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

Area of Science:

• Hand Surgery
• Pediatric Orthopedics
• Congenital Hand Anomalies

Background:

• Wassel VI radial polydactyly presents with characteristic metacarpal adduction and radial deviation.
• Understanding the underlying soft tissue abnormalities is crucial for effective surgical intervention.

Purpose of the Study:

• To characterize the soft tissue abnormalities responsible for deformities in Wassel VI radial polydactyly.
• To correlate specific anatomical variations with observed clinical deformities.

Main Methods:

• Preoperative multi-planar three-dimensional ultrasound.
• Intraoperative observation in four patients with Wassel VI radial polydactyly.

Main Results:

• Abductor pollicis brevis and flexor pollicis brevis (superficial head) inserted into the radial metacarpal.
• Adductor pollicis and flexor pollicis brevis (deep head) inserted into the ulnar thumb.
• Aberrant flexor pollicis longus and absent A1 pulley correlated with severe radial deviation; additional thenar muscle correlated with adduction.

Conclusions:

• Specific soft tissue anomalies, including muscle insertions and tendon variations, are associated with Wassel VI radial polydactyly deformities.
• This detailed anatomical knowledge improves surgical planning and understanding of this rare condition.