When the bone flap hits the floor.

Objective: There is no published data in the neurosurgical literature describing the incidence, treatment, or outcome of contaminating a bone flap. We reviewed our departmental experience to determine methods of prevention and assess our treatment strategies.

Methods: We retrospectively reviewed all incidents of dropped bone flaps during a craniotomy at a single medical center during a 16-year period. In addition, a questionnaire was mailed to neurosurgeons in the United States and abroad asking their own experience and method of management.

Results: Fourteen incidents of dropped bone flaps occurred during a 16-year period. Follow-up varied from 2 to 176 months. The bone flap was dropped while elevating the bone (n = 4), when handing the bone off the field (n = 4), and during plating (n = 4). The context was unknown in two cases. Management included soaking the flap in betadine and/or antibiotic solution (n = 8), autoclaving (n = 2), or discarding the bone flap and replacing with a mesh cranioplasty (n = 3). The treatment remains unknown in one case. No instances of infection were noted in follow-up. In response to the survey, 66% (33 out of 50) of the polled neurosurgeons had experienced this complication during their practice, and 83% would replace the bone flap after disinfection.

Conclusion: Dropping a bone flap during neurosurgery remains an uncommon but preventable complication. Treatment options include discarding the bone followed by cranioplasty versus replacing the bone after treatment with antibiotic irrigation, betadine, and/or autoclaving. Replacement after disinfection is an appropriate option for contaminated bone flaps that avoids the expense and time of cranioplasty.