2.2. Subjects

Inclusion criteria are as follows: patients aged 18 and above; eligibility for lumbar disc hernia surgery; incapacitating LRS with leg pain (numeric pain rating scale [NPRS] > 6; with or without back pain) that had lasted for a minimum of 6 weeks with or without mild neurological deficit (i.e., Medical Research Council > 3); and a magnetic resonance imaging that confirms a hernia nuclei pulposi that compromises the spinal nerve and can explain the clinical symptoms of the patient.

Exclusion criteria are as follows: spine surgery and or transforaminal injections at the same level during the previous 6 months; bony stenosis; cauda equina syndrome; spondylolisthesis; pregnancy; complicated disc herniation requiring more than one operation; severe coexisting disease (e.g., osteoporosis and dementia); patient with contraindications for steroid injections; insufficient knowledge of the Dutch language; emergency surgery as determined by the neurosurgeon; and being allergic for Iohexol 240 mg/ml (i.e., OMNIPAQUE 240).

Figure 1 shows the flow diagram of the study. Neurosurgeons or orthopaedic surgeons of the participating hospitals recruit and inform the patients about the study and the possibility to participate while they are on the waiting list for surgery. The surgeon then refers the patient to the research team who will check if the patient meets the aforementioned inclusion and exclusion criteria. If the patient is eligible and gives informed consent, the patient will be included in this study. Baseline measures will then be made and patients will be randomized to either the intervention or the control arm of the study.

Flow chart of the Preventing lumbar disc surgery (PLUS) study

Participants will be recruited from seven hospitals in the Netherlands. The hospitals were chosen due to their proximity to the four primary care‐based outpatient clinics (so‐called “Rugpoli's”) where the combination therapy will be provided.