Rotator interval lesions include SGHL, SSP and SSC tears with variable involvement of each of them. Habermeyer first described the combination of these tears with arthroscopy. According to this classification we propose an initial diagnosis with a Type I, II, III and IV pattern. Arthroscopic findings matched the proposed initial diagnosis as shown in Table 1.

Arthro-MRI confirmed its excellent accuracy in the diagnosis of rotator interval tears; its limits are mainly related to the low specificity in the identification of SGHL tears.

On the other hand, the use of dynamic acquisitions (intra and extrarotated positions) is useful in the detection of early LHBT instability and could suggest the presence of ASI.

However in our experience, according to arthroscopic dynamic tests, only complex lesions of LHBT pulley system are probably related to ASI.

Table 1.