Faculty Bibliography

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

BACKGROUND: The purpose of this study was to determine the indications for implantation of the coflex device (Paradigm Spine, LLC, New York, New York), assess long-term complications, and evaluate the long-term clinical outcomes of patients. METHODS: A total of 127 patients underwent placement of a coflex implant for various indications by one orthopaedic spine surgeon. The mean follow-up was 6.3 years. The original indications for implantation were determined based upon the data provided in the case report forms. Preoperatively and postoperatively, patients were asked to grade their low-back and leg pain using the visual analog scale (VAS) and the pain severity scale: no pain (0), mild pain (1), moderate pain (2), or severe pain (3). Patients were queried about their satisfaction with the surgical procedure. Follow-up radiographs were taken to determine any device-related issues. RESULTS: The most prevalent diagnoses for implantation were spinal stenosis (19.7%) and spinal stenosis with lumbar disc herniation (35.4%). The mean severity of low-back pain was decreased by 33% (from moderate to mild) at the 2-year follow-up (P < .001) and at the 5-year follow-up (from moderate to mild, P < .001). The mean severity of leg pain was decreased by 66% (from severe to mild) at the 2-year follow-up (P < .001) and at the 5-year follow-up (from severe to mild, P < .001). At the mean follow-up period of 6.3 years, a patient satisfaction query demonstrated that 7% were unsatisfied, 46% were satisfied, and 46% were very satisfied with their clinical outcome. Based on the follow-up radiographs, 92 of patients had no devicerelated issues and 8% had device-related issues. CONCLUSION: The data provided have demonstrated that the coflex implant provides pain relief for patients with low-back pain and leg pain. The most common indications for implantation were spinal stenosis and spinal stenosis with lumbar disc herniation. There were very few device-related complications. CLINICAL SIGNIFICANCE: Using coflex is a safe and viable option in the selection of instrumentation for spinal stabilization.

STUDY DESIGN: Biomechanical study of bovine spines. OBJECTIVE: The purpose of this study was to perform a biomechanical test to analyze intervertebral deflections following placement of both 1 and 2 semiconstrained TDRs in the subjacent segments of a long fusion. SUMMARY OF BACKGROUND DATA: Long-term sequela of long lumbar fusion for scoliosis include adjacent segment disease and flatback syndrome. Total disc replacement (TDR) is a viable option for the treatment of these conditions. Little data has been published regarding the placement of a TDR distal to a scoliosis fusion. METHODS: Six thoracolumbar bovine spines (T12-S1) were instrumented from T12 to L5, with bilateral pedicle screw fixation at each level. L5-L6 and L6-S1 served as the test levels. One TDR (FlexiCore, Stryker Spine, Allendale, NJ) was initially performed adjacent to the fusion, followed by a subsequent TDR insertion at the last spinal segment. The applied load, total specimen deflection, and local transducer deflections were recorded before and after a TDR at both levels. The results were expressed as a percentage of the intact specimen. Flexion, extension, lateral bending, and torsional deflections were recorded. RESULTS: There were no significant differences (P > 0.05) in sensor deflection observed at the L5-L6 and L6-S1 levels in the anterior and lateral transducers when compared to intact spines specimens. A similar effect was observed at the L5-L6 and L6-S1 levels in the anterior and lateral transducers when compared to intact or prior L5-L6 and intact L6-S1 constructs. CONCLUSION: This study has shown that using the FlexiCore system at 1 and/or 2 intervertebral disc spaces caudal to a scoliosis fusion model did not significantly change the sensor deflection at the 2 segments adjacent to a scoliosis fusion construct. Future research will continue to define the clinical setting and patients best suited for management by TDR systems