Traumatic brain injury (TBI) is one of the most prevalent causes of morbidity in the United States and is associated with numerous chronic sequelae long after the point of injury. One of the most common long-term complaints in patients with TBI is sleep dysfunction. It is reported that alterations in melatonin follow TBI and may be linked with various sleep and circadian disorders directly (via cellular signaling) or indirectly (via free radicals and inflammatory signaling). Work over the past two decades has contributed to our understanding of the role of melatonin as a sleep regulator and neuroprotective anti-inflammatory agent. Although there is increasing interest in the treatment of insomnia following TBI, a lack of standardization and rigor in melatonin research has left behind a trail of non-generalizable data and ambiguous treatment recommendations. This narrative review describes the underlying biochemical properties of melatonin as they are relevant to TBI. We also discuss potential benefits and a path forward regarding the therapeutic management of TBI with melatonin treatment, including its role as a neuroprotectant, a somnogen, and a modulator of the circadian rhythm.

To examine the relation between acute biomarkers of neuronal injury and trajectories of insomnia following traumatic brain injury (TBI)

Objectives: To develop and validate a novel, low-cost shoulder arthroscopy partial task trainer. Study Design: Cross-sectional study Methods: A low-cost arthroscopy model was created to simulate navigation and triangulation skills in conjunction with ABOS-certified Orthopaedic surgeons' input. Each participant performed three trials of simulated labral repair and performance data was compared between experienced surgeons and novice medical students. Results: A total of 8 orthopaedic surgeons in the experienced group and 18 medical students in the novice group participated in the study. The average age of the experienced group was 43.1 years old, with 8.3 years of post-residency experience. The average age of the novice group was 24.3 years. The experienced group completed the simulation task faster than the novice group (16.6±7.6 vs. 96.4 ±102.2 seconds; p<0.001). Conclusion: The shoulder arthroscopy model demonstrated significant differences in performance between experienced orthopaedic surgeons and novices when used to assess a standardized basic arthroscopic technical skill. This low-cost trainer discriminates between varying skill levels and may be an effective option for simulation training of arthroscopic fundamentals to novice learners. Level of Evidence: III, Case Control Keywords: Arthroscopy, Simulation, Validity Evidence, Orthopaedics, Graduate Medical Education (J Ortho Business 2022; Volume 2, Issue 4:pages 1-4)

Objectives: To compare objective costs between an in-house developed arthroscopy simulator and commercially available options. Design: Cost analysis. Setting: Orthopaedic graduate medical education. Patients/Participants: Eight board-certified orthopaedic surgeons and nineteen novice learners. Intervention: Simulation Training. Main outcome measurement: Cost difference between an in-house developed simulator and a commercially available simulator. Results and conclusions: Significant price differences exist between in-house simulator production cost and commercially available simulators. Low-cost, in-house simulators improve access to arthroscopic simulation training for novice learners by reducing up front cost by 29% and reducing recurring costs by over 90% when compared to a similar commercially available option. Level of Evidence: IV; Cost Analysis Keywords: Education; Simulation; Orthopaedics; Arthroscopy; Simulation Based Learning Theory (J Ortho Business Jan 2022;2(1):7-9)

Describe the prevalence of insomnia in TBI patients, understand separate trajectories of patient populations who suffer Insomnia post-TBI and discuss how post-TBI insomnia might be targeted for therapeutic trials.

OBJECTIVE:Following mild traumatic brain injury (mTBI), many individuals suffer from persistent post-concussive, depressive, post-traumatic stress, and sleep-related symptoms. Findings from self-report scales link these symptoms to biomarkers of neurodegeneration, although the underlying pathophysiology is unclear. Each linked self-report scale includes sleep items, raising the possibility that despite varied symptomology, disordered sleep may underlie these associations. To isolate sleep effects, we examined associations between post-mTBI biomarkers of neurodegeneration and symptom scales according to composite, non-sleep, and sleep components.METHODS:Plasma biomarkers and self-report scales were obtained from 143 mTBI-positive warfighters. Pearson's correlations and regression models were constructed to estimate associations between total, sleep, and non-sleep scale items with biomarker levels, and with measured sleep quality.RESULTS:Symptom severity positively correlated with biomarker levels across scales. Biomarker associations were largely unchanged when sleep items were included, excluded, or considered in isolation. Pittsburgh Sleep Quality Index demonstrated strong correlations with sleep and non-sleep items of all scales.CONCLUSION:The congruency of associations raises the possibility of a common pathophysiological process underlying differing symptomologies. Given its role in neurodegeneration and mood dysregulation, sleep physiology seems a likely candidate. Future longitudinal studies should test this hypothesis, with a focus on identifying novel sleep-related therapeutic targets.