Correspondence We welcome letters to the Editor concerning articles which have recently been published. Such letters will be subject to the usual stages of selection and editing; where appropriate the authors of the original article will be offered the opportunity to reply. Letters should normally be under 300 words in length, double-spaced throughout, signed by all authors and fully referenced. The edited version will be returned for approval before publication. Ipsilateral recurrent lumbar disc herniation Sir, I read with interest the article in the September 1998 issue entitled 'Ipsilateral recurrent lumbar disc herniation' by Cinotti et al. 1 In the abstract they state that in the study group, 42% of patients related the onset of recurrent radicular pain to an isolated injury, but none of the control group did so (p < 0.001). Since the control group was selected on the grounds of not having recurrent radicular pain, this is not surprising.