Saito Susumu, Ueda Maho, Murata Mai, Suzuki Shigehiko
Kyoto, Japan.
From the Department of Plastic and Reconstructive Surgery, Graduate School of Medicine and Faculty of Medicine, Kyoto University.
Plast Reconstr Surg. 2018 Jan;141(1):85e-90e. doi: 10.1097/PRS.0000000000003937.
Little is known about thenar dysplasia in radial polydactyly, other than that thenar hypoplasia occasionally occurs in radial polydactyly with triphalangism. In particular, the phenotype and level of duplication associated with thenar dysplasia remain unclear.
The abductor pollicis brevis and flexor pollicis brevis muscles were visualized using three-dimensional ultrasound, and their horizontal geometry was assessed using a biaxial level classification system. Subjects were categorized into three phenotypes according to the developmental condition of the radial thumb. The relationship between the level of distribution of the muscles and the level of the bifurcation of the radial thumb was investigated.
Nineteen patients with radial polydactyly without triphalangism were included. There were 10 patients with the nonfloating type, three with the floating type, and six with the rudimentary type. All patients with bifurcation at or more distal to the metacarpophalangeal joint had normal thenar muscle distribution, but the muscles in patients with bifurcation at or more proximal to the level of the metacarpals were confined, regardless of phenotype. The level of muscle distribution was strongly correlated with the level of the bifurcation of the radial thumb.
These findings suggest that formation of the thenar muscles in the longitudinal direction in radial polydactyly might depend on the level of bifurcation of the radial thumb. The presence of thenar dysplasia even in floating-type or rudimentary-type duplications is of clinical and etiologic importance.
除了在伴有三节指骨的桡侧多指畸形中偶尔会出现大鱼际发育不全外，关于桡侧多指畸形中的大鱼际发育异常所知甚少。特别是，与大鱼际发育异常相关的表型和重复水平仍不清楚。
使用三维超声观察拇短展肌和拇短屈肌，并使用双轴水平分类系统评估其水平几何形状。根据桡侧拇指的发育情况将受试者分为三种表型。研究肌肉分布水平与桡侧拇指分叉水平之间的关系。
纳入19例无三节指骨的桡侧多指畸形患者。其中非漂浮型10例，漂浮型3例，残指型6例。所有在掌指关节或更远端分叉的患者大鱼际肌肉分布正常，但在掌骨水平或更近端分叉的患者，无论其表型如何，肌肉均受限。肌肉分布水平与桡侧拇指分叉水平密切相关。
这些发现表明，桡侧多指畸形中大鱼际肌肉的纵向形成可能取决于桡侧拇指的分叉水平。即使在漂浮型或残指型重复畸形中出现大鱼际发育异常也具有临床和病因学意义。
