Krishna T. Kudaravalli

Radiation exposure and reduction in the operating room: Perspectives and future directions in spine surgery

Intraoperative imaging is vital for accurate placement of instrumentation in spine surgery. However, the use of biplanar fluoroscopy and other intraoperative imaging modalities is associated with the risk of significant radiation exposure in the patient, surgeon, and surgical staff. Radiation exposure in the form of ionizing radiation can lead to cellular damage via the induction of DNA lesions and the production of reactive oxygen species. These effects often result in cell death or genomic instability, leading to various radiation-associated pathologies including an increased risk of malignancy. In attempts to reduce radiation-associated health risks, radiation safety has become an important topic in the medical field. All practitioners, regardless of practice setting, can practice radiation safety techniques including shielding and distance to reduce radiation exposure. Additionally, optimization of fluoroscopic settings and techniques can be used as an effective method of radiation dose reduction. New imaging modalities and spinal navigation systems have also been developed in an effort to replace conventional fluoroscopy and reduce radiation doses. These modalities include Isocentric Three-Dimensional C-Arms, O-Arms, and intraoperative magnetic resonance imaging. While this influx of new technology has advanced radiation safety within the field of spine surgery, more work is still required to overcome specific limitations involving increased costs and inadequate training.

Multimodal Analgesia versus Intravenous Patient-controlled Analgesia For Minimally Invasive Transforaminal Lumbar Interbody Fusion Procedures.

Study Design. Retrospective analysis. Objective. To compare postoperative narcotic consumption and pain scores between multimodal analgesia (MMA) and patient-controlled analgesia (PCA) following minimally invasive transforaminal lumbar interbody fusion (MIS TLIF). Summary of Background Data. A multimodal analgesic approach to pain management may lead to decreased pain and narcotic consumption after orthopedic procedures. Additional evidence is, however, required to determine how MMA compares to intravenous PCA after MIS TLIF. Methods. Patients undergoing 1-level MIS TLIF followed by either MMA or PCA at our institution were compared in terms of inpatient pain scores, narcotic consumption, hospital length of stay, rates of surgical complications, rates of inpatient nausea/vomiting, rates of postoperative urinary retention, and rates of narcotic consumption during the months after discharge. Results. A total of 139 patients met inclusion criteria. Of these, 39 (28.1%) received MMA and 100 (71.9%) received PCA. Demographic and comorbidity characteristics did not differ between cohorts. Compared with patients receiving PCA, patients receiving MMA had a lower rate of inpatient narcotic consumption (2.8 ± 1.9 vs. 5.3 ± 4.4 oral morphine equivalents/hour, P < 0.001), a lower rate of inpatient nausea/vomiting (20.5% vs. 48.0%; P = 0.003), and a shorter hospital length of stay (53.0 ± 25.3 vs. 62.6 ± 24.4 h, P = 0.041). There were no differences in Numeric Rating Scale pain score between cohorts for day 0, postoperative day 1, or postoperative day 2 (P > 0.05 for each). There was no difference in the rate of postoperative urinary retention (P > 0.05). Similarly, there were no differences in narcotic consumption at 6 or 12 weeks postoperatively (P > 0.05 for each). Conclusion. These findings suggest that MMA results in reduced inpatient hospital narcotic consumption compared with PCA after MIS TLIF. The decrease in narcotic consumption may contribute to the observed decrease in the rate of inpatient nausea/vomiting and shorter hospital length of stay. Importantly, MMA and PCA resulted in similar analgesia for patients during the inpatient stay. Level of Evidence: 4

Cervical disc arthroplasty: do conflicts of interest influence the outcome of clinical studies?

BACKGROUND CONTEXT Cervical disc arthroplasty (CDA) is an emerging technique for the treatment of cervical degenerative disease. Multiple studies have investigated the outcomes of CDA, particularly in comparison with cervical arthrodesis techniques such as anterior cervical discectomy and fusion (ACDF). As many entities have financial interests in CDA implants, it is imperative to consider the influence of conflicts of interest on the results of studies investigating the efficacy of CDA. PURPOSE This study aimed to determine if there is an association between the presence of conflicts of interest among study authors and the reported outcome of studies involving CDA. STUDY DESIGN This is a systematic review of clinical CDA publications until October 2016. OUTCOME MEASURE The outcome measures are presence of conflicts of interest, level of evidence, and outcome for all included studies. METHODS PubMed and MEDLINE databases were searched for articles presenting clinical, radiographic, and cost outcomes of CDA. Data extracted from each article included title, authors, publication year, level of evidence, prosthesis type, number of operative levels, presence of conflicts of interest, and outcome. Conflicts of interest were determined by the presence of any conflicts for any author within manuscript disclosure sections or through Open Payments reporting. Outcomes of each study were graded as either favorable, unfavorable, or equivocal. The presence of conflicts of interest was tested for an association with the level of evidence and study outcome using Pearson chi-square analysis, Fisher exact test, or logistic regression for categorical variables. The authors report no conflicts of interest directly related to this work, and have not received any funds in support of this work. RESULTS A total of 98 articles were included in this analysis. In total, 44.9% (44) of articles had the presence of a conflict of interest, whereas 55.1% (54) of articles did not. Conflicted studies were more likely to present level I evidence and less likely to present level IV evidence than non-conflicted studies (p<.001). Furthermore, conflicted studies were more likely to report favorable outcomes after CDA than non-conflicted studies (90.9% vs. 74.1%, p=.040). CONCLUSIONS The results of this study suggest that the majority of conflicted and non-conflicted studies report favorable results in patients undergoing CDA. However, conflicted studies were also more likely to report favorable outcomes compared with non-conflicted studies. Individual clinicians must critically review published studies for potential conflicts of interest before incorporating CDA into their practice.

Lateral lumbar interbody fusion: a systematic review of complication rates

BACKGROUND CONTEXT Lateral lumbar interbody fusion (LLIF) is a frequently used technique for the treatment of lumbar pathology. Despite its overall success, LLIF has been associated with a unique set of complications. However, there has been inconsistent evidence regarding the complication rate of this approach. PURPOSE To perform a systematic review analyzing the rates of medical and surgical complications associated with LLIF. STUDY DESIGN Systematic review. PATIENT SAMPLE 6,819 patients who underwent LLIF reported in clinical studies through June 2016. OUTCOME MEASURES Frequency of complications within cardiac, vascular, pulmonary, urologic, gastrointestinal, transient neurologic, persistent neurologic, and spine (MSK) categories. METHODS This systematic review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Relevant studies that identified rates of any complication following LLIF procedures were obtained from PubMed, MEDLINE, and EMBASE databases. Articles were excluded if they did not report complications, presented mixed complication data from other procedures, or were characterized as single case reports, reviews, or case series containing less than 10 patients. The primary outcome was frequency of complications within cardiac, vascular, pulmonary, urologic, gastrointestinal, transient neurologic, persistent neurologic, and MSK categories. All rates of complications were based on the sample sizes of studies that mentioned the respective complications. The authors report no conflicts of interest directly or indirectly related to this work, and have not received any funds in support of this work. RESULTS A total of 2,232 articles were identified. Following screening of title, abstract, and full-text availability, 63 articles were included in the review. A total of 6,819 patients had 11,325 levels fused. The rate of complications for the categories included were as follows: wound (1.38%; 95% confidence interval [CI]=1.00%-1.85%), cardiac (1.86%; CI=1.33%-2.52%), vascular (0.81%; CI=0.44%-1.36%), pulmonary (1.47; CI=0.95%-2.16%), gastrointestinal (1.38%; CI=1.00%-1.87%), urologic (0.93%; CI=0.55%-1.47%), transient neurologic (36.07%; CI=34.74%-37.41%), persistent neurologic (3.98%; CI=3.42%-4.60%), and MSK or spine (9.22%; CI=8.28%-10.23%). CONCLUSIONS The current study is the first to comprehensively analyze the complication profile for LLIFs. The most significant reported complications were transient neurologic in nature. However, persistent neurologic complications occurred at a much lower rate, bringing into question the significance of transient symptoms beyond the immediate postoperative period. Through this analysis of complication profiles, surgeons can better understand the risks to and expectations for patients following LLIF procedures.

Impact of body mass index on surgical outcomes, narcotics consumption, and hospital costs following anterior cervical discectomy and fusion

OBJECTIVE Given the increasing prevalence of obesity, more patients with a high body mass index (BMI) will require surgical treatment for degenerative spinal disease. In previous investigations of lumbar spine pathology, obesity has been associated with worsened postoperative outcomes and increased costs. However, few studies have examined the association between BMI and postoperative outcomes following anterior cervical discectomy and fusion (ACDF) procedures. Thus, the purpose of this study was to compare surgical outcomes, postoperative narcotics consumption, complications, and hospital costs among BMI stratifications for patients who have undergone primary 1- to 2-level ACDF procedures. METHODS The authors retrospectively reviewed a prospectively maintained surgical database of patients who had undergone primary 1- to 2-level ACDF for degenerative spinal pathology between 2008 and 2015. Patients were stratified by BMI as follows: normal weight (< 25.0 kg/m2), overweight (25.0-29.9 kg/m2), obese I (30.0-34.9 kg/m2), or obese II-III (≥ 35.0 kg/m2). Differences in patient demographics and preoperative characteristics were compared across the BMI cohorts using 1-way ANOVA or chi-square analysis. Multivariate linear or Poisson regression with robust error variance was used to determine the presence of an association between BMI category and narcotics utilization, improvement in visual analog scale (VAS) scores, incidence of complications, arthrodesis rates, reoperation rates, and hospital costs. Regression analyses were controlled for preoperative demographic and procedural characteristics. RESULTS Two hundred seventy-seven patients were included in the analysis, of whom 20.9% (n = 58) were normal weight, 37.5% (n = 104) were overweight, 24.9% (n = 69) were obese I, and 16.6% (n = 46) were obese II-III. A higher BMI was associated with an older age (p = 0.049) and increased comorbidity burden (p = 0.001). No differences in sex, smoking status, insurance type, diagnosis, presence of neuropathy, or preoperative VAS pain scores were found among the BMI cohorts (p > 0.05). No significant differences were found among these cohorts as regards operative time, intraoperative blood loss, length of hospital stay, and number of operative levels (p > 0.05). Additionally, no significant differences in postoperative narcotics consumption, VAS score improvement, complication rates, arthrodesis rates, reoperation rates, or total direct costs existed across BMI stratifications (p > 0.05). CONCLUSIONS Patients with a higher BMI demonstrated surgical outcomes, narcotics consumption, and hospital costs comparable to those of patients with a lower BMI. Thus, ACDF procedures are both safe and effective for all patients across the entire BMI spectrum. Patients should be counseled to expect similar rates of postoperative complications and eventual clinical improvement regardless of their BMI.

Two-level cervical disc replacement: perspectives and patient selection

php and incorporate the Creative Commons Attribution – Non Commercial (unported, v3.0) License (http://creativecommons.org/licenses/by-nc/3.0/). By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms (https://www.dovepress.com/terms.php). Open Access Surgery 2017:10 1–8 Open Access Surgery Dovepress

Minimally invasive techniques for lumbar decompressions and fusions

Purpose of reviewThe purpose of this study is to summarize the recent literature investigating the use of minimally invasive (MIS) techniques in the treatment of lumbar degenerative stenosis, spondylolisthesis, and scoliosis.Recent findingsMIS lumbar decompression and fusion techniques for degenerative pathology are associated with reduced operative morbidity, shortened length of hospital stay, and reduced postoperative pain and narcotics utilization. Recent studies with long-term clinical follow-up have demonstrated equivalence in clinical outcomes between open and MIS surgical procedures. Radiographically, MIS procedures provide adequate postoperative correction of coronal alignment. Correction of sagittal alignment, however, is more variable based on current reports.SummaryMIS techniques are both safe and effective in the treatment of lumbar degenerative pathologies. While some studies have reported on long-term outcomes and costs associated with MIS procedures, more investigation into these topics is still necessary. Additionally, further work is required to analyze the training requirements and learning curves of MIS procedures to better promote adoption amongst surgeons.

Does the VAPOUR trial shed new light on the efficacy of vertebroplasty for acute painful osteoporotic fractures

As the population of the United States ages, the incidence of osteoporosis and associated complications will continue to rise (1). Up to 750,000 cases of vertebral fracture occur annually, with incidence rates in elderly women approaching 1% per year (2,3). Osteoporotic vertebral fractures are a common source of significant morbidity and disability in elderly populations (4). Back pain, spinal deformities, and substantial reductions in quality of life are common consequences of osteoporotic vertebral fractures (5). Standard treatment for this pathology consists of conservative management including physical therapy, anti-osteoporosis pharmacotherapy, analgesia, and bracing. Although conservative management is typically successful, certain subsets of patients will fail to improve with non-operative therapy. Consequently, these patients may experience long term disability, increased frequency of hospitalization, and requirements for additional care (5).

Post-market surveillance study of FLXfit™ TLIF interbody fusion device: protocol for a prospective case series study

Background: Minimally invasive (MIS) lumbar fusion is a frequently utilized treatment for lumbar degenerative pathology. Interbody cages have been the preferred fusion construct in these procedures due to their ability to facilitate fusion and provide structural stability. However, due to the anatomic small access corridor of minimally invasive lumbar fusion procedures, the interbody cages used in these techniques are often limited in size, increasing the risk for pseudarthrosis and subsidence. Expandable interbody cages have been developed to overcome these risks in limitations. However, few clinical studies have been developed and initiated to describe the fusion rates, clinical outcomes, and complication rates in patients receiving these expandable cages. Methods/Design: A prospective case series of 30 patients receiving the FLXFit expandable interbody cage device is currently underway. Patients to undergo MIS transforaminal lumbar interbody fusion (TLIF) for degenerative pathology will be recruited based on their meeting of inclusion criteria and eligibility to receive the expandable cage device. Patient follow-up will occur at 6 weeks, 3 months, 6 months, 1 year, and 2 years. The primary outcome will be fusion status at 1-year, as measured by computed tomography (CT) scan. Patient reported outcomes and radiographic measurements will be obtained preoperatively and at all postoperative time points. All complications, reoperations, and hospital readmissions occurring during follow up will also be recorded. Discussion: This protocol is designed to better describe the outcomes and complications following the utilization of the FLXFit expandable interbody cage device following MIS TLIF. The present manuscript provides the process for patient selection, intervention, and follow-up. Trial registration: ClinicalTrials.gov identifier NCT02805985; registered on June 15, 2016. Ethics: The study protocol has been approved by the Rush University Institutional Review Board (IRB), and will be performed under the ethical standards of the IRB. Informed consent: Signed informed consent will be obtained from each patient.