Preoperative trajectory planning for closed reduction of long-bone diaphyseal fracture using a computer-assisted reduction system

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<2mm (average<1mm) and angulation deviation of<1.5°. Discussion: 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 1mm gap between the edges of fractures spikes is sufficient to avoid emergency braking from spike interference.