Time Interval Reduction for Delayed Implant-Based Cranioplasty Reconstruction in the Setting of Previous Bone Flap Osteomyelitis

Background: Reinfections following implant-based cranioplasty, in the setting of previous bone flap osteomyelitis, are common and associated with significant morbidity. The timing of reconstruction following initial osteomyelitic bone flap removal remains controversial; most advocate for prolonged time intervals of approximately 6 to 12 months. Thus, the authors investigated their delayed cranioplasty outcomes following both early (between 90 and 179 days) and late (≥180 days) time intervals with custom craniofacial implants to determine whether timing affected outcomes and rates of reinfection. Methods: An institutional review board-approved retrospective cohort review of 25 consecutive cranioplasties, from 2012 to 2014, was conducted. A nonparametric bivariate analysis compared variables and complications between the two different time interval groups, defined as early cranioplasty (between 90 and 179 days) and cranioplasty (≥180 days). Results: No significant differences were found in primary and secondary outcomes in patients who underwent early versus late cranioplasty (p > 0.29). The overall reinfection rate was only 4 percent (one of 25), with the single reinfection occurring in the late group. Overall, the major complication rate was 8 percent (two of 25). Complete and subgroup analyses of specific complications yielded no significant differences between the early and late time intervals (p > 0.44). Conclusions: The results suggest that early cranioplasty is a viable treatment option for patients with previous bone flap osteomyelitis and subsequent removal. As such, a reduced time interval of 3 months-with equivalent outcomes and reinfection rates-represents a promising area for future study aiming to reduce the morbidity surrounding prolonged time intervals. Clinical Question/Level of Evidence: Therapeutic, III.