title: Dynamic Stabilization of Simple Fractures With Active Plates Delivers Stronger Healing Than Conventional Compression Plating.
abstract: OBJECTIVE
  Active plates dynamize a fracture by elastic suspension of screw holes within the plate. We hypothesized that dynamic stabilization with active plates delivers stronger healing relative to standard compression plating.
  
  
  METHODS
  Twelve sheep were randomized to receive either a standard compression plate (CP) or an active plate (ACTIVE) for stabilization of an anatomically reduced tibial osteotomy. In the CP group, absolute stabilization was pursued by interfragmentary compression with 6 cortical screws. In the ACTIVE group, dynamic stabilization after bony apposition was achieved with 6 elastically suspended locking screws. Fracture healing was analyzed weekly on radiographs. After sacrifice 9 weeks postsurgery, the torsional strength of healed tibiae and contralateral tibiae was measured. Finally, computed tomography was used to assess fracture patterns and healing modes.
  
  
  RESULTS
  Healing in both groups included periosteal callus formation. ACTIVE specimens had almost 6 times more callus area by week 9 (P < 0.001) than CP specimens. ACTIVE specimens recovered on average 64% of their native strength by week 9, and were over twice as strong as CP specimens, which recovered 24% of their native strength (P = 0.008). Microcomputed tomography demonstrated that compression plating induced a combination of primary bone healing and gap healing. Active plating consistently stimulated biological bone healing by periosteal callus formation.
  
  
  CONCLUSIONS
  Compared with compression plating, dynamic stabilization of simple fractures with active plates delivers significantly stronger healing.
authors.affiliation: *Portland Biomechanics Laboratory, Legacy Research Institute, Portland, OR; †Musculoskeletal Research Unit, Vetsuisse Faculty, University of Zürich, Zürich, Switzerland; ‡Institute of Biomechanics, Paracelsus Medical University, Salzburg, Austria; §Institute of Biomechanics, Trauma Center Murnau, Murnau, Germany; and ‖Slocum Center for Orthopedics and Sports Medicine, Eugene, OR.
authors.forename: Michael
authors.initials: M
authors.lastname: Bottlang
authors.forename: Stanley
authors.initials: S
authors.lastname: Tsai
authors.forename: Emily K
authors.initials: EK
authors.lastname: Bliven
authors.forename: Brigitte
authors.initials: B
authors.lastname: von Rechenberg
authors.forename: Philipp
authors.initials: P
authors.lastname: Kindt
authors.forename: Peter
authors.initials: P
authors.lastname: Augat
authors.forename: Julia
authors.initials: J
authors.lastname: Henschel
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Fitzpatrick
authors.forename: Steven M
authors.initials: SM
authors.lastname: Madey
mesh_terms: D000818:Animals; D001860:Bone Plates; D001863:Bone Screws; D019544:Equipment Failure Analysis; D005593:Fracture Fixation, Internal / Q000295:instrumentation* / Q000379:methods*; D017102:Fracture Healing; D011474:Prosthesis Design; D012756:Sheep; D013978:Tibial Fractures / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome