Analysis of 1027 Adverse Events Reports for Interspinous Process Devices From the US Food and Drug Administration Manufacturer and User Facility Device Experience Database.

Background: Interspinous process devices (IPDs) introduce a new class of complications to surgical decompression without fusion: hardware-related complications. The purpose of this study was to describe the adverse events associated with IPDs.

Study Design: This was a retrospective review of the Food and Drug Administration Manufacturer and User Facility Device Experience database.

Methods: The database was queried from its inception to November 2022 for reports associated with "Prosthesis, Spinous Process Spacer/Plate." Entries were categorized by event type, patient impact, and interventions.

Results: A total of 943 surgery-related adverse events were identified. The most common intraoperative events were implant malfunctions (39.7%, = 374) and fractures (2.2%, = 21). The most common postoperative events were persistent pain (26.6%, = 251), implant migration (19.1%, = 180), and fracture (6.8%, = 64). The most common resultant outcome of an adverse event was the need for revision surgery (48.8%, = 460). The need for revision surgery was common in patients who experienced fracture (47.1%), implant migration (84.5%), infection (76.7%), and neurological complications (76.9%). Implant migration, fracture, and implant malfunction, 3 complications that are unique to decompression with an IPD as compared with traditional laminectomy, accounted for 45.9% of revisions (211/460), and revision was required in 33.0% of cases where 1 of these complications was reported (211/640). Implant malfunction made up 21.2% of Coflex complications, 47.3% of Superion complications, and 5.2% of X-Stop complications.

Conclusions: The most common adverse events were implant malfunction, inadequate efficacy, implant migration, and fracture. Concerningly, these complications require revision surgery in one-third of cases when they occur. Implant-specific assessments demonstrate a high prevalence of implant malfunctions for the Coflex and Superion implants.

Clinical Relevance: Interspinous process devices introduce a new class of complications to isolated spinal decompression surgery: implant-related complications. These complications occur both intraoperatively and postoperatively, and they frequently necessitate revision surgery.