Letter to the Editor concerning “New classification for the treatment of pyogenic spondylodiscitis: validation study on a population of 250 patients with a follow-up of 2 years” by Enrico Pola et al. Eur Spine J (2017) doi:10.1007/s00586-017-5043-5

Dear Editor,

In their article, Pola et al. proposed a classification of pyogenic spondylitis as a guide to surgical management [1]. I would like to make the following observations in this regard:

The spine is a common site of infection and accounts for 2–7% of all the cases of musculoskeletal infections. Approximately 95% of pyogenic spinal infections involve the vertebral body and/or the intervertebral disc, with only 5% involving the posterior elements of the spine [2]. The most common site of infection is the lumbar spine, followed by the thoracic and cervical regions. This classification mainly includes typical pyogenic spondylitis. However, some atypical presentations such as atlanto-axial or posterior pyogenic spondylitis [2,3,4] do not find a place in the classification proposed by the authors.