Is the Robinson classification of clavicle fractures accurate enough within the setting of the Swedish Fracture Register?

Caroline Kihlström; Nils P Hailer; Olof Wolf

doi:10.1016/j.injury.2023.04.003

Is the Robinson classification of clavicle fractures accurate enough within the setting of the Swedish Fracture Register?

Injury. 2023 Apr 14:S0020-1383(23)00342-X. doi: 10.1016/j.injury.2023.04.003. Online ahead of print.

Authors

Caroline Kihlström¹, Nils P Hailer², Olof Wolf²

Affiliations

¹ Department of Surgical Sciences - Orthopedics, Uppsala University, SE-751 85 Uppsala, Sweden. Electronic address: caroline.kihlstrom@surgsci.uu.se.
² Department of Surgical Sciences - Orthopedics, Uppsala University, SE-751 85 Uppsala, Sweden.

PMID: 37142482
DOI: 10.1016/j.injury.2023.04.003

Abstract

Introduction: In the Swedish Fracture Register (SFR) clavicle fractures are classified according to the Robinson classification. This study aimed to evaluate the accuracy of the classification of clavicle fractures in the SFR. A secondary aim was to assess inter- and intraobserver agreement.

Materials and methods: Clavicle fractures (n = 132) were randomly selected from the SFR and radiographs were requested for each patient from their treating departments. Not all radiographs could be acquired, and after exclusion, 115 fractures were independently classified by three expert raters blinded to patient information. The 115 fractures were classified on two occasions, 3 months apart. The raters' consensus classification was used as a gold standard that was compared to the classification registered in the SFR. The accuracy, defined as the degree of agreement between the gold standard and SFR classifications, was reported, as was the inter- and intraobserver agreement for the expert raters.

Results: Agreement between the classification in the SFR and the gold standard classification was fair (kappa = 0.35). Fractures with only partial displacement were often incorrectly classified as fully displaced in the SFR (n = 31 of 78 displaced fractures in the SFR). The inter- and intraobserver agreement among the expert raters was almost perfect (interobserver kappa = 0.81-0.87, intraobserver kappa = 0.84-0.94).

Conclusions: The accuracy of the classification of clavicle fractures in the SFR was only fair, whereas the inter- and intraobserver agreement among the expert raters was almost perfect. Accuracy in the SFR may be improved if the classification instructions in the SFR are updated by incorporating the original classification displacement criteria, both in text and in illustrated form.

Keywords: Accuracy; Clavicle fracture; Robinson classification; SFR; Validation.