title: The frontal bone skull post for image guided surgery of the nasopharynx.
abstract: OBJECTIVE
  To describe the use of the mastoid skull post of a surgical image guidance system for image guided surgery and intraoperative navigation of the nasopharynx. This adaptation overcomes the limitations of a headset frame or head clamp and can be applied to open and closed surgery of the nasal cavities, sinuses, orbits, midface and anterior skull base.
  
  
  METHODS
  A sterile mastoid skull post of a surgical image guidance system was securely screwed into the outer table of the frontal bone and a passive reference frame fixed to it. The position of the reference frame relative to the patient's head remained constant during surgery.
  
  
  RESULTS
  Between August 2002 and November 2006, 22 patients underwent a surgical nasopharyngectomy using an image guidance system and frontal bone skull post. No surgical complications or complications of the frontal bone skull post occurred.
  
  
  CONCLUSIONS
  Using the skull post of a surgical image guidance system anchored to the frontal bone to carry a passive reference frame provides real-time visual information about the relationship of relevant anatomy to the surgical field on a fully mobile head in open or closed procedures of the midface and anterior skull base while accuracy and sterility are maintained.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin NT, Hong Kong SAR, China. lexvlantis@cuhk.edu.hk
authors.forename: Alexander C
authors.initials: AC
authors.lastname: Vlantis
authors.forename: H S
authors.initials: HS
authors.lastname: Chan
authors.forename: Terry
authors.initials: T
authors.lastname: Hung
authors.forename: Michael C F
authors.initials: MC
authors.lastname: Tong
authors.forename: C Andrew
authors.initials: CA
authors.lastname: Van Hasselt
mesh_terms: D003952:Diagnostic Imaging; D005624:Frontal Bone; D006801:Humans; D009303:Nasopharyngeal Neoplasms / Q000601:surgery*; D011859:Radiography; D019291:Skull Base / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D025321:Surgery, Computer-Assisted / Q000379:methods*