title: Biomechanical evaluation of 5 fixation devices for proximal interphalangeal joint arthrodesis.
abstract: OBJECTIVE
  To determine in a cadaver model which, among 5 fixation methods for proximal interphalangeal (PIP) joint arthrodesis, has the greatest stiffness.
  
  
  METHODS
  Thirty-five cadaver digits were randomly assigned to 1 of 5 fixation groups: oblique K-wire with coronal intraosseous wiring, tension-band wire (TBW), dorsal plate, intramedullary linked screw (IMS), and 90/90 wiring (90/90W). Testing was done by applying bending moments to the PIP joint in the sagittal and frontal planes. The force/displacement curves were used to estimate the stiffness of each construct. Ultimate strength was determined by loading to failure in extension.
  
  
  RESULTS
  The IMS had significantly higher stiffness than all wiring constructs in all planes of motion and significantly greater stiffness in extension than the dorsal plate. The IMS stiffness exceeded 10 N/mm across all bending directions and showed an ultimate strength of 21 N. The plate demonstrated higher stiffness in radial bending than the oblique K-wire with coronal intraosseous wiring and TBW. There were no differences in stiffness between the IMS and plate in all modes of testing except extension. Load-to-failure testing of the devices showed the IMS device to be significantly stronger than the TBW, 90/90W, and plating constructs.
  
  
  CONCLUSIONS
  The IMS resisted larger bending moments than all wiring constructs and showed the greatest ultimate strength when compared with 3 of the tested arthrodesis techniques. The plate was significantly better than 2 of the wiring constructs, but only in radial bending. No differences were found between the, TBW, and 90/90W when compared with each other.
  
  
  CONCLUSIONS
  The stiffness necessary for a successful PIP joint fusion has not been quantified, but according to this study, the IMS was the most favorable biomechanical construct for initial stability.
authors.affiliation: New York University Hospital for Joint Diseases, New York, NY; Woodhull Medical Center, Brooklyn, NY; Movement Analysis Laboratory, Istituto Ortopedico Rizzoli, Bologna, Italy; Joint Motion Laboratory, Department of Orthopedic Surgery, Rutgers New Jersey Medical School, Newark, NJ; Biomedical Engineering Department, School of Engineering, Rutgers University, New Brunswick, NJ.
authors.forename: John T
authors.initials: JT
authors.lastname: Capo
authors.affiliation: New York University Hospital for Joint Diseases, New York, NY; Woodhull Medical Center, Brooklyn, NY; Movement Analysis Laboratory, Istituto Ortopedico Rizzoli, Bologna, Italy; Joint Motion Laboratory, Department of Orthopedic Surgery, Rutgers New Jersey Medical School, Newark, NJ; Biomedical Engineering Department, School of Engineering, Rutgers University, New Brunswick, NJ. Electronic address: Eitan.melamed@nyumc.org.
authors.forename: Eitan
authors.initials: E
authors.lastname: Melamed
authors.affiliation: New York University Hospital for Joint Diseases, New York, NY; Woodhull Medical Center, Brooklyn, NY; Movement Analysis Laboratory, Istituto Ortopedico Rizzoli, Bologna, Italy; Joint Motion Laboratory, Department of Orthopedic Surgery, Rutgers New Jersey Medical School, Newark, NJ; Biomedical Engineering Department, School of Engineering, Rutgers University, New Brunswick, NJ.
authors.forename: Benhoor
authors.initials: B
authors.lastname: Shamian
authors.affiliation: New York University Hospital for Joint Diseases, New York, NY; Woodhull Medical Center, Brooklyn, NY; Movement Analysis Laboratory, Istituto Ortopedico Rizzoli, Bologna, Italy; Joint Motion Laboratory, Department of Orthopedic Surgery, Rutgers New Jersey Medical School, Newark, NJ; Biomedical Engineering Department, School of Engineering, Rutgers University, New Brunswick, NJ.
authors.forename: Scott R
authors.initials: SR
authors.lastname: Hadley
authors.affiliation: New York University Hospital for Joint Diseases, New York, NY; Woodhull Medical Center, Brooklyn, NY; Movement Analysis Laboratory, Istituto Ortopedico Rizzoli, Bologna, Italy; Joint Motion Laboratory, Department of Orthopedic Surgery, Rutgers New Jersey Medical School, Newark, NJ; Biomedical Engineering Department, School of Engineering, Rutgers University, New Brunswick, NJ.
authors.forename: Whitney
authors.initials: W
authors.lastname: Ng Lai
authors.affiliation: New York University Hospital for Joint Diseases, New York, NY; Woodhull Medical Center, Brooklyn, NY; Movement Analysis Laboratory, Istituto Ortopedico Rizzoli, Bologna, Italy; Joint Motion Laboratory, Department of Orthopedic Surgery, Rutgers New Jersey Medical School, Newark, NJ; Biomedical Engineering Department, School of Engineering, Rutgers University, New Brunswick, NJ.
authors.forename: Kenny
authors.initials: K
authors.lastname: Gerszberg
authors.affiliation: New York University Hospital for Joint Diseases, New York, NY; Woodhull Medical Center, Brooklyn, NY; Movement Analysis Laboratory, Istituto Ortopedico Rizzoli, Bologna, Italy; Joint Motion Laboratory, Department of Orthopedic Surgery, Rutgers New Jersey Medical School, Newark, NJ; Biomedical Engineering Department, School of Engineering, Rutgers University, New Brunswick, NJ.
authors.forename: Steven
authors.initials: S
authors.lastname: Rivero
authors.affiliation: New York University Hospital for Joint Diseases, New York, NY; Woodhull Medical Center, Brooklyn, NY; Movement Analysis Laboratory, Istituto Ortopedico Rizzoli, Bologna, Italy; Joint Motion Laboratory, Department of Orthopedic Surgery, Rutgers New Jersey Medical School, Newark, NJ; Biomedical Engineering Department, School of Engineering, Rutgers University, New Brunswick, NJ.
authors.forename: Paolo
authors.initials: P
authors.lastname: Caravaggi
mesh_terms: D000328:Adult; D001174:Arthrodesis / Q000295:instrumentation*; D001696:Biomechanical Phenomena; D001860:Bone Plates; D001863:Bone Screws; D001864:Bone Wires; D002102:Cadaver; D005260:Female; D005384:Finger Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography
keywords: Arthrodesis; PIP joint arthritis; biomechanical testing; fusion; stiffness