title: Does three-dimensional computer simulation improve results of scaphoid nonunion surgery?
abstract: The purpose of this study was to clarify the effectiveness of the three-dimensional computer simulations in scaphoid nonunion surgery. Seven consecutive clinical patients with scaphoid nonunion at the middle third comprised the study group. Surface models of the scaphoid were constructed on the computer using computed tomography data of the bilateral wrists in neutral position. The distal and proximal fragments of the nonunion model were matched to the mirror image of the contralateral scaphoid model. The rotation of the distal fragment relative to the proximal fragment was calculated, and reduction of the displaced fragment of the scaphoid nonunion was simulated. Similarly, the estimated bone defect and the appropriate site and direction of the screw insertion were simulated. Full-sized hard models of the bone, including a model with simulated reduction and screw insertion, then were made using stereolithography based on the computer data. In the actual surgery, reduction, bone grafting, and screw insertion were achieved using the hard models as guides. All the patients obtained solid bone fusion and substantial clinical improvement with normalized scapholunate and radiolunate angles after surgery. Three-dimensional computer simulations were found as useful for accurate correction of scaphoid nonunions and proper screw placement, which consequently leads to good clinical results.
authors.affiliation: Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan. murase-t@umin.ac.jp
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Murase
authors.forename: Hisao
authors.initials: H
authors.lastname: Moritomo
authors.forename: Akira
authors.initials: A
authors.lastname: Goto
authors.forename: Kazuomi
authors.initials: K
authors.lastname: Sugamoto
authors.forename: Hideki
authors.initials: H
authors.lastname: Yoshikawa
mesh_terms: D000293:Adolescent; D000328:Adult; D001863:Bone Screws; D016025:Bone Transplantation / Q000379:methods; D015331:Cohort Studies; D003198:Computer Simulation; D005260:Female; D005500:Follow-Up Studies; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000379:methods*; D017102:Fracture Healing / Q000502:physiology; D005599:Fractures, Ununited / Q000175:diagnosis* / Q000601:surgery*; D006801:Humans; D008297:Male; D011446:Prospective Studies; D016059:Range of Motion, Articular / Q000502:physiology; D020127:Recovery of Function; D018570:Risk Assessment; D021361:Scaphoid Bone / Q000293:injuries*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome; D014954:Wrist Injuries / Q000175:diagnosis / Q000601:surgery