Takahashi Ryo, Ohmichi Yusuke, Hatayama Naoyuki, Hirai Shuichi, Naito Munekazu, Nakano Takashi
Department of Anatomy, School of Medicine, Aichi Medical University, Nagakute, Aichi, 480-1195, Japan.
Department of Judo Therapy, Chuwa Professional Training College of Medical Care, Aichi, Japan.
Anat Sci Int. 2020 Jun;95(3):356-362. doi: 10.1007/s12565-020-00528-0. Epub 2020 Feb 8.
The sagittal band of the finger is an aponeurosis-like structure surrounding the metacarpophalangeal joint. Sagittal band rupture causes extensor tendon dislocation from the dorsal side of the metacarpophalangeal joint. The thumb has two extensor tendons: extensor pollicis longus and extensor pollicis brevis tendons. Multiple studies have reported variations of extensor pollicis brevis tendon insertion. However, it remains unclear how the thumb sagittal band envelopes the extensor pollicis longus and extensor pollicis brevis tendons. This study investigated the anatomical relationship between the sagittal band and the two extensor tendons of the thumb. One hundred hands (47 right, 53 left) from 54 cadavers were examined to assess the detailed structure of the thumb sagittal band and extensor pollicis longus and extensor pollicis brevis tendons. We found that the thumb sagittal band enveloped both the tendons either separately (type I) or collectively (type II). Thirty-four cases (34.0%) were type I and 66 cases (66.0%) were type II. The extensor pollicis longus and extensor pollicis brevis tendons enveloped in the type I thumb sagittal band were inserted on different sites, respectively, whereas those tendons enveloped in the type II thumb sagittal band were inserted on the same sites. This study demonstrated that differences in the type of thumb sagittal band are closely associated with variations in extensor pollicis brevis tendon insertion. We predicted that these differences contribute to the sliding distance between the extensor pollicis brevis and extensor pollicis longus tendons and affect the pathophysiology of extensor tendon dislocation.
手指的矢状带是一种围绕掌指关节的类腱膜结构。矢状带断裂会导致伸肌腱从掌指关节背侧脱位。拇指有两条伸肌腱：拇长伸肌腱和拇短伸肌腱。多项研究报道了拇短伸肌腱止点的变异情况。然而，拇指矢状带如何包绕拇长伸肌腱和拇短伸肌腱仍不清楚。本研究调查了拇指矢状带与两条伸肌腱之间的解剖关系。对54具尸体的100只手（47只右手，53只左手）进行检查，以评估拇指矢状带以及拇长伸肌腱和拇短伸肌腱的详细结构。我们发现，拇指矢状带分别（I型）或共同（II型）包绕两条肌腱。I型有34例（34.0%），II型有66例（66.0%）。I型拇指矢状带包绕的拇长伸肌腱和拇短伸肌腱分别附着于不同部位，而II型拇指矢状带包绕的那些肌腱附着于相同部位。本研究表明，拇指矢状带类型的差异与拇短伸肌腱止点的变异密切相关。我们推测这些差异会影响拇短伸肌腱和拇长伸肌腱之间的滑动距离，并影响伸肌腱脱位的病理生理过程。
