to midline and divergent of 14° (SD 2.3°) for sacral ala screw and 23° (SD 4.9°) for iliac wing screw. All screws needed to be inserted at an angle of 90° to sacral dorsum to avoid violation of root canals. Cross headed displacement across fracture site was measured and plotted against the applied vertical shear load of 300 N in five cycles each for all the four configurations. Also, the force required for cross headed displacement of 2.5 mm and 5 mm was recorded for all configurations. Transmitted load across both ischial tuberosities was measured to resolve unequal distribution of forces. Taking one screw construct (configuration 1) as standard base reference, trans-iliosacral plate construct (configuration 3) showed equal rigidity to standard reference. Two screw construct (configuration 2) was 12% stronger and trans-iliosacral plate (configuration 4) with screw was 9% stronger at 2.5 mm displacing on 300 N force, while it showed 30% and 6%, respectively, at 5 mm cross-headed displacement.
Trans-iliosacral plating is feasible anatomically, biomechanically and radiologically for sacral fractures associated with vertical shear pelvic fractures. Low profile of plate reduces the risk of hardware prominence and decreases the need for implant removal. Also, the fixation pattern of plate allows to spare mobile lumbosacral junction which is an important segment for spinal mobility. Biomechanical studies revealed that rigidity offered by plate for cross headed displacement across fracture site is equal to sacroiliac screws and further rigidity of construct can be increased with addition of one more screw. There is need for precountered thicker plate in future.
PMCID: PMC3377136  PMID: 22719112
Spinopelvic dissociation; trans-iliosacral plating; unstable sacral spine fractures
15.  Percutaneous Cement-Augmented Screws Fixation in the Fractures of the Aging Spine: Is It the Solution? 
BioMed Research International  2014;2014:610675.
Introduction. Management of elderly patients with thoracolumbar fractures is still challenging due to frequent osteoporosis and risk of screws pull-out. The aim of this study was to evaluate results of a percutaneous-only procedure to treat these fragile patients using cement-augmented screws. Methods. 12 patients diagnosed with a thoracolumbar fracture associated with an important loss of bone stock were included in this prospective study. Surgical procedure included systematically a percutaneous osteosynthesis using cemented fenestrated screws. When necessary, additional anterior support was performed using a kyphoplasty procedure. Clinical and radiographic evaluations were performed using CT scan. Results. On the whole series, 15 fractures were diagnosed and 96 cemented screws were inserted. The difference between the pre- and postoperative vertebral kyphosis was statistically significant (12.9° versus 4.4°, P = 0.0006). No extrapedicular screw was reported and one patient was diagnosed with a cement-related pulmonary embolism. During follow-up period, no infectious complications, implant failures, or pull-out screws were noticed. Discussion. Aging spine is becoming an increasing public health issue. Management of these patients requires specific attention due to the augmented risk of complications. Using percutaneous-only screws fixation with cemented screw provides satisfactory results. A rigorous technique is mandatory in order to achieve best outcomes.
PMCID: PMC3950552  PMID: 24696858
16.  Fenestrated pedicle screws for cement-augmented purchase in patients with bone softening: a review of 21 cases 
This prospective mixed cohort study was designed to evaluate the middle- to long-term purchase of cement-augmented pedicular screws in patients with poor bone quality. The growing number of surgical procedures performed in the spine has highlighted the problem of screws loosening in patients with poor bone stock due to osteoporosis and/or tumors. Different methods of increasing screw purchase have been reported in the literature, including polymethylmethacrylate (PMMA) augmentation.
Materials and methods
From September 2006 to April 2008, 21 patients with a poor bone stock condition due to osteoporosis or tumor underwent posterior stabilization by fenestrated pedicle screws and PMMA augmentation. Pain improvement and long-term clinical outcome were assessed by visual analogue scale (VAS) score and SF-36 health survey (SF-36) questionnaire. Implant stability was evaluated by plain radiography and CT scans performed three days after surgery and every three months thereafter. After the first 12 months, radiologic controls were taken once a year in all surviving patients. Complications were evaluated in all cases.
All patients were clinically and radiographically followed up for a mean of 36 months. VAS scores and SF-36 questionnaires showed a statistically significant reduction in pain and improvement in the quality of life. No radiological loosening or pulling out of screws was observed. In two cases, cement leakage occurred intraoperatively: one patient who suffered from a transitory nerve root palsy improved spontaneously, while the surgeon immediately removed the excess cement before setting in the other case. In three cases, the post-op CT scan revealed a small amount of cement in the canal without clinical relevance.
Fenestrated screws for cement augmentation provided effective and lasting purchase in patients with poor bone quality due to osteoporosis or tumors. No case of loosening was recorded after a mean follow-up of 36 months. The only clinical complication strictly related to PMMA screw augmentation did not require further surgery.
PMCID: PMC3225622  PMID: 22065147
Fenestrated pedicle screw; Polymethylmethacrylate; Osteoporotic bone; Spine tumor
17.  Percutaneous kyphoplasty and pedicle screw fixation for the management of thoraco-lumbar burst fractures 
European Spine Journal  2010;19(8):1281-1287.
The study design includes prospective evaluation of percutaneous osteosynthesis associated with cement kyphoplasty on 18 patients. The objective of the study is to assess the efficacy of a percutaneous method of treating burst vertebral fractures in patients without neurological deficits. Even if burst fractures are frequent, no therapeutic agreement is available at the moment. We report in this study the results at 2 years with a percutaneous approach for the treatment of burst fractures. 18 patients were included in this study. All the patients had burst vertebral fractures classified type A3 on the Magerl scale, between levels T9 and L2. The patients’ mean age was 53 years (range 22–78 years) and the neurological examination was normal. A percutaneous approach was systematically used and a kyphoplasty was performed via the transpedicular pathway associated with percutaneous short-segment pedicle screw osteosynthesis. The patients’ follow-up included CT scan analysis, measurement of vertebral height recovery and local kyphosis, and clinical pain assessments. With this surgical approach, the mean vertebral height was improved by 25% and a mean improvement of 11.28° in the local kyphotic angle was obtained. 3 months after the operation, none of the patients were taking class II analgesics. The mean duration of their hospital stay was 4.5 days (range 3–7 days) and the mean follow-up period was 26 months (range 17–30 months). No significant changes in the results obtained were observed at the end of the follow-up period. Minimally invasive methods of treating burst vertebral fractures can be performed via the percutaneous pathway. This approach gives similar vertebral height recovery and kyphosis correction rates to those obtained with open surgery. It provides a short hospital stay, however, and might therefore constitute a useful alternative to open surgical methods.
PMCID: PMC2989205  PMID: 20496038
Percutaneous surgery; Burst fracture; Kyphoplasty; Pedicle screw fixation
18.  Long-term results of transpedicle body augmenter in treating burst fractures 
Indian Journal of Orthopaedics  2007;41(4):362-367.
Short-segment fixation alone to treat thoracolumbar burst fractures is common but it has a 20-50% incidence of implant failure and rekyphosis. A transpedicle body augmenter (TpBA) to reinforce the vertebral body via posterior approach has been reported to prevent implant failure and increase the clinical success rate in treating burst fracture. This article is to evaluate the longterm results of short-segment fixation with TpBA for treatment of thoracolumbar burst fractures.
Materials and Methods:
Patients included in the study had a single-level burst fracture involving T11-L2 and no distraction or rotation element with limited neurological deficit. Patients in the control group (n = 42) were treated with short-segment posterior instrumentation alone, whereas patients in the augmented group (n = 90) were treated with a titanium spacer designed for transpedicle body reconstruction. The followup was 48-101 months. The radiographic and clinical results were evaluated and compared by Student's t test and Fisher's exact test.
The blood loss, operation time and hospitalization were similar in both the groups. The immediate postoperative anterior vertebral restoration rate of the augmented group was similar to that of the control group (97.6% ± 2.4% vs. 96.6% ± 3.2%). The final anterior vertebral restoration was greater in the augmented group than in the control group (93.3% ± 3.4% vs. 62.5% ± 11.2%). Immediate postoperative kyphotic angles were not significantly different between the groups (3.0° ± 1.8° vs. 5.1° ± 2.3°). The final kyphotic angles were less in the augmented group than the control group (7.3° ± 3.5° vs. 20.1° ± 5.4°). The augmented group had less (P < 0.001) implant failure [0% (n=0) vs. 23.8% (n=10)] for the control group) and more patients (P < 0.001) with no pain or minimal or occasional pain (Grade P1 or P2) than the control group [90.0% (n=81) vs. 66.7% (n=28)]. All patients in the augmented group and 39 (92.8%) patients in the control group experienced neurological recovery to Frankel Grade E. Three patients in the control group had improvement to Frankel Grade D from Frankel Grade C, but later had deterioration to Frankel Grade C because of loosening and dislodgement of the implant.
Posterior body reconstruction with TpBA can maintain kyphosis correction and vertebral restoration, prevent implant failure and lead to better clinical results.
PMCID: PMC2989517  PMID: 21139792
Burst fractures; kyphosis; posterior instrumentation; spinal trauma; thoracolumbar injury; transpedicle body augmenter
19.  Short segment fixation of thoracolumbar burst fractures without fusion 
European Spine Journal  1999;8(6):495-500.
There continues to be controversy surrounding the management of thoracolumbar burst fractures. Numerous methods of fixation have been described for this injury, but to our knowledge, spinal fusion has always been part of the stabilising procedure, whether this involves an anterior or a posterior approach. Apart from an earlier publication from this centre, there have been no reports on the use of internal fixation without fusion for this type of fracture. The aim of the study was to determine the outcome of patients with thoracolumbar burst fractures who were treated with short segment pedicle screw fixation without fusion. This is a retrospective review of 28 consecutive patients who had short segment pedicle screw fixation of thoracolumbar burst fractures without fusion performed between 1990 and 1993. All patients underwent a clinical and radiological assessment by an independent observer. Outcome was measured using the Low Back Outcome Score. The minimum follow-up period was 2 years (mean 3.1 years). Fifty percent of patients achieved an excellent result with the Low Back Outcome Score, while 12% were assessed as good, 20% fair and 16% obtained a poor result. The only significant factor affecting outcome was the influence of a compensation claim (P < 0.05). The implant failure rate (14% of patients) and the clinical outcome was similar to that from series where fusion had been performed in addition to pedicle screw fixation. The results of this study support the view that posterolateral bone grafting is not necessary when managing patients with thoracolumbar burst fractures by short segment pedicle screw fixation.
PMCID: PMC3611215  PMID: 10664310
Key words Burst fractures; Outcome; Short segment fixation; Fusion
20.  Radiological and Clinical Results of Laminectomy and Posterior Stabilization for Severe Thoracolumbar Burst Fracture : Surgical Technique for One-Stage Operation 
This study aimed to show the possibility of neural canal enlargement and restoration of bony fragments through laminectomy and minimal facetectomy without pediculectomy or an anterior approach, and also to prove the adequacy of posterior stabilization of vertebral deformities after thoracolumbar bursting fracture.
From January 2003 to June 2009, we experienced 45 patients with thoracolumbar burst fractures. All patients enrolled were presented with either a neural canal compromise of more than 40% with a Benzel-Larson Grade of VI, or more than 30% compromise with less than a Benzel-Larson Grade of V. Most important characteristic of our surgical procedure was repositioning retropulsed bone fragments using custom-designed instruments via laminectomy and minimal facetectomy without removing the fractured bone fragments. Beneath the dural sac, these custom-designed instruments could push the retropulsed bone fragments within the neural canal after the decompression and bone fragment repositioning.
The mean kyphotic deformities measured preoperatively and at follow-up within 12 months were 17.7 degrees (±6.4 degrees) and 9.6 degrees (±5.2 degrees), respectively. The mean midsagittal diameter improved from 8.8 mm (±2.8 mm) before surgery to 14.2 mm (±1.6 mm) at follow-up. The mean traumatic vertebral body height before surgery was 41.3% (±12.6%). At follow-up assessment within 12 months, this score showed a statistically significant increase to 68.3% (±12.8%). Neurological improvement occurred in all patients.
Though controversy exists in the treatment of severe thoracolumbar burst fracture, we achieved effective radiological and clinical results in the cases of burst fractures causing severe canal compromise and spinal deformity by using this novel custom-designed instruments, via posterior approach alone.
PMCID: PMC3218182  PMID: 22102953
Spinal fracture; Thoracolumbar spine; Surgical fixation devices; Spinal fusion; Surgical instrument
21.  One-stage posterior instrumentation surgery for the treatment of osteoporotic vertebral collapse with neurological deficits 
European Spine Journal  2010;19(6):907-915.
The number of reports describing osteoporotic vertebral fracture has increased as the number of elderly people has grown. Anterior decompression and fusion alone for the treatment of vertebral collapse is not easy for patients with comorbid medical problems and severe bone fragility. The purpose of the present study was to evaluate the efficacy of one-stage posterior instrumentation surgery for the treatment of osteoporotic vertebral collapse with neurological deficits. A consecutive series of 21 patients who sustained osteoporotic vertebral collapse with neurological deficits were managed with posterior decompression and short-segmental pedicle screw instrumentation augmented with ultra-high molecular weight polyethylene (UHMWP) cables with or without vertebroplasty using calcium phosphate cement. The mean follow-up was 42 months. All patients showed neurologic recovery. Segmental kyphotic angle at the instrumented level was significantly improved from an average preoperative kyphosis of 22.8–14.7 at a final follow-up. Spinal canal occupation was significantly reduced from an average before surgery of 40.4–19.1% at the final follow-up. Two patients experienced loosening of pedicle screws and three patients developed subsequent vertebral compression fractures within adjacent segments. However, these patients were effectively treated in a conservative fashion without any additional surgery. Our results indicated that one-stage posterior instrumentation surgery augmented with UHMWP cables could provide significant neurological improvement in the treatment of osteoporotic vertebral collapse.
PMCID: PMC2899987  PMID: 20157741
Osteoporosis; Vertebral collapse; Ultra-high molecular weight polyethylene cable; Posterior instrumentation
22.  Polymethylmethacrylate augmentation of the pedicle screw: the cement distribution in the vertebral body 
European Spine Journal  2011;20(8):1281-1288.
Many studies have proven that the polymethylmethacrylate (PMMA) augmentation of the pedicle screw can significantly increase stiffness and strength of spinal fixation. Some major complications have also been reported. However, there are no reports discussing cement distribution and its morphology in the osteoporotic vertebral body, which is critical in the analysis of the biomechanical strength of the pedicle screw and the risk of cement leakage after pedicle screw augmentation. In this study, we used computed tomography (CT) to evaluate the cement distribution in the osteoporotic vertebral body after PMMA augmentation of a pedicle screw and to analyze the factors leading to cement leakage. Two groups of patients were studied. Group A consisted 25 osteoporotic patients (mean age of 73 years) with spinal instrumentation who had a total of 145 pedicle screws and cement augmentation with biopsy needles. Group B consisted of 23 osteoporotic patients (mean age of 74.6 years) with spinal instrumentation who had a total of 125 cannulated pedicle screws with cement augmentation. All patients had CT evaluation of the cement distribution in the vertebral body after the surgery. The cement distribution in the vertebrae was divided into four zones in the axial CT view: anterior one-third, middle third, and posterior third of vertebral body, and the pedicle. The morphology of the cement distribution around the pedicle screw was defined as scattered type or concentrate type. The leakage pattern was divided to anterior–lateral, posterior–lateral, and canal leakage. The correlations among bone mineral density (BMD), the cement leakage rate, and cement distribution morphology were also analyzed. The results showed that most augmented pedicle screws had cement extension into three of the four zones of the vertebral body (66.3%), followed by two zones (20%), all four zones (11.5%), and only one zone (2.2%). Overall, 123 screws (84.8%) in Group A and 108 screws (86.4%) in Group B had cement concentrate type distribution. The cement leakage rate in Group A is 18.3% and 13.6% in Group B. Patients with a BMD <0.6 g/cm2 had significantly higher rates of cement leakage and tended toward a scattered cement distribution. There was only one patient who had a symptomatic leakage (sciatica) in Group B. We concluded that the cement distribution after pedicle screw augmentation with biopsy needle or cannulated screw technique was mostly localized in three zones of the vertebral body, and patients with lower BMD had a higher risk of cement leakage and scattered cement distribution.
PMCID: PMC3175839  PMID: 21533852
Cannulated pedicle screw; Cement augmentation; Osteoporosis; Polymethylmethacrylate
23.  Comparison of Posterior Fixation Alone and Supplementation with Posterolateral Fusion in Thoracolumbar Burst Fractures 
We compared the radiological and clinical outcomes between patients who underwent posterior fixation alone and supplemented with fusion following the onset of thoracolumbar burst fractures. In addition, we also evaluated the necessity of posterolateral fusion for patients treated with posterior pedicle screw fixation.
From January 2007 to December 2009, 46 consecutive patients with thoracolumbar burst fracture were included in this study. On the basis of posterolateral fusion, we divided our patients into the non-fusion group and the fusion group. The radiological assessment was performed according to the Cobb's method, and results were obtained at immediately, 3, 6, 12 months after surgery. The clinical outcomes were evaluated using the modified Mcnab criteria at the final follow-up.
The demographic data and the mean follow-up period were similar between the two groups. Patients of both groups achieved satisfactory clinical outcomes. The mean loss of kyphosis correction showed that patients of both groups experienced loss of correction with no respect to whether they underwent the posterolateral fusion. There was no significant difference in the degree of loss of correction at any time points of the follow-up between the two groups. In addition, we also compared the effect of fixed levels (i.e., short versus long segment) on loss of correction between the two groups and there was no significant difference. There were no major complications postoperatively and during follow-up period.
We suggest that posterolateral fusion may be unnecessary for patients with thoracolumbar burst fractures who underwent posterior pedicle screw fixation.
PMCID: PMC3488643  PMID: 23133723
Thoracolumbar burst fracture; Posterior pedicle screw fixation; Posterolateral fusion; Loss of kyphosis correction
24.  Reduction of the domino effect in osteoporotic vertebral compression fractures through short-segment fixation with intravertebral expandable pillars compared to percutaneous kyphoplasty: a case control study 
Osteoporotic vertebral compression fracture is the leading cause of disability and morbidity in elderly people. Treatment of this condition remains a challenge. Osteoporotic vertebral compression fractures can be managed with various approaches, but each has limitations. In this study, we compared the clinical outcomes obtained using short-segment fixation with intravertebral expandable pillars (I-VEP) to those obtained with percutaneous kyphoplasty in patients who had suffered vertebral compression fractures.
The study included 46 patients with single-level osteoporotic thoracolumbar fractures. Twenty-two patients in Group I underwent short-segment fixation with I-VEP and 24 patients in Group II underwent kyphoplasty. All patients were evaluated pre- and postoperatively using a visual analogue scale, anterior height of the fractured vertebra, and kyphotic angle of the fractured vertebra. The latter 2 radiological parameters were measured at the adjacent segments as well.
There was no significant difference between the groups in terms of gender or fracture level, but the mean age was greater in Group II patients (p = 0.008). At the 1-year follow-up, there were no significant differences in the visual analogue scale scores, anterior height of the fractured vertebra, or the value representing anterior height above the fractured vertebra and kyphotic angle below the fractured vertebra, after adjusting for the patients’ gender, fracture level, and age. When considered separately, the anterior height below the fractured vertebra was significantly higher and the kyphotic angle above the fractured vertebra was significantly smaller in Group I than in Group II (p = 0.029 and p = 0.008, respectively). The kyphotic angle of the fractured vertebra was significantly smaller in Group II than in Group I (p < 0.001).
In older individuals with vertebral compression fractures, kyphoplasty restored and maintained the collapsed vertebral body with less kyphotic deformity than that induced by short-segment fixation with I-VEP. Short-segment fixation with I-VEP was more effective in maintaining the integrity of adjacent segments, which prevented the domino effect often observed in patients with osteoporotic kyphotic spines.
PMCID: PMC3598560  PMID: 23452614
Short-segment fixation; Intravertebral expandable pillar; Percutaneous kyphoplasty; Vertebral compression fracture
25.  Management of Unstable Thoracolumbar Spinal Fractures by Pedicle Screws and Rods Fixation 
Background: The thoracolumbar junction is the most common area of injury to the axial skeleton. Forces along the long stiff kyphotic thoracic spine switch abruptly into the mobile lordotic lumbar spine at the thoracolumbar junction. Goals of treatment are to obtain a painless, balanced, stable spine with optimum neurological function and maximum spine mobility. The present prospective study has evaluated the effectiveness of pedicle screw instrumentation in various fractures around the TL spine to overcome the complications encountered in the conservative line of management of these fractures.
Materials & Methods: Thirty cases of fractures around the TL spine were operated with posterior pedicle screw fixation one or two level above and below the fracture. The cases were followed up for a mean of 9.5 months with radiological and neurological evaluation.
Results: The average age groups of the patients studied were 21 to 53 years majority were males, fall from height being the predominant mode of injury involving the T12 and L1 vertebral body. The unstable burst fractures the most common type of fracture, radiological parameters sagittal angle and index were recorded pre and post-operatively. The neurological grading was done using the ASIA score. Follow-up was done for a minimum of 5 months where sagittal angle reduction achieved was 10.75 at final follow-up from 23.5 pre-operative. The sagittal index achieved at final follow-up was 72% compared to the pre-operative mean of 53%. The neurological improvement was regarded to be fair enough for the type of injury sustained and fixation achieved.
Conclusion: We found that the application of posterior instrumentation using pedicle screw and rod resulted in a reasonable correction of the deformity with a significant reduction in recumbency-associated complications; the limiting factor being the small study group and short follow-up period.
PMCID: PMC3972526  PMID: 24701500
Thoracolumbars; pedicle screw and rod instrumentation

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