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Age / Sex : 47 / M
Chief complaint: right shoulder pain for several months
1) What is your impression?
Two weeks later, you can see the final diagnosis with a brief discussion of this case.
(Quiz는 quiz일 뿐이오니 답안은 한개만 보내주시기 바라오며, 복수의 답안을 보내주시는 분은 정답이 포함되어 있더라도 부득이 semi-correct answer로 처리토록 하겠습니다.)
Courtesy: 지원희(Won-Hee Jee), 가톨릭대서울성모병원(Seoul St. Mary's Hospital)
Diagnosis: Partial-thickness subscapularis tendon tear
Discussion
Findings: MR arthrogram
with posterior approach at 3.0T. Oblique
sagittal fat-suppressed T1-weighted MR arthrogram shows partial thickness tear
of subscapularis tendon. On axial fat-suppressed T1-weighted MR arthrogram, the
superior aspect of the lesser tuberosity is partially uncovered due to the avulsion
of the subscapularis tendon from its footprint.
Diagnosis:
Partial-thickness
subscapularis tendon tear
Discussion:
The subscapularis is an important internal rotator for
the shoulder, but it also has an important role in dynamic anterior
glenohumeral joint stability and in maintaining balanced force couples around
the shoulder. Despite surgical repair of the supraspinatus and/or
infraspinatus, if a subscapularis tendon tear was not identified by MRI or
arthroscopy, the tear can go undiagnosed and/or untreated. This could result in
an imbalance in the force couples, which can potentially lead to a failed
rotator cuff repair.
The
superior two thirds of the subscapularis has a tendinous insertion at lesser
tuberosity and the inferior third has a muscular attachment at the proximal
humeral shaft just below the lesser tuberosity. The superior fibers of the
subscapularis tendon interdigitate with the anterior fibers of the supraspinatus
tendon and contribute to the rotator interval. These fibers blend with the
medial portion of the coracohumeral ligament and superior glenohumeral ligament
that form the biceps pulley. Subscapularis tendon tears associated with
supraspinatus tendon tears are more common than isolated subscapularis tendon
tears. Typically, the articular surface of the superior subscapularis tendon is
involved initially. The symptoms of subscapularis tendon tears include
nonspecific vague anterior shoulder pain.
MR arthrography with a posterior approach is a
better option for evaluating subscapularis tendon tears as compared to an anterior
approach. Precise description of the tears with emphasis on the depth of the
tear, craniocaudal extent, and location of the tendon stump relative to glenoid
is important.
References
1.
Foad A and Wijdicks CA. The accuracy of magnetic resonance imaging and magnetic
resonance arthrogram versus arthroscopy in the diagnosis of subscapularis
tendon injury. Arthroscopy 2012;28:636-641
2. Pfirrmann C, Zanetti M, Hodler J. Subscapularis
tendon tears: detection and grading at MR arthrography. Radiology
1999;213:709-714
3. Li XX, Schweitzer ME,
Bifano JA, Lerman J, Manton GL, El-Noueam KI. MR evaluation of subscapularis
tears. J Comput Assist Tomogr 1999;23:713-717
4. Jung JY, Jee WH, Chun CW, Choi Maria, Sung JK, Kim YS. Diagnostic performance of MR arthrography with anterior
versus posterior approach for subscapularis tendon tear at 3.0T. RSNA 2012
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