Background: Previous studies have suggested that SLAP (superior labrum anterior posterior) lesions are a distinct clinical entity. The goals of this study were to define the prevalence, associated pathological findings, and clinical features of the different types of SLAP lesions with use of a common classification system.

Methods: Five hundred and forty-four patients undergoing shoulder arthroscopy for a variety of diagnoses were prospectively included in this consecutive case series. SLAP lesions were grouped with use of the Snyder classification. Demographic data, clinical data, and arthroscopic findings in the groups with SLAP lesions were compared with those in a control group with no SLAP lesion.

Results: Of 544 shoulder arthroscopy procedures, 139 (26%) demonstrated a SLAP lesion. One hundred and three (74%) of the SLAP lesions were Type I, twenty-nine (21%) were Type II, one (0.7%) was Type III, and six (4%) were Type IV. Most (123) of the SLAP lesions were found to be associated with other intra-articular lesions. Multivariate analysis revealed that a positive Speed test and a supraspinatus tear were significantly associated with Type-I lesions (p = 0.012 and p = 0.001, respectively). The findings associated with Type-II lesions differed according to the patient's age: Type-II lesions in patients who were forty years of age or younger were associated only with a Bankart lesion, whereas those in patients older than forty years of age were associated with a supraspinatus tear and osteoarthritis of the humeral head. Type-III and Type-IV lesions were associated with a high-demand occupation and a Bankart lesion.

Conclusions: This study demonstrated that the prevalence, associated pathological findings, and clinical features of the different types of SLAP lesions vary with the patient population that is studied. Also, the clinical features and pathological findings associated with the different types of SLAP lesions often overlap. Isolated SLAP lesions with no associated pathological findings are uncommon, and care must be taken when ascribing symptoms to a SLAP lesion when other lesions are present.

Level of Evidence: Diagnostic study, Level IV-1 (case-control study). See p. 2 for complete description of levels of evidence.