title: Role of magnetic resonance imaging in the diagnosis of the painful unicompartmental knee arthroplasty.
abstract: BACKGROUND
  Unicompartmental knee arthroplasty (UKA) is a well established method for the treatment of single compartment arthritis; however, a subset of patients still present with continued pain after their procedure in the setting of a normal radiographic examination. This study investigates the effectiveness of magnetic resonance imaging (MRI) in guiding the diagnosis of the painful unicompartmental knee arthroplasty.
  
  
  METHODS
  An IRB-approved retrospective review identified 300 consecutive UKAs performed over a three years period with 28 cases of symptomatic UKA (nine percent) with normal radiographic images.
  
  
  RESULTS
  MRI examination was instrumental in finding a diagnosis that went undetected on radiographs. Based on MRI findings, 10 (36%) patients underwent surgery whilst 18 (64%) were treated conservatively.
  
  
  CONCLUSIONS
  This study supports the use of MRI as a valuable imaging modality for managing symptomatic unicompartmental knee arthroplasty.
  
  
  METHODS
  Case series.
authors.affiliation: Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, NY, United States. Electronic address: caroline.park7@gmail.com.
authors.forename: Caroline N
authors.initials: CN
authors.lastname: Park
authors.affiliation: Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, NY, United States.
authors.forename: Hendrik A
authors.initials: HA
authors.lastname: Zuiderbaan
authors.affiliation: Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, NY, United States.
authors.forename: Anthony
authors.initials: A
authors.lastname: Chang
authors.affiliation: Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, NY, United States.
authors.forename: Saker
authors.initials: S
authors.lastname: Khamaisy
authors.affiliation: Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, NY, United States.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Pearle
authors.affiliation: Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, NY, United States.
authors.forename: Anil S
authors.initials: AS
authors.lastname: Ranawat
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018771:Arthralgia / Q000175:diagnosis* / Q000209:etiology; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000473:pathology* / Q000601:surgery; D007720:Knee Prosthesis / Q000009:adverse effects*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery; D010149:Postoperative Pain / Q000175:diagnosis* / Q000209:etiology; D015203:Reproducibility of Results; D012189:Retrospective Studies
keywords: Magnetic resonance imaging; Pain; Radiograph; Unicompartmental knee arthroplasty