The zig-zag deformity in pre-axial polydactyly. A new cause and its treatment

Most cases of zig-zag deformity following treatment of pre-axial polydactyly have resulted from inadequate reconstruction of bifid bony elements. We report its development after simple suture ligature of the radial component of a bifid thumb in the form of a soft tissue tag at the level of the MP joint. Successful reconstruction has been achieved with the use of similar principles proposed for the more characteristic zig-zag deformity. Parents, paediatricians, and obstetricians should be warned that simple suture ligature of the soft tissue tag may allow the development of a zig-zag deformity and require further reconstruction.