title: Carbon fiber intramedullary nails reduce artifact in postoperative advanced imaging.
abstract: OBJECTIVE
  This study assessed whether radiolucent carbon fiber reinforced-polyetheretherketone (CFR-PEEK) intramedullary nails decreased hardware artifact on magnetic resonance imaging (MRI) and computed tomography (CT) in vitro and in an oncologic patient population.
  
  
  METHODS
  In vitro and clinical evaluations were done. A qualitative assessment of metal artifact was performed using CFR-PEEK and titanium nail MRI phantoms. Eight patients with a femoral or tibial prophylactic CFR-PEEK nail were retrospectively identified. All patients had postoperative surveillance imaging by MRI, CT, and were followed for a median 20 months (range, 12-28 months). CFR-PEEK images were compared to images from a comparative group of patients with titanium femoral intramedullary nails who had a postoperative MRI or CT. A musculoskeletal-trained radiologist graded visualization of the cortex, corticomedullary junction, and bone-muscle interface, on T1-weighted (T1W), STIR, and contrast-enhanced T1-weighted fat-saturated (T1W FS) sequences of both groups with a five-point scale, performing independent reviews 4 months apart. Statistical analysis used the Wilcoxon rank-sum test and a weighted kappa.
  
  
  RESULTS
  Substantially less MRI signal loss occurred in the CFR-PEEK phantom than in the titanium phantom simulation, particularly as the angle increased with respect to direction of the static magnetic field. CFR-PEEK nails had less MRI artifact than titanium nails on scored T1W, STIR, and contrast-enhanced T1W FS MRI sequences (p ≤ 0.03). The mean weighted kappa was 0.64, showing excellent intraobserver reliability between readings.
  
  
  CONCLUSIONS
  CFR-PEEK intramedullary nail fixation is a superior alternative to minimize implant artifact on MRI or CT imaging for patients requiring long bone fixation.
authors.affiliation: Orthopaedic Surgery Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, 1275 York Ave., New York, NY, 10065, USA.
authors.forename: Melissa N
authors.initials: MN
authors.lastname: Zimel
authors.forename: Sinchun
authors.initials: S
authors.lastname: Hwang
authors.forename: Elyn R
authors.initials: ER
authors.lastname: Riedel
authors.forename: John H
authors.initials: JH
authors.lastname: Healey
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001577:Benzophenones; D001858:Bone Nails; D002244:Carbon / Q000737:chemistry*; D000077482:Carbon Fiber; D019544:Equipment Failure Analysis; D005260:Female; D005594:Fracture Fixation, Intramedullary / Q000295:instrumentation; D050723:Fractures, Bone / Q000175:diagnosis* / Q000601:surgery*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007659:Ketones / Q000737:chemistry; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D015588:Observer Variation; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers; D011182:Postoperative Care / Q000379:methods; D011379:Prognosis; D011474:Prosthesis Design; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014025:Titanium; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D001577:Benzophenones; D000077482:Carbon Fiber; D007659:Ketones; D011108:Polymers; C063834:polyetheretherketone; D011092:Polyethylene Glycols; D002244:Carbon; D014025:Titanium