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Showing papers in "Spine in 2012"


Journal ArticleDOI
01 Jan 2012-Spine
TL;DR: Frequency, utilization, and hospital charges of spinal fusion have increased at a higher rate than other notable inpatient procedures, as seen in this study from 1998 to 2008.
Abstract: STUDY DESIGN Epidemiological study using national administrative data. OBJECTIVE To provide a complete analysis of national trends in spinal fusion from 1998 to 2008 and compare with trends in laminectomy, hip replacement, knee arthroplasty, percutaneous transluminal coronary angioplasty, and coronary artery bypass graft. SUMMARY OF BACKGROUND DATA Previous studies have reported a rapid increase in volume of spinal fusions in the United States prior to 2001, but limited reports exist beyond this point, analyzing all spinal fusion procedures collectively. METHODS Data were obtained from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample for the years 1998 to 2008. Discharges were identified using International Classification of Diseases, Ninth Revision, Clinical Modification procedure codes for the following procedures: spinal fusion, laminectomy, hip replacement, knee arthroplasty, percutaneous transluminal coronary angioplasty, and coronary artery bypass graft. Population-based utilization rates were calculated from the US census data. RESULTS Between 1998 and 2008, the annual number of spinal fusion discharges increased 2.4-fold (137%) from 174,223 to 413,171 (P < 0.001). In contrast, during the same time period, laminectomy, hip replacement, knee arthroplasty, and percutaneous coronary angioplasty yielded relative increases of only 11.3%, 49.1%, 126.8%, and 38.8% in discharges, while coronary artery bypass graft experienced a decrease of 40.1%. Between 1998 and 2008, mean age for spinal fusion increased from 48.8 to 54.2 years (P < 0.001), in-hospital mortality rate decreased from 0.29% to 0.25% (P < 0.01), and mean total hospital charges associated with spinal fusion increased 3.3-fold (P < 0.001). The national bill for spinal fusion increased 7.9-fold (P < 0.001). CONCLUSION Frequency, utilization, and hospital charges of spinal fusion have increased at a higher rate than other notable inpatient procedures, as seen in this study from 1998 to 2008. In addition, patient demographics and hospital characteristics changed significantly; in particular, whereas the average age for spinal fusion increased, the in-hospital mortality rate decreased.

894 citations


Journal ArticleDOI
20 May 2012-Spine
TL;DR: Data from this study show that there is excellent inter- and intra- rater reliability and inter-rater agreement for curve type and each modifier and the high degree of reliability demonstrates that applying the classification system is easy and consistent.
Abstract: Study design Inter- and intra-rater variability study. Objective On the basis of a Scoliosis Research Society effort, this study seeks to determine whether the new adult spinal deformity (ASD) classification system is clear and reliable. Summary of background data A classification of adult ASD can serve several purposes, including consistent characterization of a clinical entity, a basis for comparing different treatments, and recommended treatments. Although pediatric scoliosis classifications are well established, an ASD classification is still being developed. A previous classification developed by Schwab et al has met with clinical relevance but did not include pelvic parameters, which have shown substantial correlation with health-related quality of life measures in recent studies. Methods Initiated by the Scoliosis Research Society Adult Deformity Committee, this study revised a previously published classification to include pelvic parameters. Modifier cutoffs were determined using health-related quality of life analysis from a multicenter database of adult deformity patients. Nine readers graded 21 premarked cases twice each, approximately 1 week apart. Inter- and intra-rater variability and agreement were determined for curve type and each modifier separately. Fleiss' kappa was used for reliability measures, with values of 0.00 to 0.20 considered slight, 0.21 to 0.40 fair, 0.41 to 0.60 moderate, 0.61 to 0.80 substantial, and 0.81 to 1.00 almost perfect agreement. Results Inter-rater kappa for curve type was 0.80 and 0.87 for the 2 readings, respectively, with modifier kappas of 0.75 and 0.86, 0.97 and 0.98, and 0.96 and 0.96 for pelvic incidence minus lumbar lordosis (PI-LL), pelvic tilt (PT), and sagittal vertical axis (SVA), respectively. By the second reading, curve type was identified by all readers consistently in 66.7%, PI-LL in 71.4%, PT in 95.2%, and SVA in 90.5% of cases. Intra-rater kappa averaged 0.94 for curve type, 0.88 for PI-LL, 0.97 for PT, and 0.97 for SVA across all readers. Conclusion Data from this study show that there is excellent inter- and intra-rater reliability and inter-rater agreement for curve type and each modifier. The high degree of reliability demonstrates that applying the classification system is easy and consistent.

892 citations


Journal ArticleDOI
15 May 2012-Spine
TL;DR: Patients with CLBP are characterized by greater comorbidity and economic burdens compared with those without CLBP, and this economic burden can be attributed to greater prescribing of pain-related medications and increased health resource utilization.
Abstract: Study Design. Retrospective analysis of an insurance claims database. Objective. To examine the comorbidities, treatment patterns, health care resource utilization, and direct medical costs of patients with chronic low back pain (CLBP) in clinical practice. Summary of Background Data. Although the socioeconomic impact of CLBP is substantial, characterization of comorbidities, pain-related pharmacotherapy, and health care resource use/costs of patients with CLBP relative to non-CLBP controls have been infrequently documented. Methods. Using the LifeLink Health Plan Claims Database (IMS Health Inc., Watertown, MA), patients with CLBP, defi ned using the International Classifi cation of Diseases, Ninth Revision, Clinical Modifi cation, were identifi ed and matched (age, sex, and region) with non-CLBP individuals. Comorbidities, pain-related pharmacotherapy, and health care service use/costs (pharmacy, outpatient, inpatient, total) were compared for the 2 groups during 2008. Results. A total of 101,294 patients with CLBP and controls were identifi ed (55% women; mean age was 47.2 ± 11.6 years). Relative to controls, patients with CLBP had a greater comorbidity burden including a signifi cantly higher ( P < 0.0001) frequency of musculoskeletal and neuropathic pain conditions and common sequelae of pain such as depression (13.0% vs. 6.1%), anxiety (8.0% vs. 3.4%), and sleep disorders (10.0% vs. 3.4%). Painrelated pharmacotherapy was signifi cantly greater ( P < 0.0001) among patients with CLBP including opioids (37.0% vs. 14.8%;

547 citations


Journal ArticleDOI
01 Aug 2012-Spine
TL;DR: In a long-term review of minimum 5 years, 76% of PJK occurred within 3 months after surgery and pre-existing low bone mineral density, posterior spinal fusion (PSF), fusion to sacrum, inappropriate global spine alignment, and greater sagittal vertical axis change were identified as significant risk factors for PJK.
Abstract: STUDY DESIGN A retrospective case series of surgically treated patients with adult scoliosis. OBJECTIVE The purpose of this study was to evaluate the incidence, risk factors, and natural course of proximal junctional kyphosis (PJK) in a long-term follow-up of patients with adult idiopathic scoliosis undergoing long instrumented spinal fusion. SUMMARY OF BACKGROUND DATA Although recent reports have showed the prevalence, clinical outcomes, and the possible risk factors of PJK, quite a few reports have showed long-term follow-up outcome. MATERIALS AND METHODS This is a retrospective review of the charts and radiographs of 76 consecutive patients with adult scoliosis treated with long instrumented spinal fusion. Radiographical measurements and demographic data were reviewed on preoperation, immediate postoperation, 2 years postoperation, 5 years postoperation, and at follow-up. Postoperative Scoliosis Research Society scores and Oswestry Disability Index were also evaluated. Means were compared with Student t test. A P value of less than 0.05 with 95% confidence interval was considered significant. RESULTS The mean age was 48.8 years (range, 23-75 yr) and the average follow-up was 7.3 years (range, 5-14 yr). PJK has been identified in 17 patients. The Scoliosis Research Society and Oswestry Disability Index did not demonstrate significant differences between PJK group and non-PJK group; 2 patients had additional surgeries performed for local pain. Seventy-six percent of PJK has been identified within 3 months after surgery. Despite the fact that 53% of total degree of PJK was progressed within 3 months after surgery, PJK continuously progressed to the final follow-up. Pre-existing low bone mineral density, posterior spinal fusion (PSF), fusion to sacrum, inappropriate global spine alignment, and greater sagittal vertical axis change were identified as significant risk factors for PJK (P = 0.04, P < 0.001, P = 0.02, P < 0.0001, and P = 0.01). CONCLUSION In a long-term review of minimum 5 years, 76% of PJK occurred within 3 months after surgery. Pre-existing low bone mineral density, PSF, fusion to the sacrum, inappropriate global spine alignment, and greater sagittal vertical axis change were significant risk factors for PJK. Careful long-term follow-up should be done for a patient with PJK.

288 citations


Journal ArticleDOI
15 Apr 2012-Spine
TL;DR: The accuracy of the conventional FH technique was superior to the RO technique and seems a vulnerable aspect potentially leading to screw malposition as well as slipping of the implantation cannula at the screw entrance point.
Abstract: Single-center prospective randomized controlled study.To evaluate the accuracy of robot-assisted (RO) implantation of lumbar/sacral pedicle screws in comparison with the freehand (FH) conventional technique.SpineAssist is a miniature robot for the implantation of thoracic, lumbar, and sacral pedicle screws. The system, studied in cadaver and cohort studies, revealed a high accuracy, so far. A direct comparison of the robot assistance with the FH technique is missing.Patients requiring mono- or bisegmental lumbar or lumbosacral stabilization were randomized in a 1:1 ratio to FH or RO pedicle screw implantation. Instrumentation was performed using fluoroscopic guidance (FH) or robot assistance. The primary end point screw position was assessed by a postoperative computed tomography, and screw position was classified (A: no cortical violation; B: cortical breach =2 mm to =4 mm to =6 mm). Secondary end points as radiation exposure, duration of surgery/planning, and hospital stay were assessed.A total of 298 pedicle screws were implanted in 60 patients (FH, 152; RO, 146). Ninety-three percent had good positions (A or B) in FH, and 85% in RO. Preparation time in the operating room (OR), overall OR time, and intraoperative radiation time were not different for both groups. Surgical time for screw placement was significantly shorter for FH (84 minutes) than for RO (95 minutes). Ten RO screws required an intraoperative conversion to the FH. One FH screw needed a secondary revision.In this study, the accuracy of the conventional FH technique was superior to the RO technique. Most malpositioned screws of the RO group showed a lateral deviation. Attachment of the robot to the spine seems a vulnerable aspect potentially leading to screw malposition as well as slipping of the implantation cannula at the screw entrance point.

267 citations


Journal ArticleDOI
01 Mar 2012-Spine
TL;DR: Ossification of the posterior longitudinal ligament (OPLL) of the cervical spine is a well-known disease that causes myelopathy, and genetic factors are important for development of OPLL, and some candidate genes have been reported.
Abstract: Study design Review article. Objective To review the etiology, natural history, measurement tools, and image diagnosis of ossification of the posterior longitudinal ligament (OPLL) of the cervical spine. Summary of background data OPLL is a well-known disease that causes myelopathy. Genetic factors are very important for development of OPLL. However, the pathogenetic gene and natural history of OPLL have not been clarified. Methods The authors reviewed studies about the etiology, natural history, measurement tools, and diagnosis of OPLL, which had been performed by the members of the Investigation Committee on the Ossification of the Spinal Ligaments of the Japanese Ministry of Health, Labour, and Welfare. Results The prevalence of OPLL in the general Japanese population was reported to be 1.9% to 4.3% among people older than 30 years. Genetic factors are important for development of OPLL, and some candidate genes have been reported. Clinical course of OPLL has been clarified by a prospective long-term follow-up study. Some radiographic predictors for development of myelopathy were introduced. Image diagnosis of OPLL is easy by plain radiographs, but magnetic resonance imaging and computed tomography are useful to determine cord compression by OPLL. Conclusion OPLL should be managed on the basis of the consideration of its natural history. Elucidation of pathogenetic genes of OPLL will introduce a new approach for management of OPLL.

244 citations


Journal ArticleDOI
15 Jun 2012-Spine
TL;DR: PSO and VCR patients with no complications had slightly higher satisfaction scores than patients with minor-only complications, major transient complications, and major permanent complications and the presence of a major complication did not affect the ultimate clinical outcomes at 2 years or more.
Abstract: Study Design. A retrospective review. Objective. To characterize the risk factors for the development of major complications in 3-column osteotomies and determine whether the presence of a major complication affects ultimate clinical outcomes. Summary of Background Data. Three-column spinal osteotomies, including pedicle subtraction osteotomy (PSO) and vertebral column resection (VCR), are common techniques to correct severe and/or rigid spinal deformities. Methods. Two hundred forty consecutive PSO (n = 156) and VCR (n = 84) procedures in 237 patients were performed at a single institution between 1995 and 2008. Of these, 105 patients (87 PSOs, 18 VCRs) had complete preoperative and minimum 2-year postoperative clinical outcomes data available for analysis. Using established criteria, we reported complications as major or minor and further stratifi ed complications as surgical versus medical and permanent versus transient. Risk factors for complications and their effect on Scoliosis Research Society (SRS) clinical outcomes at baseline and at 2 years or more were assessed. Results. Major medical and surgical complications occurred at similar rates in both PSOs and VCRs (38%, 33 of 87 vs. 22%, 4 of 18; P = 0.28). Overall, 24.8% (26 of 105) experienced major surgical complications (3 permanent) and 15.2% (16 of 105) experienced major medical complications (4 permanent). Patients with PSO were older (53 vs. 29 yr; P < 0.001), had greater estimated blood

236 citations


Journal ArticleDOI
15 Apr 2012-Spine
TL;DR: This study represents to the authors' knowledge the largest series on adult patients aged 50 years or older operated for the first time for lumbar or thoracolumbar scoliosis and excluding every other possible diagnosis.
Abstract: Study design A multicentric retrospective study on primary adult scoliosis patients operated on between 2002 and 2007. A 3-step statistical analysis was performed to describe the incidence of complications, the risk factors, and the reoperation risk with survival curves for the entire cohort. Objective To describe complication rate and risk factors as well as survival curves associated with adult primary scoliosis surgery in patients aged 50 years or older. Summary of background data Adult deformity surgery is classically associated with a high rate of complications. The identification of risk factors for developing such complications is consequently of major interest as well as survival curves that can provide useful information on reoperation risks. Although many reports exist in the literature, the cohorts analyzed are often heterogeneous and the actual prevalence of complications varies widely. This study represents to our knowledge the largest series on adult patients aged 50 years or older operated for the first time for lumbar or thoracolumbar scoliosis and excluding every other possible diagnosis. Methods A retrospective review of prospectively collected data from 6 centers in France. A total of 306 primary lumbar adult or degenerative scoliosis patients older than 50 years undergoing surgery between 2002 and 2007 were included. Demographics, comorbidities, x-ray parameters, surgical data, and complications were analyzed. Statistical analysis was performed to obtain correlations and risk factors for developing complications. Reoperation risk was calculated with Kaplan-Meier survival curves. Results A total of 306 patients aged 63 years (range, 50-83), with 83% women. Mean follow-up was 54 months. Mean Cumulative Illness Rating Scale score was 5 (range, 0-26). Main curve was 50° (range, 4-96) with apex between T12 and L2. Ten percent of patients had anterior surgery only, 18% had double anteroposterior approach, and 72% had posterior surgery only. Seventy-four percent (226 patients) had long fusions of 3 or more levels and 44% (134 patients) were fused to the sacrum. Forty percent (122 patients) had a decompression performed and 18% had an osteotomy. There were 175 complications for 119 patients (39%). No cases of death or blindness were reported. General complication rate was 13.7%, early infection occurred in 4% (12 patients), and late infection occurred in 1.2%. Neurological complications were present in 7% with 2 cases (0.6%) of late cord-level deficits and 12 reoperations (4%). Prevalence of mechanical complications was 24% (73 patients), with 58 patients (19%) needing a reoperation. Risk factors for mechanical or neurological complications were number of instrumented vertebra (P ≤ 0.01) fusion to the sacrum (P ≤ 0.001), pedicle subtraction osteotomy (PSO) (P = 0.01), and a high preoperative pelvic tilt of 26° or more (P ≤ 0.05). Kaplan-Meier survival curves showed reoperation risk of 44% at 70 months. Long fusion risk was 40% at 50 months and fusions to the sacrum reoperation risk was 48% at 49 months. Conclusion Overall complication rate was 39%, and 26% of the patients were reoperated for mechanical or neurological complications. Risk factors include number of instrumented vertebra, fusion to the sacrum, PSO, and preoperative pelvic tilt of 26° or more. There is a 44% risk of a new operation in the 6-year-period after the primary procedure.

235 citations


Journal ArticleDOI
15 Jun 2012-Spine
TL;DR: The use of wider intervertebral cages leads to a significantly lower rate of subsidence, but a longer cage does not necessarily offer a similar advantage, and wide cages should be used whenever feasible for interbody fusion in the lumbar spine.
Abstract: Study design A retrospective review. Objective The objective is to evaluate subsidence related to minimally invasive lateral retroperitoneal lumbar interbody fusion by reviewing our experience with this procedure. Summary of background data Polyetheretherketone intervertebral cages of different lengths, widths, and heights filled with various allograft types are commonly used as spacers in lumbar fusions. Subsidence is a potential complication. To date, there are no published reports specifically addressing subsidence, because it relates to a series of patients undergoing minimally invasive lateral retroperitoneal transpsoas lumbar interbody fusion. Methods An institutional review board-approved, retrospective review of a prospectively collected database was conducted. One hundred forty consecutive patients who underwent this procedure between L1 and L5 during a 2-year period were included. All patients had T scores of -2.5 or more. Postoperative radiographs during routine follow-ups were reviewed for subsidence, defined as any violation of the vertebral end plate. Results Radiographical subsidence occurred in 14.3% (20 of 140), whereas clinical subsidence occurred in 2.1%. Subsidence occurred in 8.8% (21 of 238) of levels fused. Construct length had a significant positive correlation with increasing subsidence rates. Subsidence rates decreased progressively with lower levels in the lumbar spine, but had a higher than expected rate at L4-L5. Subsidence rates of 14.1% (19 of 135) and 1.9% (2 of 103) were associated with 18-and 22-mm-wide cages, respectively. No significant trends were observed with cage lengths. Supplemental lateral plates had a higher rate of subsidence than bilateral pedicle screws. Subsidence occurred at the superior end plate 70% of the time. Conclusion The use of wider intervertebral cages leads to a significantly lower rate of subsidence, but a longer cage does not necessarily offer a similar advantage. Wide cages are protective against subsidence, and the widest cages should be used whenever feasible for interbody fusion in the lumbar spine to protect indirect compression and promote arthrodesis.

213 citations


Journal ArticleDOI
01 Dec 2012-Spine
TL;DR: The use of the O-arm in combination with a navigation system increases the accuracy of pedicle screw placement and the need to limit the radiation dose for the patient justify an additional CT scan only after careful assessment of the potential additional value.
Abstract: Study design An international, multicenter, prospective, postmarketing clinical registry to record the accuracy of pedicle screw placement, using the O-arm Complete Multidimensional Surgical Imaging System with StealthStation Navigation. Objective To evaluate the accuracy of pedicle screw placement in common neurosurgical practice and assess the patient's radiation exposure. Summary of background data Several imaging techniques have been used to increase accurate pedicle screw placement. The O-arm 3-dimensional (3D) imaging (Medtronic Navigation, Louisville, CO), an intraoperative computed tomographic (CT) scan, combined with an existing navigation system was reported to further increase accuracy of screw placement, especially because an intraoperative 3D scan provides information for screw adjustment before wound closure. Methods Patients already planned for instrumented spinal surgery were operated while using the O-arm as imaging device and the StealthStation Navigation (Medtronic Navigation, Louisville, CO) as navigation tool. At the end of all pedicle screw insertions, the placement was classified according to a validated method. The accuracy of pedicle screw placement based on the intraoperative 3D scan and the surgeon's perception of correct screw placement were assessed as well as the radiation doses the patient received during the entire procedure. Results During a 16-month period, a total of 1922 screws in 353 patients were evaluated. In 97.5%, the screws were correctly placed. Only 2.5% of the screws were considered as misplaced, and 1.8% of the screws were revised during the same procedure. When the surgeon perceived the screws to be correctly placed, the CT scan verified his assessment in 98.5% of the cases. The mean radiation dose was comparable with half the dose of a 64 multislice CT scan. Conclusion The use of the O-arm in combination with a navigation system increases the accuracy of pedicle screw placement. The accuracy of the surgeon's perception and the need to limit the radiation dose for the patient justify an additional CT scan only after careful assessment of the potential additional value.

197 citations


Journal ArticleDOI
01 Dec 2012-Spine
TL;DR: Early physical therapy following a new primary care consultation for low back pain was associated with reduced risk of subsequent health care compared with delayed physical therapy and physical therapy content showed weaker associations with subsequent care.
Abstract: Study design A retrospective cohort. Objective To describe physical therapy utilization following primary care consultation for low back pain (LBP) and evaluate associations between the timing and content of physical therapy and subsequent health care utilization and costs. Summary of background data Primary care management of LBP is highly variable and the implications for subsequent costs are not well understood. The importance of referring patients from primary care to physical therapy has been debated, and information on how the timing and content of physical therapy impact subsequent costs and utilization is needed. Methods Data were extracted from a national database of employer-sponsored health plans. A total of 32,070 patients with a new primary care LBP consultation were identified and categorized on the basis of the use of physical therapy within 90 days. Patients utilizing physical therapy were further categorized based on timing (early [within 14 d] or delayed)] and content (guideline adherent or nonadherent). LBP-related health care costs and utilization in the 18-months following primary care consultation were examined. Results Physical therapy utilization was 7.0% with significant geographic variability. Early physical therapy timing was associated with decreased risk of advanced imaging (odds ratio [OR] = 0.34, 95% confidence interval [CI]: 0.29, 0.41), additional physician visits (OR = 0.26, 95% CI: 0.21, 0.32), surgery (OR = 0.45, 95% CI: 0.32, 0.64), injections (OR = 0.42, 95% CI: 0.32, 0.64), and opioid medications (OR = 0.78, 95% CI: 0.66, 0.93) compared with delayed physical therapy. Total medical costs for LBP were $2736.23 lower (95% CI: 1810.67, 3661.78) for patients receiving early physical therapy. Physical therapy content showed weaker associations with subsequent care. Conclusion Early physical therapy following a new primary care consultation was associated with reduced risk of subsequent health care compared with delayed physical therapy. Further research is needed to clarify exactly which patients with LBP should be referred to physical therapy; however, if referral is to be made, delaying the initiation of physical therapy may increase risk for additional health care consumption and costs.

Journal ArticleDOI
01 Aug 2012-Spine
TL;DR: In this article, the authors investigated associations between various types of lumbar endplate lesions, disc degeneration (DD), and back pain history, including fracture, erosion, and calcification.
Abstract: Study design An autopsy study. Objective To investigate associations between various types of lumbar endplate lesions, disc degeneration (DD), and back pain history. Summary of background data The well-innervated vertebral endplate has been suspected as a source of back pain. Previously, we observed 4 types of lumbar endplate lesions with distinct morphological characteristics. Their roles in DD and back pain remain unclear. Methods From a lumbar spine archive of 136 men (mean age, 52 yr), back pain, back injury, and occupation history data for 69 subjects and discography data for 443 discs from 109 subjects were available for study. Back pain history was categorized as none, occasional, or frequent. DD was judged from discography. Endplate lesions were classified as Schmorl's nodes, fracture, erosion, or calcification, and lesion size was rated as none, small, moderate, or large. Associations between endplate lesions and DD, back pain history, back injury, and occupation history were examined. Results Presence of endplate lesions was associated with frequent (odds ratio [OR] = 2.57) but not occasional back pain. However, large endplate lesions were associated with both occasional (OR = 8.68) and frequent (OR = 17.88) back pain. This association remained after further controlling for DD. Also, the presence of each type of endplate lesion was associated with adjacent DD (OR = 2.40-9.71), with larger lesions associated with more severe DD. Endplate erosion lesions were more strongly associated with adjacent DD than Schmorl's nodes. Although back injury history was associated with the presence of fracture and erosion lesions, heavy occupation was associated with the presence of Schmorl's nodes. Conclusion Endplate lesions are associated with back pain as well as being closely associated with adjacent DD, with a clear dosage effect. Different types of endplate lesions seem to have different magnitudes of associations with DD. Lumbar endplate lesions may be an important key to better understand both DD and back pain.

Journal ArticleDOI
15 Mar 2012-Spine
TL;DR: The occurrence of a follow-up, not but perioperative, major complication seemed to have a negative impact on ultimate clinical outcome.
Abstract: Study design Retrospective cohort comparative study. Objective To determine the prevalence of major complications, identify risk factors, and assess long-term clinical benefit after revision adult spinal deformity surgery. Summary of background data No study has analyzed risk factors for major complications in long revision fusion surgery and whether or not occurrence of a major complication affects ultimate clinical outcome. Methods Analysis of consecutive adult patients who underwent multilevel revision surgery for spinal deformity with a minimum 2-year follow-up was performed. All complications were classified as either major or minor. Outcome analysis was conducted with the Scoliosis Research Society and Oswestry Disability Index scores. Results A total of 166 patients (mean age = 53.8 years) were identified with a mean follow-up of 3.5 years (range: 2-7). Primary diagnoses included idiopathic/de novo scoliosis (107), degenerative (35), trauma (7), neuromuscular scoliosis (6), congenital deformity (5), ankylosing spondylitis (2), tumor (2), Scheuermann kyphosis (1), and rheumatoid arthritis (1). Most common secondary diagnoses that necessitated revision surgery were adjacent segment disease, fixed sagittal imbalance, and pseudarthrosis. Overall, 34.3% of patients developed major complications (19.3% perioperative; 18.7% follow-up). Associated risk factors for perioperative complications were patient- (age > 60 years, medical comorbidities, obesity) and surgery-related (pedicle subtraction osteotomy). Performance of a 3-column osteotomy and postoperative radiographic changes that suggested progressive loss of sagittal correction were recognized as risk factors for follow-up complications. Equivalent outcome scores were reported by patients preoperatively, but those experiencing follow-up complications reported lower scores at the final follow-up. Conclusion Overall, 34.4% of patients experienced major complications after long revision fusion surgery. Different risk factors were identified for perioperative versus follow-up complications. The occurrence of a follow-up, not but perioperative, major complication seemed to have a negative impact on ultimate clinical outcome.

Journal ArticleDOI
01 Nov 2012-Spine
TL;DR: Daily subcutaneous injection of teriparatide for bone union using local bone grafting after instrumented lumbar posterolateral fusion in women with postmenopausal osteoporosis was more effective than oral administration of bisphosphonate.
Abstract: Study design Prospective trial. Objective To examine the clinical efficacy of teriparatide for bone union after instrumented lumbar posterolateral fusion using local bone grafting in women with postmenopausal osteoporosis. Summary of background data Intermittent parathyroid hormone (PTH) treatment increases bone mass and reduces the risk for osteoporotic vertebral fractures. Recombinant human PTH (1-34) has already been approved as a treatment for severe osteoporosis. Preclinical data support the efficacy of PTH for lumbar spinal fusion. However, clinical results of PTH for spinal fusion have not yet been reported. Methods Fifty-seven women with osteoporosis diagnosed with degenerative spondylolisthesis were divided into 2 treatment groups, a teriparatide group (n = 29; daily subcutaneous injection of 20 μg of teriparatide) and a bisphosphonate group (n = 28; weekly oral administration of 17.5 mg of risedronate). All patients underwent decompression and 1- or 2-level instrumented posterolateral fusion with a local bone graft. Fusion rate, duration of bone union, and pain scores were evaluated 1 year after surgery. Results Pain scores improved after surgery; however, no significant difference was noted between the groups after surgery. The rate of bone union was 82% in the teriparatide group and 68% in the bisphosphonate group. Average duration of bone union was 8 months in the teriparatide group and 10 months in the bisphosphonate group. The rate of bone union and average of duration of bone union in the teriparatide group patients were significantly superior to those in the bisphosphonate group. Conclusion Daily subcutaneous injection of teriparatide for bone union using local bone grafting after instrumented lumbar posterolateral fusion in women with postmenopausal osteoporosis was more effective than oral administration of bisphosphonate.

Journal ArticleDOI
15 May 2012-Spine
TL;DR: On multivariate analysis, morbid obesity was the most significant predictor of complications in the anterior cervical and posterior lumbar fusion groups (more than age, demography, and other comorbidity).
Abstract: STUDY DESIGN A retrospective cross-sectional study of all spinal fusions in California from 2003 to 2007. OBJECTIVE This study analyzes whether morbid obesity alters rates of complications and charges in patients undergoing spinal fusion. SUMMARY OF BACKGROUND DATA Prior studies of obesity have focused on lumbar fusion; some identified increases in wound complications. However, these studies typically do not account for comorbidities, do not examine nonlumbar fusions, and usually are small single institution series. METHODS Our study used the Healthcare Cost and Utilization Project's California State Inpatient Databases (CA-SID) to identify normal weight and morbidly obese patients admitted in California between 2003 and 2007 for 4 types of spinal fusion: anterior cervical fusion (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] procedure code 810.2), posterior cervical fusion (810.3), anterior lumbar fusion (810.6), and posterior lumbar fusion (810.8). Demographic, comorbidity, and complications data were collected. Primary outcome was in-hospital complication; secondary outcomes were total cost, length of stay, and in-hospital mortality. Multivariate logistic regression was performed. RESULTS In total 84,607 admissions were identified, of which 1455 were morbidly obese. Morbid obesity was associated with 97% higher in-hospital complication rates (13.6% vs. 6.9%), sustained across nearly all complication types (cardiac, renal, pulmonary, wound complications, among others). Mortality among the morbidly obese was slightly higher (0.41 vs. 0.13, P < 0.01) as were average hospital costs ($108,604 vs. $84,861, P < 0.0001). Length of stay was longer as well (4.8 d vs. 3.5 d, P < 0.0001). All effects were less pronounced in posterior cervical fusions. On multivariate analysis, morbid obesity was the most significant predictor of complications in the anterior cervical and posterior lumbar fusion groups (more than age, demography, and other comorbidity). CONCLUSION Morbid obesity seems to increase the risk of multiple complication types in spinal fusion surgery, most particularly in anterior cervical and posterior lumbar approaches.

Journal ArticleDOI
01 Feb 2012-Spine
TL;DR: Investigation of 750 consecutive multilevel cervical spine decompression surgeries performed by a single spine surgeon found no statistically significant difference in incidence of C5 palsy based on surgical procedure, although there was a trend toward higher rates with laminectomy and fusion.
Abstract: Study design Retrospective review of 750 consecutive multilevel cervical spine decompression surgeries performed by a single spine surgeon. Objective To determine the incidence of C5 palsy in a large consecutive series of multilevel cervical spine decompression procedures. Summary of background data Palsy of the C5 nerve is a well-known potential complication of cervical spine surgery with reported rates ranging from 0% to 30%. The etiology remains uncertain but has been attributed to iatrogenic injury during surgery, tethering from shifting of the spinal cord, spinal cord ischemia, and reperfusion injury of the spinal cord. Methods We included patients undergoing multilevel cervical corpectomy, corpectomy with posterior fusion, posterior laminectomy and fusion, and laminoplasty. Exclusion criteria included lack of follow-up data, spinal cord injury preventing preoperative or postoperative motor testing, or surgery not involving the C5 level. Incidence of C5 palsy was determined and compared to determine whether significant differences existed among the various procedures, patient age, sex, revision surgery, preoperative weakness, diabetes, smoking, number of levels decompressed, and history of previous upper extremity surgery. Results Of the 750 patients, 120 were eliminated on the basis of the exclusion criteria. The 630 patients included in the analysis consisted of 292 females and 338 males. The mean age was 58 years (range, 19-87). The incidence of C5 nerve palsy for the entire group was 42 of 630 (6.7%). The incidence was highest for the laminectomy and fusion group (9.5%), followed by the corpectomy with posterior fusion group (8.4%), the corpectomy group (5.1%), and finally the laminoplasty group (4.8%), although these differences did not reach statistical significance. There was a significantly higher incidence in males (8.6% vs. 4.5%, P = 0.05). Conclusion Incidence of C5 nerve palsy after cervical spine decompression was 6.7%. This is consistent with previously published studies and represents the largest series of North American patients to date. There is no statistically significant difference in incidence of C5 palsy based on surgical procedure, although there was a trend toward higher rates with laminectomy and fusion.

Journal ArticleDOI
15 Oct 2012-Spine
TL;DR: The development of PJK does not seem to have a detrimental effect on HRQOL outcomes, at least in milder/nonrevision forms, while patients at higher risk for PJK are those who are of older age, who had fusions to the sacrum, combined anterior/posterior surgery, thoracoplasty, and an upper instrumented vertebra at T1–T3.
Abstract: STUDY DESIGN Systematic review. OBJECTIVE To review the literature on proximal junctional kyphosis (PJK) as a specific form for proximal adjacent segment pathology and report on the incidence, timing, risk factors, and effect on health-related quality of life (HRQOL) outcomes reported for PJK. SUMMARY OF BACKGROUND DATA PJK is a complication of spinal deformity surgery that can compromise outcomes and necessitate revision surgery. Multiple risk factors have been associated with PJK, making the etiology multifactorial. Knowledge of the risk factors is important for minimizing the occurrence of PJK and to allow surgeons to take measures for its prevention when possible. METHODS A systematic search of PubMed, CINAHL, EMBASE, the Cochrane Library, and Google Scholar through February 15, 2012, was performed. The focus was on studies designed to evaluate PJK in patients who had surgery for scoliosis and/or kyphosis. Adjusted effect sizes and significance based on adjusting for confounders were reported if available, otherwise, crude risk ratios and 95% confidence intervals were calculated. RESULTS The search yielded 85 citations and 8 met the criteria for inclusion. The incidence of PJK ranged from 17% to 39% and the majority seemed to occur within 2 years of surgery. The most common patient demographic associated with a higher PJK risk was increased age. Surgery-related risk factors were fusions to the sacrum, combined anterior/posterior surgery, thoracoplasty, and upper instrumented vertebra at T1-T3. Postoperative hypokyphosis or hyperkyphosis was associated with an increased risk of PJK. Despite the presence of PJK, health-related quality of life outcomes were not affected. CONCLUSION Patients at higher risk for PJK are those who are of older age, who had fusions to the sacrum, combined anterior/posterior surgery, thoracoplasty, and an upper instrumented vertebra at T1-T3. Despite the presence of PJK, no differences were noted in health-related quality of life outcomes. CONSENSUS STATEMENT 1. The risk of developing PJK above a spinal deformity fusion is 17% to 39%, with most noted by 2 years postoperative. LEVEL OF EVIDENCE Moderate. Strength of Statement: Strong. 2. The risk factors of PJK development include increased age, fusion to sacrum, combined ASF/PSF, thoracoplasty, UIV at T1–T3, and nonanatomic restoration of thoracic kyphosis. LEVEL OF EVIDENCE Low. Strength of Statement: Weak. 3. The development of PJK does not seem to have a detrimental effect on HRQOL outcomes, at least in milder/nonrevision forms. LEVEL OF EVIDENCE Moderate. Strength of Statement: Weak.

Journal ArticleDOI
01 Mar 2012-Spine
TL;DR: ADF is considered especially suitable for cases with massive OPLL and preoperative kyphotic alignment of the cervical spine, although it leads to a higher incidence of surgery-related complications compared with LAMP.
Abstract: Study design Prospective, comparative clinical study. Objective To compare the clinical outcome of anterior decompression and fusion with floating method and laminoplasty in the treatment of cervical myelopathy caused by ossification of the posterior longitudinal ligament (OPLL). Summary of background data There have been no reports that have accurately and prospectively compared surgical outcomes after anterior decompression and posterior decompression. Methods For cervical myelopathy caused by OPLL, we performed anterior decompression and fusion with floating method (ADF) in 1997, 1999, 2001, 2003, and 2004 and French-door laminoplasty (LAMP) in 1996, 1998, 2000, and 2002 at one institution. Twenty patients in the ADF group and 22 patients in the LAMP group were evaluated for 5 years' follow-up. The following criteria were evaluated: operation time, blood loss, complications, and Japanese Orthopedic Association score. For radiographic evaluation, canal narrowing ratio of OPLL, lordotic angle at C2-C7, and postoperative progression of the ossified lesion were measured. Results The operation time in the ADF group was longer than that in the LAMP group. The average blood loss showed no statistical difference between the 2 groups. Complications occurred in 5 cases in the ADF group, but none occurred in the LAMP group. The mean Japanese Orthopedic Association score system for cervical myelopathy and the recovery rate in the ADF group were superior to those in the LAMP group, especially for cases with greater than 50% of the spinal canal compromised by OPLL or kyphotic alignment of the cervical spine, preoperatively. Postoperative progression of OPLL was observed in 5% of the ADF group and 50% of the LAMP group. Conclusion ADF is considered especially suitable for cases with massive OPLL and preoperative kyphotic alignment of the cervical spine, although it leads to a higher incidence of surgery-related complications compared with LAMP.

Journal ArticleDOI
01 Jul 2012-Spine
TL;DR: The normalized torsion mechanics and collagen content of the multiple animal discs presented are useful for selecting and interpreting results for animal disc models.
Abstract: Study Design Experimental measurement and normalization of in vitro disc torsion mechanics and collagen content for several animal species used in intervertebral disc research and comparing these to the human disc.

Journal ArticleDOI
15 Jan 2012-Spine
TL;DR: It was showed that more than functional outcomes matter; preoperative expectations and fulfillment of expectations influence postoperative satisfaction in patients undergoing lumbar and cervical spine surgery.
Abstract: Study design Analysis of prospectively collected multicenter data. Objective To explore the relationship between preoperative expectations and postoperative outcomes and satisfaction in lumbar and cervical spine surgery. Summary of background data Back pain is one of the most common health problems, leading to the utilization of health care resources, work loss, and sick benefits. Patient expectations influence posttreatment outcomes, both surgical and nonsurgical. There is little research on the importance of preoperative expectations in spine surgery. Existing studies evaluate the technical aspects of interventions and functional outcomes but fail to take into account patient expectations. The authors hypothesized that expectations dramatically affect spine patient satisfaction independent of functional outcomes. Methods Prospectively collected patient-entered data from patients undergoing lumbar and cervical spine surgery from 2 study centers collected using a Web-based patient health survey system were analyzed. The study included patients who underwent operative intervention (decompression with or without fusion) with at least a 3-month period of follow-up. Preoperative expectations were measured using the Musculoskeletal Outcomes Data Evaluation and Management System's (MODEMS) expectation survey. Postoperative satisfaction and fulfillment of expectations were measured using the MODEMS satisfaction survey. Postoperative functional outcomes were measured using the Oswestry Disability Index and 36-item short form health survey. Ordinal logistic regression multivariate modeling was used to examine predictors of postoperative satisfaction. Linear regression multivariate modeling was used to examine predictors of functional outcomes. Results Greater fulfillment of expectations led to higher postoperative satisfaction and was associated with better functional outcomes. Higher preoperative expectations led to decreased postsurgical satisfaction but were associated with improved functional outcomes. Higher postoperative satisfaction was associated with improved functional outcomes and vice versa. Type of surgery also influenced satisfaction and function, with cervical patients being less satisfied but having better functional outcomes than lumbar patients. Conclusion This study showed that more than functional outcomes matter; preoperative expectations and fulfillment of expectations influence postoperative satisfaction in patients undergoing lumbar and cervical spine surgery. This underlines the importance of taking preoperative expectations into account to obtain an informed choice on the basis of the patient's preferences.

Journal ArticleDOI
15 Aug 2012-Spine
TL;DR: Although it is not easy to master the minimally invasive TLIF technique, the surgeon's experience with this operation correlated with reduced operation time and blood loss during surgery, suggesting this technique could be an effective and reliable option for the surgical treatment of lumbar degenerative disease.
Abstract: Study Design. Consecutive case series with prospective data collection. Objective. To define and analyze the learning curve for minimally invasive transforaminal lumbar interbody fusion (TLIF). Summary of Background Data. Minimally invasive TLIF using a unilateral approach has recently been gaining popularity because of its potential for minimizing soft-tissue damage and reducing recovery time. However, a steep learning curve has been described for surgeons first performing this technique. Methods. Eighty-six consecutive patients with degenerative lumbar diseases who were treated by TLIF were included in the study. Surgeries were performed using a tubular retractor, and a cage was inserted using a unilateral transforaminal approach by a single surgeon. The corresponding segments were fixed with percutaneous pedicle screws. Eighty-three patients were followed up for more than 1 year, and the average follow-up period was 25 months. Single-level TLIF was performed in 60 cases, single-level TLIF plus adjacent-level decompression was performed in 13 cases, and double-level TLIF was performed in 13 cases. Corrected operative time per level, operative blood loss, postoperative blood drainage, total blood loss, and ambulation recovery time were measured. Transfusion rates and complication incidence were also identified. Clinical results were assessed using the Oswestry Disability Index (ODI) and a visual analogue scale (VAS). The learning curve was assessed using a logarithmic curve-fit regression analysis. In the single-level TLIF group (n = 60), 22 patients were defined as the “early” group (among the first 30 cases of the series), and the subsequent 38 cases were defined as the “late” group for comparison. Results. Corrected operative time gradually decreased as the series progressed, and an asymptote was reached after about 30 cases. ODI significantly decreased from an average of 24 at the preoperative stage to 10 at the final follow-up. Average VAS scores for lower back pain and radiating pain also significantly decreased from an average of 5.2 to 1.9 and 6.8 to 0.9, respectively. In the single-level TLIF series, operative time was significantly shorter in the late group (183 ± 23 min) than the early group (254 ± 44 min), and blood loss during the operation was significantly reduced in the late group (292 ± 280 mL) compared with the early group (508 ± 278 mL). Ambulation recovery time significantly decreased from 2.4 ± 0.6 days in the early group to 2.0 ± 0.5 in the late group. ODI and VAS scores for lower back pain and radiating pain did not differ between the 2 groups. Conclusion. Although it is not easy to master the minimally invasive TLIF technique, the surgeon's experience with this operation correlated with reduced operation time and blood loss during surgery. After the initial learning curve, this technique could be an effective and reliable option for the surgical treatment of lumbar degenerative disease.

Journal ArticleDOI
20 May 2012-Spine
TL;DR: The incidence of scoliosis increased with GMFCS level and age, and observed variations related to CP subtype were confounded by the General Motor Function Classification System, reflecting the different distribution ofGMFCS levels in the subtypes.
Abstract: Study Design. Epidemiological total population study based on a prospective follow-up CP registry.Objective. To describe the prevalence of scoliosis in a total population of children with CP, to analyse the relation between scoliosis, gross motor function and CP subtype, and to describe the age at diagnosis of scoliosis.Summary of Background Data. Children with cerebral palsy (CP) have an increased risk of developing scoliosis. The reported incidence varies, partly due to different definitions and study groups. Knowledge of the prevalence and characteristics of scoliosis in an unselected group of children with different CP types and levels of function is important for health care planning and for analysing the risk in an individual child.Methods. A total population of 666 children with CP, aged 4-18 years 1 January 2008, followed with annual examinations in a healthcare program was analysed. Gross motor function (GMFCS level), CP subtype, age at clinical diagnosis of scoliosis, and the Cobb angle at the first radiographic examination were registered.Results. Of the 666 children 116 (17%) had mild and a further 76 (11%) had moderate or severe scoliosis based on clinical examination. Radiographic examination showed a Cobb angle >10 degrees in 54 (8%) children and >20 degrees in 45 (7%) children. The risk of developing scoliosis increased with GMFCS level and age. In most children the scoliosis was diagnosed after 8 years of age. Children in GMFCS level IV or V had a 50% risk of having moderate or severe scoliosis by the age of 18, while children in GMFCS level I or II had almost no risk.Conclusions. The incidence of scoliosis increased with GMFCS level and age. Observed variations related to CP subtype were confounded by GMFCS, reflecting the different distribution of GMFCS levels in the subtypes. Follow-up programs for early detection of scoliosis should be based on the child's GMFCS level and age. (Less)

Journal ArticleDOI
01 Nov 2012-Spine
TL;DR: This study provides rates and causes of mortality associated with spine surgery for a broad range of diagnoses and includes assessments for adult and pediatric patients, and indicates increased mortality rates were associated with higher American Society of Anesthesiologists score, spinal fusion, and implants.
Abstract: STUDY DESIGN A retrospective review of a prospectively collected database. OBJECTIVE To assess rates and causes of mortality associated with spine surgery. SUMMARY OF BACKGROUND DATA Despite the best of care, all surgical procedures have inherent risks of complications, including mortality. Defining these risks is important for patient counseling and quality improvement. METHODS The Scoliosis Research Society Morbidity and Mortality database was queried for spinal surgery cases complicated by death from 2004 to 2007, including pediatric (younger than 21 yr) and adult (21 yr or older) patients. Deaths occurring within 60 days and complications within 60 days of surgery that resulted in death were assessed. RESULTS A total of 197 mortalities were reported among 108,419 patients (1.8 deaths per 1000 patients). Based on age, rates of death per 1000 patients for adult and pediatric patients were 2.0 and 1.3, respectively. Based on primary diagnosis (available for 107,996 patients), rates of death per 1000 patients were as follows: 0.9 for degenerative (n = 47,393), 1.8 for scoliosis (n = 26,421), 0.9 for spondylolisthesis (n = 11,421), 5.7 for fracture (n = 6706), 4.4 for kyphosis (n = 3600), and 3.3 for other (n = 12,455). The most common causes of mortality included: respiratory/pulmonary causes (n = 83), cardiac causes (n = 41), sepsis (n = 35), stroke (n = 15), and intraoperative blood loss (n = 8). Death occurred prior to hospital discharge for 109 (79%) of 138 deaths for which this information was reported. The specific postoperative day (POD) of death was reported for 94 (48%) patients and included POD 0 (n = 23), POD 1-3 (n = 17), POD 4-14 (n = 30), and POD >14 (n = 24). Increased mortality rates were associated with higher American Society of Anesthesiologists score, spinal fusion, and implants (P < 0.001). Mortality rates increased with age, ranging from 0.9 per 1000 to 34.3 per 1000 for patients aged 20 to 39 years and 90 years or older, respectively. CONCLUSION This study provides rates and causes of mortality associated with spine surgery for a broad range of diagnoses and includes assessments for adult and pediatric patients. These findings may prove valuable for patient counseling and efforts to improve the safety of patient care.

Journal ArticleDOI
01 Mar 2012-Spine
TL;DR: Gross pathology of IVDD in both dog types (CD and NCD) and humans showed many similarities, but the cartilaginous endplates were significantly thicker and the subchondral cortices significantly thinner in humans than in dogs.
Abstract: STUDY DESIGN Prospective observational and analytic study. OBJECTIVE To investigate whether spontaneous intervertebral disc degeneration (IVDD) occurring in both chondrodystrophic (CD) and nonchondrodystrophic dogs (NCD) can be used as a valid translational model for human IVDD research. SUMMARY OF BACKGROUND DATA Different animal models are used in IVDD research, but in most of these models IVDD is induced manually or chemically rather than occurring spontaneously. METHODS A total of 184 intervertebral discs (IVDs) from 19 dogs of different breeds were used. The extent of IVDD was evaluated by macroscopic grading, histopathology, glycosaminoglycan content, and matrix metalloproteinase 2 activity. Canine data were compared with human IVD data acquired in this study or from the literature. RESULTS Gross pathology of IVDD in both dog types (CD and NCD) and humans showed many similarities, but the cartilaginous endplates were significantly thicker and the subchondral cortices significantly thinner in humans than in dogs. Notochordal cells were still present in the IVDs of adult NCD but were not seen in the CD breeds or in humans. Signs of degeneration were seen in young dogs of CD breeds (<1 year of age), whereas this was only seen in older dogs of NCD breeds (5-7 years of age). The relative glycosaminoglycan content and metalloproteinase 2 activity in canine IVDD were similar to those in humans: metalloproteinase 2 activity increased and glycosaminoglycan content decreased with increasing severity of IVDD. CONCLUSION IVDD is similar in humans and dogs. Both CD and NCD breeds may therefore serve as models of spontaneous IVDD for human research. However, as with all animal models, it is important to recognize interspecies differences and, indeed, the intraspecies differences between CD and NCD breeds (early vs. late onset of IVDD, respectively) to develop an optimal canine model of human IVDD.

Journal ArticleDOI
01 Jul 2012-Spine
TL;DR: The results of this study provide spinal deformity surgeons evidence pertaining to this new upright 3D imaging technology that may aid in the clinical diagnosis and decision making for patients with scoliosis.
Abstract: STUDY DESIGN Experimental study for systematic evaluation of 3-dimensional (3D) reconstructions from low-dose digital stereoradiography. OBJECTIVE To assess the accuracy of EOS (EOS Imaging, Paris, France) 3-dimensional (3D) reconstructions compared with 3D computed tomography (CT) and the effect spine positioning within the EOS unit has on reconstruction accuracy. SUMMARY OF BACKGROUND DATA Scoliosis is a 3D deformity, but 3D morphological analyses are still rare. A new low-dose radiation digital stereoradiography system (EOS) was previously evaluated for intra/interobserver variability, but data are limited for 3D reconstruction accuracy. METHODS Three synthetic scoliotic phantoms (T1-pelvis) were scanned in upright position at 0°, ±5°, and ±10° of axial rotation within EOS and in supine position using CT. Three-dimensional EOS reconstructions were superimposed on corresponding 3D computed tomographic reconstructions. Shape, position, and orientation accuracy were assessed for each vertebra and the entire spine. Additional routine planer clinical deformity measurements were compared: Cobb angle, kyphosis, lordosis, and pelvic incidence. RESULTS Mean EOS vertebral body shape accuracy was 1.1 ± 0.2 mm (maximum 4.7 mm), with 95% confidence interval of 1.7 mm. Different anatomical vertebral regions were modeled well with root-mean-square (RMS) values from 1.2 to 1.6 mm. Position and orientation accuracy of each vertebra were high: RMS offset was 1.2 mm (maximum 3.7 mm) and RMS axial rotation was 1.9° (maximum 5.8°). There was no significant difference in each of the analyzed parameters (P > 0.05) associated with varying the rotational position of the phantoms in EOS machine. Planer measurements accuracy was less than 1° mean difference for pelvic incidence, Cobb angle (mean 1.6°/maximum 3.9°), and sagittal kyphosis (mean less than 1°, maximum 4.9°). CONCLUSION The EOS image acquisition and reconstruction software provides accurate 3D spinal representations of scoliotic spinal deformities. The results of this study provide spinal deformity surgeons evidence pertaining to this new upright 3D imaging technology that may aid in the clinical diagnosis and decision making for patients with scoliosis.

Journal ArticleDOI
01 Sep 2012-Spine
TL;DR: Although this study did not explore the relative effectiveness of different ambulatory services, recent increasing costs associated with providing medical care for back and neck conditions (particularly subspecialty care) are contributing to the growing economic burden of managing these conditions.
Abstract: Study Design Serial, cross-sectional, nationally representative surveys of non-institutionalized adults.

Journal ArticleDOI
01 Sep 2012-Spine
TL;DR: The findings suggest that in obese patients, the distribution of body mass is more predictive of SSI than the absolute BMI and deserves attention in preoperative evaluation.
Abstract: Study design A retrospective review. Objective The purpose of this study was to determine the role in body habitus and weight distribution on developing a surgical site infection (SSI). Summary of background data SSI after lumbar spine surgery remains a significant cause of morbidity. The literature demonstrates an increased risk of postoperative infections associated with obesity, diabetes, and multilevel surgeries. Methods A retrospective review was performed on a consecutive cohort of 298 adult patients who underwent lumbar spine fusion surgeries between 2006 and 2008 at the Duke University Medical Center. Previously identified risk factors (i.e., number of levels, diabetes, body mass index [BMI]) were collected, as well as the horizontal distance from the lamina to the skin surface (measured at L4) and thickness of subcutaneous fat at the surgical site. Results Among the 298 patients, 24 (8%) had postoperative infections. Of the previously identified risk factors, number of levels (P = 0.0078) was found to be significantly associated with infections, whereas BMI (P = 0.16) and diabetes (P = 0.13) were found not to be statistically significant. Obesity (BMI ≥30) (P = 0.025), skin to lamina distance (P = 0.046), and thickness of the subcutaneous fat (P = 0.035) were found to be significant risk factors for SSI. Conclusion Our findings suggest that in obese patients, the distribution of body mass is more predictive of SSI than the absolute BMI and deserves attention in preoperative evaluation.

Journal ArticleDOI
01 Feb 2012-Spine
TL;DR: Significant postoperative alignment changes can occur through unfused thoracic spinal segments after lumbar PSO and are not simply due to junctional failure.
Abstract: STUDY DESIGN Consecutive, multicenter retrospective review. OBJECTIVE To evaluate if change in thoracic kyphosis (TK) has a positive or negative impact on spinopelvic alignment after lumbar pedicle subtraction osteotomy (PSO) with short fusions. SUMMARY OF BACKGROUND DATA In the setting of sagittal malalignment, the effect of large vertebral resections can now be anticipated in long fusions, but their impact on unfused segments (reciprocal changes [RC]) remains poorly understood. METHODS A total of 34 adult patients (mean age = 54 years; SD = 12) who underwent lumbar PSO with upper instrumented vertebra below T10 were included. Radiographic analysis included pre- and postassessment of TK, lumbar lordosis (LL), sagittal vertical axis (SVA), T1 spinopelvic inclination (T1SPI), pelvic tilt (PT), and pelvic incidence (PI). Final SVA and PT were analyzed to determine successful realignment. RC in the thoracic spine was designated favorable or unfavorable on the basis of impact on final SVA and PT. RESULTS Mean PSO resection was 26°. LL increased from 20° to 49° (P < 0.001). SVA improved from 14 to 4 cm (P < 0.001), and PT improved from 33° to 25° (P < 0.001). Mean increase in TK was 13° (P = 0.002) but was unchanged in 11 patients. Five patients had a favorable RC, and 18 patients had an unfavorable RC. Unfavorable RC was attributed to junctional failure in 6 of 18 patients. Significant differences in the unfavorable RC group included age and greater preoperative PT, PI, SVA, and T1SPI. CONCLUSION Significant postoperative alignment changes can occur through unfused thoracic spinal segments after lumbar PSO. Unfavorable RC may limit optimal correction and lead to clinical failures. Risk factors for unfavorable thoracic RC include older patients, larger preoperative PI and PT, and worse preoperative T1SPI and are not simply due to junctional failure. Care should be taken with selective lumbar fusion and PSO in older patients and in those with severe preoperative spinopelvic parameters.

Journal ArticleDOI
15 Feb 2012-Spine
TL;DR: The incidence of TSCI in this population has remained remarkably stable, and age-related changes mirror those in the population across 10 years, while an increased tendency to surgical treatment during the 10 years of this study has not resulted in concomitant changes in patients' in-hospital mortality or length of stay.
Abstract: Study design Retrospective observational study utilizing prospectively collected population-based data. Objective To describe the epidemiology and demographics of all patients with traumatic spinal cord injury (TSCI) treated at a single institution, which represents the sole referral center and specialized SCI unit for a population of 4 million people. Summary of background data Although many studies report on the epidemiology of TSCI, studies in which patients are prospectively characterized in the acute setting with precise recording of their baseline neurological impairment are uncommon. Methods Data on all patients admitted to a level 1 trauma center with TSCI between 1995 and 2004 were prospectively collected using a customized, fully relational, locally designed, spine database. Results The incidence of TSCI averaged 35.7 per million and did not change substantially during 10 years of data collection. However, the median age of TSCI patients increased from 34.5 to 45.5 years during this period. The men-to-women ratio was 4.4:1. In those older than 55 years, cervical-level injuries with incomplete American Spinal Injury Association (ASIA) Impairment Scale (AIS) scores C and D were most common, with men demonstrating predominantly lower cervical injuries and women more likely to exhibit upper cervical injuries. Increasing rates of surgical treatment during 10 years of this study (61.8%-86.4%) were not associated with improvements in mortality rate or length of hospital stay. Patients older than 75 years who presented with an acute TSCI had a mortality rate of 20% while in hospital. Conclusion The incidence of TSCI in our population has remained remarkably stable, and age-related changes mirror those in the population across 10 years. An increased tendency to surgical treatment during the 10 years of this study has not resulted in concomitant changes in patients' in-hospital mortality or length of stay.

Journal ArticleDOI
01 Jan 2012-Spine
TL;DR: It is suggested that surgical excision of tumor and instrumented stabilization may improve clinical outcomes compared with radiation therapy alone, with regard to neurological function and pain.
Abstract: STUDY DESIGN Systematic literature review from 1970 to 2007. OBJECTIVE This study reports the results of a systematic review comparing surgical decompression ± radiation to radiation therapy alone among patients with metastatic spinal cord compression. SUMMARY OF BACKGROUND DATA Currently, the optimal treatment of metastatic spine lesions is not well defined and is inconsistent. Radiation and surgical excision are both accepted and effective. There appears to be a favorable trend for improved neurological outcome with surgical excision and stabilization as part of the management. METHODS A review of the English literature from 1970 to 2007 was performed in the Medline database using general MeSH terms. Relevant outcome studies for the treatment of metastatic spinal cord compression were selected through criteria defined a priori. The primary outcome was ambulatory capacity. A random effects model was built to compare results between treatment groups, based on calculated proportions from each study. RESULTS Of the 1595 articles screened, 33 studies (2495 patients) were selected based on our inclusion and exclusion criteria. Sixty-four percent of the patients who underwent surgical decompression, tumor excision, and stabilization had neurological improvement from nonambulatory to ambulatory status. Twenty-nine percent of the radiation therapy group regained the ability to ambulate after treatment (P < 0.001). Paraplegic patients had a 4-fold greater recovery rate to functional ambulation with surgical intervention than with radiation therapy alone (42% vs. 10%, P < 0.001). Pain relief was noted in 88% of the patients in the surgical studies and in 74% of the patients in studies of radiation therapy (P < 0.001). The overall surgical complication rate was 29%. CONCLUSION This systematic review suggests that surgical excision of tumor and instrumented stabilization may improve clinical outcomes compared with radiation therapy alone, with regard to neurological function and pain. However, most data in the current literature are from observational studies, where variations in patient population and treatments cannot be controlled. This compromised our ability to compare the results of both treatments directly.