title: Dynamic contrast-enhanced magnetic resonance imaging can assess vascularity within fracture non-unions and predicts good outcome.
abstract: OBJECTIVE
  To prospectively evaluate whether dynamic contrast-enhanced (DCE) MRI can assess vascularity within non-unions and predicts clinical outcome in combination with the clinical Non-Union Scoring System (NUSS).
  
  
  METHODS
  Fifty-eight patients with non-unions of extremities on CT underwent 3-T DCE MRI. Signal intensity curves obtained from a region-of-interest analysis were subdivided into those with more intense contrast agent uptake within the non-union than in adjacent muscle (vascularised non-union) and those with similar or less contrast uptake. The pharmacokinetic parameters of the Tofts model K trans, K ep, iAUC and V e were correlated with union at CT 1 year later (n = 49).
  
  
  RESULTS
  Despite inserted osteosynthetic material, DCE parameters could be evaluated in 57 fractures. The sensitivity/specificity of vascularised non-unions as an indicator of good outcome was 83.9%/50.0 % compared to 96.8%/33.3% using NUSS (n = 49). Logistic regression revealed a significant impact of NUSS on outcome (P = 0.04, odds ratio = 0.93). At first examination, median iAUC (initial area under the enhancement curve) for the ratio non-union/muscle was 10.28 in patients with good outcome compared with 3.77 in non-responders (P = 0.023). K trans, K ep and Ve within the non-union were not significantly different initially (n = 57) or 1 year later (n = 19).
  
  
  CONCLUSIONS
  DCE MRI can assess vascularity in fracture non-unions. A vascularised non-union correlates with good outcome.
  
  
  CONCLUSIONS
  • Dynamic contrast-enhanced magnetic resonance imaging can assess vascularity within bony non-unions. • Vascularised ununited fractures appear better at 1-year CT than poorly vascularised fractures. • Non-union healing after osteosynthesis or osteoinductive drugs fundamentally requires vascularity. • DCE MRI predicts treatment outcome better than the clinical Non-Union Scoring System. • DCE MRI is clinically feasible to predict treatment outcome in bony non-unions.
authors.affiliation: Heidelberg Trauma Research Group, Department of Orthopaedic and Trauma Surgery, University Hospital Heidelberg, Schlierbacher Landstr. 200a , D-69118, Heidelberg, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Schoierer
authors.forename: Konstantin
authors.initials: K
authors.lastname: Bloess
authors.forename: Daniel
authors.initials: D
authors.lastname: Bender
authors.forename: Iris
authors.initials: I
authors.lastname: Burkholder
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Kauczor
authors.forename: Gerhard
authors.initials: G
authors.lastname: Schmidmaier
authors.forename: Marc-André
authors.initials: MA
authors.lastname: Weber
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D005264:Femoral Fractures / Q000175:diagnosis* / Q000601:surgery; D005500:Follow-Up Studies; D005592:Fracture Fixation; D017102:Fracture Healing; D005599:Fractures, Ununited / Q000175:diagnosis* / Q000601:surgery; D005682:Gadolinium; D006801:Humans; D006810:Humeral Fractures / Q000175:diagnosis* / Q000601:surgery; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008536:Meglumine; D008875:Middle Aged; D009942:Organometallic Compounds; D011446:Prospective Studies; D013978:Tibial Fractures / Q000175:diagnosis* / Q000601:surgery; D014458:Ulna Fractures / Q000175:diagnosis* / Q000601:surgery; D055815:Young Adult
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D008536:Meglumine; D005682:Gadolinium; C072417:gadoterate meglumine