Schatzker and Mayo classification systems for olecranon fractures: Inter- and intra-observer reliability

Abstract

Background: Olecranon fracture is a relatively common injury, accounting for approximately 10% of upper limb fractures. Robust classification methods are essential for proper communication between surgeons and for comparing different treatment modalities. The aim of this study was to determine the reliability of two currently used classification systems for olecranon fractures.

Methods: The study involved examination of inter- and intra-rater reliability for retrospective analysis of radiograph data using existing diagnostic criteria. The lateral elbow radiographs of fifty consecutive patients who were treated operatively for olecranon fractures were included. Olecranon fractures were classified independently by five experienced orthopedic surgeons using the Mayo and Schatzker classification systems. Two of the surgeons also reevaluated the fractures one month following the initial evaluation. Inter-observer and intra-observer variation was assessed using kappa statistics.

Results: For Mayo classification, the mean inter-observer kappa value was 0.23 and the mean intra-observer value was 0.63. For Schatzker classification, the mean inter-observer and intra-observer kappa values were 0.35 and 0.53, respectively.

Conclusion: The two accepted classification systems for olecranon fractures revealed moderate inter-observer agreement. This should be taken into consideration when evaluating reports about different treatments for what are considered to be identical or similar fractures.