title: Reduction of Dorsal Displacement of the Proximal and Middle Phalanges Using a Neutral or Angled Implant for Joint Arthrodesis to Treat Hammertoe Deformity A Finite Element Study.
abstract: BACKGROUND
  We used finite element analysis to study the mechanical displacements at three planes of the second through fourth hammertoes during the push-off phase of gait using a new neutral or 10° angled memory alloy intramedullary implant (FDA K070598) used for proximal interphalangeal joint arthrodesis.
  
  
  METHODS
  After geometric reconstruction of the foot skeleton from computed tomographic images of a 36-year-old man, an intramedullary implant was positioned in the virtual model at the neutral and 10° angled positions at the proximal interphalangeal joints of the second through fourth hammertoes during the push-off phase of gait. The obtained displacement results in three planes were compared with those derived from the nonsurgical foot model using finite element analysis.
  
  
  RESULTS
  These results support the successful use of either a neutral or angled implant for proximal interphalangeal joint arthrodesis, with the neutral implant yielding slightly better results.
  
  
  CONCLUSIONS
  The neutral implant reduced vertical displacement to a greater extent than did the angled implant. We also highlight the potential risk of iatrogenic curly toe when performing a proximal interphalangeal joint arthrodesis using an angled implant specifically at the fourth toe.
authors.forename: Javier Bayod
authors.initials: JB
authors.lastname: López
authors.forename: Ricardo
authors.initials: R
authors.lastname: Becerro de Bengoa Vallejo
authors.forename: Marta Elena
authors.initials: ME
authors.lastname: Losa Iglesias
authors.forename: Kevin T
authors.initials: KT
authors.lastname: Jules
authors.forename: Manuel
authors.initials: M
authors.lastname: Doblaré
mesh_terms: D000328:Adult; D001174:Arthrodesis / Q000379:methods*; D020342:Finite Element Analysis; D037801:Hammer Toe Syndrome / Q000175:diagnosis / Q000601:surgery*; D006801:Humans; D008297:Male; D019736:Prostheses and Implants; D014033:Toe Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D014057:Tomography, X-Ray Computed