Soft tissue abnormalities in Wassel Type VI radial polydactyly: a detailed anatomical study

Wassel VI radial polydactyly is associated with metacarpal adduction and deviation of the metacarpophalangeal joint ulnar duplicate. The soft tissue abnormalities responsible for these deformities were characterized using preoperative multi-planar three-dimensional ultrasound intraoperative observation in four patients. In all patients, abductor pollicis brevis superficial head flexor inserted into first metacarpal, whereas adductor deep thumb. Aberrant location longus absence A1 pulley system was severe deviation. An additional thenar muscle along minimal adduction. Uneven forces on duplicate could be characteristic instability. Knowledge allows better planning surgery further insight this rare configuration. Level evidence: II