US-guided Musculoskeletal Interventions of the Body Wall and Core with MRI and US Correlation.

Chest, abdominal, and groin pain are common patient complaints that can be due to a variety of causes. Once potentially life-threatening visceral causes of pain are excluded, the evaluation should include musculoskeletal sources of pain from the body wall and core muscles. Percutaneous musculoskeletal procedures play a key role in evaluating and managing pain, although most radiologists may be unfamiliar with applications for the body wall and core muscles. US is ideally suited to guide these less commonly performed procedures owing to its low cost, portability, lack of ionizing radiation, and real-time visualization of superficial soft-tissue anatomy. US provides the operator with added confidence that the needle will be placed at the intended location and will not penetrate visceral or vascular structures. The authors review both common and uncommon US-guided procedures targeting various portions of the chest wall, abdominal wall, and core muscles with the hope of familiarizing radiologists with these techniques. Procedures include anesthetic and corticosteroid injection as well as platelet-rich plasma injection to promote tendon healing. Specific anatomic structures discussed include the sternoclavicular joint, costochondral joint, interchondral joint, intercostal nerve, scapulothoracic bursa, anterior abdominal cutaneous nerve, ilioinguinal nerve, iliohypogastric nerve, genitofemoral nerve, pubic symphysis, common aponeurotic plate, and adductor tendon origin. Relevant US anatomy is depicted with MRI correlation, and steps to performing successful safe US-guided injections are discussed. Confidence in performing these procedures will allow radiologists to continue to play an important role in diagnosis and management of many musculoskeletal pathologic conditions. ©RSNA, 2021.

Fluoroscopy-guided percutaneous needle aspiration of posterior epidural abscesses: a report of two cases.

Introduction: Spinal epidural abscesses are most commonly treated with surgical decompression and antibiotics or in specific instances managed medically with antibiotic therapy alone. Image-guided percutaneous aspiration as an alternative to surgery has only rarely been reported in the literature. Case presentation: We report two cases of successful fluoroscopy-guided needle aspiration of posterior epidural abscesses. Case 1 is a 48-year-old man who presented with several days of escalating back pain and constitutional symptoms with MRI showing a posterior epidural abscess at L2-L3 causing spinal stenosis. The patient remained neurologically intact. Percutaneous needle aspiration of the collection provided dramatic pain relief with the aspirate growing methicillin sensitive Staphylococcus aureus. The patient made a full recovery on antibiotic therapy. Case 2 is an 81-year-old man who presented with worsening upper back pain and was found to have osteomyelitis/discitis with a large posterior epidural abscess in the thoracic spine. Needle drainage was performed with the sample growing Bacteroides fragilis. This patient also responded successfully to nonsurgical management with full recovery after appropriate antibiotic therapy. Discussion: In carefully selected patients, image-guided needle aspiration of posterior epidural abscesses may be a viable and less invasive alternative to surgery.

High-energy fracture of the fabella.

Fractures of the fabella are rare, with only nine cases reported in the literature. However, they can cause severe posterolateral knee pain. Other complications include osteoarthritis and, very rarely, peroneal nerve compression. All the prior cases have been transverse fractures. Here we present a first case of a sagittally oriented fabella fracture initially diagnosed on radiographs and subsequently confirmed by computed tomography (CT) with three-dimensional volume renderings. Early recognition and conservative treatment with rest, immobilization, and physical therapy are believed to be effective at relieving symptoms.