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previously visited HIGH GRADE PARTIAL TEAR OF THE COMMON EXTENSOR TENDON
Contributed by: Fritsch & Thompson, Radiologist, Diagnostic Radiology of Houston, Texas, USA.
Patient: 51 year old male
History:

Lateral elbow pain.

History of prior corticosteroid injections.
Images:[small]larger

Fig. 1: AP ELBOW X-RAY - Suspecious of occult radial head fracture but MRI showed radial head intact.

Fig. 2: INTERNAL ROTATION OBLIQUE ELBOW

Fig. 3: LATERAL ELBOW X-RAY

Fig. 4: TI CORONAL FSE ELBOW

Fig. 5: TI CORONAL FSE ELBOW

Fig. 6: TI CORONAL FSE ELBOW

Fig. 7: PD FATSAT CORONAL ELBOW - High signal abnormality indicates common extensor tendon tear (yellow arrow) but the radial collateral ligament is intact (red arrow).

Fig. 8: PD FATSAT CORONAL

Fig. 9: PD FAT SAT CORONAL

Fig. 10: TI CORONAL FSE ELBOW

Fig. 11: PD FATSAT CORONAL

Fig. 12: PD FATSAT SAGITTAL
Findings:
MRI examination of the left elbow reveals the following:

There is no fracture or aggressive marrow abnormality. Alignment of the elbow is well maintained. The common extensor tendon shows a high-grade partial tear best depicted on coronal images 10, 11 and 12. The lateral collateral ligament remains intact. The annular ligament, medial collateral ligament and common flexor tendon are unremarkable. There are no focal osteochondral lesions identified within the elbow. There is a small amount of fluid in the elbow joint without distention of the capsule. The biceps and triceps tendon insertion positions are intact and neurovascular bundle of the elbow and surrounding periarticular musculature is unremarkable.


X-ray: Alignment does not appear acutely disrupted. There is slight irregularity of the lateral aspect of the radial articular surface noted on the AP projection, however no frank disruption of cortical outlines is noted. The appearance mimics a small fracture fragment, but is most likely the result of mild osteophyte formation along this articular margin. No focal acute disruption or cortical or trabecular patterns is identified. Joint spacing is within expected limits. No soft tissue abnormalities are identified.

Diagnosis:

MRI CONCLUSIONS:
HIGH-GRADE PARTIAL TEAR OF THE COMMON EXTENSOR TENDON WITHOUT DISRUPTION OF THE LATERAL COLLATERAL LIGAMENT.

MILD EFFUSION OF THE ELBOW JOINT WITHOUT DISTENTION.

NO ACUTE OR AGGRESSIVE OSSEOUS OR INTRA-ARTICULAR ABNORMALITY.

ECF

X-RAY CONCLUSIONS:
SMALL IRREGULARITY ALONG THE LATERAL ASPECT OF THE RADIAL HEAD ARTICULAR SURFACE. IN THE ABSENCE OF ANY RECENT ACUTE TRAUMA, THIS MOST LIKELY REPERESENTS OSTEOPHYTE FORMATION. OTHERWISE UNREMARKABLE STUDY.
JRT
Discussion: The primary abnormality of "tennis elbow" involves the origin of the extensor carpi radialis brevis and less commonly the anterior aspect of the extensor digitorum tendon. The extensor carpi radialis brevis is the most lateral muscle contracts at a higher level during daily functional tasks and contracts more powerfully during the backhand stroke of tennis. It has a complex origin, receiving contribution from the common extensor tendon, the lateral collateral ligament, the annular ligament, the overlying fascia, and intramuscular septum. These contributions are intertwined and are not always separable on either MRI, sonography or at surgery. The lateral collateral ligament lies immediately deep in relation to the common extensor origin. It is more likely to be thickened, partially torn, or completely torn with more severe grades of lateral elbow tendinosis.

The wrist extensor-supinator group falls into the category of tendons particularly vulnerable to injury. The lateral elbow tendinosis or "tennis elbow" is the most common source of elbow pain in the general population and may be produced by a variety of overuse activities. The tendons have poor vascular supply, wrap around a convex surface and are subjected to repetitive stress.

On MRI the normal common extensor tendons are seen as smooth well defined black structures of uniform thickness on all sequences. Tendinosis manifest by thickening and signal change. In the early stages, the tendon demonstrates poorly defined low to intermediate signal change on T1weighted images, with a relative increase in signal on T2 weighted images. On T2 weighted sequences with fat suppression or STIR imaging, the affected tendon returns high signal. In later stages, cystic change may occur, with focal areas of high signal seen within the tendon on T2 weighted images. This may be complicated by partial or complete tears of the tendon and be associated with collateral ligament derangement.

This case demonstrates partial tear of the common extensor tendon origin which most likely represents avulsion of the extensor carpi radialis brevis. The lateral collateral ligament is intact.

Nirschl defined the following progressive stages:
Stage 1 - Inflammatory changes that are reversible
Stage 2 - Nonreversible pathologic changes to origin of the ECRB muscle
Stage 3 - Rupture of ECRB muscle origin
Stage 4 - Secondary changes such as fibrosis or calcification

Suggested Reading:

Steven J. Thornton, JR. Rogers, WD. Prickett, WR. Dunn, AA. Allen, and JA. Hannafin.
Treatment of Recalcitrant Lateral Epicondylitis With Suture Anchor Repair. The American Journal of Sports Medicine 33:1558-1564 (2005).

Link: http://www.emedicine.com/orthoped/topic510.htm

References: REFERRING PHYSICIAN: DR. EDWIN KIEKE, DC
Comments:
No comments posted.
Additional Details:

Case Number: 4770477Last Updated: 11-21-2007
Anatomy: Skeletal System   Pathology: Trauma
Modality: Conventional Radiograph, MRExam Date: 04-27-2006Access Level: Readable by all users
Keywords: elbow, extensor tendon, tennis elbow

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