The purpose of this study was 2-fold: to evaluate the surgical outcome and surgical morbidity of the temporomandibular joint (TMJ) metal fossa-eminence hemijoint prosthesis replacement, implanted in patients with degenerative arthritis, and to establish whether future, more rigorous clinical trial assessment of the hemijoint replacement is warranted.
Eighty-four patients (79 females and 5 males) involving 108 joints (60 unilateral, 24 bilateral) were operated on, and 112 joint metal fossa-eminence prostheses were placed. Information was gathered from patient response questionnaires and clinicoradiographic medical chart review. Change in pain intensity (preoperative versus current) was measured by 2 methods: 1) pain experience (1 to 6) and 2) pain intensity (visual analog scale, 1 to 10). Chewing ability, jaw opening, and joint noise were evaluated (visual analog scales, 1 to 10). Surgical morbidity and implant survival were documented.
The average period from initial TMJ symptoms to metal fossa-eminence implant surgery was 12.3 years. The average number of previous TMJ surgeries was 1.9. Pain was reduced 56% and 61.2% by 2 methods. Chewing ability, jaw opening, and joint noise were improved by 53.4%, 50.2%, and 64%, respectively. Nine of 112 implants were explanted during the study period. Patient satisfaction for the clinical outcome was 8.3 on a scale of 0 to 10.
The surgical placement of the Co-Cr-Mo metal fossa-eminence prosthesis (partial joint replacement) provides significant focal preauricular pain relief and reduces TMJ dysfunction secondary to advanced degenerative arthritis. The results of this case series supports further investigation of this form of surgical management in a rigorously controlled prospective fashion.