Differences in behavioral roles, anatomical connectivity and gene expression patterns in the dorsal, intermediate and ventral regions of the hippocampus are well characterized. Relatively fewer studies have, however, focused on comparing the physiological properties of neurons located at different dorsoventral extents of the hippocampus. Recently we reported that dorsal CA1 neurons are less excitable than ventral neurons. There is little or no information for how neurons in the intermediate hippocampus compare to those from the dorsal and ventral ends. Also, it is not known whether the transition of properties along the dorsoventral axis is gradual or segmented. In this study, we developed a statistical model to predict the dorsoventral position of transverse hippocampal slices. Using current clamp recordings combined with this model, we found that CA1 neurons in dorsal, intermediate and ventral hippocampus have distinct electrophysiological and morphological properties and that the transition in most (but not all) of these properties from the ventral to dorsal end is gradual. Using linear and segmented regression analyses, we found that input resistance and resting membrane potential changed linearly along the V–D axis. Interestingly, the transition in resonance frequency, rebound slope, dendritic branching in stratum radiatum and action potential properties was segmented along the V–D axis. Together, the findings from this study highlight the heterogeneity in CA1 neuronal properties along the entire longitudinal axis of hippocampus.

OBJECTIVE: To determine if three-dimensional (3D) printed models can be used to improve acetabular fracture pattern recognition and be a valuable adjunct in orthopedic resident education. DESIGN: Fifteen randomized testing stations with each containing plain radiographs (XRs), two-dimensional computed tomography (CT) scans, or 3D model of an acetabular fracture. SETTING: Two orthopedic residency programs based at Level 1 trauma centers. PARTICIPANTS: Forty-one orthopedic residents, PGY 1–5. RESULTS: Senior residents were superior to junior residents at correctly identifying the provided acetabular fracture pattern. Overall, use of CT scans or the 3D model improved fracture classification as compared to standard XRs, but there was no significant difference between use of the CT scans and 3D models. Subjective survey results indicated agreement among residents that 3D models were accurate representations of acetabular fractures and that models would be a desired educational modality. CONCLUSIONS: 3D models improved the accuracy of acetabular fracture identification compared to XR. In addition, trainees were able to use 3D models to obtain similar accuracy compared to CT scans despite not having previous exposure to the models. Interobserver agreement improved when comparing CT to 3D, but did not provide greater than a fair agreement indicating that fracture patterns were difficult to accurately classify even with the use of 3D models. Residents’ subjective responses indicated a positive experience with the use of 3D models. We conclude that the incorporation of 3D models could be an important adjunct to orthopedic residency education for the evaluation complex fracture patterns, but is not significantly superior to identification with CT scans. ( J Surg Ed 000:1–6. © 2018 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.)

Study Design: This was a retrospective questionnaire study at a single academic medical center. Objective: The objective of this study was to obtain information on rates of return to sport following lumbar fusion as well as sport-specific effects to improve evidence-based preoperative patient counseling. Summary of Background Data: Lumbar spinal fusion is one of the fastest-growing surgical procedures, with the majority being in patients aged 60 years and older. Remaining active is an important consideration for elderly patients undergoing lumbar spinal fusion. Golf, swimming, and biking are common forms of recreational exercise for an older population in whom lumbar fusion is often performed. There is a lack of data in the current literature regarding rates of return to recreational sporting activities following elective lumbar fusion. Methods: Following Institutional Review Board approval, all patients undergoing lumbar fusion at a single institution from 2012 to 2016 were screened and included in this study. A minimum of 1-year postoperative follow-up was required. A total of 117 patients were identified undergoing single-level or multilevel lumbar fusion during this time period. The average age was 63 years. Questionnaires were obtained to screen and identify patients who participated in 1 of 3 recreational sports before surgery (golf, swimming, and biking). Preoperative and postoperative collected outcome measures were then compared using the Student t test. Results: Of the 117 identified lumbar fusion patients, 32 patients (27%) participated in 1 of the 3 most common recreational sporting activities of golf, swimming, or biking. Within the golf cohort (n=13), 100% of patients returned to recreational golfing postoperatively. There was a statistically significant reduction in Visual Analog Scale (VAS) pain scores postoperatively (6.3±3.7–1.8±2.4, P=0.01). Driving distance was reduced postoperatively (223.3±42.7–212.1±44.4 yards, P=0.042) and handicaps increased (12.8±8.4–17.0±11.4, P=0.02). Within the swimming cohort (n=9), 100% of patients returned to recreational swimming following lumbar fusion. There was a statistically significant reduction in VAS pain scores postoperatively (9.1±1.7–2.2±2.3, P=0.01). There was a trend towards increased amounts of swimming (times per week) postoperatively, however, this was not statistically significant (2.1±1.7–3.7±1.5, P=0.10). Within the biking cohort (n=10), 100% of patients returned to recreational biking following lumbar fusion. There was a statistically significant reduction in VAS pain scores postoperatively (6.7±4.0–1.3±1.7, P=0.03). There was a trend towards increased amounts of biking (times per week) postoperatively, however, this was not statistically significant (2.5±1.8–3.7±1.6 postoperatively, P=0.20). Conclusions: In the cohort of patients from this study who partook in golfing, swimming or bicycling, 100% were able to return to their respective sport by 3–9 months postoperatively and all had a significant reduction in pain. With regards to golfers, lumbar fusion likely has an adverse effect on their golfing ability with an increase in handicap and an expected reduction in driving distance.