Sonographic anatomy and technique to image the plantar digital nerves and aid identification of a Morton's neuroma.

Introduction: The anatomy of the forefoot is complex, and the sonographic assessment to image the plantar digital nerves and exclude, diagnose or discriminate between a Morton's neuroma and intermetatarsal bursitis can be challenging. Topic description and discussion: A good appreciation of the sonographic anatomy, technique, normal and abnormal appearances is required to undertake a sonographic assessment of the forefoot and its interspaces, particularly the plantar digital nerves. This is unpacked in this paper with associated pictorial aids. Muscles, tendons, and ligaments of the interspaces and the nearby metatarsophalangeal joints and their associated soft-tissue structures are helpful sonographic landmarks to guide imaging and assessment of the common and proper plantar digital nerves and the intermetatarsal bursa. These need to be appreciated from both dorsal and plantar sonographic approaches, in both short- and long-axis imaging planes. Conclusion: Improved understanding of the anatomy and sonographic appearances of the interspace structures can enhance the sonographic assessment of the forefoot and improve diagnosis of a Morton's neuroma and/or intermetatarsal bursitis when present to guide patient management.

Ultrasound assessment of acute Achilles tendon rupture and measurement of the tendon gap.

Achilles tendon rupture is a common sports-related injury which can carry significant morbidity to patients. Ultrasound remains the workhorse of imaging as it can confirm and localise the extent of Achilles tendon injury. The sonographic anatomy, both normal and ruptured sonographic appearances, as well as sonographic technique must be appreciated to accurately image and report findings, critical to patient management. Particular attention should be applied to the measurement of the diastasis between acutely ruptured tendon ends as this information can assist with informing the decision of conservative vs. operative management. Further work is necessary to standardise the measurement technique including correlating the degree of plantarflexion of the foot with the sonographic tendon gap measures.

Persistence of the processus vaginalis and its related disorders.

The processus vaginalis is a blind-ended evagination of the abdominal wall that develops during fetal life and typically undergoes obliteration in early life. Persistence of the processus vaginalis is associated with a number of pathologies including congenital indirect inguinal hernias, communicating hydroceles, funicular and encysted hydroceles, canal of Nuck cysts, and acquired undescended testis. Whilst all are detectable sonographically, there is little educational material relevant to the field of ultrasound with much of the literature directed at surgical and primary care physicians. Furthermore, within the literature there is a lack of consensus on several areas including the anatomy and embryology of the processus vaginalis and the mechanisms behind its obliteration. As such the objective of this paper is to distil the information regarding the persistent processus vaginalis as it is relevant to ultrasound and in doing so address the literature gap for sonographers and sonologists. The anatomy and embryology of the persistent processus vaginalis will be discussed including causative mechanisms for anomalies with their sonographic appearance highlighted.