Ryan Khanna

Comparing Short-term Complications of Inpatient Versus Outpatient Single-level Anterior Cervical Discectomy and Fusion: An Analysis of 6940 Patients Using the ACS-NSQIP Database

Study Design: Multicenter propensity score-adjusted retrospective cohort study. Objective: To determine baseline 30-day complication rates for anterior cervical discectomy and fusion (ACDF) and compare clinical complications for patients undergoing single-level ACDFs between inpatient and outpatient settings. Summary of Background Data: ACDF remains the most common procedure in the treatment of a variety of cervical disc pathologies, making it a focus of quality improvement initiatives. Outpatient single-level ACDFs are becoming more common and offer advantages including reducing nosocomial infections and costs, as well as improved patient satisfaction. Materials and Methods: The 2011–2013 NSQIP datasets were queried to identify all patients who underwent single-level ACDF procedures using current procedural terminology codes. Outpatient and inpatient cohorts were matched 1:1 using propensity score analysis to assess short-term outcomes. The outcomes assessed included 30-day medical and surgical complications, reoperation, readmission, and mortality. Results: In total, 6940 patients underwent a single-level ACDF with an overall complication rate of 4.2%. A total of 5162 patients (74.4%) had an inpatient hospital stay after surgery, whereas 1778 patients (25.6%) had outpatient surgery. After matching based on preoperative and operative characteristics to account for potential confounders, the overall complication rate was higher in the inpatient arm compared with the outpatient arm (2.5% vs. 1.2%; P=0.003). The 30-day readmission rate was also higher but not significant in the inpatient group than the outpatient group (2.2% vs. 1.8%; P=0.355). Mortality was the same with 0.1% in both groups (P=0.564). Conclusions: Patients undergoing outpatient single-level ACDF had a lower 30-day complication rates than those undergoing it in the inpatient setting. Outpatient surgery for single-level ACDF is safe and a favorable option for suitable patients. Level of Evidence: Level 3.

Utility of Readmission Rates as a Quality of Care Measure and Predictors of Readmission Within 30 Days After Spinal Surgery: a Single-Center, Multivariate Analysis.

Study Design. A retrospective review Objective. The aim of this study was to establish clinically relevant readmission rates that permit accurate comparisons, improve risk‐stratification, and direct efforts to minimize readmissions. Summary of Background Data. The 30‐day hospital readmission rate is a quality of care measure that is now being used to compare hospitals in a publicly available manner. Methods. Records from 1187 consecutive spinal surgeries at Northwestern Memorial Hospital in 2010 were retrospectively reviewed and data were collected that described the patient, surgical procedure, hospital course, complications, and readmissions. The primary outcome of interest was readmission to the hospital within 30 days. Potential risk factors were examined for association with the outcome first via bivariate analysis, with significant predictors further examined by a multivariable model. Identified readmissions were independently reviewed by attending spinal neurosurgeons not involved with the cases to determine whether the readmissions were procedure related or procedure unrelated with respect to accepted criteria. Results. The overall readmission rate was 6.1%. Of these readmissions, 37.5% were deemed procedure related upon attending review, leading to a procedure‐related readmission rate of 2.3%. Upon multivariate analysis, only 3 variables were found to be significant predictors of readmission: 2 or more patient comorbidities [odds ratio (OR) 3.72, 95% confidence interval (95% CI) 1.62–8.56], an admission to the ICU (OR 2.68, 95% CI 1.45–4.95), and each additional spinal level involved (OR 1.11, 95% CI 1.02–1.21). Conclusions. Our study suggests that predictors for all‐cause 30‐day readmission following spinal procedures include number of spinal levels performed during the surgery, number of patient comorbidities present at the time of surgery, and whether the admission required an ICU stay. Future work should focus on developing best practices to modify medical risk factors and comorbidities that have the potential to decrease 30‐day readmission rates. Level of Evidence: 3

The concave versus convex approach for minimally invasive lateral lumbar interbody fusion for thoracolumbar degenerative scoliosis.

We retrospectively reviewed patient charts to compare the approach-related (convex versus concave) neurological complications and magnitude of correction in patients undergoing lateral lumbar interbody fusion (LLIF). It is yet to be quantitatively determined if correction of adult degenerative scoliosis from either side of the curve apex using a LLIF results in a reduction in complications and/or improved corrective ability. The inclusion criteria for this study were patients who underwent a LLIF for adult degenerative thoracolumbar scoliosis and had the LLIF prior to any other supplemental procedures. Patients were grouped based on the approach toward the curve apex concavity (CAVE) or the convexity (VEX). Standard coronal and sagittal radiographic measurements were made. Neurological complications and reoperation indications were also recorded. We included 32 patients for review (CAVE: 17; VEX: 15) with a mean age of 65.5 years±a standard deviation of 10.2, and mean follow-up of 17.0 months±15.7. There were eight postoperative neurological complications in eight patients (25.0%), and seven reoperations for six patients (18.8%; CAVE: 4/17 [23.5%]; VEX: 2/15 [13.3%]). The CAVE group had 6/17 neurological complications (35.3%; four ipsilateral and two contralateral to approach side) and VEX had 2/15 (13.3%; one ipsilateral and one bilateral to approach side; p>0.05). All patients significantly improved in the mean regional and segmental Cobb angles (p<0.05), except for T11-T12 (p>0.05). There were no significant differences between the groups for any of the radiographic parameters measured (p>0.05). Approaching the curve apex from either the concave or convex side resulted in significant improvements. The concave approach was associated with more postoperative neurological complications.

The impact of steroids, methotrexate, and biologics on clinical and radiographic outcomes in patients with rheumatoid arthritis undergoing fusions at the craniovertebral junction.

Objective: Rheumatoid arthritis (RA) is an inflammatory disease that affects the craniovertebral junction (CVJ). Patients may suffer from atlantoaxial instability (AAI) and basilar invagination (BI) with variable presentations ranging from pain to quadriparesis. Managing these patients is often challenging due to their chronic use of steroids, methotrexate, and biologics; which impedes bone and wound healing. We report our experience with the surgical management of these patients undergoing fusions at the CVJ. Materials and Methods: We conducted a retrospective study identifying all patients with the diagnosis of RA who underwent spinal fusions at our institution over the past 11 years. A total of 205 patients were identified amongst which 18 patients (8.8%) who underwent 20 fusions involving the CVJ. Demographic, clinical, and radiographic data were analyzed. Results: Five patients had AAI and 13 patients had BI. Two patients with C1-2 fusions underwent reoperation: One for pseudoarthrosis and one for BI. The average preoperative Nurick was 1.4 and improved to 0.5 postoperatively (P < 0.001). After conducting analyses stratified by dichotomous preoperative variables, the presence of steroids, methotrexate, biologics, and prednisone dosage less than 7.5 mg did not affect outcomes. Prednisone dosages ≥7.5 mg had significantly smaller improvements in Nurick score compared to patients not on steroids or on prednisone dosages <7.5 mg (0.40 vs 1.36, P = 0.042). Similarly, patients on biologics had significantly smaller improvements in Nurick score compared to patients not on biologics (0.27 vs 1.16, P = 0.038). Conclusion: Fusions at the CVJ in patients with RA on daily prednisone dosages of less than 7.5 mg and/or methotrexate can be performed safely with good outcomes, fusion rates, and acceptable complication profiles. Daily prednisone dosages of more than 7.5 mg or biologics may impact clinical outcomes.

The Effect of Surgical Level on Self-Reported Clinical Outcomes After Minimally Invasive Transforaminal Lumbar Interbody Fusion: L4-L5 versus L5-S1

OBJECTIVE The anatomic and biomechanical aspects of the L5-S1 level present unique operative challenges compared with the L4-L5 level. However, it has not been determined if self-reported outcomes and complications are different between patients treated with a minimally invasive transforaminal lumbar interbody fusion at these specific levels. METHODS There were 36 consecutive patients identified who were treated with a minimally invasive transforaminal lumbar interbody fusion procedure. Surgical indications included spondylolisthesis (grade 1 or 2) and degenerative disk disease with associated clinical symptoms. Patients completed a visual analog scale (VAS) for their back and leg and Oswestry Disability Index preoperatively and postoperatively. Outcomes were compared between patients with L4-L5 involvement and patients with L5-S1 involvement. In all patients, fusion was evaluated by dynamic view flexion and extension views at 1 year. In all patients with indeterminate results or incomplete imaging, computed tomography was performed to evaluate for bridging bone and stable hardware positioning. RESULTS The surgical indications between the 2 groups were similar (χ(2) = 0.089, df = 2, P = 0.956). There was no significant difference in mean operating time, intraoperative blood loss, and hospital stay (P = 0.937, 0.627, and 0.587). There was no significant difference in the long-term postoperative questionnaire results (P = 0.819 for VAS [back], 0.626 for VAS [leg], and 0.962 for Oswestry Disability Index) or the mean preoperative to postoperative change in Cobb angle (P = 0.626) between the 2 groups. Two complications, one in each group, were a rash from an antibiotic and postoperative nausea. CONCLUSIONS Despite differences in biomechanics and unique anatomic challenges at the L5-S1 interspace, there is no difference in self-reported outcomes for patients treated with minimally invasive transforaminal lumbar interbody fusion at the L4-L5 level compared with the L5-S1 level.

Impact of Anemia and Transfusion on Readmission and Length of Stay After Spinal Surgery: A Single-center Study of 1187 Operations.

Study Design: Retrospective cohort study. Objective: To determine whether receipt of blood transfusion and preoperative anemia are associated with increased rates of 30-day all-cause readmission, and secondarily with a prolonged hospital stay after spinal surgery. Summary of Background Data: Increased focus on health care quality has led to efforts to determine postsurgical readmission rates and predictors of length of postoperative hospital stay. Although there are still no defined outcome measures specific to spinal surgery to which providers are held accountable, efforts to identify appropriate measures and to determine modifiable risk factors to optimize quality are ongoing. Methods: Records from 1187 consecutive spinal surgeries at Northwestern Memorial Hospital in 2010 were retrospectively reviewed and data were collected that described the patient, surgical procedure, hospital course, complications, and readmissions. Presence or absence of transfusion during the surgery and associated hospital course was treated as a binary variable. Multivariate negative binomial regression and logistic regression were used to model length of stay and readmission, respectively. Results: Nearly one fifth (17.8%) of surgeries received transfusions, and the overall readmission rate was 6.1%. After controlling for potential confounders, we found that the presence of a transfusion was associated with a 60% longer hospital stay [adjusted incidence rate ratio=1.60 (1.34–1.91), P<0.001], but was not significantly associated with an increased rate of readmission [adjusted odds ratio=0.81 (0.39–1.70), P=0.582]. Any degree of preoperative anemia was associated with increased length of stay, but only severe anemia was associated with an increased rate of readmission. Conclusions: Both receipt of blood transfusion and any degree of preoperative anemia were associated with increased length of hospital stay after controlling for other variables. Severe anemia, but not receipt of blood transfusion, was associated with increased rate of readmission. Our findings may help define actions to reduce length of stay and decrease rates of readmission.

Risk factors associated with distal catheter migration following ventriculoperitoneal shunt placement

Ventriculoperitoneal (VP) shunt placement is used to treat hydrocephalus. Shunt migration following VP shunt placement has been reported. The risk factors related to this complication have not been previously evaluated to our knowledge. In this retrospective cohort study, we aimed to determine risk factors leading to distal catheter migration and review the literature on the current methods of management and prevention. Adult patients undergoing VP shunt placement from June 2011 to December 2013 at a single institution were identified using electronic health records. The records were reviewed for demographic and procedural information, and subsequent treatment characteristics. The parameters of patients with distal shunt migration were compared to those undergoing new VP shunt placement for the same time period. We identified 137 patients undergoing 157 new VP shunt procedures with an average age of 57.7 ± standard deviation of 18.4 years old. There were 16 distal shunt migrations. Body mass index >30 kg/m(2) and number of previous shunt procedures were found to be independent risk factors for distal catheter migration. Obesity and number of previous shunt procedures were factors for distal catheter migration. Providers and patients should be aware of these possible risk factors prior to VP shunt placement.

Incidence of graft extrusion following minimally invasive transforaminal lumbar interbody fusion

Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) has been scrutinized for having a complex learning curve. Careful assessment of MI-TLIF complications and critical analyses of prevention may aid a safe adoption of this technique. The current report focuses on the incidence of interbody cage extrusions following MI-TLIF in a series of 513 patients. The authors discuss their experience with graft extrusions and provide methods to minimize this complication. This study retrospectively reviewed 513 prospectively followed patients who underwent MI-TLIF over a 10 year period. The inclusion criteria consisted of all patients who underwent one to three level MI-TLIF, from whom the incidence of cage extrusion was analyzed. Cage extrusion was defined as an interbody graft migrating outside the cephalad and caudal vertebral body posterior margin. Cage extrusions were diagnosed by comparing the intraoperative radiographs to the postoperative radiographs. Patients with >10° coronal curves, significant sagittal malalignment, infection, and preoperative instrumentation failure were excluded. Of 513 patients undergoing MI-TLIF, five patients (0.97%) were diagnosed with cage migrations. The mean follow-up duration was 13.6 ± standard deviation of 8.8 months. Complications included asymptomatic cage migration alone (two patients) neurological decline (two patients) and epidural hematoma (one patient). On average, cage migrations cost a university hospital an additional

The Application of the Revised Condyle–C1 Interval Method to Diagnose Traumatic Atlanto-occipital Dissociation in Adults

US17,217 for revision treatment. While the incidence of cage migrations is low (0.97%), it can lead to postoperative complications that require revision surgery and increased hospital costs. The risk for this significant complication can be minimized with proper technique and patient selection.

Thirty-day readmission risk factors following single-level transforaminal lumbar interbody fusion (TLIF) for 4992 patients from the ACS-NSQIP database

Study Design Retrospective study. Objective Traumatic atlanto-occipital dissociation (AOD) remains a diagnostic challenge, and delay in diagnosis is associated with catastrophic outcomes. Recently, a revised version of the condyl–C1 interval (CCI) utilizing parasagittal computed tomography (CT) reconstruction was used successfully with unilateral dislocation of 2.5 mm at the level of that joint diagnostic of AOD. We report the utility of this simple technique in the diagnosis of six patients with AOD. Methods Two blinded neurosurgeons assessed CTs of six patients with AOD and 30 patients without AOD. The following methodologies were applied: basion–dens interval (BDI), basion–axial interval (BAI), Lee X-lines, Powers ratio, CCI, and revised CCI. The average sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) as well as the kappa statistic indicating interrater reliability of each method were investigated. Results The average sensitivity for BDI, BAI, Lee X-lines, Power ratio, CCI, and revised CCI was 0.75, 0.33, 0.67, 0.50, 1.00, and 1.00, respectively. The average specificity was 1.00, 1.00, 0.50, 1.00, 0.94, and 1.00, respectively. The average PPV was 1.00, 1.00, 0.25, 1.00, 0.80, and 1.00, respectively. The average NPV was 0.96, 0.88, 0.89, 0.91, 1.00, and 1.00, respectively, and the kappa statistic was 0.57, 0.25, 0.25, 0.20, 1.00, and 1.00, respectively. Conclusion Based on this study, the revised CCI method is simple yet the most sensitive and reliable technique for the diagnosis of AOD.