Janette W. PoWell, PT, OCS, STC1, Peter a. HuiJbregts, PT, DPT, OCS, FAAOMPT, FCAMT2, Richard Jensen, PT, PhD3
Abstract: SLAP lesions are often complex injuries with varied defects and tissue involvement that are challenging to diagnose clinically. The literature notes the need for visualization under arthroscopy for adequate diagnostic accuracy. The goal of this article is to provide a current best-evidence synthesis with regard to physical examination tests used for the diagnosis of SLAP lesions. A literature search yielded 17 studies that investigated the diagnostic utility of clinical tests for SLAP lesions. These studies investigated 19 clinical tests. A narrative review and a systematic review of methodological quality using the QUADAS methodological quality assessment tool yielded 3 high-quality diagnostic utility studies. Current best evidence indicates that a negative finding for the passive compression test provides the therapist with the greatest evidence-based confidence that a SLAP lesion is absent. A positive finding on the anterior apprehension maneuver, the anterior slide test, the Jobe relocation test, the passive compression test, the Speed test, and the Yergason test or a combination of positive findings on the Jobe relocation test and the active compression test or the Jobe relocation test and the anterior apprehension maneuver provides the therapist with the research-based confidence required to rule in a SLAP lesion. For ruling in a SLAP lesion, the greatest diagnostic value should likely be placed on a positive finding on the passive compression test. Suggestions for future research are provided.
Keywords: Best-evidence Synthesis, Diagnostic Utility, QUADAS, SLAP Lesion, Systematic Review
Superior Labrum Anterior-to-Posterior (SLAP) lesions have been discussed, defined, and investigated since Andrews et al1 first described this pathology in 1985. These lesions, which involve the superior region of the glenoid labrum, with or without the attachment of the long head of biceps, have been noted to be challenging to diagnose conservatively2-18. Non-surgical assessment tools, i.e., manual clinical tests and imaging studies, do not seem to paint a clear diagnostic picture and many authors have noted the need for arthroscopic visualization for sufficient diagnostic accuracy2,3,5-13,15-19.
SLAP lesions are often described as complex injuries with a spectrum of locations and varied types of tissue defects in the glenoid labrum and its associated structures13. Snyder et al20 classified these pathological variations into four types on the basis of morphology (Figure 1):
- Type I: degenerative fraying with no detachment of the biceps insertion
- Type II: detachment of the biceps insertion
- Type III: a bucket-handle tear of the superior aspect of the labrum with an intact biceps tendon insertion to bone
- Type IV: an intra-substance tear of the biceps tendon with a bucket-handle tear of the superior aspect of the labrum
The Type II SLAP lesions have been further divided into three subtypes depending on whether the detachment of the labrum involves the anterior aspect of the labrum alone, the posterior aspect alone, or both aspects8,10,11,13,14,21,22. The above classification system has been expanded to include an additional three types8,10,11,21-23:
- Type V: a Bankart lesion that extends superiorly to include a Type II SLAP lesion
- Type VI: an unstable flap tear of the labrum in conjunction with a biceps tendon separation
- Type VII: a superior labrum and biceps tendon separation that extends anteriorly, inferior to the middle glenohumeral ligament
It is likely that the varied patho-anatomy and/or patho-mechanics of these differ- ent types of SLAP lesions significantly alter the clinical presentation10,14.
Further complicating the clinical presentation and correct diagnosis is the noted variability with regard to “normal” anatomy of the superior labrum including the appearance and degree of attachment of the labrum to the glenoid rim with a spectrum of foramina and recesses and the variability in the surrounding glenohumeral ligament structures8,10,13,14,21-23. Adding to these intrinsic complexities these lesions are also often associated with additional concomitant shoulder pathology10-12,14,21. SLAP lesions commonly accompany other extra- and intra-articular shoulder pathology further complicating the clinical diagnostic process14,18,23-25.
The incidence of SLAP lesions has been reported in the literature to range between 6–26% of all shoulder injuries evaluated arthroscopically10,13,14,21-23. A variety of etiologic mechanisms have been implicated; including fall on an outstretched arm, overhead work, internal impingement, traction/tension on the biceps tendon due to overhead athletic activity, and instability resulting in a “peel-back” of the superior aspect of the labrum when the biceps insertion is twisted as the arm is brought into abduction and external rotation3,8,10,11,13,14,21-23. Musgrave and Rodosky23 suggested that different mechanisms of injury were likely to be operational in the various SLAP lesion types. Huijbregts21 reported on the high sensitivity of non-specific posterior shoulder pain and the inability to perform overhead athletic activities but specificity of such history findings is clearly very limited. Similarly, a patient report of mechanical symptoms was also found lacking in diagnostic utility21.
In the currently predominant evidence-based practice paradigm, research-based data on utility of diagnostic tests supplement and replace the pathophysiologic rationale previously used for the interpretation of these tests. Because data on epidemiology, mechanism of injury, and other history findings with regard to SLAP lesions clearly provide insufficient information to allow for confident research-based clinical diagnosis the clinician typically turns to the physical examination to gather more data. Research studies on diagnostic accuracy of individual tests provide statistics such as sensitivity, specificity, predictive values, and likelihood ratios. However, the numerical value for these statistics and hence their clinical interpretation are highly dependent on the methodological quality of the study in which they were derived. Various authors have written narrative reviews discussing the diagnostic accuracy of physical examination tests for SLAP lesions but only few have combined this report of diagnostic accuracy statistics with a methodological quality assessment of the diagnostic accuracy studies in the form of a systematic review5,7,26,27. The systematic reviews by Dinnes et al26 and by Luime et al7 were published in 2003 and 2004, respectively. With 4 of the 17 studies retrieved for this review published after 2004 and another two published in the years that these reviews were published, an update was obviously justified. However, 2 more recent systematic reviews both published in 2007 seemed to question the need for this review. While Jones and Galluch5 provided descriptions of the tests as we did in this review, Hegedus et al27 did not, thereby limiting the clinical utility of their review as a stand-alone paper. Neither review provided a summary description of the studies retrieved, which we did because it allowed for a discussion of research validity other than solely relying on the methodological quality assessment tool as both other reviews did. Jones and Galluch used a non-validated assessment tool scoring only three items, whereas Hegedus et al used the same tool as in this study. Aside from the fact that our review showed that this tool does not adequately address some critical methodological errors leading us to discard in this review one of the studies deemed a higher-quality study by Hegedus et al, comparison of our scores on this tool with other sources scoring the same studies forces us to question reliability of the tool and thereby sole reliance on this tool. Finally, literature search strategies used by the other recent reviews and this review were substantially different yielding five extra references as compared to Jones and Galluch and two additional references as compared to Hegedus et al; it should be noted that the latter authors did retrieve one study we did not find.
Having thus justified the need for this review, the goal for this article is to provide the most comprehensive and clinically useful synthesis with regard to the quality of studies addressing physical examination tests used specifically for the diagnosis of SLAP lesions.