Robot-assisted posterior facet arthroplasty for lumbar spinal stenosis: a single-center experience

Lumbar spinal stenosis (LSS) often results in pain and functional impairment. The TOPS system is a novel facet replacement prosthesis that offers motion-preserving treatment for LSS, providing dynamic multiaxial stabilization across all three spinal columns while maintaining physiological motion. Although prior studies have demonstrated the safety and efficacy of the TOPS device, evidence regarding robotic assistance in this procedure remains limited. Robotic assistance might enhance the accuracy of pedicle screw placement, optimize device positioning, and shorten the surgical time. The aim of this study was to report preliminary clinical experience with robot-assisted TOPS system implantation for degenerative LSS, focusing on perioperative metrics, patient outcomes, and the safety and feasibility of robotic integration.

The authors retrospectively reviewed all patients who underwent robot-assisted TOPS device implantation between April 2024 and August 2025 at a single center. The primary outcome was reoperation. Secondary outcomes included the operative duration, estimated blood loss, symptomatic improvement, implant-related complications, and new or worsening neurological deficit.

Eight patients (50% female, median age 69.5 years) with degenerative LSS were included. All patients presented with low back pain and radiculopathy. One patient (12.5%) was treated at L1-2, 1 patient (12.5%) at L2-3, 4 patients (50%) at L3-4, and 2 patients (25%) at L4-5. The median operative duration was 160 minutes (IQR 130.2-170 minutes), with a median estimated blood loss of 175 mL (IQR 150-200 mL). No intraoperative complications occurred, including screw misplacement or the need for repositioning. The median postoperative hospital stay was 3 days (IQR 2.7-3.2 days). Over a median follow-up duration of 7 months (IQR 3-11 months), all patients reported symptomatic improvement. No patient required reoperation or experienced implant-related complications such as device malfunction, migration, or screw loosening. One patient developed an asymptomatic seroma detected on follow-up MRI. No complication was attributed to robotic assistance or the TOPS implant.

Robot-assisted implantation of the TOPS device appears safe and technically feasible for patients with degenerative LSS. Robotic assistance might facilitate accurate screw placement without the need for intraoperative adjustments, eliminate the need for conversion to fusion, and correlate with low morbidity and favorable clinical outcomes. Future prospective studies with larger cohorts and longer follow-up are warranted to validate these findings and assess the long-term durability of outcomes.