The fate of the TMJ metal fossa implant: a long-term follow-up.

The temporomandibular joint (TMJ) metal fossa (hemijoint) prosthesis was a treatment modality for select TMJ disorders starting in the 1960s, but was taken off the market in 2015. While many were placed, and some medium-term follow-up has been reported, there is a paucity of long-term follow-up on this prosthesis to guide current clinical decision-making. A cross-sectional survey of 200 Mayo Clinic patients documented to have had a hemijoint implant placed between 2000 and 2015 was performed. The primary outcome measure was the length of time the hemijoint prosthesis was retained. Secondary outcomes were quality-of-life measures (reasons for removal, patient satisfaction, range of motion or dietary restrictions, pain, occlusion, and related secondary interventions performed). At the time of survey collection, 148 (74%) of the surveyed patients still had a hemijoint in place, of whom 119 (80.4%) reported satisfaction with the prosthesis and their current level of function. Pain was the most frequent reason for hemijoint removal (30/52, 57.7%). The mean lifespan of the removed hemijoints was 7.5 years. This study suggests that many hemijoint recipients have retained their prosthesis in the long term with acceptable outcomes and it may not be necessary to remove these prostheses simply due to their presence.