Faculty Bibliography

Pronator syndrome is a median nerve entrapment neuropathy that can be difficult to diagnose due to its variable presentation and objective findings. Neurolymphomatosis is an uncommon disease in which malignant lymphocytes infiltrate central or peripheral nerve endoneurium and is often missed for prolonged periods prior to diagnosis. We present a rare case of pronator syndrome and anterior interosseous nerve palsy due to neurolymphomatosis that was occult on initial MRI in spite of the presence of a median nerve mass discovered intra-operatively during neurolysis. This case demonstrates the value of ultrasound for the examination of peripheral nerve pathology and illustrates its utility as an adjunct to MRI, in part due to the ability to screen a large region.

Ultrasound visualization affords proceduralists versatile and accurate guidance for a variety of percutaneous, minimally invasive procedures in the musculoskeletal system including joint (intra-articular) injections or aspirations, intra-bursal injections, peritendinous, and perineural injections. A variety of percutaneous procedures are traditionally performed blindly, but may be more easily or more accurately performed with the real-time assistance of ultrasound guidance. Other procedures are only possible utilizing image-guidance, due to the required precision of the injection because of delicate local anatomy or depth of the injection; ultrasound is a safe, portable, and widespread modality that can be used to assist the proceduralist in localizing the needle tip in such cases, to ensure safe and accurate delivery of the medication, most frequently a solution of steroid and anesthetic. This review aims to provide a foundational approach to ultrasound-guided procedures in the musculoskeletal system, offering tips and tricks that can be employed in many different procedures including intra-articular, juxta-articular, and perineural injections for a multitude of clinical scenarios. Technical considerations regarding ultrasound transducer selection, sonographic technique, as well as common indications, contraindications, and complications of these procedures, are presented. Additionally, a variety of pharmacologic considerations for proceduralists contemplating ultrasound-guided injections are discussed.

Multimodality imaging of the brachial plexus is essential to accurately localize the lesion and characterize the pathology and site of injury. A combination of computed tomography (CT), ultrasound, and MR imaging is useful along with clinical and nerve conduction studies. Ultrasound and MR imaging in combination are effective to accurately localize the pathology in most of the cases. Accurate reporting of the pathology with dedicated MR imaging protocols in conjunction with Doppler ultrasound and dynamic imaging provides practical and useful information to help the referring physicians and surgeons to optimize medical or surgical treatment regimens.

Preoperative localization of nonpalpable breast lesions using a radar reflector surgical guidance system has become commonplace, but the clinical utility of this emerging technology in the musculoskeletal system has not yet been well established. The system components include a console, a handpiece, an implanted radiofrequency reflector that works as a lesion marker, and an infrared light-emitting probe to guide the surgeon. The reflector can be deployed to localize small nonpalpable nodules within the subcutaneous fat as well as lesions within the deeper soft tissues. It can also be used for lymph nodes and foreign bodies. Localization can be performed both before and after treatment. The objective of this article is to describe the potential applications and our technique and initial experience for radar-reflector localization within the musculoskeletal system.

A variety of foot and ankle pathologies can impair patient's daily activities, ultimately requiring surgical management. However, with improvements in image-guided intervention, the joints, soft tissues, and osseous structures may be accessible using various percutaneous techniques as a potential alternative therapeutic tool, avoiding the need for surgery with its associated risks and morbidity. This article discusses the potential range of image-guided interventional treatments. Injections, aspiration, biopsies, cryoablation, and radiofrequency ablation are described. Newer novel treatments are also covered. Finally, the common pathologies of Morton's neuroma, Achilles tendinopathy, and plantar fasciitis are addressed.

OBJECTIVES/OBJECTIVE:To determine the incidence of infectious complications following ultrasound-guided musculoskeletal interventions performed with a disinfected uncovered ultrasound transducer footprint. METHODS:Electronic medical records of all patients who underwent an ultrasound-guided musculoskeletal procedure (including injection, calcific lavage, or ganglion cyst aspiration) performed by any of the 14 interventional musculoskeletal radiologists at our institution between January 2013 and December 2018 were retrospectively reviewed to identify procedure site infections. Biopsies and joint aspirations were excluded. The procedures were performed using a disinfected uncovered transducer footprint. First, an automated chart review identified cases with (1) positive answers to the nurse's post-procedure call, (2) an International Classification of Diseases (ICD) diagnostic code related to a musculoskeletal infection, or (3) an antibiotic prescription within 30 days post-procedure. Then, these cases were manually reviewed for evidence of procedure site infection. RESULTS:In total, 6511 procedures were included. The automated chart review identified 3 procedures (2 patients) in which post-procedural fever was reported during the nurse's post-procedure call, 33 procedures (28 patients) with an ICD code for a musculoskeletal infection, and 220 procedures (216 patients) with an antibiotic prescription within 30 post-procedural days. The manual chart review of these patients revealed no cases of confirmed infection and 1 case (0.015%) of possible site infection. CONCLUSIONS:The incidence of infectious complications after an ultrasound-guided musculoskeletal procedure performed with an uncovered transducer footprint is extremely low. This information allows radiologists to counsel their patients more precisely when obtaining informed consent. KEY POINTS/CONCLUSIONS:• Infectious complications after ultrasound-guided musculoskeletal procedures performed with a disinfected uncovered transducer footprint are extremely rare.

Musculoskeletal injections serve a variety of diagnostic and therapeutic purposes, with ultrasonography (US) guidance having many advantages: no ionizing radiation, real-time guidance, high spatial resolution, excellent soft tissue contrast, and the ability to identify and avoid critical structures. Sonography can be cost effective and afford flexibility in resource-constrained settings. This article describes US-guided musculoskeletal injections relevant to many radiology practices and provides experience-based suggestions. Structures covered include multiple joints (shoulder, hip), bursae (iliopsoas, subacromial-subdeltoid, greater trochanteric), peripheral nerves (sciatic, radial), and tendon sheaths (posterior tibial, peroneal, flexor hallucis longus, Achilles, long head of the biceps). Trigger point and similar targeted steroid injections, as well as calcific tendinopathy barbotage, are also described.

PURPOSE/OBJECTIVE:To describe our experience using ultrasound (US) to evaluate postoperative complications in the presence of in situ shoulder arthroplasty. METHODS:Review of patients who underwent US evaluation following total shoulder arthroplasty (TSA), reverse total shoulder arthroplasty (RTSA) or hemiarthroplasty from 2007 to 2020. All studies were reviewed independently by two musculoskeletal radiologists to assess for joint effusion, periarticular collection, and characterization of associated rotator cuff tears. Tendon tears were assessed with respect to (1) thickness: low grade (<50% thickness), high grade (>50% thickness), full thickness; (2) morphology (focal vs. diffuse) and location (insertion vs. critical zone). Inter-reader agreements were determined using Cohen's kappa test. RESULTS:Ninety-seven studies were performed in 72 patients following TSA, RTSA, or hemiarthroplasty. Thirty-seven exams were solely for diagnostic purposes, and 59 were for guiding joint or periarticular collection aspiration. Twenty-eight studies assessed the cuff tendons post TSA. The mean time between surgery and US examination was 29.2 months. Complete or high-grade tears were identified in 8/28 (28.6%) diagnostic exams. The most commonly torn tendon among TSA patients was the subscapularis, with 13/28 (46.4%) demonstrating at least partial tearing. Inter-reader agreement was excellent for presence of effusion (k = 0.79, p < .001) and periarticular collection (k = 0.87, p < .001), and excellent agreement for presence of subscapularis tear (k = 0.78, p < .001), with fair agreement for assessment of supraspinatus (k = 0.66, p < .001) and infraspinatus (k = 0.60, p < .001) tears. CONCLUSION/CONCLUSIONS:The most commonly torn tendon following anatomic TSA identified by US was the subscapularis, which was torn or deficient in 46.4% of cases. The majority of studies were performed for the guidance of percutaneous aspiration.