The role of sensory parameters in predicting clinical outcome after lumbar discectomy

Abstract

Background: Lumbar discectomy is considered a safe, efficacious and cost-effective treatment for selected cases of patients with leg pain associated with the presence of a disc protrusion. But despite technically successful surgery, 30 % of patients complain of persistent pain on long-term follow up. Identification of possible predictors for a negative outcome is important, in the search for appropriate pre- and/or post-operative care and prevention of persistent disability. There is some evidence in the literature that quantitative sensory testing (QST) measures may play a role in prediction of patients’ pain persistency, however, this has never been investigated in patients undergoing lumbar discectomy.

Objective: The aim of this study is to determine the predictive value of QST parameters, in combination with previously documented predictor variables such as medical/psychological/cognitive behavioural factors, in patients with lumbar radiculopathy and/or radicular pain, for predicting patients’ clinical outcome after lumbar discectomy.

Method: Participants with radiculopathy and/or radicular pain and confirmed imaging diagnosis of nerve root compression will be recruited from the elective surgery waitlist at one hospital. All participants will undergo lumbar discectomy performed by one neurosurgeon. A standardized QST protocol comprising all of the somatosensory sub-modalities that are mediated by different primary afferents (C-, Aδ-, Aβ-) will be performed prior to surgery. QST will be conducted in the patients’ main pain area and contralateral side, in the affected dermatome and at a remote control site. The presence of other predictor variables will be captured by questionnaires. Follow-up at 3 months will include QST and measurements of pain intensity, pain descriptors, functional status, health related quality of life, return to work and health care utilisation. A further 1-year follow-up will include the same measurements except QST.

Results/Conclusions: Identification of new predictor variables may assist in the development of pre-surgical screening methods and in targeted pre- and/or post-operative patient care, with the potential to improve patients’ functional status, quality of life, work capacity whilst also reducing health care costs associated with persistent disability.