Using Swallowing Quality of Life to Compare Oropharyngeal Dysphagia Following Cervical Disc Arthroplasty or Anterior Cervical Discectomy and Fusion

Objective To evaluate dysphagia outcomes using the swallowing quality of life (SWAL-QOL) questionnaire between patients undergoing cervical disk arthroplasty (CDA) or anterior cervical discectomy and fusion (ACDF). Methods Patient-reported outcome measures (PROMs) were collected using SWAL-QOL, VAS, NDI, and SF-12 PCS. All measures were recorded preoperatively to 6-month postoperatively. Patients were grouped according to cervical procedure and instrumentation used. Differences in PROMs and SWAL-QOL domains were evaluated by t-test and one-way ANOVA with post-hoc testing, respectively. Simple linear regression was employed to evaluate the relationship between number of levels operated on and postoperative outcomes. Results 161 patients were included. CDA patients had significantly worse SWAL-QOL scores at 6-months. Preoperative VAS neck was significantly worse for patients who underwent either an ACDF procedure with a stand-alone cage or CDA as compared to patients who underwent an ACDF with anterior plating. At 6-months postoperatively, CDA patients reported a significantly worse “fatigue” score compared to ACDF patients. At 6-months postoperatively, ACDF patients reported a significantly better “sleep” scores compared to CDA patients with both recipients of an anterior plate and stand-alone cage reporting significantly better scores compared to the CDA cohort (p=0.024; p<0.001). The SWAL-QOL domain of symptom frequency at 6-weeks postoperatively was significantly associated with number of levels operated (p=0.032). Conclusion Patients undergoing either an ACDF or CDA procedure largely did not demonstrate differences in pain, disability, and dysphagia scores. However, at more longitudinal timepoints CDA patients reported worse fatigue and sleep scores compared to ACDF patients

Phase phonon spectrum and melting in a quantum rotor model with diagonal disorder

We study the zero-temperature ($T = 0$) quantum rotor model with on-site disorder in the charging energy. Such a model may serve as an idealized Hamiltonian for an array of Josephson-coupled small superconducting grains, or superfluid $^4$He in a disordered environment. In the approximation of small-amplitude phase fluctuations, the Hamiltonian maps onto a system of coupled harmonic oscillators with on-site disorder. We study the effects of disorder in this harmonic regime, using the coherent potential approximation (CPA), obtaining the density of states and the lifetimes of the spin-wave-like excitations for several choices of the parameters which characterize the disorder. Finally, we estimate the parameters characterizing the $T = 0$ quantum melting of the phase order, using a suitable Lindemann criterion.Comment: 8 pages, 5 figures. To be published in Phys. Rev. B. Minor change

Diffusion of MMPs on the Surface of Collagen Fibrils: The Mobile Cell Surface – Collagen Substratum Interface

Remodeling of the extracellular matrix catalyzed by MMPs is central to morphogenetic phenomena during development and wound healing as well as in numerous pathologic conditions such as fibrosis and cancer. We have previously demonstrated that secreted MMP-2 is tethered to the cell surface and activated by MT1-MMP/TIMP-2-dependent mechanism. The resulting cell-surface collagenolytic complex (MT1-MMP)2/TIMP-2/MMP-2 can initiate (MT1-MMP) and complete (MMP-2) degradation of an underlying collagen fibril. The following question remained: What is the mechanism of substrate recognition involving the two structures of relatively restricted mobility, the cell surface enzymatic complex and a collagen fibril embedded in the ECM? Here we demonstrate that all the components of the complex are capable of processive movement on a surface of the collagen fibril. The mechanism of MT1-MMP movement is a biased diffusion with the bias component dependent on the proteolysis of its substrate, not adenosine triphosphate (ATP) hydrolysis. It is similar to that of the MMP-1 Brownian ratchet we described earlier. In addition, both MMP-2 and MMP-9 as well as their respective complexes with TIMP-1 and -2 are capable of Brownian diffusion on the surface of native collagen fibrils without noticeable dissociation while the dimerization of MMP-9 renders the enzyme immobile. Most instructive is the finding that the inactivation of the enzymatic activity of MT1-MMP has a detectable negative effect on the cell force developed in miniaturized 3D tissue constructs. We propose that the collagenolytic complex (MT1-MMP)2/TIMP-2/MMP-2 represents a Mobile Cell Surface – Collagen Substratum Interface. The biological implications of MT1-MMP acting as a molecular ratchet tethered to the cell surface in complex with MMP-2 suggest a new mechanism for the role of spatially regulated peri-cellular proteolysis in cell-matrix interactions

Using Adipose Measures from Health Care Provider-Based Imaging Data for Discovery

The location and type of adipose tissue is an important factor in metabolic syndrome. A database of picture archiving and communication system (PACS) derived abdominal computerized tomography (CT) images from a large health care provider, Geisinger, was used for large-scale research of the relationship of volume of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) with obesity-related diseases and clinical laboratory measures. Using a “greedy snake” algorithm and 2,545 CT images from the Geisinger PACS, we measured levels of VAT, SAT, total adipose tissue (TAT), and adipose ratio volumes. Sex-combined and sex-stratified association testing was done between adipose measures and 1,233 disease diagnoses and 37 clinical laboratory measures. A genome-wide association study (GWAS) for adipose measures was also performed. SAT was strongly associated with obesity and morbid obesity. VAT levels were strongly associated with type 2 diabetes-related diagnoses (p = 1.5 × 10−58), obstructive sleep apnea (p = 7.7 × 10−37), high-density lipoprotein (HDL) levels (p = 1.42 × 10−36), triglyceride levels (p = 1.44 × 10−43), and white blood cell (WBC) counts (p = 7.37 × 10−9). Sex-stratified tests revealed stronger associations among women, indicating the increased influence of VAT on obesity-related disease outcomes particularly among women. The GWAS identified some suggestive associations. This study supports the utility of pursuing future clinical and genetic discoveries with existing imaging data-derived adipose tissue measures deployed at a larger scale

The Influence of Preoperative Narcotic Consumption on Patient-Reported Outcomes of Lumbar Decompression

Study Design: Retrospective cohort.Purpose: This study aimed to assess the relationship between preoperative narcotic consumption and patient-reported outcomes (PRO) in patients undergoing minimally invasive (MIS) lumbar decompression (LD).Overview of Literature: Previous studies report negative effects of narcotic consumption on perioperative outcomes and recovery; however, its impact on quality of life and surgical outcomes is not fully understood.Methods: A surgical database was retrospectively reviewed for patients undergoing primary, single-level MIS LD from 2013 to 2020. Patients lacking preoperative narcotic consumption data were excluded. Demographics, spinal pathologies, and operative characteristics were collected. Patients were grouped based on preoperative narcotic consumption. Patient Health Questionnaire-9 (PHQ-9), Visual Analog Scale (VAS) for back and leg, Oswestry Disability Index (ODI), 12-item Short Form Physical Component Summary, and Patient-Reported Outcomes Measurement Information System physical function (PROMIS-PF) were collected preoperatively and postoperatively. Preestablished values were used to calculate achievement of minimum clinically important difference (MCID). Differences in mean PROs and MCID achievement between groups were evaluated.Results: The cohort was 453 patients; 184 used preoperative narcotics and 269 did not. Significant differences were found in American Society of Anesthesiologists classification, ethnicity, insurance type, and estimated blood loss between groups. Significant differences were also found in preoperative PHQ-9, VAS leg, ODI, and PROMIS-PF between groups (all &lt;i&gt;p&lt;/i&gt;&lt;0.05). Mean postoperative PROs did not differ by group (&lt;i&gt;p&lt;/i&gt;&gt;0.05). A higher rate of MCID achievement was associated with the narcotic group for PHQ-9 and PROMIS-PF at 6 weeks (both &lt;i&gt;p&lt;/i&gt;≤0.050), VAS leg at 1 year (&lt;i&gt;p&lt;/i&gt;=0.009), and overall for ODI and PHQ-9 (both &lt;i&gt;p&lt;/i&gt;≤0.050).Conclusions: Preoperative narcotic consumption was associated with worse preoperative depression, leg pain, disability, and physical function. In patients consuming preoperative narcotics, a higher proportion achieved an overall MCID for disability and depressive symptoms. Patients taking preoperative narcotic medications may report significantly worse preoperative PROs but demonstrate greater improvements in postoperative disability and mental health.</jats:p

Meeting Patient Expectations or Achieving a Minimum Clinically Important Difference: Predictors of Satisfaction among Lumbar Fusion Patients

Study Design: Retrospective cohort.Purpose: To investigate the impact of meeting a patient’s preoperative expectations for back or leg pain or the achievement of minimum clinically important difference (MCID) on patient satisfaction following lumbar fusion.Overview of Literature: Few studies have compared if MCID achievement or meeting preoperative expectations for pain reduction affects patient satisfaction.Methods: A surgical database was reviewed for eligible patients who underwent lumbar fusion. Patient satisfaction and Visual Analog Scale (VAS) for back and leg pain were the outcomes of interest. Meeting expectations was calculated as a difference of ≤0 between preoperative expectations and postoperative VAS scores. MCID achievement was calculated by comparing changes in VAS scores with established values. Meeting preoperative expectations or MCID achievement as predictors of patient satisfaction was evaluated using regression analysis.Results: A total of 134 patients were included in this study. Patients demonstrated significant improvements in VAS back and VAS leg (&lt;i&gt;p&lt;/i&gt;&lt;0.001). At 1 year, 56.4% of patients had their VAS back expectations met compared with 59.5% for VAS leg. Similarly, at 1 year, 77.3% and 71.3% of patients achieved MCID for VAS back and leg, respectively. Meeting expectations for VAS back was significantly associated with patient satisfaction at all postoperative timepoints; however, MCID achievement only demonstrated a significant association with patient satisfaction at 6 and 12 weeks (all, &lt;i&gt;p&lt;/i&gt;≤0.024). Meeting VAS leg expectations and MCID achievement both demonstrated a significant association with patient satisfaction at all postoperative timepoints (all, &lt;i&gt;p&lt;/i&gt;≤0.02). No differences between MCID achievement and meeting expectations as predictors of satisfaction were noted.Conclusions: The majority of patients achieved MCID and had their back and leg pain expectations met by 1 year. Both measures were significant predictors of patient satisfaction and suggest that MCID achievement may act as a suitable substitute for patient satisfaction.</jats:p

Using Swallowing Quality of Life to Compare Oropharyngeal Dysphagia Following Cervical Disc Arthroplasty or Anterior Cervical Discectomy and Fusion

Objective: To evaluate dysphagia outcomes using the swallowing quality of life (SWAL-QOL) questionnaire between patients undergoing cervical disk arthroplasty (CDA) or anterior cervical discectomy and fusion (ACDF).Methods: A retrospective review of a prospective surgical database was performed to identify individuals who underwent cervical procedures between 2014 and 2020. Patient-reported outcome measures (PROMs) were collected using SWAL-QOL, VAS, NDI, and SF-12 PCS. All measures were recorded at the preoperative to 6-month postoperative timepoint. Patients were grouped according to cervical procedure and instrumentation used. Differences in PROMs and SWAL-QOL domains were evaluated by t-test and one-way ANOVA with post-hoc testing, respectively. Simple linear regression was employed to evaluate the relationship between number of levels operated on and postoperative outcomes. Results: A total of 161 patients were included. ACDF and CDA patients demonstrated no significant differences in VAS neck and arm, or NDI at any timepoint. However, CDA patients had significantly worse SWAL-QOL scores at 6-months. Preoperative VAS neck was significantly worse for patients who underwent either an ACDF procedure with a stand alone cage or CDA as compared to patients who underwent an ACDF with anterior plating. At 6-months postoperatively, CDA patients reported a significantly worse “fatigue” score compared to ACDF patients. At 6-months postoperatively, ACDF patients reported a significantly better “sleep” scores compared to CDA patients with both recipients of an anterior plate and stand alone cage reporting significantly better scores compared to the CDA cohort (p=0.024; p&lt;0.001). No postoperative outcome studied was significantly associated with number of levels operated on, other than the SWAL-QOL domain of symptom frequency at the 6-week postoperative time point (p=0.032). Conclusion: Patients undergoing either an ACDF or CDA procedure largely did not demonstrate differences in pain, disability, and dysphagia scores. However, at more longitudinal timepoints CDA patients reported worse fatigue and sleep scores compared to ACDF patients.</jats:p

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

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 (&lt;i&gt;p&lt;/i&gt;&lt;0.001) except SF-12 MCS at 2 years (p =0.393). NDI showed a moderate- to-strong correlation (&lt;i&gt;r&lt;/i&gt;≥0.419) at most timepoints for VAS neck, VAS arm, SF-12 PCS, and SF-12 MCS (&lt;i&gt;p&lt;/i&gt;&lt;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 (&lt;i&gt;p&lt;/i&gt;&lt;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.</jats:p