The sural nerve is at risk of iatrogenic injury even during minimally invasive operative procedures to repair the calcaneal (Achilles) tendon. Through 107 cadaveric leg dissections, the data derived from the present study was used to develop a regression equation that will enable surgeons to estimate the intersection point at which the sural nerve crosses the lateral border of the Achilles tendon, an important surgical landmark. In most cases, the sural nerve crossed the lateral border of the Achilles tendon 8 to 10 cm proximal to the superior border of the calcaneal tuberosity. By simply measuring the leg length of the patient (from the base of the heel to the flexor crease of the popliteal fossa), surgeons can approximate the location of this intersection point with an interval length of 0.68 to 1.80 cm, with 90% confidence, or 0.82 to 2.15 cm, with 95% confidence. For example, for a patient with a lower leg length of 47.0 cm, the mean measurement in the present study, a surgeon can be 90% confident that the sural nerve will cross the lateral border of the Achilles tendon 8.28 to 8.96 cm (interval width of 0.68 cm) proximal to the calcaneal tuberosity. Currently, ultrasound and clinical techniques have been implemented to approximate the location of the sural nerve. The results of the present study offer surgeons another method, that is less intensive, to locate reliably and subsequently avoid damage to the sural nerve during calcaneal (Achilles) tendon repair and other procedures of the posterolateral leg and ankle.

Two variants of the fibularis (peroneus) quartus muscle were identified and photographed in the legs of a 70-year-old white male cadaver. A rare peroneocuboideus (fibulocuboideus) muscle (as described by Chudzinski) and a novel peroneocalcaneocuboideus (fibulocalcaneocuboideus) muscle was found in the right and left leg, respectively. The latter muscle has not been previously reported and was termed "peroneocalcaneocuboideus" on the basis of its origin and insertions. Also, the distal attachment of both muscles inserted onto the distal lip of the peroneal sulcus of the cuboid bone, which differs from the historical data. The insertion of the peroneocuboideus muscle was previously described as being at the tuberosity of the cuboid bone or, simply, the lateral surface of the cuboid. Therefore, the present case study provides the first gross anatomic photographs of these variant leg muscles along their entire length, identifies a novel fibularis quartus variant, and describes a new insertion site for the peroneocuboideus muscle. Throughout our report, the historical data are reviewed to list the prevalence and describe the clinical implications of the fibularis quartus muscle and its variants. The presence of variant fibularis quartus muscles has been known to cause lateral ankle pain and stenosis, ankle instability, fibular tenosynovitis, subluxation of the fibular (peroneal) tendons, and longitudinal splitting of the fibularis brevis tendon in radiologic and case studies. Therefore, surgeons, radiologists, and clinicians should be aware of these variant muscles when considering various diagnoses, interpreting radiographs, and pursuing surgical intervention to relieve lateral ankle pathologic features.

The purpose of this study was to determine how North American dental students are taught neuroscience during their preclinical dental education. This survey represents one part of a larger research project, the Basic Science Survey Series for Dentistry, which covers all of the biomedical science coursework required of preclinical students in North American dental schools. Members of the Section on Anatomical Sciences of the American Dental Education Association assembled, distributed, and analyzed the neuroscience survey, which had a 98.5 percent response from course directors of the sixty-seven North American dental schools. The eighteen-item instrument collected demographic data on the course directors, information on the content in each course, and information on how neuroscience content is presented. Findings indicate that 1) most neuroscience instruction is conducted by non-dental school faculty members; 2) large content variability exists between programs; and 3) an increase in didactic instruction, integrated curricula, and use of computer-aided instruction is occurring. It is anticipated that the information derived from the survey will help guide neuroscience curricula in dental schools and aid in identifying appropriate content.

Tarsal tunnel syndrome, or posterior tibial neuralgia, is diagnosed when the tibial nerve is compressed as it travels within the tarsal tunnel. Two variant leg muscles, flexor digitorum accessorius longus (FDAL) and peroneocalcaneus internus (PCI), have gained recent attention in the clinical literature for their involvement in this compressive entrapment neuropathy. Both of these muscles course within the tarsal tunnel and, when present, may act as space‐occupying lesions, leading to numbness, paresthesia, and pain in the foot. However, low prevalence of these two muscles and discrepancies within the literature have led to confusion distinguishing between these variants muscles. During 317 leg dissections, examples of the FDAL and PCI muscles were identified and ways to differentiate between the two muscles were determined based upon origin, course, location within the tarsal tunnel, and insertion of the muscle. The results of this study also led to the first gross anatomical photograph of the rare peroneocalcaneus internus muscle. Radiologists and clinicians should be aware of these muscles when embarking in diagnosis and imaging interpretation, especially when tarsal tunnel syndrome is within the differential diagnoses.

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