抄録
Recently many rotator cuff tears including subscapularis are repaired arthroscopically. However, there are only a few reports about the morphology of the subsccapularis muscle insertion to the humerus. The knowledge of the insertion morphology leads to appreciate the tear size and to repair anatomically. In this study, we investigated the cadaveric shoulders to clarify the morphology of the subscapularis muscle insertion and the difference between sexes and sides. We investigated 24 cadaveric shoulders (bilateral shoulders of five males and seven females; mean age 87 years old) and measured the maximum longitudinal distance (proximal-to-distal direction) and transverse distance (medial-to-lateral direction) of the subscapularis insertion. We also measured the distance between the articular cartilage edge and the most medial tendon insertion (bare area) at sites of the proximal end, maximum transverse distance position and the distal end. The data were analyzed with an unpaired-t-test or paired-t-test between sexes and sides. Statistical significance was set at p<.05. The subscapularis muscle insertion was consisted of 2 parts, proximal tendinous part and distal muscular part in all cadavers. The mean maximum longitudinal distance of the tendon insertion was 35.5 (SD, 4.2) mm. The mean transverse distance of the tendon insertion was 15.8 (SD, 2.3) mm. The mean distance of the bare area at sites of the proximal end, maximum transverse distance position and the distal end was 3.1 (SD, 2.0) mm, 5.9 (SD, 1.7) mm, 11.9 (SD, 3.4) mm, respectively. Significant differences existed between sexes in maximum transverse distance (p=0.0006), the bare area at the maximum transverse distance position (p=0.00199) and distal end position (p=0.0015). No significant differences were found between sides in all subjects. We examined the subscapularis insertion to the humerus in cadaveric shoulders. Anatomical measurements in this study may be useful in evaluating and reattaching the subscapularis to the humerus.
