GP2d - Immediate Versus Delayed Implant Placement in Fibula Free Flap Reconstruction: A Systematic Review and Meta-Analysis

Abstract: Statement of the Problem: Restoration of occlusion and masticatory function is a major component of fibula free flap reconstruction of the mandible or maxilla. Although osseointegrated implants in fibula free flaps have demonstrated favorable outcomes, the optimal timing of implant placement remains unclear. Delayed implantation has historically been favored because of concerns regarding flap viability, osseointegration, and postoperative complications. However, immediate implant placement may allow earlier rehabilitation and may permit osseointegration before the adverse effects of adjuvant radiation therapy. The purpose of this study was to systematically evaluate and analyze implant survival following immediate versus delayed implant placement in fibula free flap reconstruction based on current literature.

Materials and Methods: A systematic review and meta-analysis was performed in accordance with PRISMA principles. Studies published from 2000 onward were screened for inclusion if they involved patients undergoing fibula free flap reconstruction of the mandible and/or maxilla and reported extractable outcomes for immediate and/or delayed dental implant placement. Case reports, non-fibula osseous flaps, and studies without extractable implant outcome data were excluded. Four studies published between 2019 and 2024 met inclusion criteria for quantitative synthesis. These included retrospective cohort studies and case series evaluating implant outcomes after immediate, delayed, or implant-first/prefabricated workflows.

Methods of Data Analysis: The primary outcome was implant survival at last reported follow-up. Random-effects meta-analysis was performed to generate pooled survival estimates for immediate and delayed implants separately. Comparative analysis of implant failure risk between immediate and delayed placement was performed using studies with extractable timing-stratified outcomes. Risk ratios (RRs) with 95% confidence intervals (CIs) were calculated, with continuity correction applied to zero-event cells as needed. Heterogeneity was assessed using the I² statistic. Sensitivity analysis was performed restricting comparative analysis to implant-level studies only.

Results: A total of 265 implants were included across 4 studies. Of these, 116 implants were placed immediately and 149 were placed in a delayed fashion. Immediate implants demonstrated 7 failures, corresponding to a crude survival rate of 94.0% (109/116), whereas delayed implants demonstrated 23 failures, corresponding to a crude survival rate of 84.6% (126/149). Pooled immediate implant survival was 94.4% (95% CI, 80.3%-98.6%; I² = 49.2%). Pooled delayed implant survival was 85.3% (95% CI, 71.9%-93.0%; I² = 64.4%). Comparative analysis demonstrated that immediate implant placement was associated with a significantly lower risk of failure than delayed placement (RR 0.18; 95% CI, 0.04-0.75; I² = 0%). Sensitivity analysis restricted to implant-level studies yielded a similar result (RR 0.18; 95% CI, 0.03-0.93; I² = 0%).

Outcomes Data: Immediate implant placement demonstrated consistently high survival across studies and was associated with a lower risk of failure than delayed implantation. The most pronounced difference was observed in the setting of radiation exposure, where delayed implants placed in irradiated fibula segments showed substantially reduced survival compared with delayed implants in nonirradiated bone, while immediate implants maintained excellent outcomes. These findings suggest that the timing of implantation may be particularly important when adjuvant radiation is anticipated.

Conclusions: Immediate implant placement in fibula free flap reconstruction is associated with high implant survival and, in the available comparative literature, a lower risk of failure than delayed implantation. These data support immediate implantation as a safe and effective strategy in appropriately selected patients and suggest that it may be particularly advantageous when postoperative radiation is anticipated.