Validation of Neck Disability Index Severity among Patients Receiving One or Two-Level Anterior Cervical Surgery

Geoghegan Cara E.,Mohan Shruthi,Lynch Conor P.,Cha Elliot D. K.,Jacob Kevin C.,Patel Madhav R.,Prabhu Michael C.,Vanjani Nisheka N.,Pawlowski Hanna,Singh Kern 대한척추외과학회 2023 Asian Spine Journal Vol.17 No.1

Study Design: Retrospective cohort. Purpose: To evaluate the validity of established severity thresholds for Neck Disability Index (NDI) among patients undergoing anterior cervical discectomy and fusion (ACDF) or cervical disc arthroplasty (CDA). Overview of Literature: Few studies have examined the validity of established NDI threshold values among patients undergoing ACDF or CDA. Methods: A surgical database was reviewed to identify patients undergoing cervical spine procedures. Demographics, operative characteristics, comorbidities, NDI, Visual Analog Scale (VAS), and 12-item Short Form (SF-12) physical and mental composite scores (PCS and MCS) were recorded. NDI severity was categorized using previously established threshold values. Improvement from preoperative scores at each postoperative timepoint and convergent validity of NDI was evaluated. Discriminant validity of NDI was evaluated against VAS neck and arm and SF-12 PCS and MCS. Results: All 290 patients included in the study demonstrated significant improvements from baseline values for all patient-reported outcome measures (PROMs) at all postoperative timepoints (p<0.001) except SF-12 MCS at 2 years (p=0.393). NDI showed a moderate-to-strong correlation (r≥0.419) at most timepoints for VAS neck, VAS arm, SF-12 PCS, and SF-12 MCS (p<0.001, all). NDI severity categories demonstrated significant differences in mean VAS neck, VAS arm, SF-12 PCS, and SF-12 MCS at all timepoints (p<0.001, all). Differences between NDI severity groups were not uniform for all PROMs. VAS neck values demonstrated significant intergroup differences at most timepoints, whereas SF-12 MCS showed significantly different values between most severity groups. Conclusions: Neck disability is strongly correlated with neck and arm pain, physical function, and mental health and demonstrates worse outcomes with increasing severity. Previously established severity categories may be more applicable to pain than physical function or mental health and may be more uniformly applied preoperatively for cervical spine patients.

Design and Experimental Validation of an Output Feedback Controller for a Pneumatic System with Distributed Parameters

R. Kern,N. Gehring,J. Deutscher,M. Meißner 제어로봇시스템학회 2018 제어로봇시스템학회 국제학술대회 논문집 Vol.2018 No.10

This paper considers the model-based control of a pneumatic system, where a tank is connected to a valve via a long tube. Due to the significant distance between the control input and the pressure in the tank to be controlled, a distributed-parameter model is used for the tube, involving quasilinear hyperbolic partial differential equations. In contrast, the tank is modelled by ordinary differential equations. Experimental data verifies the validity of the corresponding quasilinear system model. Based on a less accurate, linear PDE-ODE system model, derived there upon, both, a backstepping controller and a backstepping observer are designed. The resulting output feedback controller is augmented by a flatness-based feedforward controller. Experimental results for tube lengths of approximately five and twenty meters show that this controller allows to track fast pressure changes in the tank almost perfectly.

Age-related differences in the pathogenesis of chronic rhinosinusitis

Cho, S.H.,Hong, S.J.,Han, B.,Lee, S.H.,Suh, L.,Norton, J.,Lin, D.,Conley, D.B.,Chandra, R.,Kern, R.C.,Tan, B.K.,Kato, A.,Peters, A.,Grammer, L.C.,Schleimer, R.P. Mosby 2012 The Journal of allergy and clinical immunology Vol.129 No.3

Although chronic rhinosinusitis (CRS) significantly affects the quality of life of elderly people, the inflammatory mechanisms of chronic rhinosinusitis in the elderly have not been well studied. This study demonstrates that despite the higher severity of CRS observed in elderly patients, they had lower eosinophilic cationic protein compared to non-elderly CRS patients. In addition, S100A8/9 was significantly decreased in CRS with aging process, suggesting that epithelial barrier dysfunction may continue to play an important role in the pathogenesis of CRS while eosinophilic inflammation may subside with age.

THE COMPUTATION OF THE GENERALIZED INVERSE

Kymn, Kern O.,Norsworthy, J.R.,Okamoto, Tatsuo Department of Mathematics 1980 Kyungpook mathematical journal Vol.20 No.2

History and Evolution of the Minimally Invasive Transforaminal Lumbar Interbody Fusion

Michael C. Prabhu,Kevin C. Jacob,Madhav R. Patel,Hanna Pawlowski,Nisheka N. Vanjani,Kern Singh 대한척추신경외과학회 2022 Neurospine Vol.19 No.3

The minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is a popular surgical technique for lumbar arthrodesis, widely considered to hold great efficacy while conferring an impressive safety profile through the minimization of soft tissue damage. This elegant approach to lumbar stabilization is the byproduct of several innovations throughout the past century. In 1934, Mixter and Barr’s paper in the New England Journal of Medicine elucidated the role of disc herniation in spinal instability and radiculopathy, prompting surgeons to explore new approaches and instruments to access the disc space. In 1944, Briggs and Milligan published their novel technique, the posterior lumbar interbody fusion (PLIF), involving continuous removal of vertebral bone chips and replacement of the disc with a round bone peg. The following decades witnessed several PLIF modifications, including the addition of long pedicle screws. In 1982, Harms and Rolinger sought to redefine the posterior corridor by approaching the disc space through the intervertebral foramen, establishing the transforaminal lumbar interbody fusion (TLIF). In the 1990s, lumbar spine surgery experienced a paradigm shift, with surgeons placing increased emphasis on tissuesparing minimally invasive techniques. Spurred by this revolution, Foley and Lefkowitz published the novel MIS-TLIF technique in 2002. The MIS-TLIF has demonstrated comparable surgical outcomes to the TLIF, with an improved safety profile. Here, we present a view into the history of the posterior-approach treatment of the discogenic radiculopathy, culminating in the MIS-TLIF. Additionally, we evaluate the hallmark characteristics, technical variability, and reported outcomes of the modern MIS-TLIF and take a brief look at technologies that may define the future MIS-TLIF.

Effects of Anterior Plating on Achieving Clinically Meaningful Improvement Following Single-Level Anterior Cervical Discectomy and Fusion

Conor P. Lynch,Elliot D.K. Cha,Madhav R. Patel,Caroline N. Jadczak,Shruthi Mohan,Cara E. Geoghegan,Kern Singh 대한척추신경외과학회 2022 Neurospine Vol.19 No.2

Objective: The clinical utility of anterior cervical plating for anterior cervical discectomy and fusion (ACDF) procedures remains controversial. This study aims to compare the impact of cervical plating on achievement of minimum clinically important difference (MCID) up to 2 years following ACDF. Methods: Patients undergoing primary, single-level ACDF procedures were grouped based on whether their procedure included application of an anterior cervical plate. Demographics, preoperative spinal diagnoses, operative characteristics, and patient-reported outcome measures (PROMs) were compared between plating groups. Achievement of an MCID was assessed using the following previously established thresholds: 12-item Short Form health survey physical component summary (SF-12 PCS) 8.1, visual analogue scale (VAS) neck 2.6, VAS arm 4.1, Neck Disability Index (NDI) 8.5. Rates of MCID achievement were compared between groups. Results: The cohort included 192 patients of whom 102 received plating and 90 received no plating. Plating status was significantly associated with Charlson Comorbidity Index and insurance status. Operative duration and estimated blood loss were significantly greater for the plating group. Both groups demonstrated significant improvements at the majority of postoperative timepoints. Significant intergroup differences in PROM improvement were demonstrated for VAS neck and NDI at 6 weeks. Rates of MCID achievement differed significantly between groups for NDI at 6 weeks, and 12 weeks, and SF-12 PCS overall. Conclusion: Patients improved significantly in terms of pain, disability and physical function, regardless of plating status, and with the exception of early neck pain and disability, these improvements were similar between groups. Patients that underwent plating as part of their ACDF procedure achieved an MCID for physical function at lower rates overall.

Bioinformatics-driven discovery of rational combination for overcoming EGFR-mutant lung cancer resistance to EGFR therapy

Kim, Jihye,Vasu, Vihas T.,Mishra, Rangnath,Singleton, Katherine R.,Yoo, Minjae,Leach, Sonia M.,Farias-Hesson, Eveline,Mason, Robert J.,Kang, Jaewoo,Ramamoorthy, Preveen,Kern, Jeffrey A.,Heasley, Lynn Oxford University Press 2014 Bioinformatics Vol.30 No.17

<P><B>Motivation:</B> Non–small-cell lung cancer (NSCLC) is the leading cause of cancer death in the United States. Targeted tyrosine kinase inhibitors (TKIs) directed against the epidermal growth factor receptor (EGFR) have been widely and successfully used in treating NSCLC patients with activating EGFR mutations. Unfortunately, the duration of response is short-lived, and all patients eventually relapse by acquiring resistance mechanisms.</P><P><B>Result:</B> We performed an integrative systems biology approach to determine essential kinases that drive EGFR-TKI resistance in cancer cell lines. We used a series of bioinformatics methods to analyze and integrate the functional genetics screen and RNA-seq data to identify a set of kinases that are critical in survival and proliferation in these TKI-resistant lines. By connecting the essential kinases to compounds using a novel kinase connectivity map (K-Map), we identified and validated bosutinib as an effective compound that could inhibit proliferation and induce apoptosis in TKI-resistant lines. A rational combination of bosutinib and gefitinib showed additive and synergistic effects in cancer cell lines resistant to EGFR TKI alone.</P><P><B>Conclusions:</B> We have demonstrated a bioinformatics-driven discovery roadmap for drug repurposing and development in overcoming resistance in EGFR-mutant NSCLC, which could be generalized to other cancer types in the era of personalized medicine.</P><P><B>Availability and implementation:</B> K-Map can be accessible at: http://tanlab.ucdenver.edu/kMap.</P><P><B>Contact:</B> aikchoon.tan@ucdenver.edu or finiganj@njhealth.org</P><P><B>Supplementary information:</B> Supplementary data are available at <I>Bioinformatics</I> online.</P>

Significance of Facet Fluid Index in Anterior Cervical Degenerative Spondylolisthesis

Lee Yunsoo,Heard Jeremy C.,Lambrechts Mark J.,Kern Nathaniel,Wiafe Bright,Goodman Perry,Mangan John J.,Canseco Jose A.,Kurd Mark F.,Kaye Ian D.,Hilibrand Alan S.,Vaccaro Alexander R.,Kepler Christophe 대한척추외과학회 2024 Asian Spine Journal Vol.18 No.1

Study Design: Retrospective cohort study.Purpose: To correlate cervical facet fluid characteristics to radiographic spondylolisthesis, determine if facet fluid is associated with instability in cervical degenerative spondylolisthesis, and examine whether vertebral levels with certain facet fluid characteristics and spondylolisthesis are more likely to be operated on.Overview of Literature: The relationship between facet fluid and lumbar spondylolisthesis is well-documented; however, there is a paucity of literature investigating facet fluid in degenerative cervical spondylolisthesis.Methods: Patients diagnosed with cervical degenerative spondylolisthesis were identified from a hospital’s medical records. Demographic and surgical characteristics were collected through a structured query language search and manual chart review. Radiographic measurements were made on preoperative MRIs for all vertebral levels diagnosed with spondylolisthesis and adjacent undiagnosed levels between C3 and C6. The facet fluid index was calculated by dividing the facet fluid measurement by the width of the facet. Bivariate analysis was conducted to compare facet characteristics based on radiographic spondylolisthesis and spondylolisthesis stability.Results: We included 154 patients, for whom 149 levels were classified as having spondylolisthesis and 206 levels did not. The average facet fluid index was significantly higher in patients with spondylolisthesis (0.26±0.07 vs. 0.23±0.08, p <0.001). In addition, both fluid width and facet width were significantly larger in patients with spondylolisthesis (p <0.001 each). Cervical levels in the fusion construct demonstrated a greater facet fluid index and were more likely to have unstable spondylolisthesis than stable spondylolisthesis (p <0.001 each).Conclusions: Facet fluid index is associated with cervical spondylolisthesis and an increased facet size and fluid width are associated with unstable spondylolisthesis. While cervical spondylolisthesis continues to be an inconclusive finding, vertebral levels with spondylolisthesis, especially the unstable ones, were more likely to be included in the fusion procedure than those without spondylolisthesis.

Change in Patient-Reported Outcome Measures as Predictors of Revision Lumbar Decompression Procedures

Michael T. Nolte,Elliot D.K. Cha,Conor P. Lynch,Kevin C. Jacob,Madhav R. Patel,Cara E. Geoghegan,Caroline N. Jadczak,Shruthi Mohan,Kern Singh 대한척추신경외과학회 2021 Neurospine Vol.18 No.4

Objective: To assess change in Patient-Reported Outcome Measures (PROM) as predictors for revision lumbar decompression (LD). Methods: Patients who underwent primary, single or multilevel LD were retrospectively reviewed. Patients were categorized according to whether or not they underwent revision LD within 2 years of the primary procedure. Visual analogue scale (VAS), Oswestry Disability Index (ODI), 12-item Short Form Health Survey and 12-item Veterans RAND physical component score (SF-12 PCS and VR-12 PCS), and Patient-Reported Outcome Measurement Information System physical function (PROMIS-PF) were recorded. Delta PROM scores were evaluated for differences between groups and as a risk factor for a revision LD. Results: The study included 135 patients, 91 undergoing a primary procedure only and 44 undergoing a primary and revision procedure. Matched patients did not demonstrate any significant differences in demographics or perioperative characteristics. Patients who underwent a revision had a mean time to revision of 7.4±5.7 months. Primary cohort significantly improved for all PROMs (all p<0.05), while the primary plus revision cohort significantly improved for VAS back, ODI, and PROMIS-PF (all p<0.05). However, cohorts differed in VAS back and PROMIS-PF (p<0.05). Delta PROMs were not a significant risk factor for revision except at 6 months for PROMIS-PF (p=0.024). Conclusion: LD has been associated with reliable outcomes, but early identification of patients at risk for revision is critical. This study suggests that tools such as PROMIS-PF may serve a role in predicting who is at risk and the 6-month follow-up period may be valuable for counseling patients who are not experiencing improvement.