Evan Garofalo

Stature and body mass estimation from skeletal remains in the European Holocene

Techniques that are currently available for estimating stature and body mass from European skeletal remains are all subject to various limitations. Here, we develop new prediction equations based on large skeletal samples representing much of the continent and temporal periods ranging from the Mesolithic to the 20th century. Anatomical reconstruction of stature is carried out for 501 individuals, and body mass is calculated from estimated stature and biiliac breadth in 1,145 individuals. These data are used to derive stature estimation formulae based on long bone lengths and body mass estimation formulae based on femoral head breadth. Prediction accuracy is superior to that of previously available methods. No systematic geographic or temporal variation in prediction errors is apparent, except in tibial estimation of stature, where northern and southern European formulae are necessary because of the presence of relatively longer tibiae in southern samples. Thus, these equations should bebroadly applicable to European Holocene skeletal samples.

Gradual decline in mobility with the adoption of food production in Europe

Significance Declining mobility levels following the Pleistocene had profound effects on human demography, social organization, and health, but the exact timing and pace of this critical change are unknown. Here we examine direct evidence for changing mobility levels from limb bone structural characteristics in a large sample of European skeletons spanning the past 30,000 y. Our results show that mobility first declined during the Neolithic, at the onset of food production, but that the decline was gradual, continuing for several thousand years as agriculture intensified. No change in relative limb strength occurred during the past 2,000 y. Thus, the more gracile modern human skeleton is a result of increased sedentism tied to food production, not subsequent mechanization and industrialization. Increased sedentism during the Holocene has been proposed as a major cause of decreased skeletal robusticity (bone strength relative to body size) in modern humans. When and why declining mobility occurred has profound implications for reconstructing past population history and health, but it has proven difficult to characterize archaeologically. In this study we evaluate temporal trends in relative strength of the upper and lower limb bones in a sample of 1,842 individuals from across Europe extending from the Upper Paleolithic [11,000–33,000 calibrated years (Cal y) B.P.] through the 20th century. A large decline in anteroposterior bending strength of the femur and tibia occurs beginning in the Neolithic (∼4,000–7,000 Cal y B.P.) and continues through the Iron/Roman period (∼2,000 Cal y B.P.), with no subsequent directional change. Declines in mediolateral bending strength of the lower limb bones and strength of the humerus are much smaller and less consistent. Together these results strongly implicate declining mobility as the specific behavioral factor underlying these changes. Mobility levels first declined at the onset of food production, but the transition to a more sedentary lifestyle was gradual, extending through later agricultural intensification. This finding only partially supports models that tie increased sedentism to a relatively abrupt Neolithic Demographic Transition in Europe. The lack of subsequent change in relative bone strength indicates that increasing mechanization and urbanization had only relatively small effects on skeletal robusticity, suggesting that moderate changes in activity level are not sufficient stimuli for bone deposition or resorption.

Interpreting skeletal growth in the past from a functional and physiological perspective

The study of juvenile skeletal remains can yield important insights into the health, behavior, and biological relationships of past populations. However, most studies of past skeletal growth have been limited to relatively simple metrics. Considering additional skeletal parameters and taking a broader physiological perspective can provide a more complete assessment of growth patterns and environmental and genetic effects on those patterns. We review here some alternative approaches to ontogenetic studies of archaeological and paleontological skeletal material, including analyses of body size (stature and body mass) and cortical bone structure of long bone diaphyses and the mandibular corpus. Together such analyses can shed new light on both systemic and localized influences on bone growth, and the metabolic and mechanical factors underlying variation in growth.

Anemia or scurvy: A pilot study on differential diagnosis of porous and hyperostotic lesions using differential cranial vault thickness in subadult humans

Metabolic disorders, such as scurvy, manifested in human skeletal remains provide insight into health, nutrition, and environmental quality in past populations. Porous cranial vault lesions are often used to diagnose metabolic conditions in subadult remains, but overlapping gross lesion expressions have led to over-diagnosis of anemia and under-diagnosis of scurvy. Studies by Ortner and colleagues have suggested that specific porous cranial lesions are pathognomonic of scurvy, but additional diagnostic tools are necessary. In this technical report, we offer a preliminary assessment of cranial vault thickness (CVT) at the site of porous lesions (sensu lato porotic hyperostosis, cribra orbitalia) as a method for distinguishing between scurvy and anemia in subadult crania. Computed Tomography (CT) was used to measure CVT at various landmarks associated with porotic hyperostosis and cribra orbitalia, complemented by lesion scores, from scorbutic (N=11), anemic (N=3), and non-pathological (N=28) subadult crania used as a control group. Results indicate that CVT consistently distinguishes scorbutic from non-pathological individuals, while anemic individuals overlap with both - likely a function of small sample size in this study. Despite current limitations, CVT has the potential to be an objective diagnostic tool for distinguishing scurvy and expanding reconstructions of nutritional adequacy over the life course in past populations.

Technical note: an R program for automating bone cross section reconstruction.

Many recent studies have used long bone cross-sectional geometric properties in various comparative analyses. Methods have been described for reconstructing diaphyseal cross sections from external molds and biplanar radiographs that produce accurate results (within 5% of true values on average). The manual image processing required, however, is both time and labor intensive. A new freely available program developed here for the computational freeware, R, automates much of the process. This study compares cross-sectional properties calculated using the new R program to those from peripheral quantitative CT (pQCT) and the original manual method. We find that the R program works aswell as the original manual image processing for most cross sections eliminates the chance for entry errors at several steps and greatly speeds up data collection.

Development and Validation of Trauma Surgical Skills Metrics: Preliminary Assessment of Performance after Training

BACKGROUND Maintaining trauma-specific surgical skills is an ongoing challenge for surgical training programs. An objective assessment of surgical skills is needed. We hypothesized that a validated surgical performance assessment tool could detect differences following a training intervention. METHODS We developed surgical performance assessment metrics based on discussion with expert trauma surgeons, video review of 10 experts and 10 novice surgeons performing three vascular exposure procedures and lower extremity fasciotomy on cadavers, and validated the metrics with interrater reliability testing by five reviewers blinded to level of expertise and a consensus conference. We tested these performance metrics in 12 surgical residents (Year 3–7) before and 2 weeks after vascular exposure skills training in the Advanced Surgical Skills for Exposure in Trauma (ASSET) course. Performance was assessed in three areas as follows: knowledge (anatomic, management), procedure steps, and technical skills. Time to completion of procedures was recorded, and these metrics were combined into a single performance score, the Trauma Readiness Index (TRI). Wilcoxon matched-pairs signed-ranks test compared pretraining/posttraining effects. RESULTS Mean time to complete procedures decreased by 4.3 minutes (from 13.4 minutes to 9.1 minutes). The performance component most improved by the 1-day skills training was procedure steps, completion of which increased by 21%. Technical skill scores improved by 12%. Overall knowledge improved by 3%, with 18% improvement in anatomic knowledge. TRI increased significantly from 50% to 64% with ASSET training. Interrater reliability of the surgical performance assessment metrics was validated with single intraclass correlation coefficient of 0.7 to 0.98. CONCLUSION A trauma-relevant surgical performance assessment detected improvements in specific procedure steps and anatomic knowledge taught during a 1-day course, quantified by the TRI. ASSET training reduced time to complete vascular control by one third. Future applications include assessing specific skills in a larger surgeon cohort, assessing military surgical readiness, and quantifying skill degradation with time since training.

Using an Individual Procedure Score Before and After the Advanced Surgical Skills Exposure for Trauma Course Training to Benchmark a Hemorrhage-Control Performance Metric

OBJECTIVE Test with an individual procedure score (IPS) to assess whether an unpreserved cadaver trauma training course, including upper and lower limb vascular exposure, improves correct identification of surgical landmarks, underlying anatomy, and shortens time to vascular control. DESIGN Prospective study of performance of 3 vascular exposure and control procedures (axillary, brachial, and femoral arteries) using IPS metrics by 2 colocated and trained evaluators before and after training with the Advanced Surgical Skills Exposure for Trauma (ASSET) course. IPS, including identification of anatomical landmarks, incisions, underlying structures, and time to completion of each procedure was compared before and after training using repeated measurement models. SETTING Audio-video instrumented cadaver laboratory at University of Maryland School of Medicine. PARTICIPANTS A total of 41 second to sixth year surgical residents from surgical programs throughout Mid-Atlantic States who had not previously taken the ASSET course were enrolled, 40 completed the pre- and post-ASSET performance evaluations. RESULTS After ASSET training, all components of IPS increased and time shortened for each of the 3 artery exposures. Procedure steps performed correctly increased 57%, anatomical knowledge increased 43% and skin incision to passage of a vessel loop twice around the correct vessel decreased by a mean of 2.5 minutes. An overall vascular trauma readiness index, a comprehensive IPS score for 3 procedures increased 28% with ASSET Training. CONCLUSIONS Improved knowledge of surface landmarks and underlying anatomy is associated with increased IPS, faster procedures, more accurate incision placement, and successful vascular control. Structural recognition during specific procedural steps and anatomical knowledge were key points learned during the ASSET course. Such training may accelerate acquisition of specific trauma surgery skills to compensate for shortened training hours, infrequent exposure to major vascular injuries, or when just-in-time training is necessary. IPS is a benchmark for competence in extremity vascular control.

Student laboratory presentations as a learning tool in anatomy education

Previous studies have shown that anatomy students who complete oral laboratory presentations believe they understand the material better and retain it longer than they otherwise would if they only took examinations on the material; however, we have found no studies that empirically test such outcomes. The purpose of this study was to assess the effectiveness of oral presentations through comparisons with other methods of assessment, most notably, examination performance. Specifically, we tested whether students (n = 256) performed better on examination questions on topics covered by their oral presentations than on other topics. Each student completed two graded, 12‐minute laboratory presentations on two different assigned topics during the course and took three examinations, each of which covered a third of the course material. Examination questions were characterized by type (memorization, pathway, analytical, spatial). A two‐way repeated measures analysis of variance revealed that students performed better on topics covered by their presentations than on topics not covered by their presentations (P < 0.005), regardless of presentation grade (P > 0.05) and question type (P > 0.05). These results demonstrate empirically that oral presentations are an effective learning tool. Anat Sci Educ 2: 260–264, 2009.

Performance of Vascular Exposure and Fasciotomy Among Surgical Residents Before and After Training Compared With Experts

Importance Surgical patient outcomes are related to surgeon skills. Objective To measure resident surgeon technical and nontechnical skills for trauma core competencies before and after training and up to 18 months later and to compare resident performance with the performance of expert traumatologists. Design, Setting, and Participants This longitudinal study performed from May 1, 2013, through February 29, 2016, at Maryland State Anatomy Board cadaver laboratories included 40 surgical residents and 10 expert traumatologists. Interventions Performance was measured during extremity vascular exposures and lower extremity fasciotomy in fresh cadavers before and after taking the Advanced Surgical Skills for Exposure in Trauma (ASSET) course. Main Outcomes and Measures The primary outcome variable was individual procedure score (IPS), with secondary outcomes of IPSs on 5 components of technical and nontechnical skills, Global Rating Scale scores, errors, and time to complete the procedure. Two trained evaluators located in the same laboratory evaluated performance with a standardized script and mobile touch-screen data collection. Results Thirty-eight (95%) of 40 surgical residents (mean [SD] age, 31 [2.9] years) who were evaluated before and within 4 weeks of ASSET training completed follow-up evaluations 12 to 18 months later (mean [SD], 14 [2.7] months). The experts (mean [SD] age, 52 [10.0] years) were significantly older and had a longer (mean [SD], 46 [16.3] months) interval since taking the ASSET course (both P < .001). Overall resident cohort performance improved with increased anatomy knowledge, correct procedural steps, and decreased errors from 60% to 19% after the ASSET course regardless of clinical year of training (P < .001). For 21 of 40 residents (52%), correct vascular procedural steps plotted against anatomy knowledge (the 2 IPS components most improved with training) indicates the resident’s performance was within 1 nearest-neighbor classifier of experts after ASSET training. Five residents had no improvement with training. The Trauma Readiness Index for experts (mean [SD], 74 [4]) was significantly different compared with the trained residents (mean [SD], 48 [7] before training vs 63 [7] after training [P = .004] and vs 64 [6] 14 months later [P = .002]). Critical errors that might lead to patient death were identified by pretraining IPS decile of less than 0.5. At follow-up, frequency of resident critical errors was no different from experts. The IPSs ranged from 31.6% to 76.9% among residents for core trauma competency procedures. Modeling revealed that interval experience, rather than time since training, affected skill retention up to 18 months later. Only 4 experts and 16 residents (40%) adequately decompressed and confirmed entry into all 4 lower extremity compartments, Conclusions and Relevance This study found that ASSET training improved resident procedural skills for up to 18 months. Performance was highly variable. Interval experience after training affected performance. Pretraining skill identified competency of residents vs experts. Extremity vascular and fasciotomy performance evaluations suggest the need for specific anatomical training interventions in residents with IPS deciles less than 0.5.