title: A new skill for treating unclassified thumb polydactyly: ablation via a periosteal incision.
abstract: BACKGROUND
  Thumb polydactyly is a common congenital abnormality of the hand. Surgical treatment includes reduction and reconstruction. A new type of thumb polydactyly and the achieved treatment are reported.
  
  
  METHODS
  A 4-year-old boy with thumb polydactyly is reported. The duplicated two thumbs had one complete metacarpal and a separated triphalangeal phalanx. The ulna thumb was removed via periosteal incision, and a whole complex tissue sleeve was used to repair the ulna part of the joint capsule.
  
  
  RESULTS
  The postoperative aesthetic and functional results were satisfactory.
  
  
  CONCLUSIONS
  A new type of thumb polydactyly that cannot be matched with the classification of either Wassel or Wood is described. The thumb polydactyly was treated by ablation via periosteal incision and ulna metacarpophalangeal joint capsule reconstruction. Three-dimensional computed tomography could be a good way to examine the area preoperatively.
  
  
  METHODS
  This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors at www.springer.com/00266.
authors.affiliation: No. 1 Hospital Affiliated to Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Cui
authors.initials: C
authors.lastname: Wang
authors.forename: Xinjian
authors.initials: X
authors.lastname: Huang
authors.forename: Weiqiang
authors.initials: W
authors.lastname: Tan
mesh_terms: D006801:Humans; D007223:Infant; D008297:Male; D050279:Metacarpal Bones / Q000002:abnormalities / Q000601:surgery; D010521:Periosteum / Q000601:surgery*; D017689:Polydactyly / Q000175:diagnosis / Q000601:surgery*; D016059:Range of Motion, Articular; D019651:Plastic Surgery Procedures / Q000379:methods*; D020127:Recovery of Function; D013524:Surgical Flaps; D013933:Thumb / Q000002:abnormalities* / Q000601:surgery*