Anatomy of the lateral elbow. The blue box is the region of the common extensor tendon and area of interest for ultrasound scanning
Common extensor and flexor tendinopathies are diagnosed based on pain and tenderness at the lateral and medial epicondyles and pain on resisted wrist extension or flexion. Relative rest, activity modifications, and physical therapy should be considered before an injection. Injections can be done using local anesthetic (e.g., ropivacaine) with or without steroid, platelet-rich plasma (PRP), or whole blood. The possibility of an underlying radial collateral ligament injury should be considered among patients with chronic lateral epicondylosis who have failed previous treatment, particularly corticosteroid injections. Humero-ulnar and radio-humeral (also known as radio-capitellar) joint arthritis is diagnosed on the basis of focal tenderness, painful movement, ultrasound findings of an effusion, or radiographic abnormalities.
Position: Seated or supine
Probe: Linear 5–12 MHz
The key landmark is the lateral epicondyle (LE), the origin of the common extensor tendon (CET). Additional structures include the radio-capitellar joint (J) between head of the radius (R) and capitellum (C) of the humerus, and the radial collateral ligament (RCL) (Fig. 20.5).
Medial elbow scan 1: The key landmark is the medial epicondyle (ME), from which the common flexor tendon (CFT) originates (Fig. 20.6).
Medial elbow scan 2: Short-axis views of the ulnar nerve (UN) in its usual retrocondylar position (Fig. 20.7a) and subluxed over the medial epicondyle (ME) of the humerus where it could be injured during an injection (Fig. 20.7b). Additional structures include the olecranon of ulna (U) and the triceps muscle (TM).
Posterior elbow scan 1. The position is shown in scan position 1. The key landmark is the olecranon (O) of the ulna and the triceps muscle (TM) and triceps tendon (TT). Humero-ulnar joint (HUJ) is seen between the humerus (H) and olecranon (O) (Fig. 20.8).