Query: Cadaver feet

title: Minimally invasive hallux valgus correction with Internal Hallux Fixator(r) A comparative cadaver study.
abstract: The Internal Hallux Fixator(r) (IHF(r) Waldemar Link, Hamburg, Germany) was designed for open surgical hallux valgus correction. It allows a defined lateralisation of the first metatarsal head after V shaped, Chevron like distal metatarsal osteotomy in order to correct mild to middle hallux valgus deformities. The intramedullary fixation provides dynamic compression of the osteotomy and thus postoperative full weight bearing mobilization is an integral part of the therapy. This comparative cadaver model study investigates the feasibility of implanting the device using a minimally invasive technique and compares its capability of first metatarsal head lateralisation to the established 3rd generation MICA (Minimally Invasive Chevron and Akin osteotomy) technique.  16 fresh frozen cadaveric feet (8 left, 8 right) of 8 body donors received either MICA (Group 1) or an IHF(r) in a minimally invasive technique (Group 2) The achievable first metatarsal head lateralisation and operating time were measured and pitfalls recorded.  This cadaver model study confirmed, the minimally invasive implantation of the Internal Hallux Fixator(r) can be performed reliably via 10 mm mini incision with V shaped distal metatarsal osteotomy. The mean first metatarsal head lateralisation was comparable between the groups with no statistically significant difference (7.2 1.9) mm in G1, or 8.3 0.8) mm in G2; p 0.09) The IHF(r) was inserted and fixed in mean 3.7 0.6) min, whereas double screw fixation needed 10 3.7) min.

title: Free moment induced by oblique transverse tarsal joint: investigation by constructive approach
abstract: The human foot provides numerous functions that let humans deal with various environments. Recently, study of the structure of the human foot and adjustment of an appropriate reaction force and vertical free moment during bipedal locomotion has gained attention. However, little is known about the mechanical (morphological) contribution of the foot structure to the reaction force and free moment. It is difficult to conduct a comparative experiment to investigate the contribution systematically by using conventional methods with human and cadaver foot experiments. This study focuses on the oblique transverse tarsal joint (TTJ) of the human foot, whose mechanical structure can generate appropriate free moments. We conduct comparative experiments with a rigid foot, a non oblique joint foot (i.e. mimicking only the flexion/extension of the midfoot) and an oblique joint foot. Axial loading and walking experiments were conducted with these feet. The axial loading experiment demonstrated that the oblique foot generated free moment in the direction of internal rotation, as observed in the human foot. The walking experiment showed that the magnitude of the free moment generated with the oblique foot is significantly lower than that with the rigid foot during the stance phase. Using this constructive approach, the present study demonstrated that the oblique axis of the TTJ can mechanically generate free moments. This capacity might affect the transverse motion of bipedal walking.

title: Effectiveness of three versus six feet of physical distancing for controlling spread of COVID 19 among primary and secondary students and staff: A retrospective, state wide cohort study
abstract: National and international guidelines differ about the optimal physical distancing between students for prevention of SARS CoV 2 transmission; studies directly comparing the impact of =3 versus =6 feet of physical distancing policies in school settings are lacking. Thus, our objective was to compare incident cases of SARS CoV 2 in students and staff in Massachusetts public schools among districts with different physical distancing requirements. State guidance mandates masking for all school staff and for students in grades 2 and higher; the majority of districts required universal masking.  Community incidence rates of SARS CoV 2, SARS CoV 2 cases among students in grades K 12 and staff participating in person learning, and district infection control plans were linked. Incidence rate ratios (IRR) for students and staff members in districts with =3 versus =6 feet of physical distancing were estimated using log binomial regression; models adjusted for community incidence are also reported.  Among 251 eligible school districts, 537,336 students and 99,390 staff attended in person instruction during the 16 week study period, representing 6,400,175 student learning weeks and 1,342,574 staff learning weeks. Student case rates were similar in the 242 districts with =3 feet versus =6 feet of physical distancing between students (IRR, 0.891, 95% CI, 0.594 1.335) results were similar after adjusting for community incidence (adjusted IRR, 0.904, 95% CI, 0.616 1.325) Cases among school staff in districts with =3 feet versus =6 feet of physical distancing were also similar (IRR, 1.015, 95% CI, 0.754 1.365)  Lower physical distancing policies can be adopted in school settings with masking mandates without negatively impacting student or staff safety.

title: Characteristics of the accessory tendon of the extensor hallucis longus muscle: a Taiwanese study
abstract: The main tendon of the extensor hallucis longus (EHL) muscle attaches to the dorsal aspect of the distal phalanx of the great toe. One or multiple accessory tendons of the EHL have been reported in several ethnic/regional groups, except Taiwan. This study aimed to investigate the incidence, length, and insertion of the accessory tendon of the EHL in Taiwanese people. Anatomical dissection was performed on 48 feet of 24 formalin embalmed cadavers. The occurrence and morphological characteristics of the accessory tendon of the EHL were recorded and analyzed. The accessory tendon of the EHL was found in 97.92% (47/48) of the legs that were dissected. In one male cadaver, an independent muscle belly was identified in each leg, whereas all the other accessory tendons originated from the main tendon of the EHL. In this study, the insertion of the accessory tendon were classified into four patterns. The most common insertion sites were the first metatarsophalangeal (MTP) joint capsule and proximal phalanx of the great toe. The length of the accessory tendons did not correlate with age or with sex when the two tendons with independent muscle belly were excluded. The accessory tendon of the EHL appears to be a regular feature in Taiwanese people. Most accessory tendons of the EHL (85.7% attached on the first MTP joint capsule may play a role in the prevention of capsular impingement during great toe extension.

title: CT more accurately detects foreign bodies within the equine foot than MRI or digital radiography.
abstract: Identification and characterization of foreign bodies in the distal limb of horses poses a diagnostic challenge. The aims of this prospective experimental cadaver study were to describe the appearance of five foreign body materials within the equine hoof using CT, MRI, and digital radiography (DR) and to compare interrater agreement among three reviewers. Fifty foreign bodies consisting of five materials were implanted at a solar location or a coronary location in 25 equine cadaver feet. The images were reviewed by three equine veterinarians experienced in advanced imaging interpretation, who were blinded to the material of the foreign body. Foreign bodies were graded on visibility and appearance. Sensitivity and specificity were calculated for accurate identification of the different materials. Interrater agreement was assessed using Fleiss' kappa. Computed tomography had higher visibility score, sensitivity/specificity, and interrater agreement for detection of all materials; particularly slate, glass, and dry wood, compared to the other imaging modalities. Soaked wood and plastic had lower sensitivity (31 33% on CT with a similar attenuation of the two materials. Foreign bodies were often visible on MRI, although with similar appearance and unclear details. On DR, only slate and glass were visible. The interrater agreement for identifying the correct material was almost perfect for slate, glass, and dry wood (k 0.92 1.00) and poor for plastic and soaked wood (k 0.20) on CT. Interrater agreement was poor for all materials on MRI and DR (k 0.20) with the except for fair (k 0.28) for slate on DR and moderate (k 0.28) for soaked wood on MRI.

title: Multimodal control of neck muscles for vestibular mediated head oscillation damping during walking: a pilot study
abstract: It is still in question whether head oscillation damping during walking forms a part of the vestibular function. The anatomical pathway from the vestibular system to the neck muscles via the medial vestibulospinal tract (MVST) is well known but there is a lack of knowledge of the exact influence and modulation of each other in daily life activities. (I) We fixed a head neck unit of a human cadaver specimen in a steal frame to determine the required pitch torque for a horizontal head position. The mean value of the acquired pitch torque was 0.54 Nm. (II) On a motorized treadmill we acquired kinematic data of the head, the sternum and both feet by wireless 3D IMUs for seven asymptomatic volunteers. Subsequently three randomized task conditions were performed. Condition 1 was walking without any irritation. Condition 2 imitated a sacculus irritation using a standardized cVEMP signal. The third condition used an electric neck muscle irritation (TENS) The data were analyzed by the simulation environment software OpenSim 4.0. 8 neck muscle pairs were identified. By performing three different conditions we observed some highly significant deviations of the neck muscle peak torques. Analysing Euler angles, we found during walking a LARP and RALP head pendulum, which also was strongly perturbated. Particularly the pitch down head oscillation damping is the most challenging one for neck muscles, especially under biomechanical concerns. Mainly via MVST motor activity of neck muscles might be modulated by vestibular motor signals. Two simultaneous proprioceptor effects might optimize head oscillation damping. One might be a proprioceptive feedback loop to the vestibular nucleus. Another might trigger the cervicocollic reflex (CCR)

title: Dystrophic muscle distribution in late stage muscular dystrophy
abstract: There is scant information about the comprehensive distribution of dystrophic muscles in muscular dystrophy. Despite different clinical presentations of muscular dystrophy, a recent multi center study concluded that phenotypic distribution of dystrophic muscles is independent of clinical phenotype and suggested that there is a common pattern of involved muscles. To evaluate this possibility, the present case report used cadaveric dissection to determine the whole body distribution of fat infiltrated, dystrophic muscles from a 72 year old white male cadaver with adult onset, late stage muscular dystrophy. Severely dystrophic muscles occupied the pectoral, gluteal and pelvic regions, as well as the arm, thigh and posterior leg. In contrast, muscles of the head, neck, hands and feet largely appeared unaffected. Histopathology and a CT scan supported these observations. This pattern of dystrophic muscles generally conformed with that described in the multi center study, and provides prognostic insight for patients and the physicians treating them.

title: Location of the Deep Plantar Artery: A Cadaveric Study.
abstract: The deep plantar (D PL) artery originates from the dorsalis pedis artery in the proximal first intermetatarsal space, an area where many procedures are performed to address deformity, traumatic injury and infection. The potential risk to injury of the D PL artery is concerning. The D PL artery provides vascular contribution to the base of the first metatarsal and forms the D PL arterial arch with the lateral plantar artery.  In an effort to improve our understanding of the positional relationship of the D PL artery to the first metatarsal, dissections were performed on 43 embalmed cadaver feet to measure the location of the D PL artery with respect to the base of the first metatarsal. Images of the dissected specimens were digitally acquired and saved for measurement using in house written software. The mean, standard deviation and 95% confidence intervals were calculated for all measurement parameters.  We found that the origin of the D PL artery was located at 11.5 3.9 mm (95% CI: 4.5 24.7 mm) distal to the first metatarsal base and 18.6% 6.5% (95% CI: 8.1% to 43.4% its length in reference to the proximal base. The average inter rater reliability across all measurements was 0.945.  Our study helps to clarify the anatomic location of the D PL artery by providing parameters to aid the surgeon when performing procedures in the proximal first intermetatarsal space. Care must be taken when performing procedures in the region to avoid unintended vascular injury to the D PL artery.

title: Resuming cadaver dissection during a pandemic
abstract: Methods of anatomical education have, as with many facets of normal life, been forced to evolve rapidly due to the Covid 19 pandemic. Whilst some authors claim that cadaver dissection is now under threat, we believe the centuries old practice can and must be upheld.

title: Bilateral High Division of Nervus Ischiadicus: A Cadaveric Case
abstract: Nervus (n. ischiadicus is a large nerve arising from the gluteal region and extending toward the posterior locations of the femur. It divides into two terminal branches on the proximal point of fossa poplitea: n. tibialis and n. peroneus communis. N. ischiadicus supplies somatic motor fibers to muscles in the feet, legs and posterior locations of the femur, while also providing sensitive fiber to a large part of leg skin and feet. N. ischiadicus was found to have a different course in the dissection performed on the bilateral gluteal region of the case in this study, the cadaver of a male person aged 55. The course of n. ischiadicus is a single branch in the gluteal region but it showed two branches in the case of this study. This course was found to be a bilateral example of Type b based on the classification of Beaton and Anson. It is important to know the course of this nerve for the surgical interventions to be made on this region considering the interaction between n. ischiadicus and other anatomical structures.