Reconstruction of Wassel type IV-D radial polydactyly with flexor pollicis longus transfer and rebalancing

Abstract

Objective To present the surgical techniques of transferring and rebalancing the flexor pollicis longus (FPL) in soft tissue reconstruction of Wassel type Ⅳ-D radial polydactyly,and to evaluate the preliminary results.Methods From July 2009 to December 2012 a total of 20 cases of Wassel Type Ⅳ-D radial polydactyly were treated.Patients' average age at treatment was 1.8 years.A series of soft tissue reconstruction was conducted at the ulnar duplicate thumb.In addition to joint capsule and collateral ligament manipulation to reconstruct insertions of abductor pollicis brevis and flexor pollicis brevis,and soft tissue merging to increase thumb volume,alignment of the thumb was corrected by FPL transfer to achieve dynamic balance between the two flexor tendon insertions.The key steps included preserving the FPL while removing the radial duplicate thumb and rerouting the radial thumb's FPL tendon insertion onto the ulnovolar side of the distal phalangeal base of the ulnar duplicate thumb.Results All the cases were follow-up for an average of 28 months.Results of 17 cases were used for statistic analysis.The preliminary results showed remarkable improvement of alignment of the reconstructed thumb with stable joints and good function.The size of the reconstructed thumb was comparable to that of the contralateral side.According to JHHS scoring system,the results were rated as excellent in 3 cases,good in 12 cases and fair in 2 cases.The disadvantage of this technique was restricted IP joint motion with an average of 14° extension lag and subsequent nail dystrophy.Conclusion The soft tissue reconstruction of the ulnar duplicate thumb centered on FPL transfer and rebalancing is an effective and convenient technique in treating Wassel type Ⅳ-D radial polydactyly.It provides alignment correction and stabilization of the MCP and IP joints.The cosmetic and functional results are good.The long-term results are to be expected. Key words: Thumb; Treatment outcome; Flexor pollicis longus; Radial polydactyly; Reconstruction