title: Preoperative trajectory planning for closed reduction of long-bone diaphyseal fracture using a computer-assisted reduction system.
abstract: BACKGROUND
  Balancing reduction accuracy with soft-tissue preservation is a challenge in orthopaedics. Computer-assisted orthopaedic surgery (CAOS) can improve accuracy and reduce radiation exposure. However, previous reports have not summarized the fracture patterns to which CAOS has been applied.
  
  
  METHODS
  We used a CAOS system and a stereolithography model to define a new fracture classification. Twenty reduction tests were performed to evaluate the effectiveness of preoperative trajectory planning.
  
  
  RESULTS
  Twenty tests ran automatically and smoothly. Only three slight scratches occurred. Seventy-six path points represented displacement deviations of < 2 mm (average < 1 mm) and angulation deviation of < 1.5°.
  
  
  CONCLUSIONS
  Because of the strength of muscles, mechanical sensors are used to prevent iatrogenic soft-tissue injury. Secondary fractures are prevented mainly through preoperative trajectory planning. Based on our data, a 1 mm gap between the edges of fractures spikes is sufficient to avoid emergency braking from spike interference.
authors.affiliation: Department of Orthopaedics, Chinese PLA General Hospital, Beijing, People's Republic of China.
authors.forename: Hailong
authors.initials: H
authors.lastname: Du
authors.forename: Lei
authors.initials: L
authors.lastname: Hu
authors.forename: Changsheng
authors.initials: C
authors.lastname: Li
authors.forename: Chunqing
authors.initials: C
authors.lastname: He
authors.forename: Lihai
authors.initials: L
authors.lastname: Zhang
authors.forename: Peifu
authors.initials: P
authors.lastname: Tang
mesh_terms: D018483:Diaphyses / Q000293:injuries / Q000601:surgery; D050723:Fractures, Bone / Q000145:classification / Q000473:pathology / Q000601:surgery*; D006801:Humans; D019637:Orthopedic Procedures / Q000295:instrumentation / Q000379:methods*; D012984:Software; D025321:Surgery, Computer-Assisted / Q000295:instrumentation / Q000379:methods*
keywords: computer-assisted orthopaedic surgery (CAOS); diaphysial fracture; trajectory planning