E1234. Ultrasound-Guided Musculoskeletal Injections: A Radiologist's Primer
  1. Logan Haug; Mayo Clinic - Phoenix
  2. Jacqueline Kunzelman; Mayo Clinic - Phoenix
  3. Nirvikar Dahiya; Mayo Clinic - Phoenix
  4. Jeremiah Long; Mayo Clinic - Phoenix
Ultrasound serves as practical and easy-to-use modality to facilitate intra-articular and bursal needle placement when steroidal injection or joint aspiration is requested. The purpose of this exhibit is to demonstrate safe and commonly utilized ultrasound-guided approaches to multiple joints and bursal compartments throughout the body.

Educational Goals / Teaching Points
To demonstrate a common ultrasound-guided approach to the wrist, elbow, acromioclavicular, and glenohumeral joints of the upper extremities and the tibiotalar, knee, and hip joints of the lower extremities as well as the subacromial, olecranon, iliopsoas, and trochanteric bursae. To provide a general overview of the critical periarticular and juxta-bursal anatomy to be wary of when considering needle placement and trajectory.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Elbow joint positioning is flexed to a right angle to maximize the approach to the olecranon fossa for elbow joint access. Imaging technique the probe is placed along the posterior elbow and a dorsolateral to ventromedial approach through the anconeus is commonly utilized. The dorsomedial approach is considered less favorable secondary to the proximity of the ulnar nerve. Subacromial bursal injection positioning the patient is placed in the lateral decubitus position with the side to be injected placed superiorly. Imaging technique the probe is placed in plane with the clavicle just lateral to the acromion and a lateral to medial approach through the deltoid is used. This approach places the needle, bursa, and supraspinatus perpendicular to the beam making them readily visible and allowing for precise needle localization within the bursa. Tibiotalar joint positioning the patient is supine, and the ankle is plantarflexed to maximize the approach to the tibiotalar joint. Imaging technique the probe is placed longitudinally along the anterolateral ankle joint and an anterior to posterior approach is utilized. Doppler imaging can assist with localization of the anterior tibial artery. The chosen approach should avoid it and the extensor tendons if possible. Knee joint position while the patient is positioned supine, the knee is slightly flexed with the approach targeted to the lateral suprapatellar recess. Imaging technique the probe is positioned along the superior aspect of the patella in the transverse plane and a lateral to medial approach is commonly used. The described approach minimizes the depth of injection and avoids the osseous restriction imposed by the tibiofemoral compartment of the knee joint. In the case of therapeutic injection, the dose for nearly all sites is 40mg of Depo-Medrol with 3ml of 0.5% Ropivacaine.

Ultrasound is a great modality for facilitating image-guided joint access throughout the body. Knowledge of relevant anatomy around each joint facilitates procedural safety and efficacy. Understanding the technical components of ultrasound imaging is critical for accurate needle placement. Attention to patient positioning and its effect on joint anatomy facilitates safe and easy joint access.