title: A Novel Percutaneous Guide Wire (S-Wire) for Percutaneous Pedicle Screw Insertion: Its Development, Efficacy, and Safety.
abstract: OBJECTIVE
  Minimally invasive spine stabilization (MISt) procedures, including MIS-transforaminal lumbar interbody fusion (MIS-TLIF), rely on precise placement of percutaneous pedicle screws (PPS). Serious intraoperative complications associated with PPS placement include great vessel and bowel injuries due to the guide-wire's anterior migration and penetration through the anterior aspect of the vertebral body. To address this issue, we developed a novel percutaneous guide wire (S-wire) and compared the biomechanical characteristics of S-wire and conventional wire in cadaveric spines, and to evaluate the S-wire's efficacy and safety in a clinical trial.
  
  
  METHODS
  The S-wire is hollow, with braided wires extending at one tip. We compared the push-out and penetration forces of the S-wire and conventional wire in fresh cadaveric lumbar spines, from L1 to L5.
  
  
  RESULTS
  Push-out forces caused the braided tip of the S-wire to bend or spread, and thus to resist anterior migration. The mean push-out forces for the S-wire and conventional wire were 15.5 ± 1.9 and 5.7 ± 0.8 N, respectively (P < .0001); the mean penetration forces were 69.1 ± 4.2 and 37.1± 4.8 N, respectively (P < .0005). There was no wire breakage or anterior-wall penetration in a clinical trial of 922 S-wires; interestingly, the pull-out force increased in 780 (84.6%) S-wires after placement.
  
  
  CONCLUSIONS
  The mean push-out and penetration forces for the S-wire were approximately 3 and 2 times greater than those of conventional wire, respectively. The S-wire effectively prevented guide-wire anterior migration and penetration of the anterior vertebral-body wall. The S-wire device should effectively improve the safety of MISt procedures, including MIS-TLIF and percutaneous kyphoplasty in selected patient with osteoporosis.
authors.affiliation: Keio University, Tokyo, Japan Society for Minimally Invasive Spine Stabilization, Nagoya, Aichi, Japan keni8888@z7.keio.jp.
authors.forename: Ken
authors.initials: K
authors.lastname: Ishii
authors.affiliation: Society for Minimally Invasive Spine Stabilization, Nagoya, Aichi, Japan Kawasaki Municipal Kawasaki Hospital, Kanagawa, Japan.
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Kaneko
authors.affiliation: Society for Minimally Invasive Spine Stabilization, Nagoya, Aichi, Japan Nerima General Hospital, Tokyo, Japan Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Haruki
authors.initials: H
authors.lastname: Funao
authors.affiliation: Keio University, Tokyo, Japan Society for Minimally Invasive Spine Stabilization, Nagoya, Aichi, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Ishihara
authors.affiliation: Society for Minimally Invasive Spine Stabilization, Nagoya, Aichi, Japan Jikei University Kashiwa Hospital, Chiba, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Shinohara
authors.affiliation: Society for Minimally Invasive Spine Stabilization, Nagoya, Aichi, Japan Kawasaki Medical School, Okayama, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Nakanishi
authors.affiliation: Keio University, Tokyo, Japan Society for Minimally Invasive Spine Stabilization, Nagoya, Aichi, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Hikata
authors.affiliation: Keio University, Tokyo, Japan Society for Minimally Invasive Spine Stabilization, Nagoya, Aichi, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Fujita
authors.affiliation: Keio University, Tokyo, Japan Society for Minimally Invasive Spine Stabilization, Nagoya, Aichi, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Iwanami
authors.affiliation: Keio University, Tokyo, Japan Society for Minimally Invasive Spine Stabilization, Nagoya, Aichi, Japan.
authors.forename: Naobumi
authors.initials: N
authors.lastname: Hosogane
authors.affiliation: Keio University, Tokyo, Japan.
authors.forename: Kota
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Keio University, Tokyo, Japan.
authors.forename: Takeo
authors.initials: T
authors.lastname: Nagura
authors.affiliation: Keio University, Tokyo, Japan.
authors.forename: Masaya
authors.initials: M
authors.lastname: Nakamura
authors.affiliation: Keio University, Tokyo, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Toyama
authors.affiliation: Keio University, Tokyo, Japan.
authors.forename: Morio
authors.initials: M
authors.lastname: Matsumoto
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001864:Bone Wires / Q000009:adverse effects / Q000706:statistics & numerical data; D004867:Equipment Design; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D019637:Orthopedic Procedures / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D065289:Pedicle Screws
keywords: Image-guided surgery; neurosurgery; spine surgery