Showing papers in "Spine in 2001"
TL;DR: Disc degeneration can be graded reliably on routine T2-weighted magnetic resonance images using the grading system and algorithm presented in this investigation.
Abstract: Study design A reliability study was conducted Objectives To develop a classification system for lumbar disc degeneration based on routine magnetic resonance imaging, to investigate the applicability of a simple algorithm, and to assess the reliability of this classification system Summary of background data A standardized nomenclature in the assessment of disc abnormalities is a prerequisite for a comparison of data from different investigations The reliability of the assessment has a crucial influence on the validity of the data Grading systems of disc degeneration based on state of the art magnetic resonance imaging and corresponding reproducibility studies currently are sparse Methods A grading system for lumbar disc degeneration was developed on the basis of the literature An algorithm to assess the grading was developed and optimized by reviewing lumbar magnetic resonance examinations The reliability of the algorithm in depicting intervertebral disc alterations was tested on the magnetic resonance images of 300 lumbar intervertebral discs in 60 patients (33 men and 27 women) with a mean age of 40 years (range, 10-83 years) All scans were analyzed independently by three observers Intra- and interobserver reliabilities were assessed by calculating kappa statistics Results There were 14 Grade I, 82 Grade II, 72 Grade III, 68 Grade IV, and 64 Grade V discs The kappa coefficients for intra- and interobserver agreement were substantial to excellent: intraobserver (kappa range, 084-090) and interobserver (kappa range, 069-081) Complete agreement was obtained, on the average, in 838% of all the discs A difference of one grade occurred in 159% and a difference of two or more grades in 13% of all the cases Conclusion Disc degeneration can be graded reliably on routine T2-weighted magnetic resonance images using the grading system and algorithm presented in this investigation
3,048 citations
TL;DR: Fixation of the atlantoaxial complex using polyaxial-head screws and rods seems to be a reliable technique and should be considered an efficient alternative to the previously reported techniques.
Abstract: Study design A novel technique of atlantoaxial stabilization using individual fixation of the C1 lateral mass and the C2 pedicle with minipolyaxial screws and rods is described. In addition, the initial results of this technique on 37 patients are described. Objectives To describe the technique and the initial clinical and radiographic results for posterior C1-C2 fixation with a new implant system. Summary of background data Stabilization of the atlantoaxial complex is a challenging procedure because of the unique anatomy of this region. Fixation by transarticular screws combined with posterior wiring and structural bone grafting leads to excellent fusion rates. The technique is technically demanding and has a potential risk of injury to the vertebral artery. In addition, this procedure cannot be used in the presence of fixed subluxation of C1 on C2 and in the case of an aberrant path of the vertebral artery. To address these limitations, a new technique of C1-C2 fixation has been developed: bilateral insertion of polyaxial-head screws in the lateral mass of C1 and through the pars interarticularis into the pedicle of C2, followed by a fluoroscopically controlled reduction maneuver and rod fixation. Methods After posterior exposure of the C1-C2 complex, the 3.5-mm polyaxial screws are inserted in the lateral masses of C1. Two polyaxial screws are then inserted into the pars interarticularis of C2. Drilling is guided by anatomic landmarks and fluoroscopy. If necessary, reduction of C1 onto C2 can be accomplished by manipulation of the implants, followed by fixation to the 3-mm rod. For definitive fusion, cancellous bone can be added. No structural bone graft or wiring is required. In selected cases, e.g., C1-C2 subluxation or fractures in young patients in whom only temporary fixation is necessary, the instrumentation can be removed after an appropriate time. Because the joint surfaces stay intact, the patient can regain motion in the C1-C2 joints. Results Thirty-seven patients underwent this procedure. No neural or vascular damage related to this technique has been observed. The early clinical and radiologic follow-up data indicate solid fusion in all patients. Conclusion Fixation of the atlantoaxial complex using polyaxial-head screws and rods seems to be a reliable technique and should be considered an efficient alternative to the previously reported techniques.
1,300 citations
TL;DR: Much research over the past 30 to 40 years has focused on elucidating the mechanisms of spinal cord injury, with the complex pathophysiologic processes slowly being unraveled.
Abstract: Spinal cord injury occurs through various countries throughout the world with an annual incidence of 15 to 40 cases per million, with the causes of these injuries ranging from motor vehicle accidents and community violence to recreational activities and workplace-related injuries. Survival has improved along with a greater appreciation of patterns of presentation, survival, and complications. Despite much work having been done, the only treatment to date known to ameliorate neurologic dysfunction that occurs at or below the level of neurologic injury has been intravenous methylprednisolone therapy. Much research over the past 30 to 40 years has focused on elucidating the mechanisms of spinal cord injury, with the complex pathophysiologic processes slowly being unraveled. With a greater understanding of both primary and secondary mechanisms of injury, the roles of calcium, free radicals, sodium, excitatory amino acids, vascular mediators, and apoptosis have been elucidated. This review examines the epidemiology, demographics, and pathophysiology of acute spinal cord injury.
1,289 citations
TL;DR: A new surgical strategy for spinal metastases based on the prognostic scoring system is proposed and provides appropriate guidelines for treatment in all patients with spinal metastased patients.
Abstract: Study design A new surgical strategy for treatment of patients with spinal metastases was designed, and 61 patients were treated based on this strategy. Objectives To propose a new surgical strategy for the treatment of patients with spinal metastases. Summary of background data A preoperative score composed of six parameters has been proposed by Tokuhashi et al for the prognostic assessment of patients with metastases to the spine. Their scoring system was designed for deciding between excisional or palliative procedures. Recently, aggressive surgery, such as total en bloc spondylectomy for spinal metastases, has been advocated for selected patients. Surgical strategies should include various treatments ranging from wide or marginal excision to palliative treatment with hospice care. Methods Sixty-seven patients with spinal metastases who had been treated from 1987-1991 were reviewed, and prognostic factors were evaluated retrospectively (phase 1). A new scoring system for spinal metastases that was designed based on these data consists of three prognostic factors: 1) grade of malignancy (slow growth, 1 point; moderate growth, 2 points; rapid growth, 4 points), 2) visceral metastases (no metastasis, 0 points; treatable, 2 points: untreatable, 4 points), and 3) bone metastases (solitary or isolated, 1 point; multiple, 2 points). These three factors were added together to give a prognostic score between 2-10. The treatment goal for each patient was set according to this prognostic score. The strategy for each patient was decided along with the treatment goal: a prognostic score of 2-3 points suggested a wide or marginal excision for long-term local control; 4-5 points indicated marginal or intralesional excision for middle-term local control; 6-7 points justified palliative surgery for short-term palliation; and 8-10 points indicated nonoperative supportive care. Sixty-one patients were treated prospectively according to this surgical strategy between 1993-1996 (phase 2). The extent of the spinal metastases was stratified using the surgical classification of spinal tumors, and technically appropriate and feasible surgery was performed, such as en bloc spondylectomy, piecemeal thorough excision, curettage, or palliative surgery. Results The mean survival time of the 28 patients treated with wide or marginal excision was 38.2 months (26 had successful local control). The mean survival time of the 13 patients treated with intralesional excision was 21.5 months (nine had successful local control). The mean survival time of the 11 patients treated with palliative surgery and stabilization was 10.1 months (eight had successful local control). The mean survival time of the patients with terminal care was 5.3 months. Conclusions A new surgical strategy for spinal metastases based on the prognostic scoring system is proposed. This strategy provides appropriate guidelines for treatment in all patients with spinal metastases.
1,144 citations
TL;DR: Kyphoplasty and vertebroplasty are new techniques that help decrease the pain and improve function in fractured vertebrae by realigning the spinal column and regaining height of the broken vertebra, which may help decrease pulmonary, GI and early morbidity consequences related to these fractures.
Abstract: Study design Literature review Objectives To describe new treatments for painful osteoporotic compression fractures in light of available scientific literature and clinical experience Summary of background data Painful vertebral osteoporotic compression fractures lead to significant morbidity and mortality This relates to pulmonary dysfunction, eating disorders (nutritional deficits), pain, loss of independence, and mental status change (related to pain and medications) Medications to treat osteoporosis (primarily antiresorptive) do not effectively treat the pain or the fracture, and require over 1 year to reduce the degree of osteoporosis Kyphoplasty and vertebroplasty are new techniques that help decrease the pain and improve function in fractured vertebrae Methods This is a descriptive review of the background leading to vertebroplasty and kyphoplasty, a description of the techniques, a review of the literature, as well as current ongoing studies evaluating kyphoplasty Results Both techniques have had a very high acceptance and use rate There is 95% improvement in pain and significant improvement in function following treatment by either of these percutaneous techniques Kyphoplasty improves height of the fractured vertebra, and improves kyphosis by over 50%, if performed within 3 months from the onset of the fracture (onset of pain) There is some height improvement, though not as marked, along with 95% clinical improvement, if the procedure is performed after 3 months Complications occur with both and relate to cement leakage in both, and cement emboli with vertebroplasty Conclusion Kyphoplasty and vertebroplasty are safe and effective, and have a useful role in the treatment of painful osteoporotic vertebral compression fractures that do not respond to conventional treatments Kyphoplasty offers the additional advantage of realigning the spinal column and regaining height of the fractured vertebra, which may help decrease the pulmonary, GI, and early morbidity consequences related to these fractures Both procedures are technically demanding
1,066 citations
TL;DR: Kyphoplasty is associated with early clinical improvement of pain and function as well as restoration of vertebral body height in the treatment of painful osteoporotic compression fractures.
Abstract: Study Design. An Institutional Review Board-approved Phase I efficacy study of inflatable bone tamp usage in the treatment of symptomatic osteoporotic compression fractures. Objectives. To evaluate the safety and efficacy of inflatable bone tamp reduction and cement augmentation, kyphoplasty, in the treatment of painful osteoporotic vertebral compression fractures. Summary of Background Data. Osteoporotic compression fractures can result in progressive kyphosis and chronic pain. Traditional treatment for these patients includes bed rest, analgesics, and bracing. Augmentation of vertebral compression fractures with polymethylmethacryiate, vertebroplasty, has been used to treat pain. This technique, however, makes no attempt to restore the height of the collapsed vertebral body. Kyphoplasty is a new technique that involves the introduction of inflatable bone tamps into the vertebral body. Once inflated, the bone tamps restore the vertebral body back toward its original height while creating a cavity that can be filled with bone cement. Patients and Methods. Seventy consecutive kyphoplasty procedures were performed in 30 patients. The indications included painful primary or secondary osteoporotic vertebral compression fractures. Mean duration of symptoms was 5.9 months. Symptomatic levels were identified by correlating the clinical data with MRI findings. Perioperative variables and bone tamp complications or issues were recorded and analyzed. Preoperative and postoperative radiographs were compared to calculate the percentage height restored. Outcome data were obtained by comparing preoperative and latest postoperative SF-36 data. Results. At the completion of the Phase I study there were no major complications related directly to use of this technique or use of the inflatable bone tamp. In 70% of the vertebral bodies kyphoplasty restored 47% of the lost height. Cement leakage occurred at six levels (8.6%). SF-36 scores for Bodily Pain 11.6-58.7, (P = 0.0001) and Physical Function 11.7-47.4, (P = 0.002) were among those that showed significant improvement. Conclusions. The inflatable bone tamp was efficacious in the treatment of osteoporotic vertebral compression fractures. Kyphoplasty is associated with early clinical improvement of pain and function as well as restoration of vertebral body height in the treatment of painful ostecporotic compression fractures.
960 citations
TL;DR: Lumbar fusion in a well-informed and selected group of patients with severe CLBP can diminish pain and decrease disability more efficiently than commonly used nonsurgical treatment.
Abstract: STUDY DESIGN A randomized controlled multicenter study with a 2-year follow-up by an independent observer. OBJECTIVES To determine whether fusion of the lower lumbar spine could reduce pain and diminish disability more effectively when compared with nonsurgical treatment in patients with severe chronic low back pain (CLBP). SUMMARY OF BACKGROUND DATA The reported results after fusion surgery on patients with CLBP vary considerably, and the evidence of treatment efficacy is weak in the absence of randomized controlled studies. PATIENTS AND METHODS A total of 294 patients referred to 19 spinal centers from 1992 through 1998 were randomized blindly into four treatment groups. Patients aged 25-65 years with CLBP for at least 2 years and with radiologic evidence of disc degeneration at L4-L5, L5-S1, or both were eligible to participate in the study. The surgical group (n=222) included three different fusion techniques, not analyzed separately in this study. Patients in the nonsurgical group (n=72) were treated with different kinds of physical therapy. The surgical group comprised 49.5% men, and the mean age was 43 years. The corresponding figures for the nonsurgical group were 48.6% and 44 years. The patients had suffered from low back pain for a mean of 7.8 and 8.5 years and been on sick leave due to back pain for a mean of 3.2 and 2.9 years, respectively. The Visual Analogue Scale (VAS) was used to measure pain. The Oswestry Low Back Pain Questionnaire, the Million Score and the General Function Score (GFS) were used to measure disability. The Zung Depression Scale was used to measure depressive symptoms. The overall result was assessed by the patient and by an independent observer. Records from the Swedish Social Insurance were used to evaluate work disability. Patients who changed groups were included in the analyses of significance according to the intention-to-treat principle. RESULTS At the 2-year follow-up 289 of 294 (98%) patients, including 25 who had changed groups, were examined. Back pain was reduced in the surgical group by 33% (64 to 43), compared with 7% (63 to 58) in the nonsurgical group (P=0.0002). Pain improved most during the first 6 months and then gradually deteriorated. Disability according to Oswestry was reduced by 25% (47 to 36) compared with 6% (48 to 46) among nonsurgical patients (P=0.015), according to Million by 28% (64 to 46) compared with 8% (66 to 60) (P=0.004), and accordingtoGFS by 31% (49 to 34) compared with 4% (48 to 46) (P=0.005). The depressive symptoms, according to Zung, were reduced by 20% (39 to 31) in the surgical group compared with 7% (39 to 36) in the nonsurgical group (P=0.123). In the surgical group 63% (122/195) rated themselves as "much better" or "better" compared with 29% (18/62) in the nonsurgical group (P<0.0001). The "net back to work rate" was significantly in favor of surgical treatment, or 36% vs. 13% (P=0.002). The early complication rate in the surgical group was 17%. CONCLUSION Lumbar fusion in a well-informed and selected group of patients with severe CLBP can diminish pain and decrease disability more efficiently than commonly used nonsurgical treatment.
872 citations
TL;DR: Long-term results suggest that specific exercise therapy in addition to medical management and resumption of normal activity may be more effective in reducing low back pain recurrences thanmedical management and normal activity alone.
Abstract: Study Design. A randomized clinical trial with 1-year and 3-year telephone questionnaire follow-ups. Objective. To report a specific exercise intervention’s long-term effects on recurrence rates in acute, first-episode low back pain patients. Summary of Background Data. The pain and disability associated with an initial episode of acute low back pain (LBP) is known to resolve spontaneously in the short-term in the majority of cases. However, the recurrence rate is high, and recurrent disabling episodes remain one of the most costly problems in LBP. A deficit in the multifidus muscle has been identified in acute LBP patients, and does not resolve spontaneously on resolution of painful symptoms and resumption of normal activity. Any relation between this deficit and recurrence rate was investigated in the long-term. Methods. Thirty-nine patients with acute, first-episode LBP were medically managed and randomly allocated to either a control group or specific exercise group. Medical management included advice and use of medications. Intervention consisted of exercises aimed at rehabilitating the multifidus in cocontraction with the transversus abdominis muscle. One year and three years after treatment, telephone questionnaires were conducted with patients. Results. Questionnaire results revealed that patients from the specific exercise group experienced fewer recurrences of LBP than patients from the control group. One year after treatment, specific exercise group recurrence was 30%, and control group recurrence was 84% (P , 0.001). Two to three years after treatment, specific exercise group recurrence was 35%, and control group recurrence was 75% (P , 0.01). Conclusion. Long-term results suggest that specific exercise therapy in addition to medical management and resumption of normal activity may be more effective in reducing low back pain recurrences than medical management and normal activity alone. [Key Words: multifidus, low back pain, rehabilitation]
838 citations
TL;DR: In this paper, the authors compare national clinical guidelines on low back pain on 11 different countries published from 1994 until 2000 and find that diagnostic and therapeutic recommendations were generally similar. But there were discrepancies for recommendations regarding exercise therapy, spinal manipulation, muscle relaxants, and patient information.
Abstract: Study design Descriptive study. Objectives To compare national clinical guidelines on low back pain. Summary of background data To rationalize the management of low back pain, clinical guidelines have been issued in various countries around the world. Given that the available scientific evidence is the same, irrespective of the country, one would expect these guidelines to include more or less similar recommendations regarding diagnosis and treatment. Methods Guidelines were included that met the following criteria: the target group consisted of primary care health professionals, and the guideline was published in English, German, or Dutch. Only one guideline per country was included: the one most recently published. Results Clinical guidelines from 11 different countries published from 1994 until 2000 were included in this review. The content of the guidelines appeared to be quite similar regarding the diagnostic classification (diagnostic triage) and the use of diagnostic and therapeutic interventions. Consistent features were the early and gradual activation of patients, the discouragement of prescribed bed rest, and the recognition of psychosocial factors as risk factors for chronicity. However, there were discrepancies for recommendations regarding exercise therapy, spinal manipulation, muscle relaxants, and patient information. Conclusion The comparison of clinical guidelines for the management of low back pain showed that diagnostic and therapeutic recommendations were generally similar. Updates of the guidelines are planned in most countries, although so far produced only in the United Kingdom. However, new evidence may lead to stronger conclusions and enable future guidelines to become even more concordant.
701 citations
607 citations
TL;DR: Correlation between these two phenomena suggests a common underlying pathology in the lumbar spine, and patients with chronic low back pain demonstrated poorer balance performance than healthy control volunteers, especially at the most difficult levels.
Abstract: Study Design. Balance performance in unstable sitting and trunk muscle response to quick force release were measured in 16 patients with chronic low back pain and 14 matched healthy control subjects.Objectives.To determine whether patients with low back pain will exhibit poorer postural control, whi
TL;DR: Thoracic pedicle screw fixation is a reliable method of treating spinal deformities, with an excellent deformity correction and a high margin of safety.
Abstract: Study design A retrospective study. Objective To determine the safety of pedicle screw fixation in thoracic deformity correction. Summary of background data Pedicle screw fixation enables enhanced correction of spinal deformities. However, the technique is still not widely applied for thoracic deformities for fear of neurologic complications. Materials and methods A total of 462 patients subjected to thoracic pedicle screw fixation for spinal deformities were analyzed after a minimum follow-up of 2 years. Etiologic diagnoses were idiopathic scoliosis in 330, congenital kyphoscoliosis in 68, kyphosis in 50, and others in 14. They were reviewed using the medical records and preoperative, intraoperative, and postoperative roentgenograms. Computed tomography was performed when screw position was questionable. Results A total of 4604 thoracic pedicle screws were inserted (10.1 screws/patient). There were 67 screw malpositions (1.5%) in 48 patients (10.4%). The malpositions were inferior in 33, lateral in 18, superior in 12, and medial in 4. Screw-related neurologic complications occurred in four patients (0.8%); these comprised a transient paraparesis and three dural tears. Other complications comprised 11 intraoperative pedicle fractures, 35 screw loosenings, 9 postoperative infections, and 1 pneumothorax. There were no significant screw-related neurologic or visceral complications that adversely affected the long-term result. The deformity correction was 69.9% for idiopathic scoliosis and 60.7% for congenital scoliosis. The sagittal plane deformity correction was 47 degrees for kyphosis. Conclusions Thoracic pedicle screw fixation is a reliable method of treating spinal deformities, with an excellent deformity correction and a high margin of safety.
TL;DR: Information is provided on the cement volumes needed to restore biomechanical integrity to compressed osteoporotic vertebral bodies to provide guidance on the dose–response association between cement volume and restoration of strength and stiffness.
Abstract: Study Design. Ex vivo biomechanical study using osreoporotic cadavetic vertebral bodies. Objective. To determine the association between the volume of compent injected during percutaneous vertebroplasty and the restoration of strength and stiffness in osteoporotic vertebral bodies, two investigational cements were studied: Orthocomp (Orthovita, Malvern, PA) and Simplex 20 (Simplex P with 20% by weight barium sulfate content: Stryker-Howmedica-Osteonics, Rutherford, NJ). Summary of Background Data. Previous biomechanical studies have shown that injections of 8-10 mL of cement during vertebroplasty restore or increase vertebral body strength and stiffness; however, the doseresponse association between cement volume and restoration of strength and stiffness is unknown. Methods. Compression fractures were experimentally created in 144 vertebral bodies (T6-L5) obtained from 12 osteoporotic spines harvested from female cadavers. After initial strength and stiffness were determined, the vertebral bodies were stabilized using bipedicular injections of cement totaling 2, 4, 6, or 8 mL and recompressed, after which post-treatment strength and stiffness were measured. Strength and stiffness were considered restored when post-treatment values were not significantly different from initial values. Results. Strength was restored for all regions when 2 mL of either cement was injected. To restore stiffness with Orthocomp, the thoracic and thoracolumbar regions required 4 mL, but the lumbar region required 6 mL. To restore stiffness with Simplex 20, the thoracic and lumbar regions required 4 mL, but the thoracolumbar region required 8 mL. Conclusion. These data provide guidance on the cement volumes needed to restore biomechanical integrity to compressed osteoporotic vertebral bodies.
TL;DR: The mechanical properties of multilevel human cervical spines were investigated by applying pure rotational moments to each specimen and measuring multidirectional intervertebral motions, and both rotation and translation motions were coupled with main motions.
Abstract: Study design The mechanical properties of multilevel human cervical spines were investigated by applying pure rotational moments to each specimen and measuring multidirectional intervertebral motions. Objectives To document intervertebral main and coupled motions of the cervical spine in the form of load-displacement curves. Summary of background data Although a number of in vivo and in vitro studies have attempted to delineate normal movement patterns of the cervical spine, none has explored the complexity of the whole cervical spine as a three-dimensional structure. Methods Sixteen human cadaveric specimens (C0-C7) were used for this study. Pure rotational moments of flexion-extension, bilateral axial torque, and bilateral lateral bending were applied using a specially designed loading fixture. The resulting intervertebral motions were recorded using stereophotogrammetry and depicted as a series of load-displacement curves. Results The resulting load-displacement curves were found to be nonlinear, and both rotation and translation motions were coupled with main motions. With flexion-extension moment loading, the greatest degree of flexion occurred at C1-C2 (12.3 degrees), whereas the greatest degree of extension was observed at C0-C1 (20.2 degrees). With axial moment loading, rotation at C1-C2 was the largest recorded (56.7 degrees). With lateral bending moments, the average range of motion for all vertebral levels was 7.9 degrees. Conclusions The findings of the present study are relevant to the clinical practice of examining motions of the cervical spine in three dimensions and to the understanding of spinal trauma and degenerative diseases.
TL;DR: The results support the idea that maximum cell density in the disc is regulated by nutritional constraints, and that a fall in nutrient supply reduces the number of viable cells in theDisc and thus leads to degeneration.
Abstract: Study design Disc cell viability was analyzed in relation to nutrient supply and cellular demand in vitro in a diffusion chamber. Objective To determine relations among nutrient supply, nutrient concentrations. and cell viability. Summary of background data Although a fall in nutrient supply has long been thought the cause of disc degeneration in vivo, little information exists about the effects of nutrient levels or supply on cell viability and metabolism. Methods Isolated bovine nucleus cells were cultured in agarose gels in a diffusion chamber up to 13 days. Nutrients were supplied to the open sides of the chamber and diffused through the gel to the center, 12.5 mm away from the nutrient supply, in a configuration analogous to that of the disc in vivo. Profiles of cell viability and concentration of glycosaminoglycans across the chamber were measured in relation to cell density and medium composition. Results Cells remained viable across the chamber at low cell densities. However, at higher densities, cells in the center of the chamber died. The viable distance from the nutrient supply fell with an increase in cell density. Glucose was a critical nutrient. Survival was also poor at acidic pH (6.0). At 0% oxygen, disc cells survived up to 13 days with no loss of viability, but produced very little proteoglycan. Conclusions The results support the idea that maximum cell density in the disc is regulated by nutritional constraints, and that a fall in nutrient supply reduces the number of viable cells in the disc and thus leads to degeneration.
TL;DR: The results suggest that large fill volumes may not be the most biomechanically optimal configuration, and an improvement might be achieved by use of lower cement volume with symmetric placement.
Abstract: Study design The biomechanical behavior of a single lumbar vertebral body after various surgical treatments with acrylic vertebroplasty was parametrically studied using finite-element analysis. Objectives To provide a theoretical framework for understanding and optimizing the biomechanics of vertebroplasty. Specifically, to investigate the effects of volume and distribution of bone cement on stiffness recovery of the vertebral body. Summary of background data Vertebroplasty is a treatment that stabilizes a fractured vertebra by addition of bone cement. However, there is currently no information available on the optimal volume and distribution of the filler material in terms of stiffness recovery of the damaged vertebral body. Methods An experimentally calibrated, anatomically accurate finite-element model of an elderly L1 vertebral body was developed. Damage was simulated in each element based on empirical measurements in response to a uniform compressive load. After virtual vertebroplasty (bone cement filling range of 1-7 cm3) on the damaged model, the resulting compressive stiffness of the vertebral body was computed for various spatial distributions of the filling material and different loading conditions. Results Vertebral stiffness recovery after vertebroplasty was strongly influenced by the volume fraction of the implanted cement. Only a small amount of bone cement (14% fill or 3.5 cm3) was necessary to restore stiffness of the damaged vertebral body to the predamaged value. Use of a 30% fill increased stiffness by more than 50% compared with the predamaged value. Whereas the unipedicular distributions exhibited a comparative stiffness to the bipedicular or posterolateral cases, it showed a medial-lateral bending motion ("toggle") toward the untreated side when a uniform compressive pressure load was applied. Conclusion Only a small amount of bone cement ( approximately 15% volume fraction) is needed to restore stiffness to predamage levels, and greater filling can result in substantial increase in stiffness well beyond the intact level. Such overfilling also renders the system more sensitive to the placement of the cement because asymmetric distributions with large fills can promote single-sided load transfer and thus toggle. These results suggest that large fill volumes may not be the most biomechanically optimal configuration, and an improvement might be achieved by use of lower cement volume with symmetric placement.
TL;DR: The long-term outcome of standard discectomy in this series was favorable, and although patients with preserved disc height generally had favorable results, the risk of recurrent disc herniation was high in this population.
Abstract: Study design A retrospective analysis of the long-term outcomes of standard discectomy for lumbar disc herniation Objectives To investigate the long-term outcomes of standard discectomy to address postoperative problems, including residual low back pain and recurrent herniation Summary of background data Most previous investigators found that favorable outcomes of standard discectomy were maintained for the long-term postoperative period Although they observed postoperative complications such as residual low back pain and recurrent herniation, detailed analyses of these results have not been conducted Methods The long-term follow-up results in patients who were observed for a minimum of 10 years after standard discectomy were evaluated by using the Japanese Orthopedic Association scoring system through direct examinations and questionnaires Radiography also was used in patients who agreed to visit the hospital, and findings were compared with those on preoperative radiographs Results The average recovery rate calculated by using Japanese Orthopedic Association scores was 735 +/- 217% Even though residual low back pain was found in 746% of the patients, only 127% had severe low back pain The majority of the patients with severe low back pain were under 35 years of age at the time of operation, with preoperative advanced disc degeneration The final Japanese Orthopedic Association scores in the patients with decreased disc height were significantly lower than those in patients with no decrease However, the disc height of patients with a recurrent herniation was preserved Conclusion The long-term outcome of standard discectomy in this series was favorable Although patients with preserved disc height generally had favorable results, the risk of recurrent disc herniation was high in this population
TL;DR: The results of this study suggest that patient expectations may influence clinical outcome independently of the treatment itself, and general optimism about treatment, divorced from a specific treatment, is not strongly associated with outcome.
Abstract: Study design A subanalysis of data derived from a randomized clinical trial was performed. Objective To evaluate the association of a patient's expectation for benefit from a specific treatment with improved functional outcome. Summary of background data Psychosocial factors, ambiguous diagnoses, and lack of a clearly superior treatment have complicated the management of patients with chronic low back pain. The authors hypothesized that patient expectation for benefit from a specific treatment is associated with improved functional outcomes when that treatment is administered. Methods In a randomized trial, 135 patients with chronic low back pain who received acupuncture or massage were studied. Before randomization, study participants were asked to describe their expectations regarding the helpfulness of each treatment on a scale of 0 to 10. The primary outcome was level of function at 10 weeks as measured by the modified Roland Disability scale. Results After adjustment for baseline characteristics, improved function was observed for 86% of the participants with higher expectations for the treatment they received, as compared with 68% of those with lower expectations (P = 0.01). Furthermore, patients who expected greater benefit from massage than from acupuncture were more likely to experience better outcomes with massage than with acupuncture, and vice versa (P = 0.03). Conclusions The results of this study suggest that patient expectations may influence clinical outcome independently of the treatment itself. In contrast, general optimism about treatment, divorced from a specific treatment, is not strongly associated with outcome. These results may have important implications for clinical trial design and recruitment, and may help to explain the apparent success of some conventional and alternative therapies in trials that do not control for patient expectations. The findings also may be important for therapy choices made in the clinical setting.
TL;DR: The combination of methylprednisolone and bupivacaine seems to have a short-term effect, but at 3 and 6 months, the steroid group seems to experience a “rebound” phenomenon.
Abstract: Study design A randomized, double-blind trial was conducted. Objectives To test the efficacy of periradicular corticosteroid injection for sciatica. Summary of background data The efficacy of epidural corticosteroids for sciatica is controversial. Periradicular infiltration is a targeted technique, but there are no randomized controlled trials of its efficacy. Methods In this study 160 consecutive, eligible patients with sciatica who had unilateral symptoms of 1 to 6 months duration, and who never underwent surgery were randomized for double-blind injection with methylprednisolone bupivacaine combination or saline. Objective and self-reported outcome parameters and costs were recorded at baseline, at 2 and 4 weeks, at 3 and 6 months, and at 1 year. Results Recovery was better in the steroid group at 2 weeks for leg pain (P = 0.02), straight leg raising (P = 0.03), lumbar flexion (P = 0.05), and patient satisfaction (P = 0.03). Back pain was significantly lower in the saline group at 3 and 6 months (P = 0.03 and 0.002, respectively), and leg pain at 6 months (13.5, P = 0.02). Sick leaves and medical costs were similar for both treatments, except for cost of therapy visits and drugs at 4 weeks, which were in favor of the steroid injection (P = 0.05 and 0.005, respectively). By 1 year, 18 patients in the steroid group and 15 in the saline group underwent surgery. Conclusions Improvement during the follow-up period was found in both the methylprednisolone and saline groups. The combination of methylprednisolone and bupivacaine seems to have a short-term effect, but at 3 and 6 months, the steroid group seems to experience a "rebound" phenomenon.
TL;DR: For chronic neck pain, the use of strengthening exercise, whether in combination with spinal manipulation or in the form of a high-technology MedX program, appears to be more beneficial to patients with chronic neckPain than the useof spinal manipulation alone.
Abstract: Study Design. A randomized, parallel-group, single-blinded clinical trial was performed. After a 1-week baseline period, patients were randomized to 11 weeks of therapy, with posttreatment follow-up assessment 3, 6, and 12 months later.Objectives.To compare the relative efficacy of rehabilitative ne
TL;DR: No significant differences were found between transforaminal and posterior lumbar interbody fusions in terms of blood loss, operative time, or duration of hospital stay when a single-level fusion was performed, but significantly less blood loss occurred in two-level fusions.
Abstract: STUDY DESIGN: A study of the transforaminal lumbar interbody fusion and the posterior lumbar interbody fusion techniques was performed. OBJECTIVES: To describe the transforaminal lumbar interbody fusion technique, and to compare operative data, including blood loss and operative time, with data from posterior lumbar interbody fusion technique. SUMMARY OF BACKGROUND DATA: The evolution of posterior lumbar fusion combined with anterior interbody fusion has resulted in increased fusion rates as well as improved reductions and stability. The transforaminal lumbar interbody fusion technique pioneered by Harms and Jeszensky offers potential advantages and provides a surgical alternative to more traditional methods. METHODS: In 13 consecutive months, two spinal surgeons performed 40 transforaminal lumbar interbody fusions and 34 posterior lumbar interbody fusion procedures. Data regarding blood loss, operative times, and length of hospital stay were recorded. These data were analyzed using analysis of variance to show any significant differences between the two techniques. To determine whether differences in measured variables were dependent on patient gender or number of levels fused, epsilon(chi2) analysis was used. RESULTS: No significant differences were found between transforaminal and posterior lumbar interbody fusions in terms of blood loss, operative time, or duration of hospital stay when a single-level fusion was performed. Significantly less blood loss occurred when a two-level fusion was performed using the transforaminal approach instead of the posterior approach (P < 0.01). Differences in measured variables for the two procedures were independent of patient age, gender, and the number of levels fused. There were no complications with the transforaminal approach, but the posterior approach resulted in multiple complications. CONCLUSIONS: In this comparison of patients receiving transforaminal lumbar interbody fusion versus posterior lumbar interbody fusion, no complications occurred with the transforaminal approach, whereas multiple complications were associated with the posterior approach. Similar operative times, blood loss, and duration of hospital stay were obtained in single-level fusions, but significantly less blood loss occurred with the transforaminal lumbar interbody approach in two-level fusions. The transforaminal procedure preserves the interspinous ligaments of the lumbar spine and preserves the contralateral laminar surface as an additional surface for bone graft. It may be performed at all lumbar levels because it avoids significant retraction of the dura and conus medullaris.
TL;DR: Although not proven in the primary efficacy analysis of this trial, Sygen® appears to be beneficial in patients with severe spinal cord injury.
Abstract: Study design Randomized, double-blind, sequential, multicenter clinical trial of two doses of Sygen versus placebo. Objectives To determine efficacy and safety of Sygen in acute spinal cord injury. Summary of background data An earlier, single-center trial in 28 patients showed an improvement (50.0% vs. 7.1%, P = 0.034) in marked recovery with Sygen. Methods Standard clinical trial techniques. Results The prospectively planned analysis at the prespecified endpoint time for all patients was negative. There was a significant effect in all patients in the primary outcome variable (the percentage of marked recovery) at week 8, the end of the dosing period. There was a significant effect in all patients in the time at which marked recovery is first achieved. Restricted to severity Group B, which has small sample size, the primary efficacy analysis showed a trend but did not reach significance. There is a large, consistent and, at some time points, significant effect in the primary outcome variable in the nonoperated patients through week 26. The American Spinal Injury Association motor, light touch, and pinprick scores showed a consistent trend in favor of Sygen, as also did bowel function, bladder function, sacral sensation, and anal contraction. The less severely injured patients appeared to have a greater beneficial drug effect. Evidence against an effect of Sygen was minimal and scattered. Conclusions Although not proven in the primary efficacy analysis of this trial, Sygen appears to be beneficial in patients with severe spinal cord injury.
TL;DR: The inter- and intraobserver reliabilities of the revised scoring system for cervical myelopathy proposed by the Japanese Orthopedic Association were high, suggesting that this system is useful for assessment of cervicalMyelopathy in comparative studies of treatment.
Abstract: Study Design. The inter and intraobservet reliabilities of an assessment scale for cervical compression myelopathy were exarnined statistically. This scoring system consiats of seven categories motor function of fingers shoulder and elbow, and lower extremity; sensory function of upper extrernity, trunk and lower extremay, and function of the bladder, It evaluates the severity of myelopathy by allocating points based on degree of dysfunction in each cetegory. Objectives. To determine the inter- and intraobserver reliabilities of the revised scoring system (17 - 2 points) for ceryical compression myelopathy proposed by the Japainese Orthopedic Association of Background Dats, Several scales to as sess clinical outcome from treatment of cervical compression myelopathy have been proposed, Most of these scales include items evaluated by observers. However, no syatem, including the Japanese Orthopedic Association scoring systern, has yet been validsted in terms of interethods. From five different university hospitats, 10 spine surgery specialista, 10 orthopedic surgeons who had just passed the board examination of the Japanese had just passed the board examination of the Japanese Orthopedic Association, and 13 residents in the first or second year of orthopedic residency programs were chosen. The participants in this study were 29 patients with myelopathy secondary to ossilication of the posterior longitudinal ligament selected from five perticipating university hospitals, Several surgeons interviewed each patient twice at intervals of 1 to 6 weeks. Inter- and intraobserver reliabilities of the total score for all categories were evaluated by the intreclass correlation coefficient. The extension of the kappe coefficient of Kraemer also was calculated for each category to assess reliability of multivariate ategorical data Results. The interobserver reliability of the total score for the first interview lintzaciass correlation coefficient 0.013) and the intra- and interobserver reliabilities of the total score (intraclass correlation coefficient - 0.826) were high. The revel of experience and the hospital slightly affected the reliability of the Japanese Orthopedic Assoaffected the reliability of the Japanese Orthopedic Association scoring syssem. The kappa values for intraobserverdata generally were high in each category, where asthe kappe values for interobserver data were relatively low for the categories of shoulder-elbow motor function and lower extremity sensory function. Conclusions. The inter- and intraobseriver reliabilities of the Japanese Orthopedic Association scoring system for corvical myelopathy were high, suggesting that this system is useful for assessment of cervical myelopathy in comperative studies of treatment.
TL;DR: The conceptual framework used in this study demonstrates that large cohort studies investigating a wide range of prognostic factors are necessary to improve the understanding of this problem and indicates that the insurance and compensation systems have a large impact on recovery from acute whiplash injuries.
Abstract: Study design Systematic review of prognostic studies of acute whiplash. Objectives To update the systematic review on the prognosis of acute whiplash published by the Quebec Task Force on Whiplash-Associated Disorders and to propose a new conceptual framework to conduct systematic reviews on prognosis. Summary of background data In 1995, the Quebec Task Force published a systematic review of the literature on whiplash and concluded that its prognosis is favorable. However, few prognostic factors were identified. Recent studies have added to this knowledge, and there is a need to update the review conducted by the Quebec Task Force. Methods A bibliographic search of four electronic databases was performed to identify prognostic studies of acute whiplash published after 1995. The literature was appraised with standard review criteria. The consistency of evidence across studies was assessed. A conceptual framework was designed to classify the literature according to methodologic quality, target population, and phases of investigation. Results Thirteen cohort studies were included in the review. The framework used in this study demonstrates that most of the recent prognostic studies are descriptive in nature. The prognosis of acute whiplash varies according to the population sampled and the insurance/compensation system under which individuals are allowed to claim benefits. Besides age, gender, baseline neck pain intensity, baseline headache intensity, and baseline radicular signs and symptoms, there is little consistency in the literature about the prognostic factors for the recovery of whiplash. Conclusions Scant knowledge about the prognosis of whiplash has been gained since the release of the Quebec Task Force report. However, it is becoming obvious that the insurance and compensation systems have a large impact on recovery from acute whiplash injuries. The conceptual framework used in this study demonstrates that large cohort studies investigating a wide range of prognostic factors are necessary to improve the understanding of this problem.
TL;DR: The accuracy of thoracic screw placement within the pedicle and vertebral body and the resultant transverse screw angle (TSA) were assessed by postoperative CT and the incidence of fully contained screws was directly correlated with the region of instrumentedThoracic spine.
Abstract: STUDY DESIGN A retrospective observational study of 279 transpedicular thoracic screws using postoperative computed tomography (CT). OBJECTIVE To determine the accuracy of transpedicular thoracic screws. SUMMARY OF BACKGROUND DATA Previous studies have reported the importance of properly placed transpedicular thoracic screws. To our knowledge, the in vivo accuracy of pedicle screw placement throughout the entire thoracic spine by CT is unknown. METHODS The accuracy of thoracic screw placement within the pedicle and vertebral body and the resultant transverse screw angle (TSA) were assessed by postoperative CT. Cortical perforations of the pedicle were graded in 2-mm increments. Screws were regionally grouped for analysis. RESULTS Forty consecutive patients underwent instrumented posterior spinal fusion using 279 titanium thoracic pedicle screws of various diameters (4.5-6.5 mm). The regional distribution of the screws was 39 screws at T1-T4, 77 screws at T5-T8, and 163 screws at T9-T12. Fifty-seven percent of screws were totally confined within the pedicle. Although medial perforation of the pedicle wall occurred in 14% of screws, in 2 mm of canal intrusion. Lateral pedicular perforation occurred in 68% of perforating screws and was significantly more common than medial perforation (P < 0.0005). Seventeen screws penetrated the anterior vertebral cortex by an average of 1.7 mm. Screws inserted between T1 and T4 had a decreased incidence of full containment within the pedicle (P < 0.0005) and vertebral body (P = 0.039) compared with T9-T12. The mean TSA for screws localized within the pedicle was 14.6 degrees and was significantly different from screws with either medial (mean 18.0 degrees ) or lateral (mean 11.5 degrees ) pedicle perforation (P < 0.0005). Anterior vertebral penetration was associated with a smaller mean TSA of 10.1 degrees (P = 0.01) and with lateral pedicle perforation (P < 0.0005). There were no neurologic or vascular complications. CONCLUSIONS Ninety-nine percent of screws were fully contained or were inserted with either < or =2 mm of medial cortical perforation or an acceptable lateral breech using the "in-out-in" technique. Anterior cortical penetration occurred significantly more often with lateral pedicle perforation and with a smaller mean TSA. The incidence of fully contained screws was directly correlated with the region of instrumented thoracic spine.
TL;DR: The short-term results of laminoplasty for cervical stenotic myelopathy were maintained over 10years in 78% of the patients with ossification of the posterior longitudinal ligament, and in most of the customers with cervical spondylosis, except those with athetoid cerebral palsy.
Abstract: Study Design. A retrospective study of the long-term results from double-door laminoplasty (Kurokawa’s method) for patients with myelopathy caused by ossification of the posterior longitudinal ligament and cervical spondylosis was performed. Objective. To know whether the short-term results from double-door laminoplasty were maintained over a 10-year period and, if not, the cause of late deterioration. Summary of Background Data. There are few long-term follow-up studies on the outcome of laminoplasty for cervical stenotic myelopathy. Methods. In this study, 35 patients with cervical myelopathy caused by ossification of the posterior longitudinal ligament in the cervical spine and 25 patients with cervical spondylotic myelopathy, including 5 patients with athetoid cerebral palsy, underwent double-door laminoplasty from 1980 through 1988 and were followed over the next 10 years. The average follow-up period was 153 months (range, 120–200 months) in patients with ossification of the posterior longitudinal ligament and 156 months (range, 121–218 months) in patients with cervical spondylotic myelopathy. Neurologic deficits before and after surgery were assessed using a scoring system proposed by the Japanese Orthopedic Association (JOA score). Patients who showed late deterioration received further examination including computed tomography scan and magnetic resonance imaging of the cervical spine. Results. In 32 of the patients with ossification of the posterior longitudinal ligament and 23 of the patients with cervical spondylotic myelopathy, myelopathy improved after surgery. The improvement of Japanese Orthopedic Association scores was maintained up to the final follow-up assessment in 26 of the patients with ossification of the posterior longitudinal ligament and 21 of the patients with cervical spondylotic myelopathy. Late neurologic deterioration occurred in 10 of the patients with ossification of the posterior longitudinal ligament an average of 8 years after surgery, and in 4 of the patients with cervical spondylotic myelopathy, including the 3 patients with athetoid cerebral palsy, an average of 11 years after surgery. The main causes of deterioration in patients with ossification of the posterior longitudinal ligament were a minor trauma in patients with residual cervical cord compression caused by ossification of the posterior longitudinal ligament and thoracic myelopathy resulting from ossification of the yellow ligament in the thoracic spine. Conclusions. The short-term results of laminoplasty for cervical stenotic myelopathy were maintained over 10years in 78% of the patients with ossification of the posterior longitudinal ligament, and in most of the patients with cervical spondylotic myelopathy, except those with athetoid cerebral palsy. Double-door laminoplasty is a reliable procedure for individuals with cervical stenotic myelopathy.
TL;DR: Although radiofrequency facet joint denervation may provide some short-term improvement in functional disability among patients with chronic low back pain, the efficacy of this treatment has not been established.
Abstract: Study design A prospective double-blind randomized controlled trial was performed. Objective To assess the efficacy of percutaneous radiofrequency articular facet denervation for low back pain. Summary of background data Uncontrolled observational studies in patients with low back pain have reported some benefits from the use of facet joint radiofrequency denervation. Because the efficacy of percutaneous radiofrequency had not been clearly shown in previous studies, a randomized controlled trial was conducted to assess the efficacy of the technique for improving functional disabilities and reduce pain. Methods For this study, 70 patients with low back pain lasting of more than 3 months duration and a good response after intraarticular facet injections under fluoroscopy were assigned randomly to receive percutaneous radiofrequency articular facet denervation under fluoroscopic guidance or the same procedure without effective denervation (sham therapy). The primary outcomes were functional disabilities, as assessed by the Oswestry and Roland-Morris scales, and pain indicated on a visual analog scale. Secondary outcomes included spinal mobility and strength. Results At 4 weeks, the Roland-Morris score had improved by a mean of 8.4% in the neurotomy group and 2.2% in the placebo group, showing a treatment effect of 6.2% (P = 0.05). At 4 weeks, no significant treatment effect was reflected in the Oswestry score (0.6% change) or the visual analog pain score (4.2% change). At 12 weeks, neither functional disability, as assessed by the Roland-Morris scale (2.6% change) and Oswestry scale (1.9% change), nor the pain level, as assessed by the visual analog scale (-7.6% change), showed any treatment effect. Conclusions Although radiofrequency facet joint denervation may provide some short-term improvement in functional disability among patients with chronic low back pain, the efficacy of this treatment has not been established.
TL;DR: Short-segment transpedicular instrumentation of thoracolumbar burst fractures is associated with a high rate of failure that cannot be decreased by additional transpedic intracorporeal grafting.
Abstract: STUDY DESIGN A prospective, randomized study comparing two treatment methods for thoracolumbar burst fractures: short-segment instrumentation with transpedicular grafting and the same procedure without transpedicular grafting. OBJECTIVE To evaluate the efficacy of transpedicular grafting in preventing failure of short-segment fixation for the treatment of thoracolumbar burst fractures. SUMMARY OF BACKGROUND DATA Short-segment pedicle instrumentation for thoracolumbar burst fractures is known to fail early because of the absence of anterior support. Additional transpedicular grafting has been offered as an alternative to prevent this failure. However, there is controversy about the results of transpedicular grafting. METHODS Twenty patients with thoracolumbar burst fractures were included in the study. The inclusion criterion was the presence of fractures through the T11-L3 vertebrae without neurologic compromise. The patients were randomized by a simple method into two groups. Group 1 patients were treated using short-segment instrumentation with transpedicular grafting (TPG) (n = 10), and Group 2 patients were treated by short-segment fixation alone (NTPG) (n = 10). Clinical (Likert's questionnaire) and radiologic (sagittal index, percentage of anterior body height compression, and local kyphosis) outcomes were analyzed. RESULTS The two groups were similar in age, follow-up period, and severity of the deformity and fracture. The postoperative and follow-up sagittal index, percentage of anterior body height compression, and average correction loss in local kyphosis in both groups were not significantly different. The failure rate, defined as an increase of 10 degrees or more in local kyphosis and/or screw breakage, was also not significantly different (TPG = 50%, NTPG = 40%, P = 0.99). CONCLUSIONS Short-segment transpedicular instrumentation of thoracolumbar burst fractures is associated with a high rate of failure that cannot be decreased by additional transpedicular intracorporeal grafting.
TL;DR: Only exercises provided sufficient evidence to conclude that they are an effective preventive intervention, and there is a dire lack of controlled trials examining broad-based multidimensional programs.
Abstract: Study design A review of controlled trials. Objectives To determine which interventions are used to prevent back and neck pain problems as well as what the evidence is for their utility. Summary of background data Given the difficulty in successfully treating long-term back and neck pain problems, there has been a call for preventive interventions. Little is known, however, about the value of preventive efforts for nonpatients, e.g., in the general population or workplace. Methods The literature was systematically searched to locate all investigations that were: 1) specifically designed as a preventive intervention; 2) randomized or nonrandomized controlled trials; and, 3) using subjects not seeking treatment. Outcome was evaluated on the key variables of reported pain, report of injury, dysfunction, time off work, health-care utilization, and cost. Conclusions were drawn using a grading system. Results Twenty-seven investigations meeting the criteria were found for educational efforts, lumbar supports, exercises, ergonomics, and risk factor modification. For back schools, only one of the nine randomized trials reported a significant effect, and there was strong evidence that back schools are not effective in prevention. Because the randomized trials concerning lumbar supports were consistently negative, there is strong evidence that they are not effective in prevention. Exercises, conversely, showed stable positive results in randomized controlled trials, giving consistent evidence of relatively moderate utility in prevention. Because no properly controlled trials were found for ergonomic interventions or risk factor modification, there was not good quality evidence available to draw a conclusion. Conclusions The results concerning prevention for subjects not seeking medical care are sobering. Only exercises provided sufficient evidence to conclude that they are an effective preventive intervention. There is a dire lack of controlled trials examining broad-based multidimensional programs. The need for high quality outcome studies is underscored.
TL;DR: Tamp treatment resulted in significantly greater height restoration than did percutaneous vertebroplasty, without loss of vertebral body strength or stiffness.
Abstract: of compression fracture. Methods. Compression fractures were experimentally created in 16 osteoporotic VBs assigned to either the tamp or percutaneous vertebroplasty group. The tamp treatment consisted of inserting balloon-like devices into the vertebral body, inflating the bone tamp, and filling the void with Simplex P (Howmedica, Rutherford, NJ) bone cement. The percutaneous vertebroplasty treatment consisted of directly injecting Cranioplastic bone cement (CMW, Blackpool, UK) into the vertebral body. Pre- and posttreatment heights were measured, and the repaired vertebral bodies were recompressed to determine posttreatment strength and stiffness values. Results. The tamp treatment resulted in significant restoration (97%) of vertebral body height lost after compression, whereas percutaneous vertebroplasty treatment resulted in a significantly lower restoration of lost height (30%) (P , 0.05). Both treatments resulted in significantly stronger vertebral bodies relative to their initial state (P , 0.05). The tamp treatment restored vertebral body stiffness to initial values, but the percutaneous vertebroplasty treatment did not (P , 0.05). Conclusions. Tamp treatment resulted in significantly greater height restoration than did percutaneous vertebroplasty, without loss of vertebral body strength or stiff