Radiographic and MRI Assessment of the Thrower's Elbow

Abstract

Purpose of review: Throwing athletes are vulnerable to elbow injuries, especially in the medial elbow, related to high stress and valgus load in both acute and chronic settings as a result of this complex biomechanical action. This current review details the relevant anatomy and imaging features of common elbow pathology identified with radiographs and MRI in throwing athletes.

Recent findings: Although elbow pathology in throwing athletes is well documented, advances in imaging technology and technique, particularly with MRI, have allowed for more detailed and accurate imaging description and diagnosis. Pathology of thrower's elbow occurs in predictable patterns and can be reliably identified radiologically. Clinical history and physical examination should guide radiologic evaluation initially with radiographs and followed by an MRI optimized to the clinical question. Constellation of clinical, physical, and radiologic assessments should be used to guide management.

Keywords: Elbow; MRI; Overhead throwing athlete; Thrower’s elbow.

Fig. 1

Coronal T2 MR images of the elbow in different patients demonstrate periligamentous edema about the proximal (a, arrow) and distal (b, arrow) UCL consistent with low-grade sprains

Fig. 2

Coronal T2 MR images of the elbow in different patients demonstrate a low- (a, arrow) and high-grade (b, arrow) partial thickness tears of the UCL

Fig. 3

Coronal T2 MR images of the elbow in different patients demonstrate proximal (a, arrow) and distal (b, arrow) full thickness tears of the UCL

Fig. 4

Coronal T2 MR arthrogram of the elbow demonstrates a high-grade partial thickness tear of the UCL midsubstance consistent with a 2A injury (Ramkumar classification system, arrow)

Fig. 5

Coronal T2 MR image of the elbow demonstrates chronic low signal thickening of the UCL (arrow)

Fig. 6

a Axial T1 MR image of the elbow demonstrates a small osteophyte along the posteromedial olecranon (arrow). b Axial T2 MR image demonstrates posteromedial ulnohumeral synovitis (arrow), mild pericapsular edema, and bone marrow edema-like signal in the olecranon

Fig. 7

Coronal (a) and axial (b) T2 MR images of the elbow in the same patient demonstrate medial epicondylosis with low-grade partial thickness tears (arrow) and an adjacent UCL sprain. Coronal (c) and axial (d) T2 MR images of the elbow in a different patient demonstrate medial epicondylosis with high-grade partial thickness tears (arrow) and adjacent chronic thickening of the UCL

Fig. 8

Axial T1 (a) and axial (b) and coronal (c) T2 MR images of the elbow demonstrate ulnar nerve (arrows) enlargement, loss of the normal fascicular architecture, and T2 signal hyperintensity consistent with ulnar neuritis

Fig. 9

a Lateral radiograph of the elbow demonstrates osseous irregularity and sclerosis of the capitellum with subtle fragmentation (arrow). b Sagittal T2 MR image more clearly demonstrates collapse of the capitellar subchondral bone plate with subjacent cyst-like changes consistent with an osteochondral lesion

Fig. 10

a Anteroposterior radiograph of the elbow in a patient with prolonged pain demonstrates a bulbous medial epicondyle apophysis. b Axial T2 MR image demonstrates bone marrow edema-like signal in the medial epicondyle apophysis and increased signal in the physis with adjacent soft tissue edema. Findings are consistent with medial epicondyle apophysitis

Fig. 11

Axial T1 (a) and T2 (b) MR images of the elbow demonstrate an avulsed medial epicondyle apophysis (arrowheads) with distal distraction. There is also a low-grade partial thickness tear of the proximal UCL (solid arrows)