Distal clavicle fractures: A new classification system

Abstract

Introduction: Existing various classification systems for distal clavicle fractures have low interobserver and intraobserver reliability and provide limited information for treatment decision. The objective of this study was to determine interobserver and intraobserver reliability of the new classification system and the associated treatment choice for distal clavicle fractures.

Hypothesis: The new classification system has good reliability.

Methods: Eight observers including 4 experienced shoulder specialists and 4 orthopedic fellows independently reviewed routine plain radiographs of 74 patients with distal clavicle fractures. They were asked to determine the fracture type according to the new classification system and the treatment choice for each case through web-based survey. Images from each case were randomly presented to the observers in 2 rounds 4 weeks apart. Reliability was assessed on the basis of Fleiss κ values.

Results: Interobserver and intraobserver reliability of the classification system were moderate (κ=0.434) and substantial (κ=0.644), respectively. Interobserver and intraobserver reliability of the treatment choice were moderate (κ=0.593) and substantial (κ=0.698), respectively. There were no significant differences in the level of reliability between experienced shoulder specialists and orthopedic fellows for any κ values (all p>0.05).

Conclusion: Our study demonstrated moderate interobserver and substantial intraobserver reliability of the new classification system and the associated treatment choice for distal clavicle fractures. We believe that our novel classification system will help physicians to choose treatment and implants.

Level of evidence: III, Cohort study, Diagnosis study.

Keywords: Classification; Distal clavicle; Fracture; Reliability.