Kushagra Verma

Rate of Adjacent Segment Disease in Cervical Disc Arthroplasty Versus Single-Level Fusion Meta-analysis of Prospective Studies

Study Design. Meta-analysis of randomized controlled trials. Objective. To compare the reported incidence of adjacent segment disease (ASD) requiring surgical intervention between anterior cervical decompression and fusion (ACDF) and total disc arthroplasty (TDA). Summary of Background Data. The concern for ASD has led to the development of motion-preserving technologies such as TDA. To date, however, no known study has sought to compare the incidence of ASD between ACDF and TDA in major prospective studies. Methods. A systematic review of IDE and non-IDE trials was performed using PubMed and Cochrane libraries. These databases were thoroughly searched for prospective randomized studies comparing ACDF and TDR. Six studies met the inclusion criteria for a meta-analysis and were used to report an overall rate of ASD for both ACDF and TDA. Results. Pooling data from 6 prospective studies, the overall sample size at baseline was 1586 (ACDF = 777, TDA = 809) and at the final follow-up was 1110 giving an overall follow-up of 70%. Patients after an ACDF had a lower rate of follow-up overall than those after TDR (ACDF: 67.3% vs. TDR: 72.6%, P= 0.01). Thirty-six patients required adjacent-level surgery after an ACDF at 2 to 5 years of follow-up (6.9%) compared with 30 patients after a TDA (5.1%). The corresponding reoperation rate for ASD was 2.4 ± 1.7% per year for ACDF versus 1.1 ± 1.5% per year for TDR. These differences were not statistically significant (P= 0.44). Using a Kaplan-Meier analysis and historical data, we expect 48 patients in the ACDF group and 55 patients in the TDR group to have symptomatic disease at an adjacent level. Conclusion. From a meta-analysis of prospective studies, there is no difference in the rate of ASD for ACDF versus TDA. We also report an overall lower rate of follow-up for patients with ACDF than for those with TDR. Future prospective studies should continue to focus on excellent patient follow-up and accurate assessment of patient symptoms that are attributable to an adjacent level as this has been an under-reported finding in prospective studies. Level of Evidence: 1

Predicting operative blood loss during spinal fusion for adolescent idiopathic scoliosis.

Background: Patient and surgical factors are known to influence operative blood loss in spinal fusion for adolescent idiopathic scoliosis (AIS), but have only been loosely identified. To date, there are no established recommendations to guide decisions to predonate autologous blood, and the current practice is based primarily on surgeon preference. This study is designed to determine which patient and surgical factors are correlated with, and predictive of, blood loss during spinal fusion for AIS. Methods: Retrospective analysis of 340 (81 males, 259 females; mean age, 15.2 y) consecutive AIS patients treated by a single surgeon from 2000 to 2008. Demographic (sex, age, height, weight, and associated comorbidities), laboratory (hematocrit, platelet, PT/PTT/INR), standard radiographic, and perioperative data including complications were analyzed with a linear stepwise regression to develop a predictive model of blood loss. Results: Estimated blood loss was 907±775 mL for posterior spinal fusion (PSF, n=188), 323±171 mL for anterior spinal fusion (ASF, n=124), and 1277±821 mL for combined procedures (n=28). For patients undergoing PSF, stepwise analysis identified sex, preoperative kyphosis, and operative time to be the most important predictors of increased blood loss (P<0.05). For ASF, the mean arterial pressure at incision and the operative time were predictive (P<0.05). The following formula was developed to estimate blood loss in PSF: blood loss (mL)=C+Op-time (min)×(6.4)−pre-op T2-T12 kyphosis (degrees)×(8.7), C=233 if male and −270 if female. Conclusion: We find sex, operative time, and preoperative kyphosis to be the most important predictors of increased blood loss in PSF for AIS. Mean arterial pressure and operative time were predictive of estimated blood loss in ASF. For posterior fusions, we also present a model that estimates blood loss preoperatively and can be used to guide decisions regarding predonation of blood and the use of antifibrinolytic agents. Level of Evidence: Retrospective study: Level II.

The relative efficacy of antifibrinolytics in adolescent idiopathic scoliosis: a prospective randomized trial.

BACKGROUND Antifibrinolytics can reduce intraoperative blood loss. The primary aim of this study was to determine the efficacy of intraoperative tranexamic acid, epsilon-aminocaproic acid, and placebo at reducing perioperative blood loss and the transfusion rate in patients with adolescent idiopathic scoliosis undergoing posterior spinal arthrodesis. METHODS This is a prospective, randomized, double-blind comparison of tranexamic acid, epsilon-aminocaproic acid, and placebo used intraoperatively in patients with adolescent idiopathic scoliosis. One hundred and twenty-five patients with adolescent idiopathic scoliosis were randomly assigned to the tranexamic acid, epsilon-aminocaproic acid, or control groups. Parameters recorded included estimated blood loss, hematocrit, blood product usage, drain output, and total blood losses. The primary outcomes were intraoperative blood loss and postoperative drainage. Secondary outcomes were transfusion requirements and hematocrit changes both intraoperatively and postoperatively. RESULTS One hundred and twenty-five patients (ninety-seven female and twenty-eight male, with a mean age of fifteen years) were randomized to receive tranexamic acid (thirty-six patients), epsilon-aminocaproic acid (forty-two patients), or saline solution (forty-seven patients). The groups were similar at baseline, with one exception: the saline solution group had a higher estimated blood volume at baseline than the tranexamic acid group. Both tranexamic acid and epsilon-aminocaproic acid reduced the estimated blood loss per degree and estimated blood loss per pedicle screw. Epsilon-aminocaproic acid, but not tranexamic acid, reduced estimated blood loss and estimated blood loss per level. Tranexamic acid also reduced total blood losses compared with epsilon-aminocaproic acid or saline solution. In an analysis controlling for level, degree, and number of anchors, tranexamic acid reduced drain output and total blood losses. Tranexamic acid or epsilon-aminocaproic acid had a smaller decrease in hematocrit postoperatively. In an analysis controlling for the mean arterial pressure during surgical exposure, tranexamic acid reduced estimated blood loss and total blood losses. Overall, antifibrinolytics (tranexamic acid or epsilon-aminocaproic acid) reduced estimated blood loss, total blood losses, and the decline in hematocrit postoperatively compared with saline solution. There was no difference among the groups with respect to the transfusion rate, duration of surgery, levels fused, or pedicle screws placed. CONCLUSIONS Tranexamic acid and epsilon-aminocaproic acid reduced operative blood loss but not transfusion rate. Tranexamic acid is more effective at reducing postoperative drainage and total blood losses compared with epsilon-aminocaproic acid. Maintenance of the mean arterial pressure at <75 mm Hg during surgical exposure appears to be critical for maximizing antifibrinolytic benefit. LEVEL OF EVIDENCE Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Antifibrinolytics reduce blood loss in adult spinal deformity surgery: a prospective, randomized controlled trial.

Study Design. This is a prospective, randomized, double-blinded comparison of tranexamic acid (TXA), epsilon aminocaproic acid (EACA), and placebo used intraoperatively in patients with adult spinal deformity. Objective. The purpose of this study was to provide high-quality evidence regarding the comparative efficacies of TXA, EACA, and placebo in reducing blood loss and transfusion requirements in patients undergoing posterior spinal fusion surgery. Summary of Background Data. Spine deformity surgery usually involves substantial blood loss. The antifibrinolytics TXA and EACA have been shown to improve hemostasis in large blood loss surgical procedures. Methods. Fifty-one patients undergoing posterior spinal fusion of at least 5 levels for correction of adult spinal deformity were randomized to 1 of 3 treatment groups. Primary outcome measures included intraoperative estimated blood loss, total loss, (estimated blood loss + postoperative blood loss), and transfusion rates. Results. Patients received TXA (n = 19), EACA (n = 19), or placebo (n = 13) in the operating room (mean ages: 60, 47, and 43 yr, respectively); TXA patients were significantly older and had larger estimated blood volumes than both other groups. Total losses were significantly reduced for EACA versus control, and there was a demonstrable but nonsignificant trend toward reduced intraoperative blood loss in both antifibrinolytic arms versus control. EACA had significant reductions in postoperative blood transfusions versus TXA. Conclusion. The findings in this study support the use of antifibrinolytics to reduce blood loss in posterior adult spinal deformity surgery. Level of Evidence: 1

Maximal pulmonary recovery after spinal fusion for adolescent idiopathic scoliosis: how do anterior approaches compare?

Study Design. Retrospective analysis of prospectively collected data. Objective. To compare the relative rates of pulmonary recovery and maximal pulmonary function with surgical approach. Summary of Background Data. Anterior versus posterior spinal fusion (ASF, PSF) for the treatment of adolescent idiopathic scoliosis (AIS) has been debated. Although procedures that violate the chest wall may compromise pulmonary function, lung function continues to improve after surgery at variable rates depending upon surgical approach. Methods. We reviewed the medical records from one hundred fifty nine AIS patients (age 15.6 ± 2.2; 113 women; 46 men) treated with spinal fusion from 2003 to 2007 by a single surgeon. Forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and radiographic measurements were evaluated before surgery and at 1, 3, 6, 12, and 24-months follow-up on average. Four surgical groups were compared: PSF, ASF (open thoracoabdominal approach for thoracolumbar curvature), video-assisted thoracoscopic surgical release with instrumentation (VATS-I), and VATS with PSF. FEV1 and FVC were fitted to model to evaluate the immediate postoperative pulmonary function (Yo), maximal recovery (Plateau), and rate (K) of pulmonary improvement. Results. Patients in each surgical subgroup were as follows: PSF (Lenke 1: n = 50, Lenke 2,3: n = 20), ASF (Lenke 5, n = 35), VATS-I (Lenke 1 = 31, Lenke 3 = 1), and VATS + PSF (Lenke1: n = 9, Lenke 2–6: n = 13). Early postoperative pulmonary function was higher with ASF and PSF as compared to both VATS groups (P < 0.05). Comparing all curve types, VATS-I showed a small decline of absolute FEV1 compared to PSF at 2-years follow-up. Comparing thoracic curves, however, no differences in FEV1 or FVC were noted at 6 to 12 months until 2-years follow-up. The rate of recovery (K) was equivalent for all surgical approaches and curve types. Conclusion. Compared to ASF or PSF, VATS procedures showed an initial decline in pulmonary function, which resolved fully by 6- to 12-months follow-up. Modest declines in maximal pulmonary function with VATS-I were seen when comparing all curve types together but not when comparing Lenke 1 curves alone. VATS procedures for thoracic scoliosis and open approaches for thoracolumbar curve types were associated with minimal to no permanent deficits.

Anterior spinal fusion for thoracolumbar scoliosis: comprehensive assessment of radiographic, clinical, and pulmonary outcomes on 2-years follow-up.

Background There is a continued role for anterior spinal fusion (ASF) in the treatment of thoracolumbar scoliosis. Despite numerous previous reports of ASF in the treatment of thoracolumbar scoliosis, no single study has simultaneously evaluated clinical, radiographic, and pulmonary function outcomes. Methods Retrospective review of 31 consecutive thoracolumbar adolescent idiopathic scoliosis patients (Lenke type 5) who underwent ASF by a single surgeon. Patient records were comprehensively assessed for Scoliosis Research Society (SRS)-22 score, apical trunk rotation, radiographic changes, and pulmonary function before surgery and at 2-years follow-up. Results Thoracolumbar/lumbar curve correction averaged from 45 to 11 degrees (74%) and spontaneous correction of thoracic curves averaged from 26 to 15 degrees (42%). Instrumented segment lordosis increased by 11 degrees, whereas proximal junction kyphosis increased by 3 degrees. No significant changes were noted in T2-T12 kyphosis, distal junctional kyphosis, T12-S1 lumbar lordosis, or coronal balance. Thoracolumbar apical trunk rotation improved from 12 to 3 degrees. Average SRS scores significantly improved from 3.9 to 4.4. SRS assessments of self-image and pain also improved significantly from 3.6 to 4.5 and from 4.1 to 4.6, respectively. Absolute and percent predicted forced vital capacity and forced expiratory volume in 1 second were unchanged. Two patients suffered mild intercostal neuralgia postthoracotomy. There were no other complications. Conclusions The thoracoabdominal anterior approach for thoracolumbar scoliosis facilitates excellent clinical and radiographic outcomes, minimal blood loss, powerful apical trunk rotation correction, relative maintenance of lordosis, relatively short fusion constructs, and improved SRS-22 performance, without significant pulmonary function impairment at 2 years. It continues to be an efficacious treatment for thoracolumbar scoliosis. Level of Evidence Level IV.

Prediction of Curve Progression in Idiopathic Scoliosis: Validation of the Sanders Skeletal Maturity Staging System.

Study Design. Retrospective case series. Objective. This study aimed to validate the Sanders Skeletal Maturity Staging System and to assess its correlation to curve progression in idiopathic scoliosis. Summary of Background Data. The Sanders Skeletal Maturity Staging System has been used to predict curve progression in idiopathic scoliosis. This study intended to validate that initial study with a larger sample size. Methods. We retrospectively reviewed 1100 consecutive patients with idiopathic scoliosis between 2005 and 2011. Girls aged 8 to 14 years (<2 yr postmenarche) and boys aged 10 to 16 years who had obtained at least 1 hand and spine radiograph on the same day for evaluation of skeletal age and scoliosis curve magnitude were followed to skeletal maturity (Risser stage 5 or fully capped Risser stage 4), curve progression to 50° or greater, or spinal fusion. Patients with nonidiopathic curves were excluded. Results. There were 161 patients: 131 girls (12.3 ± 1.2 yr) and 30 boys (13.9 ± 1.1 yr). The distribution of patients within Sanders stage (SS) 1 through 7 was 7, 28, 41, 45, 7, 31, and 2 patients, respectively; modified Lenke curve types 1 to 6 were 26, 12, 63, 5, 38, and 17 patients, respectively. All patients in SS2 with initial Cobb angles of 25° or greater progressed, and patients in SS1 and SS3 with initial Cobb angles of 35° or greater progressed. Similarly, all patients with initial Cobb angles of 40° or greater progressed except those in SS7. Conversely, none of the patients with initial Cobb angles of 15° or less or those in SS5, SS6, and SS7 with initial Cobb angles of 30° or less progressed. Predictive progression of 67%, 50%, 43%, 27%, and 60% was observed for subgroups SS1/30°, SS2/20°, SS3/30°, SS4/30°, and SS6/35° respectively. Conclusion. This larger cohort shows a strong predictive correlation between SS and initial Cobb angle for probability of curve progression in idiopathic scoliosis. Level of Evidence: 3

Medicare Reimbursement for Total Joint Arthroplasty: The Driving Forces

BACKGROUND Total joint arthroplasty is a large and growing part of the U.S. Medicare budget, drawing attention to how much providers are paid for their services. The purpose of this study was to examine the variables that affect total joint arthroplasty reimbursement. Along with standard economic variables, we include unique health-care variables. Given the focus on value in the Affordable Care Act, the model examines the relationship of the quality of care to total joint arthroplasty reimbursement. We hoped to find that reimbursement patterns reward quality and reflect standard economic principles. METHODS Multivariable regression was performed to identify variables that correlate with Medicare reimbursement for total joint arthroplasty. Inpatient charge or reimbursement data on Medicare reimbursements were available for 2,750 hospitals with at least 10 discharges for uncomplicated total joint arthroplasty from the Centers for Medicare & Medicaid Services (CMS) for fiscal year 2011. Reimbursement variability was examined by using the Dartmouth Atlas to group institutions into hospital referral regions and hospital service areas. Independent variables were taken from the Dartmouth Atlas, CMS, the WWAMI (Washington, Wyoming, Alaska, Montana, Idaho) Rural Health Research Center, and the United States Census. RESULTS There were 427,207 total joint arthroplasties identified, with a weighted mean reimbursement of

Simplified skeletal maturity scoring system: learning curve and methods to improve reliability.

14,324.84 (range,

International utilization of the SRS-22 instrument to assess outcomes in adolescent idiopathic scoliosis: what can we learn from a medical outreach group in Ghana?

9,103 to