title: Biomechanical Comparison of Fixation Devices for First Metatarsocuneiform Joint Arthrodesis.
abstract: Common surgical treatment of first tarsal-metatarsal arthritis is by first metatarsocuneiform joint arthrodesis. While crossed-screw and locking plate fixation are the most widely used methods, a novel construct was designed to alleviate soft tissue irritation while still providing stable fixation. Using anatomic first metatarsal and medial cuneiform composites, we compared 3 arthrodesis implants (crossed-screw, dorsal locking plate, and IO Fix) under 2 cyclic bending loading scenarios (cantilever and 4-point bending). Additionally, the optimal orientation (plantar-dorsal or dorsal-plantar) of the IO Fix construct was determined. Failure load, diastasis, joint space angle, and axial and angular stiffness were determined. Both crossed-screw fixation and the IO Fix constructs experienced significantly higher failure loads than the dorsal locking plate during both loading scenarios. Additionally, they had lower plantar diastasis and joint space angle at failure than the plate. Moreover, the plantar-dorsal IO Fix construct was significantly stiffer than the crossed-screw during cantilever bending. Finally, the plantar-dorsal orientation of the IO Fix device had higher failure load and lower diastasis and angle at failure than in the dorsal-plantar orientation. The results suggest that the IO Fix system can reduce motion at the interfragmentary site and ensure compression for healing comparable to that of the crossed-screw fixation.
  
  
  METHODS
  Level V: Bench testing.
authors.affiliation: J. Vernon Luck Sr, M.D. Orthopaedic Research Center, Orthopaedic Institute for Children/UCLA, Los Angeles, California (ARK, EE, NCH, SNS).|Los Angeles County Harbor-UCLA Medical Center, Torrance, California (JFF, TW, TGH).
authors.forename: Ashleen R
authors.initials: AR
authors.lastname: Knutsen
authors.affiliation: J. Vernon Luck Sr, M.D. Orthopaedic Research Center, Orthopaedic Institute for Children/UCLA, Los Angeles, California (ARK, EE, NCH, SNS).|Los Angeles County Harbor-UCLA Medical Center, Torrance, California (JFF, TW, TGH).
authors.forename: John F
authors.initials: JF
authors.lastname: Fleming
authors.affiliation: J. Vernon Luck Sr, M.D. Orthopaedic Research Center, Orthopaedic Institute for Children/UCLA, Los Angeles, California (ARK, EE, NCH, SNS).|Los Angeles County Harbor-UCLA Medical Center, Torrance, California (JFF, TW, TGH).
authors.forename: Edward
authors.initials: E
authors.lastname: Ebramzadeh
authors.affiliation: J. Vernon Luck Sr, M.D. Orthopaedic Research Center, Orthopaedic Institute for Children/UCLA, Los Angeles, California (ARK, EE, NCH, SNS).|Los Angeles County Harbor-UCLA Medical Center, Torrance, California (JFF, TW, TGH).
authors.forename: Nathan C
authors.initials: NC
authors.lastname: Ho
authors.affiliation: J. Vernon Luck Sr, M.D. Orthopaedic Research Center, Orthopaedic Institute for Children/UCLA, Los Angeles, California (ARK, EE, NCH, SNS).|Los Angeles County Harbor-UCLA Medical Center, Torrance, California (JFF, TW, TGH).
authors.forename: Tibor
authors.initials: T
authors.lastname: Warganich
authors.affiliation: J. Vernon Luck Sr, M.D. Orthopaedic Research Center, Orthopaedic Institute for Children/UCLA, Los Angeles, California (ARK, EE, NCH, SNS).|Los Angeles County Harbor-UCLA Medical Center, Torrance, California (JFF, TW, TGH).
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Harris
authors.affiliation: J. Vernon Luck Sr, M.D. Orthopaedic Research Center, Orthopaedic Institute for Children/UCLA, Los Angeles, California (ARK, EE, NCH, SNS).|Los Angeles County Harbor-UCLA Medical Center, Torrance, California (JFF, TW, TGH).
authors.forename: Sophia N
authors.initials: SN
authors.lastname: Sangiorgio
mesh_terms: D001174:Arthrodesis / Q000295:instrumentation* / Q000379:methods; D001696:Biomechanical Phenomena; D004867:Equipment Design; D033023:Foot Joints / Q000601:surgery*; D006801:Humans; D008422:Materials Testing; D008682:Metatarsal Bones / Q000601:surgery*; D008954:Models, Biological; D009984:Orthopedic Fixation Devices; D013639:Tarsal Bones / Q000601:surgery*
keywords: arthritis and joint diseases; internal fixation