title: Computer-designed PEEK implants: a peek into the future of cranioplasty?
abstract: BACKGROUND
  Polyetheretherketone (PEEK) is a synthetic material that was used initially in spine and hip surgery. It has the properties of being biocompatible, resistant to thermal and ionizing radiation, and resembles cortical bone biomechanically. These favorable characteristics have led to the increasing use of PEEK implants for calvarial defects which remain a significant reconstructive challenge.
  
  
  METHODS
  This study is a retrospective review of patients who underwent PEEK cranioplasty by a single surgeon. PEEK implants were fashioned from high-resolution CT scans of each patient and sterilized preoperatively before cranioplasty was performed using standard techniques. The mean follow-up period was 7 months (range 1-22).
  
  
  RESULTS
  Twelve consecutive patients (75% males; mean age = 43, range 16-67) underwent PEEK cranioplasty between January 2011 and December 2012 after a mean time interval of 10 months (range 3-40) following initial craniectomy. The mean defect size was 11 × 8 cm (range 7 × 6 to 14 × 8 cm) and no additional contouring of PEEK implants was necessary intraoperatively. The scalp was closed primarily in all patients, and no complications of implant breakdown, wound infection, or cerebrospinal fluid leak were appreciated during follow-up.
  
  
  CONCLUSIONS
  Computer-designed, patient-specific PEEK implants for cranioplasties are a viable alternative when autologous bone grafts are unavailable or unsuitable. Such prefabrication reduces operative times through minimal to no intraoperative adjustments. Although initial results are promising, longer-term follow-up and further comparative studies including randomized control trials to evaluate outcomes between different alloplastic materials for cranioplasty are necessary.
authors.affiliation: From the *Department of Neurosurgery, Singapore General Hospital, Singapore; and †Division of Neurosurgery, Changi General Hospital, Singapore, Singapore.
authors.forename: Zhi Yang
authors.initials: ZY
authors.lastname: Ng
authors.forename: Irfan
authors.initials: I
authors.lastname: Nawaz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001577:Benzophenones; D001672:Biocompatible Materials / Q000627:therapeutic use*; D017076:Computer-Aided Design; D005260:Female; D006801:Humans; D007659:Ketones / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011092:Polyethylene Glycols / Q000627:therapeutic use*; D011108:Polymers; D019736:Prostheses and Implants; D011474:Prosthesis Design / Q000379:methods*; D019651:Plastic Surgery Procedures / Q000379:methods*; D012189:Retrospective Studies; D012886:Skull / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D001577:Benzophenones; D001672:Biocompatible Materials; D007659:Ketones; D011108:Polymers; C063834:polyetheretherketone; D011092:Polyethylene Glycols