Hilton's law revisited.

Hilton's Law, put forth 150 years ago, is well known and frequently taught in anatomy courses. We critically analyzed the complex description of associated muscular, cutaneous, and articular innervations in order to assess the general applicability of Hilton's Law. We applied rules for interpretation of the Law extrapolated upon but based on Hilton's original writings, and excluded obscure supplementary clauses not considered as part of the Law. We found the Law, as originally written and as we interpreted with some latitude, to be reliable and applicable to all cranial and peripheral nerves. Hilton's Law is a powerful springboard to understand articular anatomy and pathophysiology.

The tangled web of Langer's lines.

Langer's lines are often considered to be guides for elective surgical incisions. Interestingly, Karl Langer was not the first to describe the property of skin that leads to the lines he depicted, nor are these lines in common use today. Rather, it is common that relaxed skin tension lines provide a guide for cosmetically pleasing surgical results. Nevertheless, Langer did conduct extensive studies on human skin that remain as a scholarly body of work.

Oliver Wendell Holmes, Sr. (1809-1894): physician, jurist, poet, inventor, pioneer, and anatomist.

Oliver Wendell Holmes, Sr. was a physician, dean of the Harvard Medical School, one of the best regarded American poets of the 19th century, father of a future United States Supreme Court Justice, inventor and - unknown to many - an anatomist. His friends included Ralph Waldo Emerson, Henry Wadsworth Longfellow, and Louis Pasteur. He trained with some of the most influential anatomists/surgeons of his day including Lisfranc, Larrey, Velpeau, Bigelow, and Dupuytren. As a teacher of anatomy, he had strong feelings regarding medical curricular reform and to some, was considered one of the best lecturers in the discipline. As dean, he pioneered social reform by admitting both white women and free black men to Harvard Medical School. He coined the term "anesthesia," was the first American to introduce microscopy to a medical curriculum, and made important contributions to the understanding of the spread of infectious disease. Herein, we review the life of this influential American academic and focus on his contributions to the field of anatomy.

Ultrasound-guided versus nonguided tibiotalar joint and sinus tarsi injections: a cadaveric study.

OBJECTIVE: To compare the relative accuracy rates of ultrasound (US)-guided versus nonguided ankle (tibiotalar) joint and sinus tarsi injections in a cadaveric model. DESIGN: Prospective human cadaveric study with injection technique randomized and accuracy assessed by skilled observers blinded to injection technique. SETTING: Procedural skills laboratory in a tertiary care academic medical center. METHODS: Twelve embalmed and 8 unembalmed cadavers (40 ankles) were used for this investigation. Using a predetermined randomization process, 1 ankle of each cadaver was injected with US guidance and the other without. Tibiotalar joint injections were performed via an anterior approach and sinus tarsi injections performed via an anterolateral approach. All injections were performed by the senior author using a 22-gauge, 1.5-inch needle to place 3 mL of 50% diluted blue latex solution into the target area. Two anatomists blinded to the injection technique dissected each ankle and determined injection accuracy based on previously agreed upon criteria. MAIN OUTCOME MEASUREMENTS: Injection accuracy, where an accurate injection delivered injectate within the tibiotalar joint or into the mid-portion of the sinus tarsi. RESULTS: The accuracy rate for US-guided tibiotalar joint injections was 100% (20/20) versus 85% (17/20) for nonguided injections. The accuracy rate for US-guided sinus tarsi injections was 90% (18/20) versus 35% (7/20) for nonguided injections. CONCLUSIONS: In this cadaveric study, US guidance produced superior accuracy compared with nonguided injections with respect to both the tibiotalar joint and sinus tarsi. Although further research is warranted, clinicians should consider US guidance to optimize injectate placement into these areas when optimal accuracy is necessary for diagnostic or therapeutic purposes.

The place of anatomy in medical education: AMEE Guide no 41.

This Guide, a combined work by three authors from different countries, provides perspectives into the history of teaching gross anatomy, briefly, from the earliest of times, through to a detailed examination of curricula in both traditional didactic approaches and Problem-Based Learning (PBL) curricula. The delivery of a module within a curriculum in tertiary education is interplay between the content (knowledge and skills) of a subject, the teaching staff involved, the students and their approaches to learning, and the philosophy underpinning the delivery of the learning material. The work is divided into sections that deal with approaches to learning anatomy from the perspective of students, to delivery of the content of the curriculum by lecturers, including the assessment of knowledge, and itemises the topics that could be considered important for an appropriate anatomy module in an integrated course, delivered in a way that emphasises clinical application. The work concludes by looking to the future, and considering what measures may need to be addressed to ensure the continued development of anatomy as a clinically relevant subject in any medical curriculum.

Patterns of intraneural ganglion cyst descent.

On the basis of the principles of the unifying articular theory, predictable patterns of proximal ascent have been described for fibular (peroneal) and tibial intraneural ganglion cysts in the knee region. The mechanism underlying distal descent into the terminal branches of the fibular and tibial nerves has not been previously elucidated. The purpose of this study was to demonstrate if and when cyst descent distal to the articular branch-joint connection occurs in intraneural ganglion cysts to understand directionality of intraneural cyst propagation. In Part I, the clinical records and MRIs of 20 consecutive patients treated at our institution for intraneural ganglion cysts (18 fibular and two tibial) arising from the superior tibiofibular joint were retrospectively analyzed. These patients underwent cyst decompression and disconnection of the articular branch. Five of these patients developed symptomatic cyst recurrence after cyst decompression without articular branch disconnection which was done elsewhere prior to our intervention. In Part II, five additional patients with intraneural ganglion cysts (three fibular and two tibial) treated at other institutions without disconnection of the articular branch were compared. These patients in Parts I and II demonstrated ascent of intraneural cyst to differing degrees (12 had evidence of sciatic nerve cross-over). In addition, all of these patients demonstrated previously unrecognized MRI evidence of intraneural cyst extending distally below the level of the articular branch to the joint of origin: cyst within the proximal most portions of the deep fibular and superficial fibular branches in fibular intraneural ganglion cysts and descending tibial branches in tibial intraneural ganglion cysts. The patients in Part I had complete resolution of their cysts at follow-up MRI examination 1 year postoperatively. The patients in Part II had intraneural recurrences postoperatively within the articular branch, the parent nerve, and the terminal branches, although in three cases they were subclinical. The authors demonstrate that cyst descent distal to the take-off of the articular branch to the joint of origin occurs regularly in patients with fibular and tibial intraneural ganglion cysts. The authors believe that parent terminal branch descent follows ascent up the articular branch from an affected joint of origin. This mechanism for bidirectional flow explains cyst within terminal branches of the fibular and tibial nerves and is dependent on pressure fluxes and resistances. This new pattern is consistent with principles previously described in a unified (articular) theory, is generalizable to other intraneural ganglion cysts arising from joints, and has important implications for pathogenesis and treatment of these intraneural cysts.

Cross-over: a generalizable phenomenon necessary for secondary intraneural ganglion cyst formation.

The appearances of intraneural ganglion cysts are being elucidated. We previously introduced the cross-over phenomenon to explain how a fibular (peroneal) or tibial intraneural ganglion cyst arising from the superior tibiofibular joint could give rise to multiple cysts: cyst fluid ascending up the primarily affected nerve could reach the level of the sciatic nerve, fill its common epineurial sheath and spread circumferentially (cross over), at which time pressure fluxes could result in further ascent up the sciatic or descent down the same parent nerve or the opposite, previously unaffected fibular or tibial nerves. In this study, we hypothesized that cross-over could occur in other nerves, potentially leading to the formation of more than one intraneural ganglion cyst in such situations. We analyzed the literature and identified a single case that we could review where proximal extension of an intraneural ganglion cyst involving a nerve at a different site could theoretically undergo cross-over in another major nerve large enough for available magnetic resonance images to resolve this finding. A case of a suprascapular intraneural ganglion cyst previously reported by our group that arose from the glenohumeral joint and extended to the neck was reanalyzed for the presence or absence of cross-over. An injection of dye into the outer epineurium of the suprascapular nerve in a fresh cadaveric specimen was performed to test for cross-over experimentally. Retrospective review of this case of suprascapular intraneural ganglion cyst demonstrated evidence to support previously unrecognized cross-over at the level of the upper trunk, with predominant ascent up the C5 and the C6 nerve roots and subtle descent down the anterior and posterior divisions of the upper trunk as well as the proximal portion of the suprascapular nerve. This appearance gave rise to multiple interconnected intraneural ganglion cysts arising from a single distant connection to the glenohumeral joint. The injection study also demonstrated the cross-over phenomenon and produced a similar pattern as the cyst dissection. This article illustrates that cross-over can occur in another nerve (apart from the prototype fibular nerve). Furthermore, understanding the more complex anatomic nature of the upper trunk cross-over model provides insight into important mechanistic information regarding the bidirectional propagation patterns and formation of primary and secondary intraneural ganglion cysts not afforded by the previously described sciatic nerve cross-over model.

Anatomy for biomedical engineers.

There is a perceived need for anatomy instruction for graduate students enrolled in a biomedical engineering program. This appeared especially important for students interested in and using medical images. These students typically did not have a strong background in biology. The authors arranged for students to dissect regions of the body that were of particular interest to them. Following completion of all the dissections, the students presented what they had learned to the entire class in the anatomy laboratory. This course has fulfilled an important need for our students.

The use of a video interview to enhance gross anatomy students' understanding of professionalism.

There is much room for innovation in teaching medical students professionalism. The goal of this exercise was to enhance first-year Gross Anatomy students' understanding of professionalism, including the attributes of confidentiality, respectful behavior and humanism in medicine through a video interview with a donor family member. Survey results demonstrated that students generally agreed that the video helped them better understand professionalism in the context of the gross anatomy laboratory and gave them a deeper respect for donors. Most students strongly agreed that future medical students would benefit from viewing this video interview.

Peroneal and tibial intraneural ganglia: correlation between intraepineurial compartments observed on magnetic resonance images and the potential importance of these compartments.

OBJECT: Previously the authors demonstrated that peroneal and tibial intraneural ganglia arising from the superior tibiofibular joint may occasionally extend proximally within the epineurium to reach the sciatic nerve. The dynamic nature of these cysts, dependent on intraarticular pressures, may give rise to differing clinical and imaging presentations that have remained unexplained until now. To identify the pathogenesis of these unusual cysts and to correlate their atypical magnetic resonance (MR) imaging appearance, the authors retrospectively reviewed their own experience as well as the published literature on these types of intraneural ganglia. METHODS: A careful review of MR images obtained in 22 patients with intraneural ganglia located about the knee region (18 peroneal and four tibial intraneural ganglia) allowed the authors to substantiate three different patterns: outer (epifascicular) epineurial (20 cases); inner (interfascicular) epineurial (one case); and combined outer and inner epineurial (one case). In these cases serial MR images allowed the investigators to track the movement of the cyst within the same layer of the epineurium. All lesions had connections to the superior tibiofibular joint. Nine patients were identified as having lesions with sciatic nerve extension. Seven patients harboring an outer epineurial cyst (six in whom the cyst involved the peroneal nerve and one in whom it involved the tibial nerve) had signs of sciatic nerve cross-over, with the cyst seen in the sciatic nerve and/or other terminal branches. In only two of these cases had the cyst previously been recognized to have sciatic nerve involvement. In contrast, in one case an inner epineurial cyst involving the tibial nerve ascended within the tibial division of the sciatic nerve and did not cross over. A single patient had a combination of both outer and inner epineurial cysts; these were easily distinguished by their distinctive imaging patterns. CONCLUSIONS: This anatomical compartmentalization of intraneural cysts can be used to explain varied clinical and imaging patterns of cleavage planes for cyst formation and propagation. Compartmentalization elucidates the mechanism for cases of outer epineurial cysts in which there are primary ascent, sciatic cross-over, and descent of the lesion down terminal branches; correlates these cysts' atypical MR imaging features; and contrasts a different pattern of inner epineurial cysts in which ascent and descent occur without cross-over. The authors present data demonstrating that the dynamic phases of these intraneural ganglia frequently involve the sciatic nerve. Their imaging features are subtle and serve to explain the underrecognition and underreporting of the longitudinal extension of these cysts. Importantly, cysts extending to the sciatic nerve are still derived from the superior tibiofibular joint. Combined with the authors' previous experimental data, the current observations help the reader understand intraneural ganglia with a different, deeper degree of anatomical detail.

Epineurial compartments and their role in intraneural ganglion cyst propagation: an experimental study.

New patterns of intraneural ganglion cyst formation are emerging that have not previously been explained in current pathoanatomic terms. We believe there are three important elements underlying the appearance of these cysts: (a) an articular branch of the nerve that connects to a nearby synovial joint; (b) ejected synovial fluid following the path of least resistance along tissue planes; and (c) the additional effects of pressure and pressure fluxes. The dynamic nature of cyst formation has become clearly apparent to us in our clinical, operative and pathologic practice, but the precise mechanism underlying the process has not been critically studied. To test our hypothesis that a fibular (peroneal) or tibial intraneural cyst derived from the superior tibiofibular joint could ascend proximally into the sciatic nerve, expand within it and descend into terminal branches of this major nerve, we designed a series of simple, qualitative laboratory experiments in two cadavers (four specimens, six experiments). Injecting dye into the outer or "epifascicular" epineurium of the fibular and the tibial nerves we observed its ascent, cross over and descent patterns in three of three specimens as well as its cross over after an outer epineurial sciatic injection. In contrast, injecting dye into the inner or "interfascicular" epineurium led to its ascent within the tibial nerve and its division within the sciatic nerve in one specimen and lack of cross over in a sciatic nerve injection. Histologic cross-sections of the nerves at varying levels demonstrated a tract of disruption within the outer epineurium of the nerve injected and the nerve(s) into which the dye, after cross over, descended. Those specimens injected in the inner epineurium demonstrated dye within this tract but without disruption of or dye intrusion into the outer epineurium. In no case did the dye pass through the perineurial layers. Coupled with our observations in previous detailed studies, these anatomic findings provide proof of concept that sciatic cross over occurs due to the filling of its common epineurial sheath; furthermore, these findings, support the unifying articular theory, even in cases wherein patterns of intraneural ganglion cyst formation are unusual. Additional work is needed to be done to correlate these anatomic findings with magnetic resonance imaging and surgical pathology.

Anatomic compartments of the foot: a 3-Tesla magnetic resonance imaging study.

There is neither consensus on the number nor agreement on the location of the anatomic compartments of the foot. This project utilized high-resolution magnetic resonance imaging (MRI) to identify foot compartments. The purpose of this study was to devise a new system using 3-Tesla (3T) MRI that assessed the number and location of these compartments. Six feet from healthy volunteers were imaged. From these, 10 compartments were described: (1) medial, (2) calcaneal, (3) lateral, (4) central superficial, (5) central deep (adductor), (6-9) interossei, and (10) skin. The 3T MRI and foot/ankle coil allowed us to assess the number and location of foot compartments.

Latin and Greek in gross anatomy.

BACKGROUND: Medical students and practitioners learn and use a vocabulary originating almost entirely from classical Latin and Greek languages. Previous generations required Latin or Greek prior to medical school, but the current generation does not have such requirements. Anecdotal evidence suggests that understanding Latin or Greek helps students to learn and practitioners to recall otherwise foreign terminology. This study evaluated students' familiarity with Latin and Greek etymologies before and after a gross anatomy course that incorporated etymologies into its curriculum. METHODS: First-year medical students at Mayo Clinic College of Medicine were taught Latin and Greek etymologies through lectures and handouts during their gross anatomy course. They took a pretest and a posttest before and after the course to assess their understanding of etymologies. In addition, students from all four years of medical school, residents, and staff physicians also took a general etymology quiz to assess their understanding of etymologies. RESULTS: After their gross anatomy course emphasizing etymologies, first-year students scored higher on the posttest than they did on the pretest. First-year students also reported that learning etymologies enhanced anatomy learning, made the experience more enjoyable, and proved to be less difficult than they thought it would be prior to the course. Medical students, residents, and staff physicians scored almost equally on the general etymology quiz and almost equally reported that etymologies enhanced learning and recalling terminology. Medical students, residents, and staff physicians almost equally endorsed incorporating etymologies into medical education. CONCLUSIONS: This study provides novel scientific evidence that a basic understanding of Latin and Greek etymologies enhances performance and comfort when learning and using medical terminology.

Leadership and professionalism curriculum in the Gross Anatomy course.

INTRODUCTION: Today's physicians must demonstrate both professionalism and leadership skills in order to succeed in largely team-based healthcare environments. The purpose of this study was to determine if professionalism attributes, leadership style, and leadership style adaptability are associated with academic performance among first-year students early in their medical curriculum. MATERIALS AND METHODS: Students were divided into 4-member dissection groups for the duration of the Gross and Developmental Anatomy course. Leadership responsibility was randomly assigned to a team member on a rotating basis every 5 weeks. After each 5-week block, student performance was measured by written and practical examinations, and each student assessed their leader's or their own professionalism attributes and leadership style using validated survey instruments. RESULTS: Most students demonstrated either a "selling" only (57%) or "participating" only (30%) leadership style with low to moderate leadership adaptability. "Participating" and "delegating" leadership styles have the highest average group written exam scores (89.4%, P <0.008). "Telling" only or "selling" only leaders have the lowest average group exam scores (83.5%, P <0.001). "Selling" and "participating" leaders have significantly lower average group practical exam scores than other styles (81.5%, P <0.007). Positive associations were observed between the written and practical examination scores and the leader's integrity (P = 0.003, P = 0.002) and responsibility (P <0.001, P = 0.037). CONCLUSIONS: This study demonstrates that various situational leadership styles and aspects of professionalism are associated with written and practical examination scores in the Gross and Developmental Anatomy course. Furthermore, it demonstrates that first-year medical students are in need of leadership skill development.

Transsciatic foramen pedicle VRAM coverage of gluteal defects.

Tumors of the gluteal region are rare. Defects from resection often can be closed primarily. Some patients require local flaps such as a gluteus maximus V-Y advancement flap. Such flaps typically result in some muscle dysfunction. In addition, the use of local irradiated tissue may lead to wound complications and prolonged hospitalization. Avoiding local radiated tissue, such as the gluteal muscles, can be beneficial. We report our experience using a novel route by passage through the transsciatic foramen to transpose a pedicle vertical rectus abdominis myocutaneous flap. This regional option avoids gluteal muscle dysfunction and potential wound complication from irradiated tissue.