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Tae Kyun Kim, MD, PhD et al ABSTRACT A SLAP lesion is a tear of the
labrum of the shoulder, specifically Superior Labrum Anterior to
Posterior. Causes include
falling on an outstretched arm, traction to the biceps tendon, and
overhead throwing activities where the tendon of the biceps can impart a
traction force on the labrum. The injury was initially broken
into 4 types: Type I
indicated fraying and degeneration of the labrum with no detachment of the
biceps. Type II had
detachment of the biceps insertion. Type
III shows a bucket handle tear of the superior aspect of the labrum with
an intact biceps tendon insertion into the bone.
Type IV has an instrasubstance tear of the biceps tendon with a
bucket handle tear of the anterior superior labrum.
Morgan et al further broke down the Type II lesions depending on
whether the detachment of the labrum involved the anterior aspect of the
labrum, the posterior aspect, or both. Studies performed have shown varied
degrees of the lesion in the population. One study of 2375 patients undergoing arthroscopic
examination displayed a 6% SLAP lesion rate, while another revealed 12%.
The variability exists because of the extreme variations seen in
the biceps attachment, and how the surgeon classifies the attachment.
It is often difficult to distinguish between detachment of the
labral anchor and a normal meniscoid labrum with a sublabral recess. There has been discussion and
debate as to whether there is concomitant laxity and instability when
there is a SLAP lesion. One
study found no EMG deficits in the biceps tendon with persons having
instability, indicating it does not play a role in stability.
Other studies have shown the presence of instability without a SLAP
lesion, plus these lesions are found when other syndromes occur in the
shoulder. For this study, 544 patients
undergoing arthroscopic examination of their shoulder for conditions such
as frozen shoulder, AC arthritis, instability, rotator cuff disease, and
others were used to find the actual incidence of SLAP lesions, along with
clinical presentation. This
stuffy found 26% of the subjects had SLAP lesions, with 74% being Type I,
21% being Type II, and less than 5% being Types III and IV. Univariate analysis found
significant correlations between Type I lesions and age, a positive
Speed’s test, a supraspinatus tear, OA of the humeral head, and a
primary diagnosis of rotator cuff disease or GH instability.
Type II lesions were associated with overhead sports and OA of the
humeral head. Type III and IV
lesions were grouped together due to their low incidence, and a
relationship was found with high demand jobs, a Bankart lesion, sports
related injury, and a primary diagnosis of GH instability.
Further breakdown found that of those with a Type II lesion that
were over the age of 40 had a high incidence of supraspinatus tear, OA of
the humeral head, and rotator cuff disease.
Those under the age of 40 with a Type II lesion had associations
with overhead sports and a Bankart lesion. Multivariate analysis found Type I
lesions were associated with supraspinatus tears and a positive Speed’s
test. Type II lesions were
associated with participation in overhead throwing sports and OA of the
humeral head. Types III and
IV lesions were associated with a Bankart lesion and a high demand job. COMMENTS Diagnosis of this lesion can be
quite difficult, and you almost have to go by gut feeling, poor response
to usual treatment, and their complaints.
Often the MRI is performed, and even an arthrogram, which come up
negative. The crepitus, loud
cracking and complaints of instability and locking could also be from a
subluxing biceps tendon in the groove.
If you have a patient with limited
motion causing impingment pain, a history of throwing or even pitching,
crepitus, feelings of instability, biceps tendonitis and pain and
apprehension, he/she may have a SLAP lesion.
This study used both male and female subjects, and the males
accounted for 57% of the volume. I once asked 5 different ortho
surgeons which test, if any, they felt was best to detect SLAP lesions,
and they all reported that there is nothing really definitive, and the
condition can be baffling and present in many different ways.
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