Jelsing, Elena J.

Objective: Determine the radiological prevalence of popliteal artery entrapment (PAE) in subjects with anterior leg compartment chronic exertional compartment syndrome (CECS). Design: Retrospective review. Setting: Tertiary care center. Patients: Of 71 patients diagnosed with anterior leg compartment CECS using an in-scanner exercise-based magnetic resonance imaging (MRI), 64 also completed Fast Imaging Employing Steady-State Acquisition (FIESTA) imaging. Interventions: Electronic health records of patients diagnosed with anterior leg compartment CECS using an in-scanner exercise-based MRI between 2009 and 2018 were reviewed. Main Outcome Measures: Demographics, symptom laterality, and results of vascular work-up. Results: Magnetic resonance imaging was positive for PAE in 33 of 64 (51.6%). Vascular evaluation was performed in 30 of 33 (90.9%). Of these 30, ankle-brachial indices (ABIs) with PAE maneuvers were performed in 29 (96.7%) and positive in 25 (86.2%). Pre-exercise and post-exercise ABIs were performed in 29 (96.7%) and abnormal in 20 (69.0%). Thirteen arterial duplex ultrasounds were performed; 10 were consistent with PAE (76.9%). An MR angiogram was performed in 8 (26.7%) and consistent with PAE in all. One computed tomography angiogram (3.3%) was completed and was normal. Overall, one or more tests were positive for PAE in all 30 with vascular evaluation. Conclusions: The radiological prevalence of PAE and anterior leg CECS was 51.6%. All subjects with vascular studies (90.9%) had one or more tests confirming radiological PAE. These findings suggest that the coexistence of PAE and CECS is common, and the PAE protocol used has a high correlation with vascular studies.

Active learning has the benefit of being more engaging and interactive, making it more suitable for adult learners who prefer a task/problem centered approach to learning. Implementation of small‐group sessions in the material‐rich course is not always possible and other alternatives that engage learners should be explored. To incorporate active learning strategies, a team learning exercise “Talking Points” (TP), was introduced in a microscopic anatomy sessions for first year medical students. At the beginning of the laboratory period, students were given 5–7 subject‐related basic science/clinical problems and were encouraged to discuss within small “ad hoc” formed teams. Near the end of the laboratory session, these items were discussed by the entire group. This exercise gave the students the opportunity to learn relevant clinical material within small teams and present their findings to other classmates. Many students remarked that TP facilitated their learning of the material, stimulated questions, encouraged peer teaching, and provided a preview of learning strategies for the final examination. The participation and students' performance during TP was not included in the final grade. Incorporation of the TP into the microscopic anatomy curriculum increased students' participation and ended the laboratory session with an enthusiastic conclusion.

Abstract: We present 2 cases where the initial history and examination were similar to a Morton's/interdigital neuroma. In both cases, however, diagnostic ultrasound revealed symptomatic snapping of the proper digital nerve of the fifth toe. The anatomy of the proper digital nerve of the fifth toe may predispose it to a snapping phenomenon. Clinical awareness of this atypical cause of forefoot pain can help guide the diagnosis and treatment in those patients with persistent and refractory lateral forefoot pain and paresthesias.

Objectives To determine the ability to sonographically identify the posterior cutaneous nerve of the forearm (PCNF) and its distal epicondylar branches using sonographically guided perineural injections in an unembalmed cadaveric model. Methods A single experienced operator used a 12–3‐MHz linear array transducer to identify the PCNF and its distal epicondylar region branches in 10 unembalmed cadaveric specimens (6 right and 4 left) obtained from 10 donors. Sonographically guided perineural PCNF injections were then completed with a 22‐gauge, 38‐mm stainless steel needle to deliver 0.25 mL of 50% diluted colored latex at 3 points along the PCNF. The latex location was then confirmed via dissection. Results The 10 donors included 4 male and 6 female cadavers aged 48 to 94 years (mean, 73 years) with body mass indices of 19 to 37 kg/m 2 (mean, 26 kg/m 2 ). The operator sonographically identified the PCNF and several distal branches traversing over or directly adjacent to the lateral epicondyle in all 10 specimens. Only 7 of 10 specimens showed a distinct PCNF bifurcation into anterior and posterior divisions, and all 7 were accurately identified and localized on sonography. There was no evidence of latex overflow to clinically relevant adjacent structures or injury to regional vessels or nerves. Conclusions High‐resolution sonography can identify the PCNF and its distal epicondylar branches. Sonographic evaluation of the PCNF should be included in the evaluation of patients presenting with refractory or atypical lateral elbow pain syndromes. Diagnostic and therapeutic sonographically guided procedures targeting the PCNF or its lateral epicondylar branches are feasible and warrant further investigation.

A 33-year-old elite female runner presented to a tertiary care sports medicine clinic with a 2-year history of progressive anterior thigh and circumferential leg pain with associated foot paresthesias brought on by high-intensity running. She had both external iliac artery vasospasm and chronic exertional compartment syndrome. External iliac artery vasospasm is a rare cause of exertional leg pain, particularly in the running population. This case highlights the unique features of this condition, addresses the multidisciplinary approach that led to the accurate diagnoses, and demonstrates that more than 1 etiology for exertional leg pain can coexist in an athlete.

ABSTRACTIntroduction: The primary aim of this investigation was to determine whether use of write‐zoom magnification affects sonographically determined cross‐sectional area (CSA) of peripheral nerves. Methods: CSAs of the median (MN) and posterior interosseous (PIN) nerves were measured in 22 limbs from 11 asymptomatic volunteers using both standard imaging and write‐zoom magnification. CSA measurements were repeated on the same images 1 week later. Results: The average CSA of write‐zoomed images for the MN was significantly larger at both measurement sessions (week 1: 11.1 mm2 write‐zoom vs. 10.0 mm2 standard, P = 0.019; week 2: 11.8 mm2 vs. 10.4 mm2, P = 0.023). Similar differences were noted for the PIN (week 1: 2.3 mm2 vs. 1.9 mm2, P = 0.002; week 2: 2.5 mm2 vs. 1.9 mm2, P = 0.001). Conclusions: Write‐zoom magnification may significantly increase the measured CSA of peripheral nerves. These changes appear to be more substantial when smaller nerves are measured. Muscle Nerve 51: 30–34, 2015