title: Computer-guided CO2-laser osteotomy of the sheep tibia: technical prerequisites and first results.
abstract: OBJECTIVE
  The purpose of this study was to examine for the first time the feasibility of performing complete osteotomy of sheep tibia using a computer-guided CO2-laser osteotome, and to examine bone healing under functional loading.
  
  
  BACKGROUND
  Bone cutting without aggravating thermal side effects has been demonstrated with scanning CO2-laser osteotomy. Further research is necessary to develop a clinically usable laser osteotome, which may allow new types of bone surgical procedures.
  
  
  METHODS
  The scanning parameters for performing tibial osteotomies were determined in preliminary ex vivo trials. Osteotomies were performed in the mid-diaphysis of sheep tibia using either the prototype laser osteotome (osteoLAS, study group; n = 12), or an oscillating saw (control group; n = 12). Both groups were divided into two subgroups each (n = 6), and the two groups were sacrificed after 4 and 12 wk. Radiographs were taken postoperatively and after 4, 8, and 12 wk to compare the course of bone healing.
  
  
  RESULTS
  Laser osteotomies of sheep tibia up to a depth of 20 mm were possible without visible thermal damage to the bone. A sequential PC-controlled cut geometry with artificial widening of the osteotomy gap was required for a complete osteotomy. Both clinically and radiologically, the laser and control groups showed undisturbed primary gap healing. Bone healing was similar and undelayed after both laser osteotomy and osteotomy done by mechanical saw.
  
  
  CONCLUSIONS
  Osteotomy of multi-layered bones with a scanning CO2-laser demonstrates clinical and radiological healing patterns comparable to those seen with osteotomy done by standard mechanical instruments. It is, however, a technically demanding procedure, and complete laser osteotomies of long bones are only reasonable in bones with a diameter <20 mm, which will likely restrict the use of this technique to bones 7-10 mm thick. Through the use of computer guidance, extremely precise osteotomies and sophisticated cut geometries are possible using this technique. For practical applications, precise control of the depth of laser cutting and easier manipulation of the osteotome are required.
authors.affiliation: Clinic for Oral and Maxillofacial Surgery, Kantonsspital Luzern, Lucerne, Switzerland. johannes.kuttenberger@ksl.ch
authors.forename: Johannes J
authors.initials: JJ
authors.lastname: Kuttenberger
authors.forename: Stefan
authors.initials: S
authors.lastname: Stübinger
authors.forename: Alessa
authors.initials: A
authors.lastname: Waibel
authors.forename: Martin
authors.initials: M
authors.lastname: Werner
authors.forename: Manfred
authors.initials: M
authors.lastname: Klasing
authors.forename: Mikhail
authors.initials: M
authors.lastname: Ivanenko
authors.forename: Peter
authors.initials: P
authors.lastname: Hering
authors.forename: Brigitte
authors.initials: B
authors.lastname: Von Rechenberg
authors.forename: Robert
authors.initials: R
authors.lastname: Sader
authors.forename: Hans-Florian
authors.initials: HF
authors.lastname: Zeilhofer
mesh_terms: D000818:Animals; D005240:Feasibility Studies; D017102:Fracture Healing; D053685:Laser Therapy; D054020:Lasers, Gas; D010027:Osteotomy / Q000295:instrumentation*; D012756:Sheep; D025321:Surgery, Computer-Assisted; D013977:Tibia / Q000601:surgery*; D046509:Tissue Culture Techniques