A SLAP tear means the labrum is torn away from the acetabulum in two directions: forward (anterior) and back (posterior). The word superior tells us the tear is along the upper rim or top of the acetabulum.
This is a serious injury that doesn’t happen very often. Overhead athletes are at greatest risk. Cocking the arm back to throw puts the shoulder in a position that can cause a SLAP tear.
There are four basic types of SLAP lesions labeled I through IV. They represent type of tear, location of tear, and severity of tear. For example, with type I there is fraying of the labrum. In Type II the tear extends into the biceps tendon, which attaches to the labrum. Type III is a bucket-handle shaped tear. It does not include the biceps. And type IV is a bucket-handle shaped tear with involvement of the biceps tendon.
The physician uses a wide range of tests and measures to diagnose and classify a SLAP tear. Most physicians rely on a group of commonly applied clinical tests. If any of these tests are positive, then further diagnostic measures are needed.
Range-of-motion testing must be done comparing the involved side to the normal (pain free) shoulder. The examiner is specifically looking for a glenohumeral internal rotation deficit (GIRD). Without normal rotational patterns, athletes lose the ability to throw overhand effectively.
These clinical tests don’t usually tell whether the lesion is Grade I, II, III, or IV. Advanced imaging with magnetic resonance arthrography (MRA) is needed to confirm the clinical diagnosis. MRA is considered accurate, sensitive, and specific enough to rely upon.
The final diagnosis, of course, is made arthroscopically when the surgeon attempts to look inside the joint and surgically repair the damage. Studies do show the reliability of interobserver reliability for arthroscopic exams is very poor.
This means that if 10 physicians looked at the arthroscopic video to evaluate and diagnose the condition, only six of the 10 would agree. That is only slightly more than half, which means 40 per cent disagree on the diagnosis. This low level of agreement/disagreement suggests the need to look at arthroscopic exams very carefully before making a final diagnosis. Given this statistic, a second opinion may or may not help.