Comparison of Adult Female and Male PMHS Pelvis and Lumbar Response to Underbody Blast.

The goal of this study was to gather and compare kinematic response and injury data on both female and male whole-body Post-mortem Human Surrogates (PMHS) responses to Underbody Blast (UBB) loading. Midsized males (50th percentile, MM) have historically been most used in biomechanical testing and were the focus of the Warrior Injury Assessment Manikin (WIAMan) program, thus this population subgroup was selected to be the baseline for female comparison. Both small female (5th percentile, SF) and large female (75th percentile, LF) PMHS were included in the test series to attempt to discern whether differences between male and female responses were predominantly driven by sex or size. Eleven tests, using 20 whole-body PMHS, were conducted by the research team. Preparation of the rig and execution of the tests took place at the Aberdeen Proving Grounds (APG) in Aberdeen, MD. Two PMHS were used in each test. The Accelerative Loading Fixture (ALF) version 2, located at APG's Bear Point range was used for all male and female whole-body tests in this series. The ALF was an outdoor test rig that was driven by a buried explosive charge, to accelerate a platform holding two symmetrically mounted seats. The platform was designed as a large, rigid frame with a deformable center section that could be tuned to simulate the floor deformation of a vehicle during a UBB event. PMHS were restrained with a 5-point harness, common in military vehicle seats. Six-degree-of-freedom motion blocks were fixed to L3, the sacrum, and the left and right iliac wings. A three-degree-of freedom block was fixed to T12. Strain gages were placed on L4 and multiple locations on the pelvis. Accelerometers on the floor and seat of the ALF provided input data for each PMHS' feet and pelvis. Time histories and mean peak responses in z-axis acceleration were similar among the three PMHS groups in this body region. Injury outcomes were different and seemed to be influenced by both sex and size contributions. Small females incurred pelvis injuries in absence of lumbar injures. Midsized males had lumbar vertebral body fractures without pelvis injuries. And large females with injuries had both pelvis and lumbar VB fractures. This study provides evidence supporting the need for female biomechanical testing to generate female response and injury thresholds. Without the inclusion of female PMHS, the differences in the injury patterns between the small female and midsized male groups would not have been recognized. Standard scaling methods assume equivalent injury patterns between the experimental and scaled data. In this study, small female damage occurred in a different anatomical structure than for the midsized males. This is an important discovery for the development of anthropomorphic test devices, injury criteria, and injury mitigating technologies. The clear separation of small female damage results, in combination with seat speeds, suggest that the small female pelvis injury threshold in UBB events lies between 4 - 5 m/s seat speed. No inference can be made about the small female lumbar threshold, other than it is likely at higher speeds and/or over longer duration. Male lumbar spine damage occurred in both the higher- and lower lower-rate tests, indicating the injury threshold would be below the seat pulses tested in these experiments. Large females exhibited injury patterns that reflected both the small female and midsized male groups - with damaged PMHS having fractures in both pelvis and lumbar, and in both higher- and lower- rate tests. The difference in damage patterns between the sex and size groups should be considered in the development of injury mitigation strategies to protect across the full population.

A comparison of fracture response in female and male lumbar spine in simulated under body blast component tests.

Underbody blasts (UBB) from mines and improvised explosive devices in military combat can cause debilitating spine injuries to vehicle mounted soldiers. Due to the exclusion of females in combat roles in prior US Department of Defense policy, UBB exposure and injury have predominantly affected male soldiers. Recent policy changes have opened many combat roles to women serving in the US Military (Carter, 2015) and have increased the need to understand the injury potential for female Warfighters. The goal of this study was to investigate the fracture response of adult female lumbar spines compared to adult male spines in UBB relevant loading to identify potential differences in either fracture mechanism or force. Results are presented for 15 simulated UBB spine compression tests using three small female (SF), five large female (LF), and seven mid-sized male (MM) post-mortem human subjects (PMHS). These PMHS groups align to 5th- and 75th-percentile female and 50th-percentile males, based on height and weight from the 2012 Anthropometric Survey of U.S. Army Personnel (Gordon et al., 2014). Both small females and large females (similar in size to the males) were included to assess the role of size and/or sex in the response. Tests were conducted at Virginia Tech on a cam-driven linear compression rig, which included a 6-axis load cell and ram accelerometer to evaluate the fracture. Fracture was visualized through high-speed x-ray video. All female and male spines exhibited similar fracture initiation at the end plates and progression through the vertebral body. The resulting severe compression and burst fractures were representative of reported theatre injuries (Freedman et al., 2014). Mean axial fracture forces were -4182 ± 940 N (SF), -6225 ± 1180 N (LF), -5459 ± 1472 N (All Females) and -7993 ± 2445 N (MM). The SF group was found to have statistically significant differences in mean fracture force compared to both LF and MM groups, while no significant difference was found between LF and MM groups, although the mean force at initial fracture was lower for the LF group. The All-Females group Fz mean was significantly different from the MM group. These data suggest that the significant difference in weight between the SF and LF groups, did have an influence on the Fz outcome, when controlling for sex. Conversely, controlling for size in the LF and MM comparison, sex did influence the mean Fz, but was not statistically significant. Groups with combined sex and size differences, however, did show significant differences in mean Fz. Further study is warranted to understand whether sex or size has a larger effect on fracture force. Mean ram displacement (spine compression) values at fracture initiation were -6.0 ± 5.3 mm (SF), -4.4 ± 0.8 mm (LF), -5.0 ± 3.0 mm (All Females), -6.2 ± 4.5 mm (MM). Spine compression did not seem to be largely influenced by either sex or size, and none of the groups was found to have significant differences in mean displacement values.

Up Front and Open? Shrouded in Secrecy? Or Somewhere in Between? A Meta-Research Systematic Review of Open Science Practices in Sport Medicine Research.

OBJECTIVE: To investigate open science practices in research published in the top 5 sports medicine journals from May 1, 2022, and October 1, 2022. DESIGN: A meta-research systematic review. LITERATURE SEARCH: Open science practices were searched in MEDLINE. STUDY SELECTION CRITERIA: We included original scientific research published in one of the identified top 5 sports medicine journals in 2022 as ranked by Clarivate: (1) British Journal of Sports Medicine, (2) Journal of Sport and Health Science, (3) American Journal of Sports Medicine, (4) Medicine and Science in Sports and Exercise, and (5) Sports Medicine-Open. Studies were excluded if they were systematic reviews, qualitative research, gray literature, or animal or cadaver models. DATA SYNTHESIS: Open science practices were extracted in accordance with the Transparency and Openness Promotion guidelines and patient and public involvement. RESULTS: Two hundred forty-three studies were included. The median number of open science practices in each study was 2, out of a maximum of 12 (range: 0-8; interquartile range: 2). Two hundred thirty-four studies (96%, 95% confidence interval [CI]: 94%-99%) provided an author conflict-of-interest statement and 163 (67%, 95% CI: 62%-73%) reported funding. Twenty-one studies (9%, 95% CI: 5%-12%) provided open-access data. Fifty-four studies (22%, 95% CI: 17%-27%) included a data availability statement and 3 (1%, 95% CI: 0%-3%) made code available. Seventy-six studies (32%, 95% CI: 25%-37%) had transparent materials and 30 (12%, 95% CI: 8%-16%) used a reporting guideline. Twenty-eight studies (12%, 95% CI: 8%-16%) were preregistered. Six studies (3%, 95% CI: 1%-4%) published a protocol. Four studies (2%, 95% CI: 0%-3%) reported an analysis plan a priori. Seven studies (3%, 95% CI: 1%-5%) reported patient and public involvement. CONCLUSION: Open science practices in the sports medicine field are extremely limited. The least followed practices were sharing code, data, and analysis plans. J Orthop Sports Phys Ther 2023;53(12):1-13. Epub 20 October 2023. doi:10.2519/jospt.2023.12016.

Barriers and facilitators to implementation of musculoskeletal injury mitigation programmes for military service members around the world: a scoping review.

INTRODUCTION: Musculoskeletal injury (MSK-I) mitigation and prevention programmes (MSK-IMPPs) have been developed and implemented across militaries worldwide. Although programme efficacy is often reported, development and implementation details are often overlooked, limiting their scalability, sustainability and effectiveness. This scoping review aimed to identify the following in military populations: (1) barriers and facilitators to implementing and scaling MSK-IMPPs; (2) gaps in MSK-IMPP research and (3) future research priorities. METHODS: A scoping review assessed literature from inception to April 2022 that included studies on MSK-IMPP implementation and/or effectiveness in military populations. Barriers and facilitators to implementing these programmes were identified. RESULTS: From 132 articles, most were primary research studies (90; 68.2%); the remainder were review papers (42; 31.8%). Among primary studies, 3 (3.3%) investigated only women, 62 (69%) only men and 25 (27.8%) both. Barriers included limited resources, lack of stakeholder engagement, competing military priorities and equipment-related factors. Facilitators included strong stakeholder engagement, targeted programme design, involvement/proximity of MSK-I experts, providing MSK-I mitigation education, low burden on resources and emphasising end-user acceptability. Research gaps included variability in reported MSK-I outcomes and no consensus on relevant surveillance metrics and definitions. CONCLUSION: Despite a robust body of literature, there is a dearth of information about programme implementation; specifically, barriers or facilitators to success. Additionally, variability in outcomes and lack of consensus on MSK-I definitions may affect the development, implementation evaluation and comparison of MSK-IMPPs. There is a need for international consensus on definitions and optimal data reporting elements when conducting injury risk mitigation research in the military.

Patient-Reported Outcomes and Reoperation Rates Following Lumbar Tubular Microdecompression: Six-year Follow-Up.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: To report reoperation rates after lumbar tubular microdecompression (LTM) and to compare patient-reported outcomes (PROs) six years after surgery between those who did and did not need revision at the index level. SUMMARY OF BACKGROUND DATA: Long-term data describing PROs and reoperation rates after LTMs are lacking. MATERIALS AND METHODS: Patients with lumbar spinal stenosis underwent one or more of three LTM procedures. Demographic, PROs [Oswestry Disability Index (ODI) and visual analog scale (VAS) for back and leg pain], and reoperation data were collected. Failure of an index LTM was defined as any revision surgery at the index level. Revision LTM at a different level was not considered failure. Failure and revision LTM incidence at a different level and cumulative incidence were prospectively collected up to six years. Mixed effects linear regressions with 95% CIs were performed to assess potential differences in ODI and reported VAS back and leg pain between patients that reported failure and those that did not. RESULTS: A total of 418 patients were included with median follow-up of 3.0 (1.9, 4.1) years. In all, 25% had a reoperation by six years. Sixty-five (16%) failed and 35 (9%) underwent a second LTM at another level. Cumulative failure incidence was 9% within the first two years. Failure patients had a statistically higher ODI [12.1 (95% CI, 3.2, 20.1) and VAS back [2.3 (95% CI, 0.9, 3.8)] and leg pain [1.6 (95% CI, 0.2, 3.1)] throughout follow-up. The overall dural tear rate was 7.2%. CONCLUSIONS: LTM is an effective treatment for lumbar spinal stenosis with sustained six-year PROs. Most failures occur within two years postoperatively and stabilize to 4% yearly incidence by year 5. The yearly incidence of reoperation with LTM stabilizes at 3% by year 6 postoperatively. LEVEL OF EVIDENCE: 2.

Orthopaedic Surgery Training in North Carolina: The Impact of The Flexner Report and The Sherman Antitrust Act.

The current medical schools and orthopaedic residency programs in the state of North Carolina have evolved based upon geopolitical, economic events, historical reports and regulations. The American Medical Association Committee on Medical Education, the Flexner Report and the Sherman Antitrust Act and their recommendations were codified by state regulatory agencies and state law. These important pressures created the programs as they are known today. The result was the forced closure of most early medical institutions in the state of North Carolina in the early 1900s. Industrial resource consolidation by monopolies was the motivation for the Sherman antitrust act. Enforced by Theodore Roosevelt, this legislation disbanded major monopolies and encouraged philanthropy. This manuscript details the evolution of modern medical education and highlights the impact of historical social, economic and political events on the development of Duke, Wake Forest, University of North Carolina and Charlotte/ Atrium Health orthopedic programs in North Carolina. (Journal of Surgical Orthopaedic Advances 31(3):139-143, 2022).

An Innovative Seven-year Physician Scientist Residency Training Program That Addresses the Shortage of Academic Surgeons.

Due to the declining number of scientifically trained physicians and increasing demand for high-quality literature, our institution pioneered a seven-year Physician Scientist Training Program (PSTP) to provide research-oriented residents the knowledge and skills for a successful academic career. The present study sought to identify orthopaedic surgeons with MD/PhD degrees, residency programs with dedicated research tracks, and to assess the effectiveness of the novel seven-year program in training prospective academic orthopaedic surgeons. Surgeons with MD/PhD degrees account for 2.3% of all 3,408 orthopaedic faculty positions in U.S. residency programs. During the last 23 years, our PSTP residents produced 752 peer-reviewed publications and received $349,354 from 23 resident-authored extramural grants. Eleven of our seven-year alumni practice orthopaedic surgery in an academic setting. The seven-year PSTP successfully develops clinically trained surgeon scientists with refined skills in basic science and clinical experimental design, grant proposals, scientific presentations, and manuscript preparation. (Journal of Surgical Orthopaedic Advances 31(3):144-149, 2022).

Distal Radius Fractures and Bone Health: A Survey of Hand Surgeons.

Following low-energy distal radius fractures (DRF) patients rarely receive a bone health evaluation. The purpose of this survey was to investigate the attitudes and practices of American Society for Surgery of the Hand (ASSH) members regarding osteoporosis and low-energy DRF. An electronic survey was sent to 4,125 members of the ASSH. Physicians were asked about referral patterns, comfort level with labs and imaging related to bone health, and barriers. There were 475 responses (response rate 11.5%). Most respondents always (33.1%) or often (32.8%) talk about osteoporosis risk after low-energy DRF. Most respondents (87.6%) do not routinely order metabolic labs. Less than half knew of an available Fracture Liaison Service. Barriers to discussion included not enough time (32.6%), not comfortable with the topic (12.6%), and not within practice scope (33.3%). Respondents reported variable comfort levels discussing and implementing osteoporosis care in the setting of low-energy DRF. (Journal of Surgical Orthopaedic Advances 31(3):155-160, 2022).

Medical Students' Perceptions and Retention of Skills From Active Resilience Training.

BACKGROUND AND OBJECTIVES: Medical students face difficult transitions throughout their training that increase their risk of burnout. Resiliency training may prepare students to better face the demands of their medical careers. This project is an initial investigation into medical students' long-term utilization of learned resiliency skills. METHODS: Medical students completed a survey 1-18 months following Active Resilience Training (ART). The computerized survey assessed the program's success in meeting its stated objectives and how often students used the skills they had learned during the training. RESULTS: ART is highly effective in increasing awareness of the benefits of resiliency training. The majority of participants would recommend the course to their peers. Students continued to utilize the skills learned for more than 18 months after completing the training. These skills include planned breaks, prioritizing sleep, building support systems, and mindfulness techniques. CONCLUSIONS: This work adds to the existing literature regarding participants' valuation of novel resilience curricula. Students utilized the skills learned in ART as long as 18 months after completing the program. More study evaluating the specific effects of ART on traditional measures of resilience such as the Brief Resilience Scale (BRS) is needed.

Contributions of Pubic Rami Fracture Morphology and Fixation to Pelvic Ring Stability in Type 1 Lateral Compression Injuries: A Biomechanical Cadaveric Study.

BACKGROUND: Treatment of lateral compression type 1 (LC-1) injuries has historically been nonoperative with immediate weight-bearing. However, management of these injuries remains controversial, with reports of displacement at follow-up for nonoperatively managed LC-1 fractures. The goal of our study was to determine the effect of superior pubic ramus fracture morphology and fixation construct on pelvic stability. METHODS: Ten fresh-frozen cadaveric were transected into hemi-pelvises. Incomplete Denis type 1 sacral fractures were made. Hemi-pelvises were randomized to receive a transverse-type or oblique-type superior pubic ramus fracture with the contralateral hemi-pelvis receiving the opposing morphology. A lateral load to 135N was applied with an Instron materials testing machine and lateral displacement of the hemi-pelvis was recorded. Deflection and stiffness were calculated. Statistical analysis was conducted using a t test assuming unequal variances with an alpha = 0.05. RESULTS: Oblique-type superior pubic ramus fractures allowed more deflection compared with transverse-type fractures in the absence of fixation (P = 0.018). The posterior-only and combined anterior and posterior fixation configurations on average reduced deflection more than no fixation or anterior fixation only. In all fixation configuration cases, the average deflection for transverse-type fractures was less than that of the oblique-type fractures. CONCLUSIONS: Our findings suggest that displacement of LC-1 pelvic injuries may be related to pubic rami fracture morphology. When looking at initial injury imaging, oblique-type pubic rami fractures may suggest an increased potential for displacement over time. In such cases, we recommend an examination under anesthesia to evaluate for underlying instability and consideration for fixation. LEVEL OF EVIDENCE: Therapeutic Level V.

Lumbopelvic postural differences in adolescent idiopathic scoliosis: A pilot study.

BACKGROUND: A primary etiology of adolescent idiopathic scoliosis (AIS) is currently unknown, but poor postural control of the spinal extensor musculature has been identified as an AIS risk factor. Identifiable postural differences would aid in advancing the precise postural behaviors that should be modified during Physiotherapy Scoliosis Specific Exercise (PSSE) to help limit the progression of AIS. RESEARCH QUESTION: Are there any determinable differences in lumbopelvic posture or range of motion between subjects with AIS and controls? METHODS: This prospective cohort pilot study consisted of 53 subjects (27 AIS and 26 control) aged 11-17 years. Subjects had their lumbopelvic posture assessed and monitored using the ViMove DorsaVi sensor package. All subjects underwent a live assessment to obtain initial lumbopelvic (LP) range of motion (ROM) measurements. Subjects were then monitored while continuing with normal activities of daily living (ADLs) for 12 h. With an alpha level of 0.05, nonparametric analyses were performed for each variable via a Mann-Whitney U-test. RESULTS: During the live assessment, controls exhibited a significantly greater anterior pelvic tilt ROM in the sitting position than the AIS group (p = 0.0433). When compared to female controls, females with AIS had a sitting pelvic tilt ROM that was significantly more retroverted (p = 0.0232) and less anteverted (p = 0.0010). During ADLs, female controls exhibited a higher total number of extension events than their female with AIS (p = 0.0263). These associations did not strengthen with greater spinal deformity. SIGNIFICANCE: This work demonstrates postural differences between patients with AIS and controls. Further study is necessary to determine why patients with AIS adopt these postures, and if PSSEs can be utilized to limit the progression of AIS.

Methodology for Evaluation of WIAMan Injury Assessment Reference Curves Using Whole Body Match-Paired Data.

Development of the Warrior Injury Assessment Manikin (WIAMan) capability has included the creation of injury assessment reference curves (IARCs) specific to under-body blast (UBB) loading mechanisms and injuries. The WIAMan IARCs were created from high-rate vertical loading tests of component post-mortem human surrogates (PMHS) and analogous components of the WIAMan anthropomorphic test device (ATD). Validation of the WIAMan IARCs is required prior to the WIAMan ATD being utilized for injury assessment in live-fire vehicle test events. A portion of the validation process involves evaluating the ability of the IARCs to predict injury at the system level (whole body). This study evaluates a methodology to assess the performance of the WIAMan IARCs using match-paired tests of whole body PMHS and the WIAMan ATD. The methodology includes a qualitative analysis designed to identify false-positive and false-negative ATD predictions, as well as a quantitative analysis that utilizes area under the receiver-operating characteristic curve (AROC) and Brier score indices to grade IARC performance. Three WIAMan IARCs were used to exemplify the proposed methodology and results are provided. Attributes of the false-prediction, AROC, and Brier score portions of the methodology are presented, with results indicating the new methodology is thorough and robust in evaluation of IARCs.

Forward Surgical Teams as a Model for Humanitarian Orthopedic Surgical Care: A Review of Current Literature.

INTRODUCTION: Orthopedic trauma is a significant portion of global burden of disease in low- and middle-income countries (LMICs). This has led the World Health Organization to advocate for increased surgical intervention in LMICs. The two largest barriers to orthopedic surgical care for LMICs are cost of procedure and geographic access to centers with appropriate surgical capabilities. There is no current consensus on how to structure surgical interventional teams. The overall objective of this study is to describe the composition of a forward surgical team (FST), including its abilities and limitations. It is hypothesized that an FST is an effective model for orthopedic surgical relief efforts in LMICs. METHODS: A narrative literature review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis standards published by the National Academies of Medicine. Studies were evaluated by structured review procedures to identify an FST's capacity for orthopedic surgery, as well as applicability for humanitarian care. Articles detailing FST logistics, types of orthopedic treatment provided, and instances of humanitarian care while deployed in austere environments were included for review. RESULTS: The FST is a military surgical unit operating with a small crew of surgeons and supporting staff who use tents or trailers that can be positioned near points of conflict, often in remote or austere environments. FSTs were designed to treat traumatic injuries, including orthopedic trauma from RTIs. If used as a sponsored humanitarian aid mission, FSTs can provide surgical care at free or greatly reduced costs. Because FSTs carry limited supplies and personnel, they are highly mobile surgical units that can be transported via truck. CONCLUSION: FSTs are effective models for humanitarian orthopedic surgery in LMICs. FSTs were designed to treat orthopedic trauma, the largest burden of orthopedic care in LMICs. Efficient use of limited equipment allows FSTs to be cost effective for funding sources and highly mobile to reduce the geographic barrier to care. Further research is needed to determine the cost to operate an FST and ethical consideration for military intervention for foreign humanitarian aid.

Improved osseointegration using porcine xenograft compared to demineralized bone matrix for the treatment of critical defects in a small animal model.

BACKGROUND: Autograft (AG) is the gold standard bone graft due to biocompatibility, osteoconductivity, osteogenicity, and osteoinductivity. Alternatives include allografts and xenografts (XG). METHODS: We investigated the osseointegration and biocompatibility of a decellularized porcine XG within a critical defect animal model. We hypothesized that the XG will result in superior osseointegration compared to demineralized bone matrix (DBM) and equivalent immune response to AG. Critical defects were created in rat femurs and treated with XG, XG plus bone morphogenetic protein (BMP)-2, DBM, or AG. Interleukin (IL)-2 and IFN-gamma levels (inflammatory markers) were measured from animal blood draws at 1 week and 1 month post-operatively. At 1 month, samples underwent micro-positron-emission tomography (microPET) scans following 18-NaF injection. At 16 weeks, femurs were retrieved and sent for micro-computerized tomography (microCT) scans for blinded grading of osseointegration or were processed for histologic analysis with tartrate resistant acid phosphatase (TRAP) and pentachrome. RESULTS: Enzyme linked immunosorbent assay testing demonstrated greater IL-2 levels in the XG vs. AG 1 week post-op; which normalized by 28 days post-op. MicroPET scans showed increased uptake within the AG compared to all groups. XG and XG + BMP-2 showed a trend toward increased uptake compared with DBM. MicroCT scans demonstrated increased osseointegration in XG and XG + BMP groups compared to DBM. Pentachrome staining demonstrated angiogenesis and endochondral bone formation. Furthermore, positive TRAP staining in samples from all groups indicated bone remodeling. CONCLUSIONS: These data suggest that decellularized and oxidized porcine XG is biocompatible and at least equivalent to DBM in the treatment of a critical defect in a rat femur model.

Newer generation of proximal tibia locking plates demonstrate large variability in their ability to capture the posteromedial fragment in bicondylar tibial plateau fractures.

INTRODUCTION: The early generations of proximal tibial locking plates demonstrated inferior results when compared to dual plating in bicondylar tibial plateau fractures with posteromedial fragments (PMF). Modern plates have multiple rows of locking screws and variable angle technology -which tote the ability to capture the PMF. The purpose of this study was to determine if the modern plates could capture the PMF in a large series of bicondylar tibial plateau fractures. MATERIALS & METHODS: Axial computer topography (CT) scans of 114 bicondylar tibial plateau fractures with PMF were analyzed. Five proximal tibia locking plates-in seven total configurations-were applied to radiopaque tibiae models. All possible screws were placed. Templates of screw trajectories were created based on the model CT scans. These were superimposed onto patient CT scan images to assess for screw penetration into the PMF. Number of screws fully within the PMF were recorded. Capture of the PMF was defined as having at least two screws within the fragment. RESULTS: On average, all plates were able to capture 81.6% of PMF with an average of 3.77 [95% Confidence Interval (CI): 3.47-4.07] screws. However, their ability to capture all fragments varied greatly, from 55.7%-95.2% in fixed angle constructs. Overall, variable angle constructs had a significantly higher capture rate (98.5% vs. 74.9%; p<0.0001) and more screws in the PMF (5.88 [95% CI: 5.58-6.17] vs 2.93 [95% CI: 2.62-3.24]; p<0.0001) when compared to fixed angle constructs. CONCLUSION: Newer generation locking plates vary greatly in their ability to capture the PMF. Variable angle technology dramatically increases the ability to capture the majority of PMFs. Prior biomechanical and clinical studies may yield substantially different results if repeated with these newer implants. Use of newer generation locked plates should not replace thorough preoperative planning.

The Effect of the Strengthen Opioid Misuse Prevention Act on Opiate Prescription Practices Within the Orthopaedic Surgery Department of an Academic Medical Center.

In 2017, the Department of Health and Human Service declared a public health emergency known as the opioid crisis. In North Carolina, the "Strengthen Opioid Misuse Prevention Act of 2017" (STOP Act) went into effect on January 1, 2018, seeking to strengthen oversight over opioid prescriptions. Among other mandates, this legislation limited the duration of the initial prescription to 5 or 7 days. The purpose of this study was to compare narcotic prescription practices within the Department of Orthopaedic Surgery at an academic medical center before and after the enactment of the STOP Act. We hypothesized that there would be a statistically significant decrease in the amount of postoperative opioids prescribed after the STOP Act and that this decrease would be consistent across all types of providers in the Orthopaedic Surgery Department. Methods: Opiate prescriptions data from all orthopaedic surgery providers at our academic institution were collected from January to the end of September in 2017 and from January to the end of September in 2018. After filtering the providers by our study's inclusion and exclusion criteria, we included data from 49 providers in our analysis. We used a paired t-test to compare the prescription data between the two periods. Results: There was a 35% decrease in morphine milligram equivalents prescribed at our institution between 2017 and 2018 (P = 0.0003). This reduction was statistically significant and equaled 27,374 less morphine milligram equivalents prescribed per provider (95% confidence interval 13,226 to 41,523). The average number of opiate prescriptions per provider decreased from 171.5 in 2017 to 161 in 2018 (P = 0.48), although this was not statistically significant. Conclusion: The STOP Act effectively decreased the amount of opiates prescribed within our Orthopaedic Surgery Department. Similar legislation may be effective in other states and at the federal level to decrease narcotic prescriptions and subsequent abuse.

Optimizing the Double-Row Construct: An Untied Medial Row Demonstrates Equivalent Mean Contact Pressures in a Rotator Cuff Model.

BACKGROUND: The merits of a double-row rotator cuff repair (RCR) construct are well-established for restoration of the footprint and lateral-row security. The theoretical benefit of leaving the medial row untied is to prevent damage to the rotator cuff by tissue strangulation, and the benefit of suture tape is a more even distribution of force across the repair site. These benefits, to our knowledge, have not been evaluated in the laboratory. HYPOTHESIS: Leaving the medial row untied and using a suture bridge technique with suture tape will offer more even pressure distribution across the repair site without compromising total contact force. STUDY DESIGN: Controlled laboratory study. METHODS: A laboratory model of RCR was created using biomechanical research-grade composite humeri and human dermal allografts. The pressure distribution in a double-row suture bridge repair construct was analyzed using the following testing matrix: double-loaded suture anchors with the medial row tied (n = 15) versus untied (n = 15) compared with double-loaded suture tape and anchors with the medial row tied (n = 15) versus untied (n = 15). A digital pressure sensor was used to measure pressure over time after tensioning of the repair site. A multivariate analysis of variance was used for statistical analysis with post hoc testing. RESULTS: The total contact force did not significantly differ between constructs. The contact force between double-loaded suture anchors and double-loaded suture tape and anchors was similar when tied (P = .15) and untied (P = .44). An untied medial row resulted in similar contact forces in both the double-loaded suture anchor (P = .16) and double-loaded suture tape and anchor (P = .25) constructs. Qualitative increases in focal contact pressure were seen when the medial row was tied. CONCLUSION: An untied medial row did not significantly affect the total contact force with double-loaded suture anchors and with double-loaded suture tape and anchors. Tying the medial row qualitatively increased crimping at the construct's periphery, which may contribute to tissue strangulation and hinder clinical healing. Qualitative improvements in force distribution were seen with double-loaded suture tape and anchors. CLINICAL RELEVANCE: Both tied and untied medial rows demonstrated similar pressures across the repair construct.

Comparing the Efficiency, Radiation Exposure, and Accuracy Using C-Arm versus O-Arm With 3D Navigation in Placement of Transiliac-Transsacral and Iliosacral Screws: A Cadaveric Study Evaluating an Early Career Surgeon.

OBJECTIVES: To compare the efficiency, radiation exposure to surgeon and patient, and accuracy of C-arm versus O-arm with navigation in the placement of transiliac-transsacral and iliosacral screws by an orthopaedic trauma fellow, for a surgeon early in practice. METHODS: Twelve fresh frozen cadavers were obtained. Preoperative computed tomography scans were reviewed to assess for safe corridors in the S1 and S2 segments. Iliosacral screws were assigned to the S1 segment in dysmorphic pelvises. Screws were randomized to modality and laterality. An orthopaedic trauma fellow placed all screws. Time of procedure and radiation exposure to the cadaver and surgeon were recorded. Three fellowship-trained orthopaedic trauma surgeons rated the safety of each screw on postoperative computed tomography scan. RESULTS: Six normal and 6 dysmorphic pelvises were identified. Eighteen transiliac-transsacral screws and 6 iliosacral screws were distributed evenly between C-arm and O-arm. Average operative duration per screw was significantly shorter using C-arm compared with O-arm (15.7 minutes ± 6.1 vs. 23.7 ± 8.5, P = 0.014). Screw placement with C-arm exposed the surgeon to a significantly greater amount of radiation (3.87 × 10 rads vs. 0.32 × 10, P < 0.001) while O-arm exposed the cadaver to a significantly greater amount of radiation (0.03 vs. 2.76 rads, P < 0.001). Two S2 transiliac-transsacral screws (1 C-arm and 1 O-arm) were categorized as unsafe based on scoring. There was no difference in screw accuracy between modalities. CONCLUSIONS: A difference in accuracy between modalities could not be elucidated, whereas efficiency was improved with utilization of C-arm, with statistical significance. A statistically significant increase in radiation exposure to the surgeon using C-arm was found, which may be clinically significant over a career. The results of this study can be extrapolated to a fellow or surgeon early in practice. The decision between use of these modalities will vary depending on surgeon preference and hospital resources.

Investigating the Osteoinductive Potential of a Decellularized Xenograft Bone Substitute.

Bone grafting is the second most common tissue transplantation procedure worldwide. One of the alternative methods for bone repair under investigation is a tissue-engineered bone substitute. An ideal property of tissue-engineered bone substitutes is osteoinductivity, defined as the ability to stimulate primitive cells to differentiate into a bone-forming lineage. In the current study, we use a decellularization and oxidation protocol to produce a porcine bone scaffold and examine whether it possesses osteoinductive potential and can be used to create a tissue-engineered bone microenvironment. The decellularization protocol was patented by our lab and consists of chemical decellularization and oxidation steps using combinations of deionized water, trypsin, antimicrobials, peracetic acid, and triton-X100. To test if the bone scaffold was a viable host, preosteoblasts were seeded and analyzed for markers of osteogenic differentiation. The osteoinductive potential was observed in vitro with similar osteogenic markers being expressed in preosteoblasts seeded on the scaffolds and demineralized bone matrix. To assess these properties in vivo, scaffolds with and without preosteoblasts preseeded were subcutaneously implanted in mice for 4 weeks. MicroCT scanning revealed 1.6-fold increased bone volume to total volume ratio and 1.4-fold increase in trabecular thickness in scaffolds after implantation. The histological analysis demonstrates new bone formation and blood vessel formation with pentachrome staining demonstrating osteogenesis and angiogenesis, respectively, within the scaffold. Furthermore, CD31+ staining confirmed the endothelial lining of the blood vessels. These results demonstrate that porcine bone maintains its osteoinductive properties after the application of a patented decellularization and oxidation protocol developed in our laboratory. Future work must be performed to definitively prove osteogenesis of human mesenchymal stem cells, biocompatibility in large animal models, and osteoinduction/osseointegration in a relevant clinical model in vivo. The ability to create a functional bone microenvironment using decellularized xenografts will impact regenerative medicine, orthopedic reconstruction, and could be used in the research of multiple diseases.

Development of a Homemade Spinal Model for Simulation to Teach Ultrasound Guidance for Lumbar Puncture.

BACKGROUND: Spinal procedures such as lumbar punctures (LPs), epidurals, and spinal blocks are essential components to clinical practice but are challenging to teach, learn, or practice on real patients due to patient safety and comfort limiting the number of attempts. Resident physicians traditionally learn these spinal procedural skills through observation of a more senior physician before attempting the procedure. Simulation using models can improve providers' competency without introducing an added risk to patients. A difficulty encountered with access to simulation training for such procedures is the limited availability of simulators. While there are several high-quality, commercially available models that mimic the anatomy of lumbar spine, the cost of these models often limits the access to students and practitioners. The other challenge is access to simulators with versatility that can be used for palpation as well as ultrasound (US)-guided procedures. A simulator that can combine practice of both palpation and US-guided modalities would be efficacious in reducing cost to the teaching institutions. We attempted to overcome the access barrier to spinal models by developing an alternative that provides a good simulator for both palpation and US-guided LP while keeping the cost low. Our model can be easily manufactured by not only clinicians but also medical students. METHODS: A literature review was conducted to assess the available research and information on the production and use of simulators for practicing LPs and other spinal procedures. Publications queried described the production of models and utilizing the information compiled we devised and fabricated a model. RESULTS: A lumbar spine model was developed using computed tomography spine data of an average-sized male patient without lumbar spine pathology. The model was created using medical imaging processing software and printed on 3D printer using nylon plastic. This model was then utilized by residents, advanced practice providers, and medical students for palpation and US-guided LP simulation training. CONCLUSIONS: An inexpensive reusable non-commercial LP simulator can be an effective method for teaching invasive procedures like LPs, especially if it can be used both for palpation and US-guided procedures. The method outlined here can be easily reproduced in a relatively short amount of time. We recognize one limitation in the widespread dissemination of this technique being access to a 3D printer and digital designs for printing. Future studies will be necessary to determine the efficacy of the homemade LP simulator in teaching neurointensivist in training.