Introduction and objectives: The purpose of the research is to show the agreement and reproducibility among 5 observers when they are questioned about 51 open fractures using two open fracture classifications for long bones (Gustilo and Aybar), interpreting the results obtained between both classifications.

Material and Method: A classification protocol is established for open fractures. The fractures are graded independently using each of the systems being evaluated (Gustilo and Aybar), by visualising slides with clinical and radiologic images in addition to a report of the data in the clinical history. The survey is conducted twice with a time difference of one to eight weeks. 5 members of the Orthopedic and Traumatologic Surgery Department (OTSD) were questioned (1 Professor, 2 Specialists and 2 Residents). The statistical method used to analyse the results was the interobserver agreement percentage and the inter- and intraobserver kappa index.

Results: The interobserver agreement percentage for the Gustilo classification was 58.82% and 39.21% for the Aybar classification. The kappa index for the interobserver agreement for the Gustilo classification was 0.51 and for the Aybar classification was 0.54. The kappa index for the intraobserver reproducibility was 0.69 for the Gustilo classification and 0.58 for the Aybar one.

Conclusions: The interobserver agreemnet was considered moderate-poor for the Gustilo and Aybar classifications. The intraobserver reproducibility was considered substantial for the Gustilo classification and moderate for the Aybar one. We conclude that this agreement shows too much variability as to accept just one classification as the only valid method to take therapeutic decisions or for comparing results. Therefore, it’s necessary to create a more detailed and careful classification, which is quick to use, reliable, reproducible and which contains a more objective criteria.