title: Anatomic fit of six different radial head plates: comparison of precontoured low-profile radial head plates.
abstract: OBJECTIVE
  Bulky implants may lead to symptomatic soft tissue irritation after open reduction and internal fixation of radial head and neck fractures. The purpose of our study was to compare the anatomic fit of precontoured radial head plates.
  
  
  METHODS
  We stripped 22 embalmed human cadaveric radiuses of soft tissues. We investigated 6 radial head plates: (1) the Medartis radial head buttress plate (MBP), (2) the Medartis radial head rim plate (MRP), (3) the Synthes radial neck plate (SNP), (4) the Synthes radial head plate (SHP), (5) the Acumed radial head plate (AHP), and (6) the Wright radial head plate (WHP). Each plate was applied to each radial head at the place of best fit within the safe zone. We tested 4 parameters of anatomic fit: (1) plate-to-bone distance, (2) plate contact judged by 3 different observers, (3) pin-subchondral zone distance, and (4) plate-to-bone contact after adjustment of the plates.
  
  
  RESULTS
  The MBP and MRP showed the lowest profile by objective measurements, the SNP and AHP had a moderate profile, and the SHP and WHP demonstrated the bulkiest profile. The subjective assessments also demonstrated the best fit for the MBP, a good fit for the SNP, a moderate fit for the MRP and AHP, and a poor fit for the SHP and WHP. The MBP, MRP, and AHP could always provide pin-subchondral zone contact, unlike the SHP, SNP, and WHP. After bending, significant improvement of plate-to-bone distance could only be seen for the MBP, MRP, and WHP. The ranking among plates remained the same except for the WHP, which showed a significantly lower plate-to-bone distance than the SHP.
  
  
  CONCLUSIONS
  Currently available radial head implants are heterogeneous. The MBP and MRP showed the lowest profile and best anatomic fit. Owing to the complex radial head anatomy, to date there is no one radial head plate that perfectly fits all radial heads.
  
  
  CONCLUSIONS
  Conformance of existing plates to the radial head and neck is not perfect. Careful plate selection and modification, when necessary, may minimize interference of this hardware with the surrounding soft tissues and facilitate recovery of motion.
authors.affiliation: Department of Orthopaedic and Trauma Surgery, University of Cologne, Germany. klaus.burkhart@ukkoeln.de
authors.forename: Klaus Josef
authors.initials: KJ
authors.lastname: Burkhart
authors.forename: Tobias E
authors.initials: TE
authors.lastname: Nowak
authors.forename: Yoon-Joo
authors.initials: YJ
authors.lastname: Kim
authors.forename: Pol M
authors.initials: PM
authors.lastname: Rommens
authors.forename: Lars P
authors.initials: LP
authors.lastname: Müller
mesh_terms: D001696:Biomechanical Phenomena; D001858:Bone Nails; D001860:Bone Plates; D002102:Cadaver; D004551:Elbow Joint / Q000601:surgery; D004838:Epiphyses / Q000601:surgery*; D005593:Fracture Fixation, Internal / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D007593:Joint Instability / Q000517:prevention & control; D011474:Prosthesis Design; D017755:Prosthesis Fitting / Q000295:instrumentation*; D011884:Radius / Q000601:surgery*; D011885:Radius Fractures / Q000601:surgery*; D016059:Range of Motion, Articular / Q000502:physiology; D018570:Risk Assessment