Presentation
Status post corticosteroid injections for lateral epicondylitis, now worse after a clunk
Patient Data
Findings
Radiocapitellar (lateral) compartment
-
extensive tear of the common extensor origin in the anterior part involving the following:
extensor digitorum communis (EDC)/extensor digiti minimi (EDM)
disruption of the radial collateral ligament and extensive tear of the lateral ulnar collateral ligament (LUCL)
Ulnohumeral (medial) compartment
normal configuration
common flexor origin with mild tendinopathy
mildly high signal of the proximal ulnar collateral ligament
cubital tunnel inconspicuous
Proximal radioulnar joint
normal configuration
mild hyperintensity and fiber irregularity of the annular ligament
small joint effusion
Biceps tendon
normal insertion of anterior (caput brevis) and posterior (caput longum) portions of the distal biceps tendon at the radial tuberosity
Impression
Extensive common extensor tendon tear with proximal disruption of the extensor carpi radialis brevis and extensor digitorum as well as tear of the extensor carpi ulnaris.
Disruption of the radial collateral ligament, extensive tear of the lateral ulnar collateral ligament and strain of the annular ligament.
Exam courtesy: Jeanette Moses & Sven Winzler (radiographers)
Case Discussion
Common extensor tendon injuries are frequent tendon injuries of the elbow 1. This is an example of an extensive tear with involvement of the extensor carpi radialis brevis, extensor digitorum/digiti minimi and extensor carpi ulnaris origins and the radial collateral ligament complex. With this degree of injury, an associated injury of the lateral ulnar collateral ligament is common 2.
In contrast to this injury, the usual tennis elbow is characterized by micro-tears 3 and would only show a thickened common extensor origin with internal hyperintense foci on MRI 2.
Case courtesy: Alexander Streck