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The anatomy of Wassel type IV-D thumb duplication

B He1,2, G Liu3, G Nan1,2

  • 11 Ministry of Education Key Laboratory of Child Development and Disorders, Key Laboratory of Pediatrics in Chongqing, Chongqing International Science and Technology Cooperation Centre for Child Development and Disorders, China.

The Journal of Hand Surgery, European Volume
|February 16, 2017
PubMed

Insights

This study details the anatomy of Wassel type IV-D thumb duplication, focusing on the flexor pollicis longus tendon. Findings reveal variations in tendon structure and pulley involvement, impacting thumb alignment and function.

Area of Science:

  • Pediatric Orthopedics
  • Hand Surgery
  • Congenital Hand Anomalies

Background:

  • Wassel type IV-D is a complex thumb duplication requiring detailed anatomical understanding.
  • Variations in the flexor pollicis longus tendon and its pulley system are implicated in the deformity.

Purpose of the Study:

  • To elucidate the detailed anatomy of the flexor pollicis longus tendon in Wassel type IV-D thumb duplication.
  • To correlate anatomical findings with surgical outcomes and secondary deformities.

Main Methods:

  • Surgical observation and anatomical study of 12 hands with Wassel type IV-D thumb duplication in 11 children.
  • Detailed analysis of the flexor pollicis longus tendon structure, course, and pulley system (A2 pulley).

Main Results:

  • Described variations in the flexor pollicis longus tendon, including division and anomalous attachments.
  • Identified absent or membranous A2 pulleys in secondary deformities, with tendon adherence to the radial thumb side.
  • Observed ulnar angulation of the distal phalanx in relation to the radial portion of the duplication.

Conclusions:

  • The anatomical variations of the flexor pollicis longus tendon and A2 pulley are critical in Wassel type IV-D thumb duplication.
  • Understanding these specific anatomical features is essential for surgical planning and correction of associated deformities.

Keywords:
Wassel type IV-D thumb duplicationanatomysecondary deformity

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