title: [Follow-up of scaphoid pseudarthroses and scaphoid fractures after Herbert screw implantation in the extremities--MRI (low-field MRI)].
abstract: From January 1993 to September 1996, 59 patients with a scaphoid nonunion (38 times mid/distal third, 21 times proximal third) and 21 patients with a scaphoid fracture (17 times mid/distal third, four proximal third) underwent surgery in our clinic. Fractures of the scaphoid were treated by Herbert screw fixation. The operative treatment of nonunions of the scaphoid included the transplantation of an iliac crest graft and Herbert screw fixation. In all cases, an MRI of the carpus in a low-field MRI was carried out pre-operatively in addition to standard X-ray examination. Post-operatively, all patients were again controlled by MRI within defined intervals. The signal intensities of the MRI in the fragments of the scaphoid were determined qualitatively and quantitatively by computer calculation, comparing the pre- and post-operative results with one another. It was possible to depict the entire scaphoid and to determine the signal intensities of the proximal and distal fragments after Herbert screw fixation due to reduced artefacts on T1-weighted images in all cases. 41 patients with scaphoid nonunion and five patients with a scaphoid fracture showed a pre-operative diminishing of the signal in the proximal fragment compared to the distal fragment. For these patients, the fusion rate was lower than in patients without pre-operative signal reduction.
authors.affiliation: Orthopädische Klinik und Poliklinik, Freien Universität Berlin.
authors.forename: M
authors.initials: M
authors.lastname: Lautenbach
authors.forename: M
authors.initials: M
authors.lastname: Mochkabadi
authors.forename: A
authors.initials: A
authors.lastname: Eisenschenk
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001863:Bone Screws; D002348:Carpal Bones / Q000293:injuries* / Q000473:pathology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D017102:Fracture Healing / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis / Q000601:surgery*; D011542:Pseudarthrosis / Q000175:diagnosis / Q000601:surgery*; D014954:Wrist Injuries / Q000175:diagnosis / Q000601:surgery*