PTED study: design of a non-inferiority, randomised controlled trial to compare the effectiveness and cost-effectiveness of percutaneous transforaminal endoscopic discectomy (PTED) versus open microdiscectomy for patients with a symptomatic lumbar disc herniation.

INTRODUCTION: Lumbosacral radicular syndrome is often caused by a disc herniation. The standard surgical technique to remove a disc herniation is open microdiscectomy. An alternative technique is percutaneous transforaminal endoscopic discectomy (PTED), which is less invasive. In the Netherlands, PTED is not currently considered as standard care, and therefore not reimbursed within public health insurance. A pragmatic, multicentre, non-inferiority, randomised controlled trial has been designed to determine the effectiveness and cost-effectiveness of PTED versus open microdiscectomy for the treatment of lumbar disc herniation.

METHOD AND ANALYSIS: In total, 682 patients between 18 and 70 years of age with >10 weeks of radiating pain or with >6 weeks of excessive radiating pain are to be recruited from participating centres. Patients must have an indication for surgery based on an MRI demonstrating compression of the nerve root from a lumbar disc herniation. Patients are to be randomised to PTED or open microdiscectomy. The primary outcome is self-reported leg pain measured by the 0-100 mm Visual Analogue Scale. Secondary outcomes include self-reported health and functional status, back pain, self-perceived recovery and a physical examination. Outcomes will be measured the day following surgery, at 2, 4 and 6 weeks, and at 3, 6, 9, 12 and 24 months. Physical examination will be performed at 6 weeks, and 3 and 12 months. An economic evaluation will be performed from a societal perspective and cost questionnaires will be used (eg, EQ-5D-5L). The data will be analysed longitudinally; the non-inferiority margin for the primary outcome is 5. Bootstrapping techniques will be used for the economic evaluation.

ETHICS AND DISSEMINATION: This study has received approval of the Medical Ethical Committee of the VU Medical Centre Amsterdam: NL50951.029.14. The results will be published in an international peer-reviewed scientific journal.

TRIAL REGISTRATION NUMBER: NCT02602093; Pre-results, recruiting stage.