title: Patient-specific instrument can achieve same accuracy with less resection time than navigation assistance in periacetabular pelvic tumor surgery: a cadaveric study.
abstract: OBJECTIVE
  Inaccurate resection in pelvic tumors can result in compromised margins with increase local recurrence. Navigation-assisted and patient-specific instrument (PSI) techniques have recently been reported in assisting pelvic tumor surgery with the tendency of improving surgical accuracy. We examined and compared the accuracy of transferring a virtual pelvic resection plan to actual surgery using navigation-assisted or PSI technique in a cadaver study.
  
  
  METHODS
  We performed CT scan in twelve cadaveric bodies including whole pelvic bones. Either supraacetabular or partial acetabular resection was virtually planned in a hemipelvis using engineering software. The virtual resection plan was transferred to a CT-based navigation system or was used for design and fabrication of PSI. Pelvic resections were performed using navigation assistance in six cadavers and PSI in another six. Post-resection images were co-registered with preoperative planning for comparative analysis of resection accuracy in the two techniques.
  
  
  RESULTS
  The mean average deviation error from the planned resection was no different ([Formula: see text]) for the navigation and the PSI groups: 1.9 versus 1.4 mm, respectively. The mean time required for the bone resection was greater ([Formula: see text]) for the navigation group than for the PSI group: 16.2 versus 1.1 min, respectively.
  
  
  CONCLUSIONS
  In simulated periacetabular pelvic tumor resections, PSI technique enabled surgeons to reproduce the virtual surgical plan with similar accuracy but with less bone resection time when compared with navigation assistance. Further studies are required to investigate the clinical benefits of PSI technique in pelvic tumor surgery.
authors.affiliation: Department of Orthopaedics and Traumatology, Prince of Wales Hospital, Shatin, Hong Kong. skcwong3@gmail.com.
authors.forename: Kwok-Chuen
authors.initials: KC
authors.lastname: Wong
authors.affiliation: Technology Applications in Biomed Unit, Industrial Centre, The Hong Kong Polytechnic University, Hung Hom, Hong Kong. louis.sze@polyu.edu.hk.
authors.forename: Kwan-Yik
authors.initials: KY
authors.lastname: Sze
authors.affiliation: Division of Health Economics, Policy and Management, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China. iolwong@hku.hk.
authors.forename: Irene Oi-Ling
authors.initials: IO
authors.lastname: Wong
authors.affiliation: Head of Rapid Prototyping and Tooling Unit, Industrial Centre, The Hong Kong Polytechnic University, Hung Hom, Hong Kong. icmwong@polyu.edu.hk.
authors.forename: Chung-Ming
authors.initials: CM
authors.lastname: Wong
authors.affiliation: Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong. kumta@cuhk.edu.hk.
authors.forename: Shekhar-Madhukar
authors.initials: SM
authors.lastname: Kumta
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging / Q000601:surgery*; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D002102:Cadaver; D006801:Humans; D019637:Orthopedic Procedures / Q000379:methods*; D010384:Pelvic Bones / Q000000981:diagnostic imaging / Q000601:surgery*; D015203:Reproducibility of Results; D025321:Surgery, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed
keywords: Navigation assistance; Patient-specific instruments; Periacetabular pelvic tumors; Surgical accuracy