Thumb reconstruction without formal pollicization in mirror hand deformity: a series of four cases.

Thumb reconstruction in mirror hands is usually done by pollicization. However, objective pinch strength and power grip data in mirror hands following pollicization are lacking. Alternative thumb reconstruction techniques include doing nothing, rotation osteotomy or syndactylization of the radial digits. In this article, we report a series of four cases of mirror hand deformity where the thumb was not reconstructed by formal pollicization. Two cases had non-classic mirror hand deformity (the forearm contained a radius and an ulna) and the other two had classic ulnar dimelia. In all cases, thumb reconstruction was done by keeping one of the radial fingers in place (without pollicization) as the new thumb; and then (if required) performing a secondary osteotomy procedure to rotate the new thumb into pronation. The four cases were recalled back to the clinic for functional assessment at ages 20 years, 5 years, 4 years and 2 years, respectively. The overall hand function was considered 'fair' in the case with concurrent unique features, and was considered 'excellent' in the other three cases. It was concluded that the technique of thumb reconstruction used in the current series is an acceptable option. However, objective measurements, especially with regards to pinch strength and power grip, need to be compared with the pollicization technique.