Heterotopic Ossification in Bony Free Flaps Used in Head-and-neck Reconstruction

Introduction: Heterotopic ossification (HO) is a rare occurrence in bony free flaps used in head-and-neck reconstructive surgery. HO is an incidental finding, described as a rare phenomenon in the literature. The periosteal theory is one of the most emphasized physiopathological descriptions for HO. This study aimed to address the causes, outcomes, and prevention of HO. Methods: This retrospective study included 30 patients undergoing reconstructive surgery for head-and-neck bone defects using bony free flaps. The patients underwent postoperative clinical examinations and computed tomography imaging. The age, sex, indications for reconstruction, ossification time, symptoms, and clinical findings were collected and reviewed. Results: The reviewed medical records showed that 5 patients developed HO after reconstruction with bony free flaps. Free fibula flap was used in 4 patients, whereas free medial femoral condylar flap was used in 1 patient. Conclusion: Clinical signs of HO were not observed in any patient. A modified approach with preservation of the periosteum is recommended in selected patients to avoid HO. Surgical ossification removal should be performed only in patients with symptoms.