Showing papers in "Spine in 2014"

Proximal junctional kyphosis and failure after spinal deformity surgery: a systematic review of the literature as a background to classification development.

Abstract: Study design Systematic review of literature. Objective To perform a comprehensive English language systematic literature review of proximal junctional kyphosis (PJK) and proximal junctional failure (PJF), concentrating on incidence, risk factors, health related quality of life impact, prevention strategy, and classification systems. Summary of background data PJK and PJF are well described clinical pathologies and are a frequent cause of revision surgery. The development of a PJK classification that correlates with clinical outcomes and guides treatment decisions and possible prevention strategies would be of significant benefit to patients and surgeons. Methods The phrases "proximal junctional," "proximal junctional kyphosis," and "proximal junctional failure" were used as search terms in PubMed for all years up to 2014 to identify all articles that included at least one of these terms. Results Fifty-three articles were identified overall. Eighteen articles assessed for risk factors. Eight studies specifically reviewed prevention strategies. There were no randomized prospective studies. There were 3 published studies that have attempted to classify PJK. The reported incidence of PJK ranged widely, from 5% to 46% in patients undergoing spinal instrumentation and fusion for adult spinal deformity. It is reported that 66% of PJK occurs within 3 months and 80% within 18 months after surgery. The reported revision rates due to PJK range from 13% to 55%. Modifiable and nonmodifiable risk factors for PJK have been characterized. Conclusion PJK and PJF affect many patients after long segment instrumentation after the correction of adult spinal deformity. The epidemiology and risk factors for the disease are well defined. A PJK and PJF scoring system may help describe the severity of disease and guide the need for revision surgery. The development and prospective validation of a PJK classification system is important considering the prevalence of the problem and its clinical and economic impact. Level of evidence N/A.

Preoperative opioid use and its association with perioperative opioid demand and postoperative opioid independence in patients undergoing spine surgery

Abstract: STUDY DESIGN Prospective cohort. OBJECTIVE To assess whether preoperative opioid use is associated with increased perioperative opioid demand and postoperative opioid independence in patients undergoing spine surgery. SUMMARY OF BACKGROUND DATA Previous work has demonstrated increased opioid requirements during the intraoperative and immediate postoperative period in patients with high levels of preoperative opioid use. Despite this, they remain a common agent class used for the management of pain in patients prior to spine surgery. METHODS A total of 583 patients were included. Self-reported daily opioid consumption was obtained preoperatively and converted into morphine equivalent amounts and opioid use was recorded at the 12-month postoperative time. Intraoperative and immediate postoperative opioid demand was calculated. Linear regression analyses for intraoperative and immediate postoperative opioid demand while logistic regression analyses for opioid independence at 12 months including relevant covariates such as depression and anxiety were performed. RESULTS The median preoperative morphine equivalent amount for the cohort was 8.75 mg, with 55% of patients reporting some degree of opioid use. Younger age, more invasive surgery, anxiety, and primary surgery were significantly associated with increased intraoperative opioid demand (P < 0.05). Younger age, anxiety, and greater preoperative opioid use were significantly associated with increased immediate postoperative opioid demand (P < 0.05). More invasive surgery, anxiety, revision surgery, and greater preoperative opioid use were significantly associated with a decreased incidence of opioid independence at 12 months postoperatively (P < 0.01). CONCLUSION Greater preoperative opioid use prior to undergoing spine surgery predicts increased immediate postoperative opioid demand and decreased incidence of postoperative opioid independence. Psychiatric diagnoses in those using preoperative opioids were predictors of continued opioid use at 12 months. Patients may benefit from preoperative counseling that emphasizes minimizing opioid use prior to undergoing spine surgery. LEVEL OF EVIDENCE 2.

Patients with proximal junctional kyphosis requiring revision surgery have higher postoperative lumbar lordosis and larger sagittal balance corrections.

Abstract: Study design Case control study. Objective To evaluate risk factors in patients in 3 groups: those without proximal junctional kyphosis (PJK) (N), with PJK but not requiring revision (P), and then those with PJK requiring revision surgery (S). Summary of background data It is becoming clear that some patients maintain stable PJK angles, whereas others progress and develop severe PJK necessitating revision surgery. Methods A total of 206 patients at a single institution from 2002 to 2007 with adult scoliosis with 2-year minimum follow-up (average 3.5 yr) were analyzed. Inclusion criteria were age more than 18 years and primary fusions greater than 5 levels from any thoracic upper instrumented vertebra to any lower instrumented vertebrae. Revisions were excluded. Radiographical assessment included Cobb measurements in the coronal/sagittal plane and measurements of the PJK angle at postoperative time points: 1 to 2 months, 2 years, and final follow-up. PJK was defined as an angle greater than 10°. Results The prevalence of PJK was 34%. The average age in N was 49.9 vs. 51.3 years in P and 60.1 years in S. Sex, body mass index, and smoking status were not significantly different between groups. Fusions extending to the pelvis were 74%, 85%, and 91% of the cases in groups N, P, and S. Instrumentation type was significantly different between groups N and S, with a higher number of upper instrumented vertebra hooks in group N. Radiographical parameters demonstrated a higher postoperative lumbar lordosis and a larger sagittal balance change, with surgery in those with PJK requiring revision surgery. Scoliosis Research Society postoperative pain scores were inferior in group N vs. P and S, and Oswestry Disability Index scores were similar between all groups. Conclusion Patients with PJK requiring revision were older, had higher postoperative lumbar lordosis, and larger sagittal balance corrections than patients without PJK. Based on these data, it seems as though older patients with large corrections in their lumbar lordosis and sagittal balance were at risk for developing PJK, requiring revision surgery. Level of evidence 3.

Opioids compared with placebo or other treatments for chronic low back pain: an update of the Cochrane Review.

Abstract: STUDY DESIGN Systematic review and meta-analysis. OBJECTIVE To assess the efficacy of opioids in adults with chronic low back pain (CLBP). SUMMARY OF BACKGROUND DATA Opioids for CLBP has increased dramatically. However, the benefits and risks remain unclear. METHODS We updated a 2007 Cochrane Review through October 2012 of randomized controlled trials from multiple databases. Use of noninjectable opioids in CLBP for at least 4 weeks was compared with placebo or other treatments; comparisons with different opioids were excluded. Outcomes included pain and function using standardized mean difference (SMD) or risk ratios with 95% confidence intervals (CIs), and absolute risk difference with 95% CI for adverse effects. Study quality was evaluated using Grading of Recommendations Assessment, Development, and Evaluation criteria. RESULTS Fifteen trials (5540 participants), including twelve new, met the criteria. Tramadol was better than placebo for pain (SMD, -0.55; 95% CI, -0.66 to -0.44) and function (SMD, -0.18; 95% CI, -0.29 to -0.07). Compared with placebo, transdermal buprenorphine decreased pain (SMD, -2.47; 95% CI, -2.69 to -2.25), but not function (SMD, -0.14; 95% CI, -0.53 to 0.25). Strong opioids (morphine, hydromorphone, oxycodone, oxymorphone, and tapentadol), were better than placebo for pain (SMD, -0.43; 95% CI, -0.52 to -0.33) and function (SMD, -0.26; 95% CI, -0.37 to -0.15). One trial demonstrated little difference with tramadol compared with celecoxib for pain relief. Two trials (272 participants) found no difference between opioids and antidepressants for pain or function. Reviewed trials had low to moderate quality, high drop-out rates, short duration, and limited interpretability of functional improvement. No serious adverse effects, risks (addiction or overdose), or complications (sleep apnea, opioid-induced hyperalgesia, hypogonadism) were reported. CONCLUSION There is evidence of short-term efficacy (moderate for pain and small for function) of opioids to treat CLBP compared with placebo. The effectiveness and safety of long-term opioid therapy for treatment of CLBP remains unproven.

Report of the NIH task force on research standards for chronic low back pain

Abstract: UNLABELLED Despite rapidly increasing intervention, functional disability due to chronic low back pain (cLBP) has increased in recent decades. We often cannot identify mechanisms to explain the major negative impact cLBP has on patients' lives. Such cLBP is often termed nonspecific and may be due to multiple biologic and behavioral etiologies. Researchers use varied inclusion criteria, definitions, baseline assessments, and outcome measures, which impede comparisons and consensus. Therefore, NIH Pain Consortium charged a research task force to draft standards for research on cLBP. The resulting multidisciplinary panel recommended using 2 questions to define cLBP; classifying cLBP by its impact (defined by pain intensity, pain interference, and physical function); use of a minimum data set to describe research participants (drawing heavily on the Patient Reported Outcomes Measurement Information System methodology); reporting "responder analyses" in addition to mean outcome scores; and suggestions for future research and dissemination. The Pain Consortium has approved the recommendations, which investigators should incorporate into NIH grant proposals. The research task force believes that these recommendations will advance the field, help resolve controversies, and facilitate future research addressing the genomic, neurological, and other mechanistic substrates of cLBP. We expect that the research task force recommendations will become a dynamic document and undergo continual improvement. PERSPECTIVE A task force was convened by the NIH Pain Consortium with the goal of developing research standards for cLBP. The results included recommendations for definitions, a minimum data set, reporting outcomes, and future research. Greater consistency in reporting should facilitate comparisons among studies and the development of phenotypes.

In vivo analysis of insertional torque during pedicle screwing using cortical bone trajectory technique.

Abstract: STUDY DESIGN The insertional torque of pedicle screws using the cortical bone trajectory (CBT) was measured in vivo. OBJECTIVE To investigate the effectiveness of the CBT technique by measurement of the insertional torque. SUMMARY OF BACKGROUND DATA The CBT follows a mediolateral and caudocephalad directed path, engaging with cortical bone maximally from the pedicle to the vertebral body. Some biomechanical studies have demonstrated favorable characteristics of the CBT technique in cadaveric lumbar spine. However, no in vivo study has been reported on the mechanical behavior of this new trajectory. METHODS The insertional torque of pedicle screws using CBT and traditional techniques were measured intraoperatively in 48 consecutive patients. A total of 162 screws using the CBT technique and 36 screws using the traditional technique were compared. In 8 of 48 patients, the side-by-side comparison of 2 different insertional techniques for each vertebra were performed, which formed the H group. In addition, the insertional torque was correlated with bone mineral density. RESULTS The mean maximum insertional torque of CBT screws and traditional screws were 2.49 ± 0.99 Nm and 1.24 ± 0.54 Nm, respectively. The CBT screws showed 2.01 times higher torque and the difference was significant between the 2 techniques (P < 0.01). In the H group, the insertional torque were 2.71 ± 1.36 Nm in the CBT screws and 1.58 ± 0.44 Nm in the traditional screws. The CBT screws demonstrated 1.71 times higher torque and statistical significance was achieved (P < 0.01). Positive linear correlations between maximum insertional torque and bone mineral density were found in both technique, the correlation coefficient of traditional screws (r = 0.63, P < 0.01) was higher than that of the CBT screws (r = 0.59, P < 0.01). CONCLUSION The insertional torque using the CBT technique is about 1.7 times higher than the traditional technique. LEVEL OF EVIDENCE 2.

Influence of catastrophizing on treatment outcome in patients with nonspecific low back pain: a systematic review.

Abstract: Study design Systematic review. Objective The aim of this study was to assess the effect of catastrophizing on treatment efficacy and outcome in patients treated for low back pain. Summary of background data Psychological factors including catastrophizing thoughts are thought to increase the risk for chronic low back pain. The influence of catastrophizing is debated. Methods In September 2012, the following databases were searched: BIOSIS, CINAHL, Cochrane Library, EMBASE, OTseeker, PeDRO, PsycINFO, MEDLINE, Scopus, and Web of Science. For 50 of 706 references, full text was assessed. Results based on 11 studies were included in this analysis. Results In the 11 studies, a total of 2269 patients were included. Seven studies were of good and 4 of moderate methodological quality. Heterogeneity in study settings, treatments, outcomes, and patient populations impeded meta-analysis. Catastrophizing at baseline was predictive for disability at follow-up in 4 studies and for pain in 2 studies. Three studies found no predictive effect of catastrophizing. A mediating effect was found in all studies (n = 5) assessing the impact of a decrease in catastrophizing during treatment. A greater decrease was associated with better outcome. Most studies that investigated the moderating effects on treatment efficacy found no effect (n = 5). However, most studies did not look for a direct interaction between the treatment and catastrophizing thoughts. No study investigated the influence of catastrophizing on work-related outcomes including return to work. Conclusion Catastrophizing predicted degree of pain and disability and mediated treatment efficacy in most studies. The presence of catastrophizing should be considered in patients with persisting back pain. Limited evidence was found for the moderating effects on treatment efficacy. Future research should aim to clarify the role of catastrophizing as a moderator of outcome and investigate its importance for work-related outcomes. Level of evidence 1.

Causes and risk factors for 30-day unplanned readmissions after lumbar spine surgery.

Abstract: STUDY DESIGN Retrospective review of a prospective cohort. OBJECTIVE To determine the incidence, causes, and risk factors for 30-day unplanned readmissions after lumbar spine surgery. SUMMARY OF BACKGROUND DATA The rising costs associated with lumbar spinal surgery have received national attention. Recently, the government has chosen to target 30-day readmissions as a quality measure. Few studies have specifically analyzed the incidence, causes, and risk factors for readmission in a multicenter patient cohort. METHODS A large, multicenter clinical registry was queried for all patients undergoing lumbar spine surgery in 2012. Current Procedural Terminology codes were used to select patients undergoing lumbar discectomy, laminectomy, anterior and posterior fusions, and multilevel deformity surgery. Thirty-day readmissions rates and causes were identified and analyzed. Univariate and multivariate logistic regression analyses were used to identify patient characteristics, comorbidities, and operative variables predictive of readmission. RESULTS Overall, 695 of 15,668 patients undergoing lumbar spine surgery had unplanned 30-day hospital readmissions (4.4%). When separated by procedure type, readmissions were lowest after discectomy, 3.3%, and highest after deformity surgery, 9.0% (P < 0.001). The top causes for readmission were wound-related (38.6%), pain-related (22.4%), thromboembolic (9.4%), and systemic infections (8.0%). Predictors of readmission included advanced patient age more than 80 years (P = 0.03), African American race (P = 0.03), recent weight loss (P = 0.04), chronic obstructive pulmonary disorder (P < 0.01), history of cancer (P = 0.04), creatinine more than 1.2 (P < 0.01), elevated ASA class (P = 0.01), operative time more than 4 hours (P = 0.01), and prolonged hospital length of stay more than 4 days (P < 0.01). CONCLUSION Thirty-day unplanned readmission rates increased with procedure invasiveness. Both medical and surgical reasons contributed to readmission, many unavoidable. Surgeons should explore optimization measures for those at risk of early, unplanned readmission. LEVEL OF EVIDENCE 3.

Characterization and surgical outcomes of proximal junctional failure in surgically treated patients with adult spinal deformity.

Abstract: Study Design. Retrospective case series of surgically treated patients with adult spine deformity (ASD). Objective. To report the incidence of proximal junctional failure (PJF), characterize PJF and evaluate the outcome of revision surgery for PJF. A modified classification is also proposed. Summary of Background Data. Although recent reports have shown the catastrophic results of PJF, few reports have shown the incidence, characteristics, and clinical outcomes of PJF in ASD. Methods. This retrospective analysis reviewed data entered prospectively into a multicenter database. Surgically treated patients with ASD with a minimum 2-year follow-up were included. PJF was defined as any type of symptomatic proximal junctional kyphosis (PJK) requiring surgery. On the basis of our previous classification, the following modified PJK classification was established: grade A, proximal junctional increase of 10° to 19°; grade B, 20° to 29°; and grade C, 30° or more. Three types of PJK were also defined: ligamentous failure (type 1), bone failure (type 2), and implant/bone interface failure (type 3). An additional criterion was added for the presence or absence of spondylolisthesis above the upper instrumentation vertebra (UIV). Results. PJF developed in 23 of the 1668 patients with ASD. The incidence of PJF was 1.4%. The mean age was 62.3 ± 7.9 years, and the mean follow-up was 4.0 ± 2.3 years. Seventeen patients had undergone prior surgical procedures. Six patients had UIV above T8, and 17 had UIV below T9. Six patients had associated spondylolisthesis above the UIV (PJF-S), whereas 17 patients did not (PJF-N). The radiographical data show a significant difference in the preoperative sagittal vertical axis between the PJF-S and PJF-N groups, whereas no significant difference was observed in the preoperative sagittal parameters (5.2 ± 3.9 cm vs. 11.4 ± 6.0 cm, P = 0.04). The most common type of PJF was type 2N. The PJF symptoms consisted of intolerable pain (n = 17), neurological deficits (n = 6), and progressive trunk deformity (n = 1). Eleven patients had additional PJK/PJF and 9 required additional revision surgical procedures. Conclusion. The incidence of PJF among surgically treated patients with ASD was 1.4%. The most common type of PJF was 2N. Preoperative large sagittal vertical axis change and large amount of correction was a causative factor for spondylolisthesis above the UIV. After the revision surgery, further PJF was a commonly occurred event. Conclusion. Level of Evidence: 3

Operative duration as an independent risk factor for postoperative complications in single-level lumbar fusion: an analysis of 4588 surgical cases.

Abstract: Study design Multicenter retrospective cohort study. Objective To estimate the impact of increasing surgical duration on outcomes after single-level lumbar fusion. Summary of background data Lumbar fusion is a widely used practice for the treatment of disability and chronic low back pain. Longer operative duration is shown to correlate with increased morbidity and mortality in various surgical disciplines, but no large-scale study has been performed to validate this relationship in lumbar spine surgery. Methods The American College of Surgeons National Surgical Quality Improvement Program was retrospectively reviewed to identify all patients who underwent lumbar fusion procedures during 2006 to 2011. Thirty-day morbidity and mortality rates were reported on the basis of operative time, whereas multivariate logistic regression model was used to examine operative duration as an independent risk factor for outcomes. Results A total of 4588 patients were included in the analysis. The mean operative duration for all patients was 197 ± 105 minutes. Our multivariate risk-adjusted regression models demonstrated that increasing operative time was associated with step-wise increase in risk for overall complications (odds ratio [OR], 2.09-5.73), medical complications (OR, 2.18-6.21), surgical complications (OR, 1.65-2.90), superficial surgical site infection (OR, 2.65-3.97), and postoperative transfusions (OR, 3.25-12.19). Operative duration of 5 hours or more was also associated with increased risk of reoperation (OR, 2.17), organ/space surgical site infection (OR, 9.72), sepsis/septic shock (OR, 4.41), wound dehiscence (OR, 10.98), and deep vein thrombosis (OR, 17.22). Conclusion Our data suggest that increasing operative duration is associated with a wide array of complications. Operative duration is, therefore, an important quality metric in the performance of lumbar fusion. Strategies to reduce operative time and further research to identify risk factors that are associated with longer surgical duration are needed for improved patient outcomes. Level of evidence 3.

Anterior vertebral body tethering for idiopathic scoliosis: two-year results.

Abstract: Study design Retrospective review. Objective To report the 2-year results of the initial cohort undergoing anterior vertebral body tethering (VBT). Summary of background data Anterior VBT is a promising new technique with abundant preclinical studies but very few clinical results. It is a growth modulation technique, which utilizes patients' growth to attain progressive correction of their scoliosis. We report 2-year results of the initial cohort undergoing this procedure. Methods After obtaining institutional review board approval, we retrospectively reviewed our first 11 consecutive patients who underwent anterior VBT with 2-year follow-up. We collected pertinent preoperative, intraoperative, and most recent clinical and radiographical data. Student t test and Fisher exact test were utilized to compare different time points. Results Eleven patients with thoracic idiopathic scoliosis (8 females) were identified, with a mean age of 12.3 ± 1.6 years. Preoperatively, all were skeletally immature (Sanders mean = 3.4 ± 1.1; Risser mean = 0.6 ± 1.1). All underwent tethering of an average of 7.8 ± 0.9 (range: 7-9) levels, with the most proximal being T5 and the most distal L2. Preoperative thoracic Cobb angle averaged 44.2 ± 9.0° and corrected to 20.3 ± 11.0° on first erect, with progressive improvement at 2 years (Cobb angle = 13.5 ± 11.6°, % correction = 70%; P Conclusion Anterior VBT is a promising technique for skeletally immature patients with idiopathic scoliosis. This technique can be performed safely and can result in progressive correction. Level of evidence 4.

Biomechanical risk factors for proximal junctional kyphosis: a detailed numerical analysis of surgical instrumentation variables.

Abstract: Study Design.Biomechanical analysis of proximal junctional kyphosis (PJK) through computer simulations and sensitivity analysis.Objective.To gain biomechanical knowledge on the risk of PJK and find surgical solutions to reduce the risks.Summary of Background Data.PJK is a pathological kyphotic defor

Comparison of standard 2-rod constructs to multiple-rod constructs for fixation across 3-column spinal osteotomies

Abstract: Study design Retrospective matched-cohort comparative study. Objective Compare radiographical outcomes after the use of a standard 2-rod construct (2-RC) versus a multiple-rod construct (multi-RC) across 3-column osteotomy sites in a matched cohort with severe kyphosis and/or scoliosis with minimum 2-year follow-up. Summary of background data Three-column osteotomies are used for treating severe spinal deformities, typically with a standard 2-RC across the highly unstable osteotomy site. Methods Between 1996 and 2010, patients undergoing a 3-column osteotomy by a single surgeon were matched for age/diagnosis/vertebra(e) resected/levels fused and curve magnitude. Sixty-six control patients with a 2-RC were identified and appropriately matched to 66 consecutive patients with a multi-RC across the 3-column osteotomy site. Each group included 50 patients with lumbar pedicle subtraction osteotomy and 16 patients with vertebral column resection. Radiographs were measured using standard adult deformity criteria. Results Averages were compared for 2-RC versus multi-RC demonstrating no statistical differences in mean age at surgery, vertebrae resected, levels fused, bone morphogenetic protein used (patients), or average preoperative Cobb magnitude. There were significant differences in the occurrence of rod breakage and revision surgery for pseudarthroses at the 3-column osteotomy site (rod breakage: 2-RC: 11 vs. multi-RC: 2, P=0.002; and revision: 2-RC: 6 vs. multi-RC: 0, P=0.011). There was no complete implant failure in the multi-RC group but 2 patients had partial implant failure without symptomatic pseudarthrosis. Eight patients in each group (12%) developed a pseudarthrosis above or below the osteotomy site. Conclusion The use of a multi-RC is a safe, simple, and effective method to provide increased stability across 3-column osteotomy sites to significantly prevent implant failure and symptomatic pseudarthrosis versus a standard 2-RC. We strongly recommend using a multi-RC to stabilize 3-column osteotomies of the thoracic and lumbar spine. Level of evidence 3.

Preoperative pain neuroscience education for lumbar radiculopathy: a multicenter randomized controlled trial with 1-year follow-up.

Abstract: Study Design. Multicenter, randomized, controlled trial on preoperative pain neuroscience education (NE) for lumbar radiculopathy. Objective. To determine if the addition of NE to usual preoperative education would result in superior outcomes with regard to pain, function, surgical experience, and health care utilization postsurgery. Summary of Background Data. One in 4 patients after lumbar surgery (LS) for radiculopathy experience persistent pain and disability, which is nonresponsive to perioperative treatments. NE focusing on the neurophysiology of pain has been shown to decrease pain and disability in populations with chronic low back pain. Methods. Eligible patients scheduled for LS for radiculopathy were randomized to receive either preoperative usual care (UC) or a combination of UC plus 1 session of NE delivered by a physical therapist (verbal one-on-one format) and a NE booklet. Sixty-seven patients completed the following outcomes prior to LS (baseline), and 1, 3, 6, and 12 months after LS: low back pain (numeric rating scale), leg pain (numeric rating scale), function (Oswestry Disability Index), various beliefs and experiences related to LS (10-item survey with Likert scale responses), and postoperative utilization of health care (utilization of health care questionnaire). Results. At 1-year follow-up, there were no statistical differences between the experimental and control groups with regard to primary outcome measure of low back pain ( P = 0.183), leg pain ( P = 0.075), and function ( P = 0.365). In a majority of the categories regarding

National trends in the use of fusion techniques to treat degenerative spondylolisthesis.

Abstract: STUDY DESIGN: Retrospective review. OBJECTIVE: (1) To describe change in treatment patterns for degenerative spondylolisthesis (DS). (2) To report regional variation in treatment of DS. (3) To describe variation in surgeon-reported outcomes for DS based on treatment. SUMMARY OF BACKGROUND DATA: Spinal stenosis associated with DS is commonly treated with decompression and fusion but little is known about the optimal fusion technique. During a 6-month period, American Board of Orthopaedic Surgery step II candidates submit procedure lists; these lists have been stored in an electronic database since 1999. METHODS: The American Board of Orthopaedic Surgery database was retrospectively queried to identify patients who underwent surgery for DS from 1999 to 2011. Included patients underwent uninstrumented fusion, fusion with posterior instrumentation, fusion using interbody device, or decompression without fusion. Utilization of these procedures was analyzed by year and geographic region. RESULTS: The study period included 5639 cases; the annual number of cases doubled during the study period. The percentage of cases treated with interbody fusion (IF) increased significantly throughout the study period, from 13.6% (1999-2001) to 32% (2009-2011) (P 10% higher than any other region (P<0.001) and more than 23% higher than the Southeast (P<0.001). CONCLUSION: Despite little evidence guiding treatment strategy for DS, national treatment patterns have changed dramatically during the past 13 years. The rapid adoption of IF and substantial regional variation in treatment utilization patterns raises questions about drivers of change including perceptions about associated fusion rates, the importance of sagittal balance and differential reimbursement. LEVEL OF EVIDENCE: 4.

Psychometric properties of the PROMIS physical function item bank in patients with spinal disorders.

Abstract: Study design Patient-reported outcomes provide vital information when assessing effectiveness of clinical care. Yet, most patient-reported outcome instruments are limited by lack of validation and reliability to measure PF adequately. As part of the Patient-Reported Outcomes Measurement Information System (PROMIS), a PF item bank consisting of 124 items has been developed. Objective There is validation evidence for the PROMIS PF item bank in the general orthopedic patient population in general, but has yet to be validated in the patient with spinal disorders. This study aims to evaluate the psychometric properties of the PROMIS PF item bank specifically for patients presenting with spine-related complaints. Summary of background data Data were collected from adult patients visiting a university spine clinic for back and neck problems. All patients older than 18 years were eligible to participate. A total of 438 patients (49% male) were enrolled in this prospective study. Patients were 18- to 89-year old and presented with back problems (n = 286) and neck problems (n = 152). All patients were administered a 131 item questionnaire. Methods Conventional descriptive statistics such as means, standard deviations, and proportions were conducted to examine patient characteristics. A Rasch model was used to examine the psychometric properties of the instrument including dimensionality, floor/ceiling effects, reliabilities, and item bias. Results Results showed that a single PF dimension was supported by the data (i.e., unexplained variance was 2.9%). The instrument had 1.7% ceiling effect and 0.2% floor effect. Item reliability was 1.00 and person reliability was 0.99. We found evidence of item response bias associated with sex, age, and education in some items. Conclusion The PROMIS PF item bank adequately addressed outcomes of patients with spinal disorders as reliabilities were excellent, minimal ceiling/floor effect existed, and item bias was limited. Future effort should be focused on eliminating, rescaling, or modifying those items that had item bias. Level of evidence 2.

Radiation exposure to the surgeon and the patient during posterior lumbar spinal instrumentation: a prospective randomized comparison of navigated versus non-navigated freehand techniques.

Abstract: A prospective randomized studyTo compare occupational radiation exposure to the surgeon, as well as the patient, during posterior lumbar spine instrumentation in 10 navigated cases (navigated) versus 11 cases using the freehand technique (non-navigated)The use of navigation increases the accuracy of posterior lumbar instrumentationA further speculated benefit of navigation is the reduction of radiation exposure of the surgeon However, this has so far not been evaluated in such comparative mannerRadiation exposure to the surgeon was measured by digital dosimeters placed at the level of the eye, chest, and dominant forearm Radiation exposure was measured from the time of positioning of the patient to the end of the procedure both for navigated (intraoperative 3-dimensional [3D] fluoroscopy-based) and non-navigated (2-dimensional fluoroscopy-guided) freehand posterior lumbar spine instrumentations A 3D fluoroscopic scan was routinely performed at the end of the procedure for all patientsPatients were distributed evenly in the 2 groups in terms of sex, age, body mass index, and the number of operated levels The accumulated radiation dose for the surgeon was significantly higher in the non-navigated group; up to 996 times The radiation dose for the patient was higher with the freehand technique, 18848 cGy·cm (non-navigated) versus 887 cGy·cm (navigated), without reaching a statistically significant levelRadiation exposure to the surgeon during pedicle screw placement with the freehand technique is up to 996 times greater than with the use of navigation In the latter group, the only radiation exposure comes from the preoperative-level control and positioning of the 3D C-arm before 3D fluoroscopic acquisition Furthermore, neuronavigation also reduces the cumulative dose for the patient2

Current trends in demographics, practice, and in-hospital outcomes in cervical spine surgery: a national database analysis between 2002 and 2011.

Abstract: STUDY DESIGN Retrospective database analysis. OBJECTIVE To investigate national trends of cervical spine surgical procedures from 2002 to 2011. SUMMARY OF BACKGROUND DATA There is a paucity of literature assessing the current practice trends and outcomes of cervical spine surgery following the 2008 Food and Drug Administration public health notifications regarding bone morphogenetic protein (BMP) utilization in cervical spine surgical procedures. METHODS The National Inpatient Sample database was accessed for each year across 2002 to 2011. Patients undergoing anterior cervical fusion, posterior cervical fusion, and posterior cervical decompression were identified. Patient and hospitalization parameters including demographics, BMP utilization, costs, early postoperative outcomes, and mortality were assessed for each surgical cohort. A Pearson correlation coefficient with a 95% confidence interval (P < 0.05) was used to analyze trends in patient and hospital outcome parameters during this 10-year period. RESULTS A total of 307,188 cervical spine procedures were performed from 2002 to 2011. Both the anterior cervical fusion and posterior cervical fusion cohort demonstrated a statistically significant increase in the number of procedures performed over time (r = +0.9, P < 0.001). A significant uptrend in patient age (r = +1.0, P < 0.001) and comorbidity burden (r = +0.9, P < 0.001) was demonstrated during the studied decade. Overall, BMP utilization (r = +0.7, P = 0.02) also demonstrated a significant increase during this time period, but demonstrated a decline after peaking in 2007. The posterior cervical fusion cohort demonstrated the greatest comorbidity, length of stay, costs, and mortality. CONCLUSION This study demonstrates that the number of cervical spine procedures has increased between 2002 and 2011, irrespective of the change in BMP utilization after the 2008 Food and Drug Administration warning. Despite an older patient population with greater comorbidities undergoing cervical spine surgeries, hospital length of stay and mortality has not significantly changed. However, we did note a significant increase in costs during this time period. These findings may be related to advances in surgical technology and instrumentation that may be associated with rising hospital costs.

Sagittal alignment of spine and pelvis in asymptomatic adults: norms in Chinese populations.

Abstract: Study design A prospective, cross-sectional study. Objective To investigate the normal values of sagittal spinal and pelvic parameters in Chinese populations and to determine the influence of age, sex, weight, and ethnicity on variations of these parameters. Summary of background data A few studies have been conducted to evaluate the morphology and orientation of pelvis in asymptomatic adults of Caucasian populations. However, there is still a lack of investigation concerning the normal range of spinal and pelvic alignment in Asian populations. Methods A cohort of 260 asymptomatic adult volunteers from Chinese Han populations was prospectively recruited. The following 6 radiological parameters on lateral radiograph were evaluated for each subject, including sacral slope (SS), pelvic tilt, pelvic incidence, thoracic kyphosis, lumbar lordosis, and C7 tilt. Comparisons of these parameters between the male and the female and between Chinese Han populations and Caucasian populations were carried out with Student t tests. The relationships between all parameters and age and weight were assessed using the Pearson correlation analysis. Results The mean values of spinopelvic parameters of the cohort were 44.6 ± 11.2° for pelvic incidence, 11.2 ± 7.8° for pelvic tilt, and 32.5 ± 6.5° for SS, respectively. With the age matched, subjects from Chinese populations were found to have significantly smaller pelvic incidence and SS than those from Caucasian populations. The females were found to have significantly higher lumbar lordosis than the males. Presenting significant but small correlations with age of both male and female adults, thoracic kyphosis and pelvic tilt tended to increase with age, whereas SS had a tendency to decrease with age. Weight was significantly correlated with thoracic kyphosis, SS, and lumbar lordosis. Conclusion The normal values of sagittal spinal and pelvic parameters in Chinese populations could be significantly influenced by age, weight, and sex. Moreover, obvious variations of spinopelvic parameters were found between populations with different ethnicity background. Level of evidence N/A.

Postoperative cervical sagittal imbalance negatively affects outcomes after surgery for cervical spondylotic myelopathy.

Abstract: Study design Prospective observational cohort study. Objective To determine if postoperative cervical sagittal balance is an independent predictor of health-related quality of life outcome after surgery for cervical spondylotic myelopathy. Summary of background data Both ventral and dorsal fusion procedures for CSM are effective at reducing the symptoms of myelopathy. The importance of cervical sagittal balance in predicting overall health-related quality of life outcome after ventral versus dorsal surgery for CSM has not been previously explored. Methods A prospective, nonrandomized cohort of 49 patients undergoing dorsal and ventral fusion surgery for CSM was examined. Preoperative and postoperative C2-C7 sagittal vertical axis was measured on standing lateral cervical spine radiographs. Outcome was assessed with 2 disease-specific measures-the modified Japanese Orthopedic Association scale and the Oswestry Neck Disability Index and 2 generalized outcome measures-the Short-Form 36 physical component summary (SF-36 PCS) and Euro-QOL-5D. Assessments were performed preoperatively, and at 3 months, 6 months, and 1 year postoperatively. Statistical analyses were performed using SAS version 9.3 (SAS Institute). Results Most patients experienced improvement in all outcome measures regardless of approach. Both preoperative and postoperative C2-C7 sagittal vertical axis measurements were independent predictors of clinically significant improvement in SF-36 PCS scores (P = 0.03 and P = 0.02). The majority of patients with C2-C7 sagittal vertical axis values greater than 40 mm did not improve from an overall health-related quality of life perspective (SF-36 PCS) despite improvement in myelopathy. The postoperative sagittal balance value was inversely correlated with a clinically significant improvement of SF-36 PCS scores in patients undergoing dorsal surgery but not ventral surgery (P = 0.03 vs. P = 0.93). Conclusion Preoperative and postoperative sagittal balance measurements independently predict clinical outcomes after surgery for CSM. Level of evidence 2.

Effect of physiological loads on cortical and traditional pedicle screw fixation.

Abstract: Study design Human cadaveric biomechanical study. Objective To determine the fixation strength of laterally directed, cortical pedicle screws under physiological loads. Summary of background data Lateral trajectory cortical pedicle screws have been described as a means of obtaining improved fixation while minimizing soft-tissue dissection during lumbar instrumentation. Biomechanical data have demonstrated equivalent strength in a quasi-static model; however, no biomechanical information is available comparing the fixation of cortical with traditional pedicle screws under cyclic physiological loads. Methods Seventeen vertebral levels (T11-L5) underwent quantitative computed tomography. On 1 side, a laterally directed, cortical pedicle screw was inserted with a traditional, medially directed pedicle screw placed on the contralateral side. With the specimen constrained in a testing apparatus, each screw underwent cyclic craniocaudal toggling under incrementally increasing physiological loads until 2 mm of head displacement occurred. Next, uniaxial pullout of each toggled screw was performed. The number of craniocaudal toggle cycles and load (N) required to achieve pedicle screw movement as well as axial pullout resistance (N) were compared between the 2 techniques. Results The mean trabecular bone mineral density of the specimens was 202 K2HPO4 mg/cm. Cortical pedicle screws demonstrated significantly improved resistance to toggle testing, requiring 184 cycles to reach 2 mm of displacement compared with 102 cycles for the traditional pedicle screws (P=0.002). The force necessary to displace the screws was also significantly greater for the cortical versus the traditional screws (398 N vs. 300 N, P=0.004). There was no statistical difference in axial pullout strength between the previously toggled cortical and traditional pedicle screws (1722 N vs. 1741 N, P=0.837). Conclusion Laterally directed cortical pedicle screws have superior resistance to craniocaudal toggling compared with traditional pedicle screws. Level of evidence N/A.

Risk factors of adjacent segment disease requiring surgery after lumbar spinal fusion: comparison of posterior lumbar interbody fusion and posterolateral fusion.

Abstract: Study design A retrospective study. Objective To determine the incidence and risk factors of adjacent segment disease (ASD) requiring surgery among patients previously treated with spinal fusion for degenerative lumbar disease and to compare the survivorship of adjacent segment according to various risk factors including comparison of fusion methods: posterior lumbar interbody fusion (PLIF) versus posterolateral fusion (PLF). Summary of background data One of the major issues after lumbar spinal fusion is the development of adjacent segment disease. Biomechanically, PLIF has been reported to be more rigid than PLF, and therefore, patients who undergo PLIF are suspected to experience a higher incidence of ASD than those who underwent PLF. There have been many studies analyzing the risk factors of ASD, but we are not aware of any study comparing PLIF with PLF in incidence of ASD requiring surgery. Methods A consecutive series of 490 patients who had undergone lumbar spinal fusion of 3 or fewer segments to treat degenerative lumbar disease was identified. The mean age at index operation was 53 years, and the mean follow-up period was 51 months (12-236 mo). The number of patients treated by PLF and PLIF were 103 and 387, respectively. The incidence and prevalence of revision surgery for ASD were calculated by Kaplan-Meier method. For risk factor analysis, we used log-rank test and Cox regression analysis with fusion methods, sex, age, number of fused segments, and presence of laminectomy adjacent to index fusion. Results After index spinal fusion, 23 patients (4.7%) had undergone additional surgery for ASD. Kaplan-Meier analysis predicted a disease-free survival rate of adjacent segments in 94.2% of patients at 5 years and 89.6% at 10 years after the index operation. In the analysis of risk factors, PLIF was associated with 3.4 times higher incidence of ASD requiring surgery than PLF (P = 0.037). Patients older than 60 years at the time of index operation were 2.5 times more likely to undergo revision operation than those younger than 60 years (P = 0.038). There were no significant differences in survival rates of the adjacent segment according to sex, preoperative diagnosis, number of fused segments, and concomitant laminectomy to adjacent segment. Conclusion It was predicted that 10% of patients would undergo additional surgery for treating ASD within 10 years after index lumbar fusion. In this study, PLIF showed higher incidence of ASD than did PLF. Patient age greater than 60 years was another independent risk factor. Surgeons should carefully consider these factors at the time of surgical planning of lumbar fusion. Level of evidence 3.

Body mass index as a predictor of complications and mortality after lumbar spine surgery

Abstract: Study design Retrospective analysis. Objective A national population-based database was analyzed to characterize the risks of postoperative complications and mortality associated with the patient's body mass index (BMI) after lumbar spinal surgery. Summary of background data Obesity has been associated with greater perioperative complications and worsened surgical outcomes after lumbar spinal surgery. However, the stratified BMI risks of postoperative complications relative to normal weight patients have not been well characterized. Methods The American College of Surgeons National Surgical Quality Improvement Program database was queried to identify patients who underwent lumbar spinal surgery between 2006 and 2011. Patients were stratified into BMI cohorts: normal (18.5-24.99 kg/m), overweight (25.00-29.99 kg/m), class 1 (30.00-34.99 kg/m), class 2 (35.00-39.99 kg/m), and class 3 (≥40 kg/m) obesity. Preoperative patient characteristics and perioperative outcomes were assessed. The relative risks of 30-day postoperative complications and mortality for each BMI cohort were calculated in reference to the normal weight cohort using a 95% confidence interval. Results A total of 24,196 patients underwent lumbar spine surgery between 2006 and 2011 of which 19,195 (79.3%) were overweight or obese. The risk for deep vein thrombosis increased beginning with overweight patients and compounded for the subsequent obesity classes. The risk for superficial wound infection and pulmonary embolism increased beginning with the class 1 obesity cohort. Furthermore, the relative risk increase for urinary tract infection, acute renal failure, and sepsis was significantly increased only among class 3 obesity patients. Lastly, there was no relative risk increase in 30-day mortality in any cohort after lumbar spine surgery. Conclusion Overweight and obese patients demonstrated an increased risk of postoperative complications relative to normal weight patients. Despite these findings, a BMI 25 kg/m or more was not associated with a greater risk of mortality. Further studies are warranted to characterize the impact of postoperative complications associated with overweight and obese patients on hospital resource utilization and costs after lumbar spine surgery.

Psychiatric disorders and major spine surgery: epidemiology and perioperative outcomes.

Abstract: Study Design. Analysis of the National Hospital Discharge Survey database from 1990 to 2007. Objective. To evaluate the influence of preoperative depression, anxiety, schizophrenia, or dementia on in-hospital (1) adverse events, (2) mortality, and (3) nonroutine discharge in patients undergoing major spine surgery. Summary of Background Data. Psychiatric comorbidity is a known risk factor for impaired health-related quality of life and poor long-term outcomes after spine surgery, yet little is known about its impact in the perioperative spine surgery setting. Methods. Using the National Hospital Discharge Survey database, all patients undergoing either spinal fusion or laminectomy between 1990 and 2007 were identified and separated into groups with and without psychiatric disorders. Multivariable regression analysis was performed for each of the outcome variables. Results. Between 1990 and 2007, a total estimated number of 5,382,343 spinal fusions and laminectomies were performed. The prevalence of diagnosed depression, anxiety, and schizophrenia among the study population increased significantly over time. Depression, anxiety, schizophrenia, and dementia were associated with higher rates of nonroutine discharge. Depression, schizophrenia, and dementia were associated with higher rates of adverse events. Dementia was the only psychiatric disorder associated with a higher risk of in-hospital mortality. Conclusion. Patients with preoperative psychiatric disorders undergoing major spine surgery are at increased risk for perioperative adverse events and posthospitalization care, but its effect in perioperative mortality is more limited. Presurgical psychological screening of candidates undergoing spine surgery might ultimately lead to the enhancement of perioperative outcomes in this growing segment of the US population. Conclusion. Level of Evidence: N/A

The National Neurosurgery Quality and Outcomes Database (N2QOD): a collaborative North American outcomes registry to advance value-based spine care.

Abstract: Study design National Prospective Observational Registry. Objective Describe our preliminary experience with the National Neurosurgery Quality and Outcomes Database (NQOD), a national collaborative registry of quality and outcomes reporting after low back surgery. Summary of background data All major health care stakeholders are now requiring objective data regarding the value of medical services. Surgical therapies for spinal disorders have faced particular scrutiny in recent value-based discussions, in large part due to the dramatic growth in the cost and application of these procedures. Reliable data are fundamental to understanding the value of delivered health care. Clinical registries are increasingly used to provide such data. Methods The NQOD is a prospective observational registry designed to establish risk-adjusted expected morbidity and 1-year outcomes for the most common lumbar surgical procedures performed by spine surgeons; provide practice groups and hospitals immediate infrastructure for analyzing their 30-day morbidity and mortality and 3- and 12-month quality data in real-time; generate surgeon-, practice-, and specialty-specific quality and efficacy data; and generate nationwide quality and effectiveness data on specific surgical treatments. Results In its first 2 years of operation, the NQOD has proven to be a robust data collection platform that has helped demonstrate the objective quality of surgical interventions for medically refractory disorders of the lumbar spine. Lumbar spine surgery was found to be safe and effective at the group mean level in routine practice. Subgroups of patients did not report improvement using validated outcome measures. Substantial variation in treatment response was observed among individual patients. Conclusion The NQOD is now positioned to determine the combined contribution of patient variables to specific clinical and patient-reported outcomes. These analyses will ultimately facilitate shared decision making and encourage efficient allocation of health care resources, thus significantly advancing the value paradigm in spine care. Level of evidence 3.

Long-term results of cervical myelopathy due to ossification of the posterior longitudinal ligament with an occupying ratio of 60% or more.

Abstract: STUDY DESIGN Retrospective study. OBJECTIVE We sought to determine the long-term outcomes of laminoplasty versus anterior decompression and fusion in the treatment of cervical myelopathy caused by ossification of the posterior longitudinal ligament (OPLL) and to ascertain what factors should be considered in selecting appropriate surgical procedure. SUMMARY OF BACKGROUND DATA There are little data about long-term results of cervical myelopathy due to OPLL with an occupying ratio 60% or more. METHODS We retrospectively studied 27 patients having OPLL with an occupying ratio 60% or more and a follow-up period of at least 2 years. Clinical outcome was evaluated using Japanese Orthopaedic Association scores and recovery rates (≥75%, excellent; 50%-74%, good; 25%-50%, fair; and <25%, poor). RESULTS The mean age and the mean duration of follow-up were 57 years and 10.2 years. The mean Japanese Orthopaedic Association score was 9.3 before surgery and 12.4 at the final follow-up examination. There were 15 patients in the laminoplasty group (LAM group) and 12 patients in the anterior decompression and fusion group (ADF group). The ADF group had a significantly better recovery rate at final evaluation (53% vs. 30%; P = 0.04), a longer duration of surgery (314 vs. 128 min; P < 0.01), and greater blood loss (600 vs. 240 mL; P < 0.01) than did the LAM group. In the LAM group, 4 patients with excellent or good results had a significantly larger degree of cervical lordosis (30°vs. 10°; P = 0.002) than others. CONCLUSION The ADF group had a significantly better recovery rate than the LAM group, although the degree of surgical invasiveness was high. ADF is generally recommended for OPLL with an occupying ratio 60% or more. LEVEL OF EVIDENCE 3.

Spinal surgery: variations in health care costs and implications for episode-based bundled payments.

Abstract: Study design Retrospective, observational. Objective To simulate what episodes of care in spinal surgery might look like in a bundled payment system and to evaluate the associated costs and characteristics. Summary of background data Episode-based payment bundling has received considerable attention as a potential method to help curb the rise in health care spending and is being investigated as a new payment model as part of the Affordable Care Act. Although earlier studies investigated bundled payments in a number of surgical settings, very few focused on spine surgery, specifically. Methods We analyzed data from MarketScan. Patients were included in the study if they underwent cervical or lumbar spinal surgery during 2000-2009, had at least 2-year preoperative and 90-day postoperative follow-up data. Patients were grouped on the basis of their diagnosis-related group (DRG) and then tracked in simulated episodes-of-care/payment bundles that lasted for the duration of 30, 60, and 90 days after the discharge from the index-surgical hospitalization. The total cost associated with each episode-of-care duration was measured and characterized. Results A total of 196,918 patients met our inclusion criteria. Significant variation existed between DRGs, ranging from $11,180 (30-day bundle, DRG 491) to $107,642 (30-day bundle, DRG 456). There were significant cost variations within each individual DRG. Postdischarge care accounted for a relatively small portion of overall bundle costs (range, 4%-8% in 90-day bundles). Total bundle costs remained relatively flat as bundle-length increased (total average cost of 30-day bundle: $33,522 vs. $35,165 for 90-day bundle). Payments to hospitals accounted for the largest portion of bundle costs (76%). Conclusion There exists significant variation in total health care costs for patients who undergo spinal surgery, even within a given DRG. Better characterization of impacts of a bundled payment system in spine surgery is important for understanding the costs of index procedure hospital, physician services, and postoperative care on potential future health care policy decision making. Level of evidence N/A.

Intraoperative vancomycin use in spinal surgery: single institution experience and microbial trends.

Abstract: Study design Retrospective case series. Objective To demonstrate the microbial trends of spinal surgical site infections in patients who had previously received crystallized vancomycin in the operative bed. Summary of background data Prior large, case control series demonstrate the significant decrease in surgical site infection with the administration of vancomycin in the wound bed. Methods A single institution, electronic database search was conducted for all patients who underwent spinal surgery who had received prophylactic crystalline vancomycin powder in the wound bed. Patients with a prior history of wound infection, intrathecal pumps, or spinal stimulators were excluded. Results A total of 981 consecutive patients (494 males, 487 females; mean age, 59.4 yr; range, 16-95 yr) were identified from January 2011 to June 2013. The average dose of vancomycin powder was 1.13 g (range, 1-6 g). Sixty-six patients (6.71%) were diagnosed with a surgical site infection, of which 51 patients had positive wound cultures (5.2%). Of the 51 positive cultures, the most common organism was Staphylococcus aureus. The average dose of vancomycin was 1.3 g in the 38 cases where a gram-positive organism was cultured. A number of gram-negative infections were encountered such as Serratia marcescens, Enterobacter aerogenes, Bacteroides fragilis, Enterobacter cloacae, Citrobacter koseri, and Pseudomonas aeruginosa. The average dose of vancomycin was 1.2 g in 23 cases where a gram-negative infection was cultured. Fifteen of the 51 positive cultures (29.4%) were polymicrobial. Eight (53%) of these 15 polymicrobial cultures contained 3 or more distinct organisms. Conclusion Prophylactic intraoperative vancomycin use in the wound bed in spinal surgery may increase the incidence of gram-negative or polymicrobial spinal infections. The use of intraoperative vancomycin may correlate with postoperative seromas, due to the high incidence of nonpositive cultures. Large, randomized, prospective trials are needed to demonstrate causation and dose-response relationship.

Predictors of postoperative pain trajectories in adolescent idiopathic scoliosis.

Abstract: STUDY DESIGN Prospective observational study. OBJECTIVE To determine the typical trajectory of pain during the first 6 months after spinal fusion surgery for adolescent idiopathic scoliosis (AIS) and the extent to which certain demographic, medical, and psychological variables modify this trajectory. SUMMARY OF BACKGROUND DATA Pain after spinal fusion surgery for AIS may not improve predictably with elapsed healing time, and limited data exist on predictors of the course of pain during the initial months after surgery. METHODS Fifty patients ages 11 to 17 (mean = 14.5, standard deviation = 1.9) with AIS and undergoing posterior spinal fusion surgery comprised the study sample. Pain outcomes were assessed at 4 time points after surgery (2-week, 6-week, 3-month, and 6-month postsurgery). Preoperative predictor variables comprising demographics, baseline Cobb angle, body mass index, baseline pain, and psychological variables (anxiety, negative mood, and confidence in ability to control pain) were assessed 2 weeks before surgery. Perioperative predictor variables comprising pain, pain coping efficacy, negative mood, surgery length, length and lowest level of fusion, and analgesic use were assessed by self-report or record review. Multilevel growth models were used to evaluate hypotheses pertaining to predictors of pain trajectories. RESULTS Pain level on average declined predictably with days since surgery (b = -0.14 to -0.19, P < 0.01). For 22% of adolescents, pain was at or above baseline levels through 6 months after surgery. Greater baseline pain and anxiety predicted slower improvement in pain, whereas greater confidence in ability to control pain predicted more rapid declines in pain. None of the demographic or medical variables reliably modified postsurgical pain trajectories. CONCLUSION Although pain typically declines predictably with healing time from spinal fusion surgery for AIS, higher preoperative levels of pain and anxiety may be risk factors for chronic postsurgical pain whereas greater pain coping efficacy may help optimize postsurgical pain outcomes. LEVEL OF EVIDENCE 3.

T1 pelvic angle (TPA) effectively evaluates sagittal deformity and assesses radiographical surgical outcomes longitudinally.

Abstract: Study design Retrospective review of a multicenter database of consecutive patients undergoing 3-column osteotomy for treatment of adult spinal deformity (ASD). Objective To rigorously develop a T1 pelvic angle (TPA) categorization paradigm and use it to assess the surgical management of patients with ASD. Summary of background data TPA, the angle between the hips-T1 line and hips-S1 endplate line, is a novel spinopelvic parameter that assesses the combined effect of a loss of lordosis on trunk inclination and pelvic retroversion. Methods A prospective, multicenter database of consecutive patients with ASD was queried to identify the severe deformity threshold and meaningful change values for TPA by correlation with Oswestry Disability Index. A separate multicenter, consecutive, retrospective database of patients with ASD treated with single lumbar 3-column osteotomy was then analyzed at baseline, 3-month, and 1-year follow-up. Subjects were classified into well-aligned or poorly aligned groups at 3 months on the basis of TPA. Patients "deteriorated" if they lost more than 1 meaningful change in TPA between 3 months and 1 year and had TPA more than deformity threshold at 1 year. Results The severe deformity threshold for TPA was 20° (Oswestry Disability Index > 40) and the meaningful change was 4.1° (Oswestry Disability Index change = 15). Review of the 3-column osteotomy database identified 179 patients with preoperative severe deformity; 63 were well-aligned (TPA 20°) at 3-month follow-up. This newly developed TPA categorization mechanism grouped patients in a manner comparable with the Scoliosis Research Society-Schwab Classification. Subjects who were well-aligned at 3 months had less severe baseline deformity, but received more correction, than poorly aligned subjects. Four well-aligned patients and 13 poorly aligned patients deteriorated between 3 months and 1 year after surgery. Conclusion TPA accounts for sagittal vertical axis and pelvic tilt and shows great promise as a classification tool. Longitudinal analysis demonstrated undercorrection among patients with more severe preoperative deformity. We propose a surgical target of 10° for TPA. Level of evidence 4.