“On-Top Plasty” for Radial Polydactyly Reconstruction

Bryce Bell, Lesley Butler, Janith Mills, Chris Stutz, Marybeth Ezaki, Scott Oishi

Research output: Contribution to journalArticlepeer-review

19 Scopus citations


Purpose To introduce the “on-top plasty” technique and report our long-term outcomes. Methods We evaluated 5 thumbs in 5 patients who underwent radial polydactyly reconstruction using the “on-top plasty” technique between 1998 and 2003. This technique was used when it was felt that neither thumb possessed adequate proximal and distal structures to provide a functional and aesthetically pleasing thumb. Our study group included 1 Flatt type III and 4 Flatt type VII thumbs. The average age at time of surgery was 1.4 years and at final follow-up was 13.5 years. Subjective patient evaluation, objective outcomes values, and validated patient-oriented outcome measures were obtained. Results There was no soft tissue loss and union was achieved in all thumbs with no further surgery required in any thumb. Mean flexion-extension arc for the metacarpophalangeal joint was 60° (range, 10° extension to 70° flexion) and at the interphalangeal joint was 19° (range, 25° extension to 35° flexion). Mean percentage of age-matched norms for lateral, tripod, and tip pinch were 47.0%, 45.9%, and 47.8%, respectively. Mean grip strength was 54.2% of age-matched norm. The mean Pediatric Quality of Life Inventory (PedsQL) score for parent questionnaires was 89.0 and for teen/child questionnaires was 89.1. The Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire revealed a mean score of 4.3. Conclusions For patients with radial polydactyly in which neither thumb possesses adequate distal and proximal components, the on-top plasty is a reliable method of polydactyly reconstruction with durable results at longer than 10 years’ follow-up. Type of study/level of evidence Therapeutic V.

Original languageEnglish (US)
Pages (from-to)753.e1-753.e6
JournalJournal of Hand Surgery
Issue number9
StatePublished - Sep 2017


  • Radial polydactyly
  • on-top plasty
  • thumb duplication
  • thumb polydactyly

ASJC Scopus subject areas

  • Surgery
  • Orthopedics and Sports Medicine


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