STUDY DESIGN:A retrospective Cohort Study. OBJECTIVE:The aim of this study is to investigate the associations between posterior muscle health characteristics and disk geometry parameters between L1 and S1. SUMMARY OF BACKGROUND DATA:Paralumbar muscle changes have been associated with clinical outcomes. However, the relationship between disk geometry and paralumbar muscle changes has not been defined. METHODS:Axial T2 MRI was analyzed for paralumbar muscle measurements, and lateral radiographs were analyzed for disk geometry parameters in patients with disk degeneration. Associations between disk shape and muscle health at each individual lumbar level were evaluated using a partial correlation controlling for age and sex. Demographic data were compared between the listhesis groups, and an ANCOVA analysis controlling for significant demographic parameters was conducted to evaluate differences in muscle characteristics. RESULTS:In all, 435 patients were included (age: 55.6±15, BMI: 29.5±6, 60.9% female, 41.3% White). Muscle health median characteristics were CSA/BMI=140, LIV=13, and Goutallier Classification of 1. Partial correlations between focal disk parameters and muscle health controlling for age and sex showed moderate significant positive associations between focal lordosis and lumbar indentation value (LIV) at every level L1-S1 (mean r =0.264 between L1 and L5, P <0.001), weak positive association between focal lordosis and CSA/BMI (mean r =0.113 at L2-L5, P <0.03), and weak negative associations between disk height and Goutallier Classification (mean r =0.158 at L1-L5, P <0.03). Listhesis at L4-S1 was stratified, and ANCOVA controlling for sex and age demonstrated no significant association between S and R groups and CSA/BMI, LIV, or Goutallier classification ( P >0.1). CONCLUSIONS:Posterior muscle health was significantly associated with disk shape, especially disk height and disk lordosis, with larger and more lordotic disks being associated with better muscle health. Disk listhesis was not significantly associated with muscle quality when controlling for demographic characteristics, and no differences in muscle health parameters were observed in patients with spondylolisthesis versus retrolisthesis. Overall, the results highlight important associations between lumbar compensation, disk geometry, and posterior muscle health.

INTRODUCTION:Our analysis was designed to characterize the demographics and disparities between the diagnosis of pancreas cancer during emergency presentation (EP) and the outpatient setting (OP) and to see the impact of our institutions pancreatic multidisciplinary clinic (PMDC) on these disparities. METHODS:Institutional review board-approved retrospective review of our institutional cancer registry and PMDC databases identified patients diagnosed/treated for pancreatic ductal adenocarcinoma between 2014 and 2022. Chi-square tests were used for categorical variables, and one-way ANOVA with a Bonferroni correction was used for continuous variables. Statistical significance was set at p < 0.05. RESULTS:A total of 286 patients met inclusion criteria. Eighty-nine patients (31.1%) were underrepresented minorities (URM). Fifty-seven (64.0%) URMs presented during an EP versus 100 (50.8%) non-URMs (p = 0.037). Forty-one (46.1%) URMs were reviewed at PMDC versus 71 (36.0%) non-URMs (p = 0.10). No differences in clinical and pathologic stage between the cohorts (p = 0.28) were present. URMs took 22 days longer on average to receive treatment (66.5 days vs. 44.8 days, p = 0.003) in the EP cohort and 18 days longer in OP cohort (58.0 days vs. 40.5 days, p < 0.001) compared with non-URMs. Pancreatic Multidisciplinary Clinic enrollment in EP cohort eliminated the difference in time to treatment between cohorts (48.3 days vs. 37.0 days; p = 0.151). RESULTS:Underrepresented minorities were more likely to be diagnosed via EP and showed delayed times to treatment compared with non-URM counterparts. Our PMDC alleviated some of these observed disparities. Future studies are required to elucidate the specific factors that resulted in these findings and to identify solutions.

-OBJECTIVE: Paralumbar muscle volume has been indi-cated as an important factor for patients reporting back pain. Our goal was to determine if there is a statistically significant relationship between the duration of patients' back pain symptoms (>12 weeks or 512 weeks) and paralumbar muscle volume.-METHODS: In this retrospective cohort study, paral-umbar muscles on axial T2-weighted lumbar magnetic resonance images were outlined using ImageJ to deter-mine the paralumbar cross-sectional area (PL-CSA) and lumbar indentation value (LIV) at the center of disc spaces from L1 to L5. The Goutallier classification was determined by the primary author. Quantile regression was performed to compare the PL-CSA, PL-CSA normalized by body mass index, and LIV between the 2 cohorts. Cohort A consisted of patients reporting symptoms 512 weeks, and cohort B included patients with symptoms >12 weeks. Negative binomial regression was used to compare Goutallier class. -RESULTS: A total of 551 patients operated on by a single surgeon with lumbar magnetic resonance imaging within the past 12 months and recorded duration of symptoms were included. Cohort A consisted of 229 patients (41.6%), and cohort B included 322 patients (58.4%). Statistical significance was not found at any lumbar level for PL-CSA, PL-CSA normalized by body mass index, Goutallier class, and LIV. -CONCLUSIONS: Our results suggest that duration of symptoms may not be an accurate indicator for lumbarmuscle volume. These novel findings are clinically valu-able because lumbar muscle volume has been shown to be a marker for recovery. With this information, patients pre-viously believed to be inoperable because of long-standing symptoms can be reevaluated.

Fallon, John; Demyan, Lyudmyla MD; Standring, Oliver MD; Gazzara, Emma MD; Parakrama, Ruwan MD; King, Daniel A MD; Herman, Joseph; Weiss, Matthew J MD, FACS; DePeralta, Danielle MD, FACS; Deutsch, Gary MD, FACS Author Information

BACKGROUND CONTEXT:Prior studies have suggested that muscle strength and quality may be associated with low back pain. Recently, a novel magnetic resonance imaging (MRI)-based lumbar muscle health grade was shown to correlate with health-related quality of life scores after spine surgery. However, the potential association between history of lumbar spine surgery and paralumbar muscle health requires further investigation. PURPOSE:To compare MRI-based paralumbar muscle health parameters between patients with versus without a history of surgery for degenerative lumbar spinal disease. STUDY DESIGN/SETTING:Retrospective cohort study. PATIENT SAMPLE:Consecutive series of patients who presented to the spine surgery clinic of a single surgeon. OUTCOME MEASURES:MRI-based measurements of paralumbar cross-sectional area (PL-CSA), Goutallier grade, lumbar indentation value (LIV). METHODS:A retrospective analysis was performed on a consecutive series of patients of a single surgeon, and patients were included based on availability of lumbar MRI. Axial T2-weighted lumbar MRIs were analyzed for PL-CSA, Goutallier classification, and LIV. Measurements were performed at the center of disc spaces from L1 to L5. Patients with and without history of spine surgery were matched based on age, sex, race, ethnicity, and body mass index (BMI) via propensity score matching. Normality of each muscle health variable was assessed using Kolmogorov-Smirnov test. Mann-Whitney U test or independent t-test performed to compare the matched cohorts, as appropriate. RESULTS:A total of 615 patients were assessed. For final analysis, 89 patients with a history of previous spine surgery were matched with 89 patients without a history of spine surgery. There were no statistically significant differences in age, sex, race, ethnicity, or BMI between the matched cohorts. History of spine surgery was generally associated with worse lumbar muscle health. At all 4 intervertebral levels between L1-L5, PL-CSA was significantly smaller among patients with history of spine surgery. At L4-L5, patients with prior spine surgery had significantly smaller PL-CSA/BMI. Patients with prior spine surgery were found to have greater fatty infiltration of the muscles, with higher average Goutallier grades at levels L1-L2, L2-L3, and L4-L5. In addition, history of spine surgery was associated with smaller LIV at L1-L2, L3-L4, and L4-L5. CONCLUSIONS:The current study demonstrates that history of lumbar spine surgery is associated with worse paralumbar muscle health based on quantitative and qualitative measurements on MRI. On average, patients with history of spine surgery were found to have smaller cross-sectional areas of the paralumbar muscles, greater amounts of fatty infiltration based on Goutallier classification, and smaller lumbar indentation values.