title: Technical problems and complications in the removal of the less invasive stabilization system.
abstract: OBJECTIVE
  This study was designed to evaluate the frequency of intraoperative problems and complications involved with Less Invasive Stabilization System (LISS) plate removal.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  Single academic level I trauma center.
  
  
  METHODS
  Medical records were reviewed for demographics, surgical technique, plate length, number and position of screws, time from internal fixation to plate removal, reason for removal, operating time for removal, and perioperative complications. Pre- and post-op radiographs were also reviewed to confirm plate and screw positions. The independent factors including age, sex, plate site, plate screws placed/available holes, union status, and time from internal fixation to removal were compared between patients in whom screw removal was complicated to those in whom screw removal proceeded without difficulty. Mann-Whitney and Fisher Exact tests were calculated with the level of significance at P < 0.05.
  
  
  RESULTS
  There were 33 patients (24 men and 9 women) that underwent LISS plate removal from 36 extremities (15 tibias and 21 femurs). The average time from internal fixation to removal was 13.2 months. The plates removed were 13-hole plates (16 cases), 9-hole plates (18 cases), and 5-hole plates (2 cases), which included a total of 349 screws. The specific reasons for plate removal were symptomatic implants after bone union (21 cases), nonunion requiring additional fixation (12 cases), early loss of fixation (2 cases), and a peri-implant fracture after bone union (1 case). The average operating time for plate removal was 71.3 minutes (range, 28-180 minutes). Five cases required more than 120 minutes. Difficulty with screw removal was encountered in 37 screws (10.6%) from 14 cases (38.9%). Two plates and 11 screw heads required cutting using a carbide or diamond tipped burr. Six cases required tearing the plate off bone by levering with a total of 10 screws still attached. Five screws were cut using a large bolt cutter. The other screws were stripped and removed with a stripped screw removal tap. Two patients developed a postoperative superficial wound infection that required treatment with oral antibiotics. One patient had a postoperative peroneal nerve palsy that recovered spontaneously. There were no statistical differences in predictors for patients with screw removal difficulty.
  
  
  CONCLUSIONS
  Difficulty with removal due to cold welding or screw head stripping is common in locking LISS plate screws. LISS plate removal can often require prolonged operating time and the use of specialized removal tools. Surgeons should anticipate the possibility of difficulties when removing these implants and be appropriately prepared.
authors.affiliation: Department of Orthopaedic Surgery, Denver Health Medical Centre, University of Colorado at Denver, School of Medicine, Denver, CO, USA.
authors.forename: Takashi
authors.initials: T
authors.lastname: Suzuki
authors.forename: Wade R
authors.initials: WR
authors.lastname: Smith
authors.forename: Philip F
authors.initials: PF
authors.lastname: Stahel
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Morgan
authors.forename: Andrea J
authors.initials: AJ
authors.lastname: Baron
authors.forename: David J
authors.initials: DJ
authors.lastname: Hak
mesh_terms: D000328:Adult; D000368:Aged; D001860:Bone Plates / Q000009:adverse effects*; D001863:Bone Screws / Q000009:adverse effects*; D005260:Female; D005264:Femoral Fractures / Q000601:surgery; D005594:Fracture Fixation, Intramedullary / Q000009:adverse effects* / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012086:Reoperation / Q000379:methods; D012189:Retrospective Studies; D013978:Tibial Fractures / Q000601:surgery