title: Comparison of Er:YAG laser and piezoelectric osteotomy: An animal study in sheep.
abstract: OBJECTIVE
  It was the aim of this study to compare the feasibility of complete osteotomy of long bones in sheep using a newly designed variable square pulsed Er:YAG laser and piezoelectric surgery. In addition to uneventful bone healing after laser osteotomy, the goal was to assess the possibility to cut thick bony structures with both techniques in a surgically acceptable time frame of 2-3 minutes.
  
  
  METHODS
  A tibia midshaft osteotomy was performed in 24 sheep using either an Er:YAG laser (n = 12) or piezoelectric device (n = 12). Laser and piezoelectric groups were divided in two subgroups (n = 6) with sheep sacrificed after 2 and 3 months, respectively. A complete radiological, histological and histomorphometric analysis was performed to compare the course of bone/fracture healing and remodelling.
  
  
  RESULTS
  Laser and piezoelectric osteotomies of the sheep tibia up to a depth of 22 mm were possible without any thermal damage. Radiological and histological results after 2 months showed primary gap healing with distinct periosteal callus formation on the transcortex. After 3 months, radiological and histological analysis revealed less callus formation on the transcortex, with almost no visible osteotomy gap and a distinct formation of lamellar bone crossing the original osteotomy gap.
  
  
  CONCLUSIONS
  Er:YAG laser osteotomy can successfully be used in long bones with a depth of up to 22 mm, thus challenging the dogma of adverse effects of laser osteotomy due to thermal or other damages.
authors.affiliation: Competence Center for Applied Biotechnology and Molecular Medicine, University of Zürich, Winterthurerstr. 190, CH-8057 Zürich, Switzerland. stefan.stuebinger@cabmm.uzh.ch
authors.forename: Stefan
authors.initials: S
authors.lastname: Stübinger
authors.forename: Katja
authors.initials: K
authors.lastname: Nuss
authors.forename: Michaela
authors.initials: M
authors.lastname: Pongratz
authors.forename: Jill
authors.initials: J
authors.lastname: Price
authors.forename: Robert
authors.initials: R
authors.lastname: Sader
authors.forename: Hans-Florian
authors.initials: HF
authors.lastname: Zeilhofer
authors.forename: Brigitte
authors.initials: B
authors.lastname: von Rechenberg
mesh_terms: D000818:Animals; D005240:Feasibility Studies; D005260:Female; D053685:Laser Therapy; D053844:Lasers, Solid-State; D010027:Osteotomy / Q000295:instrumentation*; D012756:Sheep; D013977:Tibia / Q000473:pathology / Q000601:surgery*; D014465:Ultrasonics