Purpose: We reviewed a series of pollicizations in children with congenital thumb malformations. The purpose of this study was to assess the influence of anatomic or technical factors on functional and cosmetic outcome.
Material: The series included 33 operations in 26 children. The Blauth classification was: grade IIIA (n=1), grade IIIB (n=8), grade IV (n=8), grade V (n=13), mirror hand (n=8). We noted the type of skin incision, technique used to fix the metacarpal head on the carpus, and tendon shortenings. Results were assessed at mean 4 years follow-up on the basis of the cosmetic aspect (parent satisfaction) and functional outcome measured with the Kapandji index and flexion-extension of inter-phalangeal joint, thumb finger opposition, and sensitivity.
Results: Mean age at surgery was 32 months. Fixation was achieved with sutures in 24 cases and pinning in nine. Tendon shortening was performed in 16 cases on the extensor system and in one case on the deep flexor system. Mean follow-up was four years. There was no significant difference between groups A and B for cosmetic outcome. The main factor influencing objective functional outcome was the association of a grade III or IV radial club hand. In these patients, the final outcome was compromised by the stiffness or deformation of the radiocarpal joint and the stiffness of the preoperative Kapandji index which was 7 (mean) in group A and 4.75 in group B.
Discussion and conclusion: The following technical aspects did not have a significant effect on the final functional result in our series: type of skin incision, type of carpal fixation, shortening the extensor or flexor system. Technical aspects which must be performed with particular care include reconstruction of the thenar muscles using interosseous muscles, curettage of the growth cartilage of the head of the second metacarpus, and hyper-extension of the head of the second metacarpus during fixation onto the carpus. Careful technique avoids future complications such as excessive growth of the neometa-carpus or Z-thumb.
