Identifying Pain Generators and Potentiators of Residual Complaints Following Lumbar Discectomy

Identifying Pain Generators and Potentiators of Residual Complaints Following Lumbar Discectomy

Lumbar discectomy (i.e. surgically removing a hernia) is frequently performed in Belgium to treat lumbar radiculopathy. Every year >12,000 interventions are performed with variable long-term results. The treatment success of this procedure varies and up to 41% of the patients report post-operative persistent pain complaints, and consequently suffer from failed back surgery syndrome (FBSS). Chronic complaints in FBSS following lumbar discectomy are usually treated with symptomatic interventions (including painkillers, neuromodulation, etc), rather than from a biopsychosocial perspective.

In order to develop a focused and effective treatment strategy, it is crucial to first gain insight into how persons with persistent complaints after lumbar discectomy differ from those without persistent symptoms. Different known contributing factors entail type of surgery, muscle and psychosocial impairments. Although in scientific and clinical literature it is assumed that dysfunctional pain processing also plays an important mechanistic role in FBSS, there is a lack of research to support this. However, this knowledge is crucial to depict the full mechanistic picture of pain generators and potentiators in FBSS.

Therefore, we will examine whether residual complaints persisting following lumbar discectomy can be accounted for by underlying dysfunctional pain processing and whether a clinical classification algorithm can be used to identify the predominant pain mechanism in these patients.

Inclusion Criteria:

• Dutch speaking
• Body mass index below 35kg/m²
• Lumbar radiculopathy patients, classified as ASA I to II without any symptoms of spinal cord compression (i.e. bilateral leg pain), who are scheduled for a first-time, single-level, unilateral lumbar discectomy
• Healthy, pain-free controls (score 0 on a visual analogue scale from 0 to 100)

Exclusion Criteria:

• Female participants will be excluded if pregnant, lactating or <1 year postnatal
• Having (a history) of severe medical disorders either respiratory (e.g. cystic fibrosis), orthopedic (e.g. whiplash trauma), neurologic (e.g. cerebrovascular incident), cardiovascular (e.g. severe hypertension), endocrinological (e.g. diabetes), psychiatric (e.g. post-traumatic stress disorder
• Having a history of spinal surgery (e.g. discectomy), spinal traumata (e.g. vertebral fracture) or severe spinal deformities (e.g. spondylolisthesis)
• Having a pacemaker or defibrillator
• Healthy controls will be excluded if having suffered low back pain in the preceding year of score 2 or higher on the visual analog scale and which limited their activities of daily living or for which they consulted a (para)medic.