Diagnostic Accuracy to Predict SLAP Lesions in the Shoulder

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Clinical Scenario:

A 19-year old, male baseball player comes into the ATR complaining of right anterior shoulder pain that he noticed a week ago that gets worse with throwing. He is a center fielder that commonly dives for the ball and makes high velocity throws to Homeplate. He reports 5/10 pain, not being able to throw as far and as hard, and clicking within his shoulder but can’t remember anything during practice aside from ‘not feeling right’. He says that during ADL and class, there is minimal discomfort except for when he needs to get something from a cabinet’s top shelf.

Pre-test Probability:

— In 2008, prevalence of SLAP lesions were reported at 10.1% (Weber et al., 2012) in the general population needing surgery from the American Board of Orthopedic Surgery (ABOS) database

-- 26.3% of patients undergoing SLAP lesion repairs did not a report symptom of pain

— Wilk et al. (2012) described the following clinical evaluation findings for SLAP lesions:

-- Single traumatic event: fall onto the outstretched arm, incidence of sudden traction, or a blow to the shoulder

-- Non-specific pain

-- Pain that subsides with rest

-- Pain usually intermittent and associated with overhead activity

-- Painful clicking or catching of the shoulder

-- Overhead athletes: loss of velocity and accuracy, general uneasiness of the shoulder

>> Present in 50% of patients

— Therefore, based on the patient’s clinical presentation (5 out of 6 most common SLAP symptoms) and accounting for the lack of specificity of these symptoms to other shoulder pathologies, the pre-test probability is given at 60%.

Likelihood Ratios:

Passive Distraction Test (PDT) & Active Compression Test (ACT) (Schleter et al., 2009):

<> Sensitivity: 70%

<> Specificity: 90%

<> LR (+) = 7.00

<> LR (−) = 0.11

Interpretation of Results: If patient tests (+) for PDT and ACT, 90% sure they actually have a SLAP tear. If test (-) for PDT and ACT, 15% sure they still have a SLAP tear.

Discussion of Results:

This analysis should be taken with caution when considering the current clinical scenario. The diagnostic tests (PDT and ACT) under review did not give results within a sporting or youth/young adult population (mean age=44 years), and while history of athletic activities was taken during the clinical evaluation of each participant, it was not reported with relevance to sensitivity and specificity.

A strength of the study is the large sample size (n= 254) and length of time for collection (between May 2001 and November 2003). Additionally, the provocation results from this review were compared to the gold standard for intraarticular diagnosis, arthroscopic shoulder evaluation, and which arthroscopic findings were used to determine a positive finding. It is noteworthy that three diagnostic tests were performed with sensitivity, specificity, and predictive values determined separately and in clustering. This is important because it narrows down that the PDT and ACT give the greatest post-test probability of those items and clustered combinations. Another thing to note is that each of the tests were completed on the participants by the senior author alone. Although this fails to address the reliability and ICC score across multiple clinicians completing these tests, a detailed description of each tests completed is outlined in the report which increases the ability for the results to be reproduced by other health care professionals.

Despite the strength of recommend

ation by comparing results to the gold standard for diagnosis, one large methodologic weakness of this study is the recruitment of cases through presentation of shoulder pain and/or dysfunction. Having this prejudice for shoulder dysfunction increases the likelihood of symptom provocation through the completion of these tests specific for SLAP lesions and also increases the examining clinician’s bias when using the tests to diagnose a SLAP lesion. Another limitation from this study is that other pathologies were not examined arthroscopically to observe if these tests could be reliable and valid for any other shoulder pathologies.

Clinical Bottom Line:

I think that the clustering of PDT and ACT provides a good clinical indication for the absence of a SLAP tear due to the low negative likelihood ratio. The positive likelihood ratio post-test probability can be used with moderate confidence in the presence of SLAP lesions but should be used in coordination with other clinical exam diagnostic findings. With a lower pre-test probability due to differing signs and symptoms of SLAP lesions, using PDT and ACT can be used to indicate if further diagnostic imaging should be done or if another pathology needs to be considered.

References

Schlechter, J., Summa, S., & Rubin, B. (2009). The Passive Distraction Test: A New Diagnostic Aid for Clinically Significant Superior Labral Pathology. The Journal of Arthroscopic and Related Surgery, 25(12), 1374-1379.

Weber, S., Martin, D., Seiler, J., & Harrast, J. (2012). Superior Labrum Anterior and Posterior Lesions of the Shoulder: Incidence Rates, Complications, and Outcomes as Reported by American Board of Orthopedic Surgery Part II Candidates. The American Journal of Sports Medicine, 40(7), 1538-1543.

Wilk, K., Macrina, L., Cain, E. L., Dugas, J., & Andrews, J. (2013). The Recognition And Treatment Of Superior Labral (Slap) Lesions In The Overhead Athlete. The International Journal of Sports Physical Therapy, 8(5), 579-600

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