Purpose To evaluate clinical and radiologic outcome of a series of patients treated with a removable percutaneous interspinous process spacer (IPS) (LobsterProject® Techlamed®) for symptomatic degenerative lumbar spinal stenosis (DLSS).

Methods All patients treated in the two considered Centres with this IPS during 2019 were retrospectively reviewed. Patients with incomplete clinical or radiological documentation were not included. Procedures were performed under deep sedation or general anaesthesia by two interventional radiologists. Patients were clinically evaluated before intervention and at 3-month follow-up with Visual Analog Scale for pain (VAS), Oswestry Disability Index (ODI) and radiologically with MRI or CT scans. Neural foramina were independently measured for each patient on pre- and post-procedural CT scans by two radiologists.

Inclusion Criteria:

• removable percutaneous IPS treatment
• attended interventional radiology outpatient consultations for back pain and NIC, refractory to medical treatment

Exclusion Criteria:

• PS positioning included cauda equina syndrome
• permanent motor deficit,
• previous spine surgery,
• spondylolisthesis greater than Meyerding grade I,
• local or systemic infection and severe osteoarthritis with pronounced osteophytosis or bone bridges

All patients treated with this removable percutaneous IPS in our two Centres from December 2018 to February 2020 were retrospectively reviewed and those with complete imaging and clinical data were selected. Patients attended interventional radiology outpatient consultations for back pain and NIC, refractory to medical treatment.