Hardware Exposure After Mandibular Reconstruction: Bone Versus Soft Tissue Free Flap Comparison.

[OBJECTIVE] Hardware exposure after microvascular free tissue transfer (MFTT) for mandibular reconstruction is a significant complication. While osteocutaneous MFTTs are the preferred option, some patients require soft tissue-only MFTTs due to medical or anatomic limitations. Data comparing hardware exposure risk between these approaches are limited. This study compares the rate and timing of hardware exposure between osteocutaneous and soft tissue MFTTs.

[METHODS] We conducted a retrospective review of patients undergoing MFTT for mandibular defects at a tertiary care center (11/2011-6/2023). Patients with non-mandibular defects or under age 18 were excluded. The primary exposure was flap type (osteocutaneous vs. soft tissue). The primary outcome was time to hardware exposure; the secondary outcome was exposure rate at defined follow-up intervals.

[RESULTS] One hundred and seventy-eight patients met inclusion criteria. At 1 year, hardware exposure occurred in 5.2% of osteocutaneous and 8.7% of soft tissue MFTT patients. At 3 years, exposure increased to 14.2% and 17.4%, respectively. After adjustment, there was no significant difference in time to hardware exposure between flap types at 1 year [HR 1.69 (95% CI 0.34-8.37), p = 0.520] or 3 years [HR 1.69 (95% CI 0.59-4.43), p = 0.346]. Adjuvant radiation and/or chemoradiation was associated with increased hazard of hardware exposure at 1 year [HR 7.72 (95% CI 0.97-61.4), p = 0.053] and at 3 years [HR 3.68 (95% CI 1.38-9.78), p = 0.009].

[CONCLUSIONS] Flap type was not associated with differences in hardware exposure timing, but adjuvant therapy significantly increased exposure risk. Exposure rates rose by ~10% from 1 to 3 years postoperatively.