I had submitted an article to the Acta Orthopædica Belgica since jan 2018 and still no response has been observed from the journal. how much time they took for the first review comments and further time taken for publication.
My rule of thumb for myself is that I wait for three months after submitting the manuscript, and if I have not heard back, I send an email to the editor with a respectful inquiry about the status of the review.