title: Field testing the Unified Classification System for peri-prosthetic fractures of the pelvis and femur around a total hip replacement : an international collaboration.
abstract: The Unified Classification System (UCS) emphasises the key principles in the assessment and management of peri-prosthetic fractures complicating partial or total joint replacement. We tested the inter- and intra-observer agreement for the UCS as applied to the pelvis and femur using 20 examples of peri-prosthetic fracture in 17 patients. Each subtype of the UCS was represented by at least one case. Specialist orthopaedic surgeons (experts) and orthopaedic residents (pre-experts) assessed reliability on two separate occasions. For the pelvis, the UCS showed inter-observer agreement of 0.837 (95% confidence intervals (CI) 0.798 to 0.876) for the experts and 0.728 (95% CI 0.689 to 0.767) for the pre-experts. The intra-observer agreement for the experts was 0.861 (95% CI 0.760 to 0.963) and 0.803 (95% 0.688 to 0.918) for the pre-experts. For the femur, the UCS showed an inter-observer kappa value of 0.805 (95% CI 0.765 to 0.845) for the experts and a value of 0.732 (95% CI 0.690 to 0.773) for the pre-experts. The intra-observer agreement was 0.920 (95% CI 0.867 to 0.973) for the experts, and 0.772 (95% CI 0.652 to 0.892) for the pre-experts. This corresponds to a substantial and 'almost perfect' inter- and intra-observer agreement for the UCS for peri-prosthetic fractures of the pelvis and femur. We hope that unifying the terminology of these injuries will assist in their assessment, treatment and outcome.
authors.affiliation: University of British Columbia, Department of Orthopaedics, Vancouver, British Columbia, Canada.
authors.forename: M H
authors.initials: MH
authors.lastname: Vioreanu
authors.affiliation: University of British Columbia, Department of Orthopaedics, Vancouver, British Columbia, Canada.
authors.forename: M C
authors.initials: MC
authors.lastname: Parry
authors.affiliation: University College London Hospitals, 235 Euston Road, London NW1 2BU, UK.
authors.forename: F S
authors.initials: FS
authors.lastname: Haddad
authors.affiliation: University of British Columbia, Department of Orthopaedics, Vancouver, British Columbia, Canada.
authors.forename: C P
authors.initials: CP
authors.lastname: Duncan
mesh_terms: D019644:Arthroplasty, Replacement, Hip; D005500:Follow-Up Studies; D014943:Global Health; D006801:Humans; D015994:Incidence; D007391:International Cooperation; D008297:Male; D057068:Periprosthetic Fractures / Q000145:classification* / Q000453:epidemiology*; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies
keywords: Peri-prosthetic fractures; Classification System; Pelvis; Femur; Total Hip Arthroplasty.