The purpose of this study is to investigate the pathological significance of peel back phenomenon (PBP) of the superior labrum of the shoulder by arhthroscopic dynamic examination. We studied 55 shoulders of 55 patients who underwent arthroscopic surgery. There were 39 male and 16 female patients. The average age at operation was 28.7 years old (range 14-65). Shoulder instability and posterior tightness were evaluated under general anesthesia. The type of SLAP lesion, and the grade of PBP with shoulder abduction and external rotation simulating late cocking position was evaluated arthroscopically. There were 39 shoulders with positive SLAP lesion (type I:22, II:13, III:3, IV:1) and 16 shoulders with negative SLAP lesions. There were 25 shoulders with positive PBP and 30 shoulders with negative PBP. No significant differences in PBP positive rate were observed with or without SLAP lesion, displaceability of the superior labrum, anterior instability, and posterior tightness. There were no relationships observed between PBP and SLAP lesion, anterior instability, and posterior tightness of the shoulder. Peel back phenomenon of the superior labrum of the shoulder was supposed to be dynamic variant.
