The recalled products include the EBI Osteogen implantable bone growth stimulator, the SpF PLUS-Mini, and the SpF-XL implantable spinal fusion stimulators. All serial numbers expiring before March 31, 2019 are affected. Zimmer Biomet's recall notification letter to customers instructed surgeons to monitor patients who had one of the affected devices implanted. Hospital risk managers were advised to set aside the products so they could be retrieved, quarantined, and sent back to the company.