Plastination Procedure @ PCOM: Current Practice and Future Uses

Introduction: Since its invention by German anatomist Gunther von Hagens, the process of forced-impregnation plastination of organic specimens has become the standard for the preservation of biological tissue specimens. This practice serves as the most practical method to preserve these specimens for study and is utilized at PCOM regularly for this purpose. During the steps of plastination, aqueous and lipid tissues are replaced by a curable polymer to produce plastinates that do not decompose, can be handled without gloves, and retain most characteristics of the original specimens. For decades, PCOM used this method to prepare a permanent teaching collection in support of medical education. In the last five years, the lab has been reactivated and prepares specimens for allied health professional education, enrichment of the Doctor of Osteopathy curriculum, and outreach at regional institutions (e.g., The Franklin Institute, The Nebinger School, etc.). Objectives: The purpose of this poster is to inform the PCOM community of current plastination practices and suggest future uses. Methods: To prepare specimens for plastination, they must be preserved in fixative. We currently dissect and stage all tissues after the fixative process. Dissections are prepared by work-study students at PCOM who have completed the relevant anatomy course (interested students please contact Dr. Claeson). After fixation, tissues are dehydrated in progressively more concentrated washes of cold-temperature acetone (-20ºC) until concentration is between 98-100%. After dehydration, they are placed into a silicone polymer bath and brought to room temperature. The room temperature bath technique is the primary deviation from von Hagen (1977). Once at room temperature in the bath, vacuum pressure is used to replace the acetone that fills each cell with silicone. A hardening agent is then administered to finish the process. Results & Conclusions: Current initiatives have included building a collection of heart specimens to support a cardiac workshop which pairs anatomy and physiology. Most recently, a brain anatomy collection is being built. Brain specimens include axial cross sections, whole and half brains, and pathological specimens. These specimens are currently used at many outreach events and will be incorporated into a featured anatomy series as part of the medical school curriculum. Future research initiatives may also begin via current practices

Conus medullaris termination in adult females

Objective: The primary objective of this study was to determine the termination level of the spinal cord in a sample population of adult female cadavers. Introduction: The conus medullaris represents the tapered, distal-most end of the spinal cord. It tends to be found somewhere between the L1-L2 lumbar vertebrae and can sometimes be higher or lower. Studies report the conus medullaris can be found anywhere from the lower third of T11 to the upper third of L3 with the average termination point around the lower third of L1. We aim to describe the level of conus medullaris termination in a sample of female cadavers. Methods: Twenty-four female cadavers were dissected as part of the Doctor of Osteopathic Medicine curriculum at the Philadelphia College of Osteopathic Medicine. The end of the conus medullaris was defined as the point where tapering ends distal to the last branches of the posterior nerve rootlets. Using the articulation of the 12th rib as a landmark the termination of the conus medullaris was noted to be either at the level of an intervertebral disc or vertebral body. In the latter cases the vertebral body was divided into upper, middle, and lower thirds. Results: Conus Medullaris termination ranged from the T12-L1 intervertebral disc to the L2-L3 intervertebral disc. The L1-L2 intervertebral disc was the most common termination point with 42% of cadavers demonstrating spinal cord termination at this level. Conclusions: These results demonstrate that there is variation of spinal cord termination, which can play a role in lumbar punctures, spinal anesthesia, and obstetric anesthesia. Due to the risk of cord damage it is imperative to perform any sort of anesthetic procedure fully below the level of L3 in the L3-L4 space or L4-L5 space. An epidural injection above the level of L3 may cause severe spinal cord damage if there is dural puncture and an anatomical variant in which the conus medullaris extends to the L3 level

The Philadelphia surgery conference: a value analysis of a hands-on surgical skill-building event.

Context: Limited opportunities exist to practice technical skills and to be exposed to various surgical specialties during preclinical medical education. Objectives: To assess the value of workshop-based educational opportunities to medical students during preclinical training. Methods: One hundred and 75 medical and physician assistant students from 10 medical schools attended the 2019 Philadelphia Surgery Conference. All students received STOP THE BLEED® bleeding control training and participated in four workshops, chosen from a list of 23, that demonstrated a variety of surgical skills. Data collection was accomplished using both a pre- and postconference survey to assess changes in confidence of personal capabilities, knowledge base, and opinions regarding preclinical medical training. Results: Preconference survey results indicated low baseline confidence in personal surgical skills (mean [SD], 1.9 [1.0], on a Likert scale of 1-5), and knowledge of various surgical specialties (2.7 [1.0]). Students highly valued skill-building experiences (mean [SD], 4.2 [1.1]) and face-to-face interactions with resident and attending physicians (4.4 [0.9]). Postconference survey analysis demonstrated increased confidence in surgical ability by 52.6% (mean [SD], 2.9 [1.0]; p\u3c0.001) and knowledge base by 34.6% (3.5 [0.8]; p\u3c0.001). Value scores increased for both preclinical surgical skill-building opportunities (mean [SD], 4.4 [0.9]; p=0.014) and interactions with resident and attending physicians (4.7 [0.6]; p=0.002). Conclusions: The Philadelphia Surgery Conference provided a highly valuable experience to participating students, increasing confidence in personal knowledge base and surgical skills while facilitating a collaboration between students and resident and attending physicians from various surgical specialties

Evaluation of the Gross Anatomical Incidence of Fabellae in a North American Cadaveric Population

Introduction: The fabella is a sesamoid bone found in the tendinous portion of the lateral head of the gastrocnemius muscle. It is present in 10-30% of humans, with an incidence as high as 87% in certain Asian populations (Driessen et al., 2014). No such evaluation of incidence has been conducted in a North American cadaveric population. Objectives: The primary objective of this study was to examine the incidence, phenotype and composition of fabellae in a sample population of American cadavers from Pennsylvania. Methods: Bilateral dissections were performed on the lateral and medial heads of the gastrocnemius muscles on 182 knees from 91 cadavers. The tendinous portion of the gastrocnemius muscle and fibrous capsule surrounding the lateral and medial condyles of the femur were reflected to expose the bone. Presence of both a bony or cartilaginous fabella, and of an impression on the posterior aspect of the femoral condyles were noted. Fabella composition was initially determined by inspection and palpation in the gastrocnemius muscle containing it as adapted from Kato et al. (2012). Femoral impressions were classified as medial or lateral in reference to their location to the condylar ridge of the lateral femoral condyle. Results: Thirty cadavers had at least one fabella for a total cadaveric incidence of 32.9%. Twenty-two cadavers (24.2%) displayed bilateral presence, while 8 cadavers (8.8%) displayed a unilateral presence. Twenty-three cadavers (25.3%) displayed a bony fabella, while 7 cadavers (7.7%) displayed a cartilaginous fabella. Twenty-one cadavers (23%) displayed a medial phenotype while 8 (8.8%) displayed a lateral phenotype. Conclusions: The general incidence of fabellae in this sample population was found to be slightly higher than the worldwide average of 30%. Further histological analysis needs to be conducted to analyze the cellular composition of the cartilaginous faballae found. The incidence of fabellae in the sample population may have implications in orthopedics and sports medicine, but there is a lack of data for clinical routine. Postero-lateral pathology such as fabella-associated ligament tears may be masked by extensive symptoms from cruciate ligament injury. Untreated damage in the postero-lateral compartment of the knee may prolong the healing process of cruciate ligament repair if the fabella and its associated structures are not noted during knee examination