title: Prognostic value of age and Wassel classification in the reconstruction of thumb duplication.
abstract: BACKGROUND
  Various surgical techniques for thumb duplication have been described. The main goal in thumb reconstruction is to achieve optimal function, stability, and shape. Few publications have quantified the functional results of each surgical option and factors that may affect these outcomes.
  
  
  METHODS
  We performed a retrospective review during the period from 1990 to 2011 of 115 surgery patients, 99 of whom had a mean postoperative follow-up of 44.1 months. They were classified according to the Wassel classification. We assessed the surgical technique, functional results, and complications, and evaluated the probable prognostic value of age and Wassel classification.
  
  
  RESULTS
  This case series comprised mainly female patients (62 %) and the right hand (74 %), with a mean age at operation of 20 months. The most common group was Wassel type IV (54 %). On the basis of the Tada scoring system, we obtained 91 good results (91 %). Complications occurred in 27 patients (27 %), mainly instability and axis deformation. In a comparison of preoperative factors (age at the time of surgery and Wassel classification) with the final results (Tada score and complications), the association between older age at surgery and complications (p = 0.0001) and Wassel types III and IV and complications (p = 0.0210 and p = 0.0095) was statistically significant.
  
  
  CONCLUSIONS
  Following the basic concepts of anatomical reconstruction, we obtained good results in most patients. The main complications were instability and axial deformity. These were most common in patients who underwent operations at an age of more than 12 months, and patients with Wassel types III and IV deformities.
authors.affiliation: Hand and Malformation Division, Department of Pediatric Orthopaedics, Sant Joan de Déu Children's Hospital, University of Barcelona, Passeig Sant Joan de Déu, 2, ES08950, Esplugues de Llobregat, Barcelona, Spain.
authors.forename: Marisa
authors.initials: M
authors.lastname: Cabrera González
authors.affiliation: Hand and Malformation Division, Department of Pediatric Orthopaedics, Sant Joan de Déu Children's Hospital, University of Barcelona, Passeig Sant Joan de Déu, 2, ES08950, Esplugues de Llobregat, Barcelona, Spain.
authors.forename: Laura M
authors.initials: LM
authors.lastname: Pérez López
authors.affiliation: School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Gino
authors.initials: G
authors.lastname: Martínez Soto
authors.affiliation: Hand and Malformation Division, Department of Pediatric Orthopaedics, Sant Joan de Déu Children's Hospital, University of Barcelona, Passeig Sant Joan de Déu, 2, ES08950, Esplugues de Llobregat, Barcelona, Spain.
authors.forename: Diego
authors.initials: D
authors.lastname: Gutiérrez de la Iglesia
keywords: Hand reconstructive surgery; Polydactyly; Prognostic value; Tada score; Thumb duplication; Wassel classification