Ultrasound is a well‐proven imaging modality for showing peripheral nerve disorders and guiding perineural injections. The aim of this review is to focus on small peripheral nerve abnormalities, which are usually not recognized by sonologists. In fact, most of these small nerves have a tiny diameter (<2 mm), and their anatomy is less familiar. We describe the most common causes of small peripheral nerve disorders, providing an accurate description of their anatomic locations and relationships with adjacent structures; we also focus on technical hints that may help in their evaluation.

Disorders of retinacula are frequent in acute and repetitive microtrauma of the ankle. Ultrasound (US), thanks to its spatial resolution and dynamic capabilities, is routinely used in the evaluation of the posttraumatic ankle for accurate delineation of ligaments and tendons. In addition, US can provide a depiction of normal retinacula and a detailed assessment of their pathologic changes. An accurate US assessment of ankle retinacula is helpful in choosing the proper treatment. In this pictorial essay, we briefly review the normal anatomy of ankle retinacula, describe their normal US appearance, and present a wide range of US pathologic abnormalities.

The fractures of sesamoid bones of the hand are rare, sometimes the diagnosis is missed. We report a case of fracture of both the ulnar and radial sesamoids of the metacarpophalangeal (MCP) joint of the thumb. The trauma (hyperextension of the thumb during a soccer match) also caused a lesion of the volar plate. The diagnosis was made by ultrasound (US) and confirmed by CT scan.Riassunto Le fratture dei sesamoidi della mano sono eventi rari, talvolta non diagnosticati. Presentiamo il caso di una frattura che ha interessato sia il sesamoide radiale che ulnare della articolazione metacarpofalangea (MCP) del pollice. Il trauma (iperestensione del pollice durante una partita di calcio) ha inoltre causato la lesione della placca volare. La diagnosi è stata fatta con l'ecografia (US) e confermata alla TC.

This pictorial review focuses on the ultrasound (US) appearance of the normal and pathological radial nerve (RN) and its branches and provides tips with which to locate them and avoid misinterpretation of normal findings. A wide range of our pathological cases are reviewed and presented to help in familiarizing the reader with common and uncommon clinical scenarios that affect the RN and its main branches.

Calcific tendinopathy of the shoulder is a common condition caused by calcium hydroxyapatite crystals, affecting the tendons of the rotator cuff. Among uncommon complication, one is the migration of the calcium in the subacromion-subdeltoid bursa. More rare is the intraosseous migration. We present four cases of an even more rare condition, not well described in literature yet, the intramuscular migration of calcium.Keywords Calcific tendinopathy Á Intramuscular migration Á Shoulder pain Á Ultrasound Á Calcium hydroxyapatite crystal deposition disease Á Rotator cuff Riassunto La tendinopatia calcifica della spalla è una condizione comune causata da cristalli di idrossiapatite di calcio, che colpisce i tendini della cuffia dei rotatori. Tra le complicanze non comuni, una è la migrazione di calcio nella borsa subacromion-subdeltoidea. Più rara è la migrazione intraossea. Presentiamo quattro casi di una condizione ancora più rara, poco descritta in letteratura, la migrazione intramuscolare di calcio.