To describe the pattern of various shoulder abnormalities with an associated superior labrum anterior to posterior (SLAP) lesion type II using magnetic resonance (MR) arthrography, and to assess the clinical significance of the associated abnormalities.

A retrospective review of the MR arthrographic findings of 92 cases of a shoulder with an arthroscopically confirmed SLAP lesion type II was performed. The MR arthrography images were reviewed and analyzed. MR arthrographic analysis noted the presence of a rotator cuff abnormality, acromioclavicular arthritis, adhesive capsulitis, glenohumeral arthritis, a labral abnormality besides the SLAP lesion, and a paralabral cyst. The patients with SLAP lesions were divided into two age groups: those over 40 years of age and those forty years old or younger. Statistical analysis was performed to evaluate the influence of age on the various shoulder abnormalities with associated SLAP lesion.

Of the 92 SLAP lesions type II, there were 7 cases (8%) of isolated SLAP lesions without any associated any shoulder abnormality. Eighty-five (92%) SLAP lesions were associated with various shoulder abnormalities including rotator cuff tendinosis (30/92, 33%), partial-thickness tear (36/92, 39%), full-thickness tear (2/92, 2%), acromioclavicular arthritis (46/92, 50%), adhesive capsulitis (7/92, 8%), glenohumeral arthritis (15/92, 16%), labral abnormality (26/92, 28 %) and paralabral cyst (7/92, 8%). The SLAP lesions (60/92, 65%) in patients over forty years of age were accompanied by a significantly high number of rotator cuff abnormalities (p < 0.001), glenohumeral osteoarthritis (p = 0.001), and acromioclavicular osteoarthritis (p < 0.001). In contrast, the SLAP lesions (32/92, 35%) in patients forty years old or younger had a significantly high number of anterior or posterior labral lesions (p < 0.001).

Isolated SLAP lesions type II without other associated shoulder abnormalities are uncommon, and the age of the patient influences the prevalence of other shoulder abnormalities associated with SLAP lesions. In addition, MR arthrography can help detect shoulder abnormalities accompanying the SLAP lesions.