Increasing adverse event reports coincide with declining Medicare billings for interspinous devices

ISDs treat spinal stenosis via a minimally invasive approach, but limited studies assess their efficacy and durability. The objective of this study was to characterize the incidence of adverse event reports (AERs) compared to Medicare claims for interspinous devices (ISDs).

AERs for ISDs between 2017 and 2022 were downloaded from the Manufacturer and User Facility Device Experience (MAUDE) database. Reports were tabulated by brand, device problem, and patient problem. Centers for Medicare and Medicaid Services (CMS) files were surveyed to obtain the total number of Medicare procedures reported for the implantation of an ISD (Current Procedural Technology codes 22867-22870), serving as a proxy for the number of annual procedures.

A total of 1,009 MAUDE reports and 82,255 Medicare procedures were identified. Since 2019, ISD implantation procedures decreased by 47%, and the ratio of AERs to total procedures increased by 290%. X-Stop devices constituted the majority of AERs before 2020, but Superion had the majority after 2020. Reports from 2017 to 2020 frequently cited patient symptoms (>80%), whereas < 50% were symptomatic in 2021-2022. Before 2021, device problems were nonspecific, while from 2021 to 22, >40% of reports listed "material integrity problem." Superion devices more often had material integrity and migration problems, while pain and vertebral fractures occurred across brands.

The rate of AERs per ISD implantation procedure has increased since 2019. These findings suggest potential technological shortcomings, and ISDs may not be clinically viable for use in spinal surgery in their current form.