title: [Manufacture and clinical application of medical metal debris adsorption apparatus].
abstract: OBJECTIVE
  To introduce a medical metal debris adsorption apparatus and to discuss the application value in removal of locking plate internal fixation.
  
  
  METHODS
  Between January 2011 and May 2013, 83 cases underwent removal of locking plate fixation. There were 44 males and 39 females, aged 21-59 years (mean, 35.4 years). The time from the first operation to internal fixation removal was 16-40 months (mean, 22.6 months). Thirty-two screws of 9 patients were removed difficultly due to slide fastener. The screws were removed eventually after plates and screws were separated by grinding locking screw with manganese steel drill. In the process of grinding, the medical metal debris adsorption apparatus was used in 16 screws of 4 patients (group A), and was not used in 16 screws of 5 patients (group B). The operation time, removal time of single slipping screw, intraoperative blood loss, and the score of metal debris residues were compared between 2 groups. And the postoperative complications were recorded.
  
  
  RESULTS
  A total of 658 screws were removed, and 32 slipping screws were found, accounting for 4.86%. The lock screw slipping rates of 3.5 mm and 4.5 or 5.0 mm respectively were 6.53% and 2.31%; and the lock screw slip ping rates of internal fixation time < 2 years and > 2 years respectively were 3.21% and 6.08%. The operation time, removal time of single slipping screw, intraoperative blood loss, and the score of metal debris residues of group A were significantly lower than those of group B (P < 0.05). Re-fracture (1 case) and incision infection (1 case) occurred in group B, and no complication was observed in group A. The cases of 2 groups were followed up 8-35 months (mean, 23.4 months). No heterotopic ossification occurred in both groups during the follow-up.
  
  
  CONCLUSIONS
  The medical metal debris adsorption apparatus can significantly shorten the operation time, reduce the residual metal debris and surgical bleeding when removing the slipping screws in removal of locking plate internal fixation.
authors.affiliation: Department of Orthopaedics, Tianjin Dongli Hospital, P.R. China. yqw1233068@sina.com
authors.forename: Qingwei
authors.initials: Q
authors.lastname: Yin
authors.forename: Haibin
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000327:Adsorption; D000328:Adult; D001860:Bone Plates; D001863:Bone Screws; D020878:Device Removal / Q000379:methods*; D005260:Female; D005264:Femoral Fractures / Q000601:surgery; D005593:Fracture Fixation, Internal / Q000295:instrumentation* / Q000379:methods; D050723:Fractures, Bone; D006801:Humans; D008297:Male; D008670:Metals; D008875:Middle Aged
chemical_list: D008670:Metals