To determine the outcomes of osseointegrated implants in patients treated for head and neck cancer.
Retrospective cohort study of patients who have received osseointegrated implants placed at a single head and neck center between January 1st 2008 to June 31st 2018. The Kaplan-Meier method was utilised for survival estimates of implants placed into native bone and reconstructed bone. Cox regression was used for multivariate analysis of factors affecting implants survival.
A total of 244 implants were placed into native bone and 236 into vascularised bone grafts with follow up ranging from 6 to 108 months. Implants placed into free flap bone compared to native bone had a higher failure rate (HR 7.26, 95%CI 1.8-28.5, p=0.005). Radiation, chemotherapy, hyperbaric oxygen, smoking and position had no effect overall. Comparing implant survival in free flaps by donor site including fibula, iliac crest, scapula, radial forearm and medial femoral condyle showed no difference in survival (p=0.68). One and five year survival rates in more commonly utilised flaps were 97% and 82% for fibula, 97% and 87% for iliac crest and 96% and 74% for scapula. Factors that negatively affected implant survival in composite free flaps included previous smoking (HR 9.53, 95%CI 2.25-79.16, p=0.037), current smoking (HR 20.3, 95%CI 2.41-171.26, p=0.006) and placement in radiation exposed bone (HR 3.79, 95%CI 1.03-13.85, p=0.04).
Implant survival rates in head and neck cancer patients are acceptable, however, they are lower in composite free flaps compared to native bone. There is no difference in implant survival among different composite free flaps. Smoking history and radiation exposure have a negative effect on implant survival when placed in composite free flaps.