Abstract
Introduction: The incidence of post-operative peri-prosthetic fractures is increasing. This is a consequence of the larger number of revision cases being undertaken, the increase in the use of cementless implants and a number of patients who develop undetected osteolysis as a result of poor follow up. The Vancouver classification has been shown to be a valid and reliable method for determining the configuration of periprosthetic fractures. This is essential in directing the further management of periprosthetic fractures appropriately.
Methods: We have revalidated this classification system independently from the original authors at our institution. The radiographs from 30 patients with peri-prosthetic fractures were reviewed by 6 expert consultant surgeons, 6 non-experts at registrar level and 6 medical students, who had received no specialist training in this area, in order to assess intra and inter-observer reliability and reproducibility. Each observer read the radiographs on 2 separate occasions and classified the fracture according to its type (A, B1, B2, B3, and C).
Results: The results were subjected to weighted κ analysis and were: Intraobserver agreement 0.72 for experts,0.68 for non experts and 0.61 for medical students. Interobserver agreement was 0.63 for the first reading and 0.67 for the second reading. Validity analysis showed a κ value of 0.79 (substantial agreement).
Discussion: Our results confirm the reliability and reproducibility of this classification system. In addition we have shown that substantial agreement can even be found between individuals with no specialist training. This is a classification system that can be used by non-experts, between centres and across continents.
Correspondence should be addressed to Mr John Hodgkinson, BHS, c/o BOA, The Royal College of Surgeons, 35–43 Lincoln’s Inn Fields, London WC2A 3PE.
