title: Complex angular and torsional deformities (distal femoral malunions). Preoperative planning using stereolithography and surgical correction with locking plate fixation in four dogs.
abstract: OBJECTIVE
  To describe the surgical technique of complex distal femoral deformity correction with the aid of stereolithography apparatus (SLA) biomodels, stabilized with locking plate fixation.
  
  
  METHODS
  Full-size replica epoxy bone biomodels of the affected femurs (4 dogs/ 5 limbs) were used as templates for surgical planning. A rehearsal procedure was performed on the biomodels aided by a guide wire technique and stabilized with locking plate fixation. Surgery performed in all dogs was guided by the rehearsal procedure. All pre-contoured implants were subsequently used in the definitive surgical procedure with minimal modification.
  
  
  RESULTS
  All dogs had markedly improved, with near normal functional outcomes; all but one had a mild persistent lameness at the final in-hospital follow-up examination (mean: 54.4 weeks; range: 24-113 weeks after surgery). All femurs healed without complications (mean: 34 weeks, median: 12 weeks; range: 8-12 weeks for closing osteotomies, and 26-113 weeks for opening wedge osteotomies). Long-term follow-up examination (mean: 28.6 months; range: 5-42 months) revealed all but one owner to be highly satisfied with the outcome. Complications were observed in two dogs: prolonged tibiotarsal joint decreased flexion that resolved with physical therapy. In one of these dogs, iatrogenic transection of the long digital extensor tendon was repaired, and the other had a peroneal nerve neurapraxia.
  
  
  CONCLUSIONS
  Stereolithography apparatus biomodels and rehearsal surgery simplified the definitive surgical corrections of complex femoral malunions and resulted in good functional outcomes.
authors.forename: Michael D
authors.initials: MD
authors.lastname: DeTora
authors.affiliation: Randy J. Boudrieau, DVM, Diplomate ACVS & ECVS, Cummings School of Veterinary Medicine at Tufts University, Department of Clinical Sciences, 200 Westboro Road, N. Grafton, MA 01536, United States, E-mail: randy.boudrieau@tufts.edu.
authors.forename: Randy J
authors.initials: RJ
authors.lastname: Boudrieau
mesh_terms: D000818:Animals; D001860:Bone Plates / Q000662:veterinary*; D004285:Dogs / Q000002:abnormalities* / Q000601:surgery; D005260:Female; D005269:Femur / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000601:surgery; D008297:Male; D010027:Osteotomy / Q000379:methods / Q000662:veterinary; D011300:Preoperative Care / Q000662:veterinary; D066330:Printing, Three-Dimensional; D011859:Radiography / Q000662:veterinary; D014057:Tomography, X-Ray Computed / Q000662:veterinary; D014102:Torsion Abnormality / Q000000981:diagnostic imaging / Q000601:surgery / Q000662:veterinary*
keywords: Angular limb deformity; corrective osteotomy; preoperative planning; stereolithography