This guidance has been withdrawn because Cartiva Synthetic Cartilage Implant (SCI) has been recalled, and the evidence for this guidance was based solely on Cartiva SCI. More information is available in the field safety notice issued by Stryker. Surgeons are advised not to implant this device, to return any unused devices to Stryker and to consider reviewing any patients who have had Cartiva SCI. NICE will consider issuing new guidance on synthetic cartilage implant insertion for first metatarsophalangeal joint osteoarthritis (hallux rigidus) if evidence using an appropriately CE-marked device becomes available.