title: Biodegradable X-ray markers of controlled radio-opacity. Temporary position measurements in bone.
abstract: In order to analyze X-ray markers for potential use in biodegradable implants or radiostereogrammatic analysis (RSA), we combined iopromide contrast fluid with biodegradable calcium phosphate cement. The radio-opacity of 10 x 10 mm markers containing different iodine concentrations (0, 120, 240, 360 and 720 mg per gram cement) was compared to an aluminium wedge of increasing (1-10 mm) thickness. The addition of iopromide increased the radio-opacity in a dose-dependent manner, which was comparable to 9-mm aluminium at concentrations of 240-720 mg/g. Radiographs of markers placed in explanted rabbit and in human femora were made to investigate the clinical accuracy for position determination. Markers of 1 x 1 mm (120 mg/g) were clearly discernable in all femora, and could be used to adequately measure distances of 5-45 mm (accuracy 0.10-2.19 mm). These markers might be embedded in biodegradable implants or used as temporary markers in the bone to analyze postoperative position on radiographs.
authors.affiliation: Department of Orthopaedic Surgery, VU Medical Center, NL-1007 MB Amsterdam, The Netherlands.
authors.forename: Hein P
authors.initials: HP
authors.lastname: Stallmann
authors.forename: Chris
authors.initials: C
authors.lastname: Faber
authors.forename: Herbert M
authors.initials: HM
authors.lastname: Plokker
authors.forename: Paul I J M
authors.initials: PI
authors.lastname: Wuisman
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001843:Bone Cements; D002130:Calcium Phosphates; D003287:Contrast Media; D005269:Femur / Q000000981:diagnostic imaging*; D006801:Humans; D011817:Rabbits; D011856:Radiographic Image Enhancement
chemical_list: D001843:Bone Cements; D002130:Calcium Phosphates; D003287:Contrast Media