Paul Tierney

The infrapatellar fat pad: anatomy and clinical correlations

This study examined the anatomy of the infrapatellar fat pad (IFP) in relation to knee pathology and surgical approaches. Eight embalmed knees were dissected via semicircular parapatellar incisions and each IFP was examined. Their volume, shape and constituent features were recorded. They were found in all knees and were constant in shape, consisting of a central body with medial and lateral extensions. The ligamentum mucosum was found inferior to the central body in all eight knees, while a fat tag was located superior to the central body in seven cases. Two clefts were consistently found on the posterior aspect of the IFP, a horizontal cleft below the ligamentum mucosum in six knees and a vertical cleft above, in seven cases. Our study found that the IFP is a constant structure in the knee joint, which may play a number of roles in knee joint function and pathology. Its significance in knee surgery is discussed.

Anatomy education for the YouTube generation

Anatomy remains a cornerstone of medical education despite challenges that have seen a significant reduction in contact hours over recent decades; however, the rise of the “YouTube Generation” or “Generation Connected” (Gen C), offers new possibilities for anatomy education. Gen C, which consists of 80% Millennials, actively interact with social media and integrate it into their education experience. Most are willing to merge their online presence with their degree programs by engaging with course materials and sharing their knowledge freely using these platforms. This integration of social media into undergraduate learning, and the attitudes and mindset of Gen C, who routinely creates and publishes blogs, podcasts, and videos online, has changed traditional learning approaches and the student/teacher relationship. To gauge this, second year undergraduate medical and radiation therapy students (n = 73) were surveyed regarding their use of online social media in relation to anatomy learning. The vast majority of students had employed web‐based platforms to source information with 78% using YouTube as their primary source of anatomy‐related video clips. These findings suggest that the academic anatomy community may find value in the integration of social media into blended learning approaches in anatomy programs. This will ensure continued connection with the YouTube generation of students while also allowing for academic and ethical oversight regarding the use of online video clips whose provenance may not otherwise be known. Anat Sci Educ.

Chronic Exertional Compartment Syndrome The Controversial “Fifth” Compartment of the Leg

Background The existence of a “fifth” compartment in the leg capable of developing distinct chronic exertional compartment syndrome remains a subject of controversy. Hypothesis Specific pressure recordings and dissection will confirm or disprove the existence of a fifth compartment. Study Design Empirical anatomic study. Methods Radiopaque dye was injected directly into the tibialis posterior muscle of 25 embalmed cadaveric legs while intracompartmental pressure was monitored. Radiographs demonstrated dye distribution, and dissection-documented fascial and epimysial layers. Results Evidence was found that the fibular origin of the flexor digitorum longus muscle, when present, could create subcompartments within the deep posterior compartment. The nature of this attachment varied from being absent, to small (<8 cm), to extensive (>8 cm). The attachment partially covered the tibialis posterior muscle in the majority of the 14 legs that developed high pressures, and it was limited or absent in the 11 legs that did not. Radiographs demonstrated that the dye was confined to the tibialis posterior muscle in four legs. Conclusions No consistent fifth compartment exists in the leg; however, subcompartments within the deep posterior compartment created by the fibular origin of the flexor digitorum longus muscle may develop pressures congruent with chronic exertional compartment syndrome. Clinical Relevance Potential deep posterior subcompartments demand accurate pressure investigation. A modified technique to decompress the entire deep posterior compartment, including the tibialis posterior muscle, is necessary for successful treatment of chronic exertional compartment syndrome.

Anatomical variations within the deep posterior compartment of the leg and important clinical consequences

The management of musculoskeletal conditions makes up a large part of a sports medicine practitioners practice. A thorough knowledge of anatomy is an essential component of the armament necessary to decipher the large number of potential conditions that may confront these practitioners. To cloud the issue further, anatomical variations may be present, such as supernumerary muscles, thickened fascial bands or variant courses of nerves and blood vessels, which can themselves manifest as acute or chronic conditions that lead to significant morbidity or limitation of activity. There are a number of contentious areas within the literature surrounding the anatomy of the leg, particularly involving the deep posterior compartment. Conditions such as chronic exertional compartment syndrome, tibial periostitis (shin splints), peripheral nerve entrapment and tarsal tunnel syndrome may all be affected by subtle anatomical variations. This paper primarily focuses on the deep posterior compartment of the leg and uses the gross dissection of cadaveric specimens to describe definitively the anatomy of the deep posterior compartment. Variant fascial attachments of flexor digitorum longus are documented and potential clinical sequelae such as chronic exertional compartment syndrome and tarsal tunnel syndrome are discussed.

Biomechanical analysis of a salt-modified polyvinyl alcohol hydrogel for knee meniscus applications, including comparison with human donor samples

The primary objective of this research was the biomechanical analysis of a salt-modified polyvinyl alcohol hydrogel, in order to assess its potential for use as an artificial meniscal implant. Aqueous polyvinyl alcohol (PVA) was treated with a sodium sulphate (Na2SO4) solution to precipitate out the polyvinyl alcohol resulting in a pliable hydrogel. The freeze-thaw process, a strictly physical method of crosslinking, was employed to crosslink the hydrogel. Development of a meniscal shaped mould and sample housing unit allowed the production of meniscal shaped hydrogels for direct comparison to human meniscal tissue. Results obtained show that compressive responses were slightly higher in PVA/Na2SO4 menisci, displaying maximum compressive loads of 2472N, 2482N and 2476N for samples having undergone 1, 3 and 5 freeze-thaw cycles respectively. When compared to the human meniscal tissue tested under the same conditions, an average maximum load of 2467.5N was observed. This suggests that the PVA/Na2SO4 menisci are mechanically comparable to the human meniscus. Biocompatibility analysis of PVA/Na2SO4 hydrogels revealed no acute cytotoxicity. The work described herein has innovative potential in load bearing applications, specifically as an alternative to meniscectomy as replacement of critically damaged meniscal tissue in the knee joint where repair is not viable.

The need for ethical and pedagogical frameworks for developing online media in anatomy education

We read with interest Miller and Lewis’ Letter to the Editor (Miller and Lewis, 2016) in which they discuss aspects of our original article “Anatomy education for the YouTube generation” published in your journal (Barry et al., 2016). We agree fully with Miller and Lewis that the ethical issues associated with online videos of human cadaveric material is of grave significance as the general neglect of ethical oversight of online resources is likely to have a corrosive effect on standards of professionalism within the healthcare sector. Nonetheless, the pressure on academics to increase research output coupled to increasing student-staff ratios (Drake et al., 2009) is ensuring anatomy staff will seldom be in a position to facilitate and guide the process of user-generated online content, or to check the validity of information and clarity of delivery once uploaded. However, educators do have a critical role to play in reinforcing codes of professional conduct by selecting images or video clips of appropriate validity, clarity, and sensitivity for teaching purposes. Furthermore, of analogous concern is the proliferation of online video clips of surgical procedures and patients displaying pathological signs. An unpublished survey of YouTube sites for teaching purposes by the present authors found that of 2,000 anatomy-related video clips, 22.5% were of live subjects and just 1.3% cited consent to broadcast. While consent to use video for teaching purposes including broadcast may have been provided by the subject, this is not easy to establish. Many YouTube video clips make a declaration of the “Standard YouTube License” or “Creative Commons License,” which cover the copyright entitlements of those who upload the videos, yet do not make any mention of the subjects consent. In many cases, this may be implicit as the subjects are video recording themselves, or may be healthcare students mimicking pathological signs, yet many are also of patients which generally offer the greatest impact, garnering more views. Therefore, despite the perceived benefit to the student (Topping, 2014) the use of human tissue-based video, alive or dead is fraught with a number of legal, moral, and ethical considerations. An overlay narration by academics when using these as teaching resources would help fulfil the ethical obligations of educators (Miller and Lewis, 2016). The need for this is highlighted in a recent study of human heart anatomy videos on YouTube, where it was reported that 21% of available videos featured cadaveric material that achieved over 500,000 views, while, in contrast to this, plastinated specimens achieved 433 views (Raikos and Waidyasekara, 2014). Corroborating Miller and Lewis’ view, this study found that the majority of videos (86.7%) were uploaded by individuals, while only 13.3% were endorsed by institutions and the numbers of uploaded videos tripled between 2009 and 2012 (Raikos and Waidyasekara, 2014). Given these statistics, can much be done to highlight the ethical issues associated with the unregulated distribution and use of human material particularly in a healthcare education context? This will be challenging, although tools such as Google Trends R may allow assessment of search patterns in anatomical syllabi (Smith et al., 2016), which may be useful to institutions to identify particular aspects of anatomy in which to develop targeted online supports for student learning. Miller and Lewis (2016) also flag the need for consideration of the educational benefits of using online videos in anatomy education. Blended learning is recognized as a more effective approach in optimizing student insight into functional and clinical anatomy (Pereira et al., 2007; Green and Whitburn, 2016). From a scholarship of teaching and learning perspective, the four dimensions of disciplinary understanding—knowledge, method, purpose, and form may also be addressed more effectively by incorporating diverse online resources (Mansilla and Gardner, 1998). Historically, there has been a tendency to teach anatomy with a focus on the knowledge domain or rather what we treat as knowledge (Sch€ on, 1995), particularly if we define knowledge as not merely what a student knows, but what they can do with this information. There is now a greater integration of clinical skills with anatomy and this change is being driven by course compression and reduced contact hours requiring greater efficiency of integration. Confounding this shift are changes in assessment as highlighted by Rowland and colleagues who found that medical students who graduated before 2005 were assessed more frequently by practical (94.2 vs. 33.3%) and oral (84.5 vs. 13.1%) methods than those whose graduated after (Rowland et al., 2011). This would seem to be a regressive emphasis on the “knowledge” dimension of anatomy rather than its application, possibly due to the increasingly litigious environment of third level education. In this context, the three specific benefits we feel online resources can offer are firstly, animations or live videos showing the *Correspondence to: Dr. Denis Barry, Department of Anatomy, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland. E-mail: debarry@tcd.ie (or) Dr. Gerard O’Keeffe, Department of Anatomy and Neuroscience, School of Medicine, University College Cork, Cork, Ireland. E-mail: g.okeeffe@ucc.ie

Awakening Neuropsychiatric Research Into the Stria Medullaris: Development of a Diffusion-Weighted Imaging Tractography Protocol of This Key Limbic Structure

The Stria medullaris (SM) Thalami is a discrete white matter tract that directly connects frontolimbic areas to the habenula, allowing the forebrain to influence midbrain monoaminergic output. Habenular dysfunction has been shown in various neuropsychiatric conditions. However, there exists a paucity of research into the habenula’s principal afferent tract, the SM. Diffusion-weighted tractography may provide insights into the properties of the SM in vivo, opening up investigation of this tract in conditions of monoamine dysregulation such as depression, schizophrenia, addiction and pain. We present a reliable method for reconstructing the SM using diffusion-weighted imaging, and examine the effects of age and gender on tract diffusion metrics. We also investigate reproducibility of the method through inter-rater comparisons. In consultation with neuroanatomists, a Boolean logic gate protocol was developed for use in ExploreDTI to extract the SM from constrained spherical deconvolution based whole brain tractography. Particular emphasis was placed on the reproducibility of the tract, attention to crossing white matter tract proximity and anatomical consistency of anterior and posterior boundaries. The anterior commissure, pineal gland and mid point of the thalamus were defined as anatomical fixed points used for reconstruction. Fifty subjects were scanned using High Angular Resolution Diffusion Imaging (HARDI; 61 directions, b-value 1500 mm3). Following constrained spherical deconvolution whole brain tractography, two independent raters isolated the SM. Each output was checked, examined and cleaned for extraneous streamlines inconsistent with known anatomy of the tract by the rater and a neuroanatomist. A second neuroanatomist assessed tracts for face validity. The SM was reconstructed with excellent inter-rater reliability for dimensions and diffusion metrics. Gender had no effect on the dimensions or diffusion metrics, however radial diffusivity (RD) showed a positive correlation with age. Reliable identification and quantification of diffusion metrics of the SM invites further exploration of this key habenula linked structure in neuropsychiatric disorders such as depression, anxiety, chronic pain and addiction. The accurate anatomical localization of the SM may also aid preoperative stereotactic localization of the tract for deep brain stimulation (DBS) treatment.

Audiovisual preconditioning enhances the efficacy of an anatomical dissection course: A randomised study☆

UNLABELLED The benefits of incorporating audiovisual materials into learning are well recognised. The outcome of integrating such a modality in to anatomical education has not been reported previously. The aim of this randomised study was to determine whether audiovisual preconditioning is a useful adjunct to learning at an upper limb dissection course. Prior to instruction participants completed a standardised pre course multiple-choice questionnaire (MCQ). The intervention group was subsequently shown a video with a pre-recorded commentary. Following initial dissection, both groups completed a second MCQ. The final MCQ was completed at the conclusion of the course. Statistical analysis confirmed a significant improvement in the performance in both groups over the duration of the three MCQs. The intervention group significantly outperformed their control group counterparts immediately following audiovisual preconditioning and in the post course MCQ. Audiovisual preconditioning is a practical and effective tool that should be incorporated in to future course curricula to optimise learning. Level of evidence This study appraises an intervention in medical education. LEVEL OF EVIDENCE Kirkpatrick Level 2b (modification of knowledge).