Faculty Bibliography

BACKGROUND CONTEXT: Adult spinal deformities (ASD) are disabling conditions. Surgical management of ASD has demonstrated effectiveness in clinical outcome scores. Despite this, the surgical management has come under fire within the landscape of escalating healthcare expenditure due to the cost of acute management. A cost-utility analysis of operative ASD patients comparing pre-operative and post-operative outcome scores has never been performed. PURPOSE: To determine the potential for cost-effectiveness in the surgical correction of ASD. STUDY DESIGN/SETTING: Review of prospectively collected data and application of cost-utility analysis. PATIENT SAMPLE: Adult patients diagnosed with a spinal deformity and treated with anterior, posterior, or combined spinal fusion. OUTCOME MEASURES: Primary outcome measures included patientcentered outcome scores (SRS 23 and Oswestry Disability Index), utility values, and treatment costs. METHODS: 233 patients undergoing primary surgery for ASD including Idiopathic Scoliosis (IS, n5189), Degenerative Scoliosis (DS, n539) and Congenital Scoliosis (CS, n55) were reviewed. We report pre and postoperative outcome scores (SRS, ODI) with 2 year follow-up. Quality Adjusted Life Years (QALYs) were calculated based on reported regression formulas. Medicare DRG hospital and CPT physician (Surgeon, Anesthesia and Neuromonitoring) re-imbursement codes were used to establish an acute care cost (ACC). The ACC and QALY values were used to perform a cost-utility analysis of the operative intervention for ASD. RESULTS: DS patients were significantly older (62.2) vs IS (47.9) but not CS (44.2). Height and weight were similar. DS patients were more likely to have osteoarthritis, leg pain, and leg pain with ambulation (p<.05). IS patients had a significantly lower pre-op ODI and a higher corresponding utility score vs DS patients. Pre-operative SRS scores were similar. At 2 year follow-up, all groups improved on ODI and in each domain of SRS. The only significant difference on SRS was higher mental health scores in DS vs IS. Post-operative utility values were similar. Total QALYs gained at 2 years were significantly greater for DS (0.20) vs IS (0.12), but not vs CS (0.11). Total reimbursements averaged <=35,883, <=37,482, and <=38,787, respectively. At 2 years, the cost/QALY was <=299,025 for IS, <=187,410 for DS, and <=352,609 for CS. Single revision surgery rate within 2 years was 20.6% and multiple revisions was 3.9%. CONCLUSIONS: Our results confirm that surgical correction improves patient outcome in ASD. High ACC of ASD correction has cost-effectiveness ratios above accepted thresholds (O<=50,000) at short-term follow-up. The durability of surgical correction may bring the cost of treatment into an accepted range with long-term follow-up. A thought experiment estimating outpatient expenditure and revision surgery cost over a 10-year followup will be demonstrated. Non-operative patients are unlikely to improve on outcome scores while operative patients likely maintain their improvement despite relatively high revision rates. The possible result is an economic benefit of surgical management when considered over the patient's lifetime

BACKGROUND CONTEXT: Laminectomy and posterior spinal fusion are commonly performed for patients with degenerative spondylolisthesis and spinal stenosis with significant low back pain. Long-term untoward sequelae of lumbar fusion have led to the search for motion-preserving, lessinvasive alternatives. PURPOSE: To evaluate the safety and efficacy of the coflex interlaminar device compared to posterior spinal fusion in the treatment of 1- and 2- level spinal stenosis and degenerative spondylolisthesis. STUDY DESIGN/SETTING: Prospective, randomized, multicenter FDA IDE trial comparing direct decompression and coflex interlaminar stabilization with laminectomy and posterior spinal fusion. PATIENT SAMPLE: 219 patients (146 coflex and 73 fusion controls) were randomized and treated from 21 sites in the United States to receive direct decompression and coflex interlaminar stabilization or laminectomy and posterolateral spinal fusion with spinal instrumentation in a 2:1 ratio. OUTCOME MEASURES: Perioperative data, ODI, VAS Back, VAS (worse) Leg, SF-12, ZCQ, and radiographic outcomes at minimum 2 years. Overall device success was a composite ofO15-point reduction in ODI, no reoperations, no major device-related complications, and no post-operative epidural injections. METHODS: Study inclusion consisted of moderate spinal stenosis with significant low back pain (VAS Back Pain <=50/100) and significant disability (ODI<=40%), with up to Grade I spondylolisthesis, at spinal segments from L1-L5. Data were collected preoperatively, then at 6 week, 3 month, 6 month, 12 month, 18 month, and 24 month time points. RESULTS: Patient follow-up at a minimum of 2 years was 96.6% and 98.6% for coflex and fusion control groups, respectively. There were no group differences at baseline in any demographic, clinical, or radiographic parameter. Coflex patients experienced significantly shorter operative times (p<.0001), estimated blood loss (p<.0001), and length of stay (p<.0001) compared with to fusion controls. At 2 years, mean ODI scores were significantly better in the coflexcohort (p<.021) with a trend towards a greater proportion achieving a 15-point reduction in ODI (p<.06). Both groups demonstrated significant improvement in all VAS Back and Leg parameters. Coflex patients had significantly greater improvement in SF-12 Physical Health outcomes (p<.027) and similar Mental Health outcomes. Coflex subjects had greater improvement in all ZCQ outcomes compared with fusion (Symptom Severity (p<.013); Physical Function (p<.013); Satisfaction (p5025)). Based on the stringent FDA composite for overall success, 66.4% of coflex and 59.7% of fusions succeeded, respectively. The overall complication rate was similar between the groups. At 2 years fusion controls exhibited significantly increased sagittal plane translation (p<.05) and angulation (p<.0001) at the superior adjacent level, while coflexmaintained normal operative and adjacent level motion. CONCLUSIONS: Our results demonstrate safety, efficacy, and noninferiority of decompression followed by coflex interlaminar stabilization compared to fusion in the treatment of spinal stenosis and degenerative spondylolisthesis. Coflex stabilization led to significantly improved perioperative outcomes, multiple clinical outcomes measures, and maintenance of motion at operative and adjacent levels compared with fusion at 2 years. Coflex interlaminar stabilization is a safe and efficacious alternative, and provides several distinct advantages over lumbar spinal fusion with pedicle screw instrumentation

BACKGROUND CONTEXT: Anti-fibrinolytics have been proven effective in reducing intra-operative blood loss in several settings. However, their value in Adolescent Idiopathic Scoliosis (AIS) remains unclear. No previous study has compared tranexamic acid (TXA), epsilon aminocaproic acid (EACA), and placebo in regards to their ability to limit operative blood loss, post-operative drain output, and transfusion rate. PURPOSE: To determine the efficacy of intra-operative anti-fibrinolytics at reducing peri-operative blood loss and transfusion rate in patients with adolescent idiopathic scoliosis undergoing posterior spinal fusion of at least 5 levels. STUDY DESIGN/SETTING: Prospective, double-blind, randomized clinical trial. PATIENT SAMPLE: Patients between the ages of 10-21 with a diagnosis of adolescent idiopathic scoliosis treated with posterior spinal fusion of at least five levels were prospectively enrolled. OUTCOME MEASURES: Primary outcome measures include estimated blood loss, drain output, total blood loss, and transfusion rate. Secondary outcome measures include pre-, intra-, and post-operative hematocrit, duration of surgery, complications, and length of hospital stay. METHODS: This is a prospective, randomized, double-blind comparison of TXA, EACA and placebo used intra-operatively in patients with AIS. 119 AIS patients were randomly assigned to TXA, EACA, or control. TXA was administered at 10 mg/ kg for a loading dose followed by 1 mg/kg-hr, while EACA was given at a 10 fold higher dose. Parameters recorded included estimated blood loss (EBL), pre, intra and post-operative hematocrit, blood product usage, post-operative drain output, and total blood loss. RESULTS: 119 patients were randomized to TXA (n535), EACA (n538), or placebo (n546). There were 93 females and 26 males, average age 15. Most pre-operative characteristics were similar, however saline patients had significantly greater height, weight, and estimated blood volume vs TXA (p<.05). TXA patients had significantly lower hematocrit at anesthesia start vs saline (33.2 vs 35.7, p<.05). There was no difference in transfusion rate, duration of surgery, levels fused, or anchors placed. When controlling for mean arterial pressure (MAP) during exposure, TXA reduced EBL vs saline (p<.05), and reduced total blood loss, total blood loss per anchor, and total blood loss per degree of curve vs saline (p<.05). Additionally, EACA reduced EBL per anchor vs saline in patients with reduced mean exposure MAP (p<.05). Neither TXA nor EACA reduced EBL or total blood loss in patients with mean exposure MAPO75. While total drain output was not reduced for TXA or EACA vs saline, TXA showed reduced drain output per anchor and degree curve (p<.05) compared to saline. CONCLUSIONS: Our results suggest that anti-fibrinolytics safely reduce blood loss in patients with AIS. However, transfusion rates were not impacted. Further, mean arterial pressure during surgical exposure appears to be a critical factor in the efficacy of anti-fibrinolytic action

BACKGROUND CONTEXT: The use of a postoperative spinal drain for spine surgery patients is widely thought to increase the risk of postoperative infection. While antibiotics are commonly given postoperatively to decrease bacterial seeding of the hematoma, the duration of postoperative antibiotics is more debatable, and protocols may vary. PURPOSE: To determine if the continuation of postoperative antibiotics for the duration of the timea spinal drain is in place reduces the risk of acute surgical site infection, in comparison with postoperative antibiotics given for 24 hours only. STUDY DESIGN/SETTING: Prospective, randomized double-blind study. PATIENT SAMPLE: Patients undergoing multilevel thoracolumbar spine surgery in which a drain is used. OUTCOME MEASURES: Surgical site infections were defined as purulent drainage; organisms obtained from an aseptically obtained culture; pain, swelling and redness; and/or diagnosis of infection by a surgeon. METHODS: 315 patients who underwent multilevel thoracolumbar spine surgery requiring a postoperative drain were enrolled and randomized into two groups: one group receiving 24 hours of perioperative antibiotics and one group receiving antibiotics for the duration that the drain was in place. Data collected included demographics, medical co-morbidities, type of spine surgery and surgical site infection. RESULTS: 13/170 (7.6%) in the 24 hours of antibiotic group developed a surgical site infection while 21/145 (14.5%) in the antibiotic for the duration of the drain were found to have a surgical site infection. The differences between each group were significant (p<.05). There were no significant differences between the groups with respect to demographics, surgical time, type of surgery, drain output or length of stay. CONCLUSIONS: Continuing postoperative antibiotics for the entire duration a drain is in place after spine surgery does not decrease the rate of surgical site infections

BACKGROUND: Traditional surgical treatment of isthmic spondylolisthesis is posterior-lateral fusion, but the addition of anterior surgery has been explored. The purpose of this study was to evaluate the surgical and clinical outcomes of anterior-posterior surgical treatment for low-grade isthmic spondylolisthesis. METHODS: Retrospectively, we enrolled 23 consecutive patients (mean age of 50) who underwent surgical treatment for low grade isthmic spondylolisthesis. The mean follow-up was 10 months. Basic demographic and radiographic data was collected. Pre- and post-surgical clinical surveys (VAS, ODI, and SF-36) were collected. RESULTS: All 23 patients underwent anterior interbody fusion with a femoral ring allograft or ICBG in combination with posterior lumbar decompression and fusion with instrumentation. The average slip percentage decreased from 23.2% to 19.0% (p = 0.24) while slip angle increased from 9.8 degrees to 17.9 degrees (p < 0.001) and average disc height decreased from 1.9 cm to 0.80 cm (p < 0.001). VAS scores decreased from 7.1 to 2.4 (p < 0.001), ODI scores decreased from 52.5 to 28.1 (p < 0.001), and SF-36 scores increased in the Physical Component Scale (PCS) from 29.5 to 42.6 (p < 0.001). CONCLUSION: In our study, patients demonstrated an improvement in the ODI as well the physical component scores of the SF-36, thus having a good clinical outcome.

BACKGROUND: Although achieving clinical success is the main goal in the surgical treatment of adolescent idiopathic scoliosis, it is becoming increasingly important to do so in a cost-effective manner. The goal of the present study was to determine the surgical and hospitalization costs, charges, and reimbursements for adolescent idiopathic scoliosis correction surgery at one institution. METHODS: We performed a retrospective review of 16,536 individual costs and charges, including overall reimbursements, for 125 consecutive patients who were managed surgically for the treatment of adolescent idiopathic scoliosis by three different surgeons between 2006 and 2007. Demographic, surgical, and radiographic data were recorded for each patient. Stepwise multiple linear regression analysis was employed to assess independent correlation with total cost and charge. Nonparametric descriptive statistics were calculated for total cost with use of the Lenke curve-classification system. RESULTS: The mean age of the patients was 15.2 years. The mean main thoracic curve measured 50 degrees, and the thoracolumbar curve measured 41 degrees. The cost varied with Lenke curve type: $29,955 for type 1, $31,414 for type 2, $31,975 for type 3, $60,754 for type 4, $32,652 for type 5, and $33,416 for type 6. Independently significant increases for total cost were found in association with the number of pedicle screws placed, the total number of vertebral levels fused, and the type of surgical approach (R(2) = 0.35, p <or= 0.03). Independently significant increases for reimbursement were found in association with the number of pedicle screws placed and the type of surgical approach (R(2) = 0.12, p <or= 0.02). The hospital was reimbursed 53% of total charges and 120% of total costs. Reimbursement was highly correlated with charge (r = 0.45, p < 0.001). For rehospitalizations, the hospital was reimbursed 65% of charges and 93% of costs. CONCLUSIONS: The largest contributors to overall cost were implants (29%), intensive care unit and inpatient room costs (22%), operating room time (9.9%), and bone grafts (6%). There were three significant independent predictors of increased total cost: the surgical approach used, the number of pedicle screws placed, and the number of vertebral levels fused. This study characterizes the relative contributions of factors that contribute to total costs, charges, and reimbursements that can, in time, identify potential areas for cost reduction or redistribution of resources in the surgical treatment of adolescent idiopathic scoliosis

BACKGROUND: Multilevel spinal fusion surgery has typically been associated with significant blood loss. To limit both the need for transfusions and co-morbidities associated with blood loss, the use of anti-fibrinolytic agents has been proposed. While there is some literature comparing the effectiveness of tranexamic acid (TXA) to epsilon aminocaproic acid (EACA) in cardiac procedures, there is currently no literature directly comparing TXA to EACA in orthopedic surgery. METHODS/DESIGN: Here we propose a prospective, randomized, double-blinded control study evaluating the effects of TXA, EACA, and placebo for treatment of adolescent idiopathic scoliosis (AIS), neuromuscular scoliosis (NMS), and adult deformity (AD) via corrective spinal surgery. Efficacy will be determined by intraoperative and postoperative blood loss. Other clinical outcomes that will be compared include transfusion rates, preoperative and postoperative hemodynamic values, and length of hospital stay after the procedure. DISCUSSION: The primary goal of the study is to determine perioperative blood loss as a measure of the efficacy of TXA, EACA, and placebo. Based on current literature and the mechanism by which the medications act, we hypothesize that TXA will be more effective at reducing blood loss than EACA or placebo and result in improved patient outcomes. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT00958581

STUDY DESIGN: A subanalysis study. OBJECTIVE: The purpose of this study was to determine the impact of multilevel lumbar stenosis with or without degenerative spondylolisthesis compared to single level disease on patients' baseline symptoms and clinical outcomes over time. SUMMARY OF BACKGROUND DATA: Previous studies have demonstrated better clinical outcomes with surgery than nonoperative treatment in patients with spinal stenosis with or without degenerative spondylolisthesis. However, the impact of multilevel stenosis has not been studied in these patients. METHODS: The results from a multicenter randomized and observational study, the Spine Patient Outcomes Research Trial (SPORT) comparing surgical versus nonoperative treatment for spinal stenosis with or without spondylolisthesis, were analyzed. The primary outcomes measures were the Bodily Pain and Physical Function scales of the Medical Outcomes Study 36-item Short-Form General Health Survey (SF-36) and the modified Oswestry Disability Index at 6 weeks, 3 months, 6 months, 1 year, and 2 years. Secondary outcome measures included the stenosis bothersomeness index, leg pain bothersomeness, low back pain bothersomeness, and patient satisfaction. RESULTS: In this subanalysis of SPORT data, multilevel spinal stenosis did not demonstrate worse baseline symptoms or worse treatment outcomes in isolated spinal stenosis; however, if concomitant degenerative spondylolisthesis existed, patients with only single level stenosis tended to improve more than those with multilevel stenosis, particularly after surgery. CONCLUSION: Patients with spinal stenosis without associated degenerative spondylolisthesis or scoliosis can be managed nonoperatively irrespective of the number of levels involved. If surgery is performed, the number of levels treated does not predict outcome. In contrast, patients with concomitant degenerative spondylolisthesis and single level stenosis do better surgically than those with additional levels of stenosis. This study emphasizes the importance of shared decision-making between the physician and patient when considering treatment for spinal stenosis.

STUDY DESIGN: Retrospective review. OBJECTIVE: The purpose of this study was to assess the preoperative neurologic risk in a consecutive series of spinal deformity patients undergoing correction surgery at one institution. SUMMARY OF BACKGROUND DATA: During spinal deformity correction surgery, neurologic monitoring techniques are commonly applied to reduce the risk of neurologic deficits. While previous studies have demonstrated risk factors for neurologic changes in the setting of spinal surgery, these involved long time spans and heterogeneous patient populations. METHODS: Of 301 cases performed over 1 year, 281 cases were monitorable. Patients were grouped according to diagnosis: neuromuscular (NM) scoliosis, Sagittal Plane deformity, and Scoliosis. Demographic and surgical data were collected for neurologically monitorable patients. Coronal and sagittal parameters were measured using digital images of radiographs. Neurologic status was measured with somatosensory-evoked potentials and/or motor-evoked potentials. RESULTS: Primary NM scoliosis cases had the highest incidence of neurologic monitoring changes (NMC) (10%) while revision sagittal plane deformity had the second highest (9.8%). Sensitivity and specificity were both 100%. Overall incidence of neurologic deficit was 1.1%. Of the 13 NMCs patients, 3 patients had persistent neurologic deficit. Majority of NMCs occurred before deformity correction. In patients with NM scoliosis, NMCs increased with hybrid constructs with wires (P < 0.01). In patients with scoliosis, NMCs increased with increased body mass index, estimated blood loss, operative time, and postoperative coronal thoracolumbar curve magnitude (P < 0.04). In patients with primarily sagittal plane deformity, NMCs increased with preoperative proximal curve, postoperative proximal and thoracolumbar curves, and postoperative kyphosis and lordosis (P < 0.04). CONCLUSION: Primary NM scoliosis and revision sagittal plane deformities appear to carry greatest incidence of NMCs during surgical intervention. Most observed NMCs did not result in a permanent neurologic deficit. Neuromonitoring should be assessed throughout the entire surgical procedure. This study may aid surgeons and patients to better assess neurologic risks related to spinal deformity surgery