J Korean Radiol Soc.  1997 Jan;36(1):141-147.

MR Arthrography of the Labral-Capsular-Ligamentous Complex: Normal Anatomy, Anatomic Variations, and Pitfalls - Preliminary Study

• Lee JY
• Kwon JH
• Kim JE
• Lee JH
• Park YH
• Park JG

Abstract

PURPOSE
To evaluate anatomic variations and pitfalls of the labral-capsular-ligamentous complex in the shoulder joint for the proper interpretation of magnetic reasonance arthrographic images.
MATERIALS AND METHODS
To determine the presence of sublabral sulci, undercutting of the base of the glenoid labrum by the articular cartilage, and the proximity of the middle glenohumeral ligament to the anterior glenoid labrum, 56 MR arthrograms of 41 asymptomatic volunteers were prospectively evalvated for labral shape and capsular insertion. We also evaluated the axillary fold, which was often confused with a loose body.
RESULTS
The anterior and posterior parts of the labra, varied but their shape showed several dominant features; triangular(72%, 36%, respectively), rounded(13%, 35%), cleaved(8%, 1%), notched(2%, 0%), flat(5%, 24%), and absent(0%, 4%). Anterior capsular insertion was type 1 in 82% of cases, type 2 in 13% and type 3 in 5%, whereas posterior insertion was type 1 in 62%, type 2 in 36% and type 3 in 2%. We could also detect many pitfalls, such as undercutting of the base of theglenoid labrum by the articular cartilage(29%), sublabral sulci(25%), a prominent axillary fold(38%), and the middle glenohumeral ligament in proximity to the anterior labrum(5%).
CONCLUSION
Our study revealed wide variability in the MR arthrographic appearance of the labral-capsular-ligamentous complex in asymptomatic shoulders. A good understanding of normal variation and pitfalls of the normal shoulder may be helpful pathologic condition in case of glenouhumeral instability.

Keyword

Shoulder, anatomy; Shoulder, MR

MeSH Terms

Arthrography*
Cartilage, Articular
Ligaments
Prospective Studies
Shoulder
Shoulder Joint
Volunteers