Groningen TMJ total joint replacement prosthesis: 3 to 7-year follow-up on surgical and patient reported outcomes.

A prosthetic total joint replacement (TJR) may be indicated for patients who suffer from severe dysfunction or resorption of the temporomandibular joint (TMJ). Currently, the patient-specific or custom TMJ-TJR prosthesis options are plentiful. However, there is a lack of thorough (long term) follow-up studies. The aim of this prospective study was to assess the 3 to 7-year follow-up outcomes of the patient-specific Groningen temporomandibular joint total joint replacement (G-TMJ-TJR) prosthesis (Xilloc Medical®, Geleen, the Netherlands). Longitudinal assessments of surgical outcomes, changes in maximum interincisal opening (MIO), laterotrusion, protrusion and patient reported outcomes (PROMs) on functional mandibular impairment (MFIQ) and pain (VAS) were studied. These outcomes were collected preoperatively, and 6, 12 and 24 months postoperatively for all included patients, while MIO, VAS pain and MFIQ were reported till up to 60 months postoperatively. Fourteen patients (13 female, 1 male) who had received a patient-specific G-TMJ-TJR, with a minimum follow-up period of 24 months, were included. The average age at implantation was 53.7 (sd 11.3) years. A patient-specific G-TMJ-TJR prosthesis was successfully implanted in all 14 patients without any mechanical failures or adverse effects during the minimum 2-year follow-up (mean 57 months) period. All G-TMJ-TJR devices were accurately implanted according to the 3D-VSP. There were no post-operative infections but temporary weakness of a facial nerve branch was reported by two patients. The median MIO increased from 19.5 to 30.0 mm, while the median VAS pain (R: 0-10) score reduced from 7.2 to 0.9 cm. The median MFIQ (R: 0-68) diminished from 47.0 to 9. Pain was relieved by the G-TMJ-TJR prosthesis in all but one patient with chronic pain. Protrusion and laterotrusion to both sides increased, indicating more freedom of movement in the operated joint and resulting in a more natural jaw movement. This study shows considerable functional improvement compared to a prior follow up of a former G-TMJ-TJR study. This indicates that thorough 3D planning, subsequent patient-specific modelling, and accurate guided placement of the G-TMJ-TJR improves clinical outcomes significantly.