Purpose
Glenohumeral instability is a common cause of shoulder pain and loss of shoulder function.
Glenohumeral instability can be regarded as either traumatic unidirectional or atraumatic multidirectional,
but this classification is not comprehensive enough to include minor shoulder instability,
including superior instability (supra-equatorial instability).
The aim of our study is to evaluate the effectiveness of MR-arthrography in the detection and classification of lesions that may cause superior instability.
Methods and Materials
From January 2003 to January 2009,
we retrospectively reviewed 42 patients (30 males and 12 females) with a mean age of 36 years (ranging from 19 to 62 years) who underwent MR-arthrography of the shoulder followed by arthroscopic surgery.
All patients had clinical signs of shoulder supraequatorial chronic instability with diffuse shoulder pain that was difficult to pinpoint,
radiated to the arm,
was exacerbated by external rotation and arm extension and was associated with weakness.
Symptoms were present for a period of 3-6 months,
and...
Results
We detected 31 superior labral anterior-posterior (SLAP) lesions; all were confirmed on arthroscopy; however,
there were 3 cases of underestimation.
In the detection of SLAP lesions,
the sensitivity,
specificity,
accuracy,
predictive value of a positive test (PVPT) and predictive value of a negative test (PVNT) of MR-arthrography were all 100%.
In the evaluation of the real type of SLAP lesions,
the sensitivity was 100%,
the specificity was 78.5%,
the accuracy was 92.8%,
the PVPT was 71.7% and the PVNT was 100%.
All capsular laxity (13/42)...
Conclusion
Superior instability is frequently associated with different pathological conditions or anatomic variants,
such as SLAP lesions.
The role of MR-arthrography is to describe key features of the superior findings,
including the location,
morphology,
extent of the abnormality and associated injuries and to correlate these features with clinical symptoms.
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SLAP lesions: anatomy,
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