@article{oai:repo.qst.go.jp:00081761,
 author = {Nakashima, Daisuke and Mikami, Katsuhiro and Kikuchi, Shunsuke and Nishikino, Masaharu and Kitamura, Toshiyuki and Hasegawa, Noboru and Matsumoto , Morio and Nakamura , Masaya and Nagura, Takeo and Masaharu, Nishikino and Toshiyuki, Kitamura and Noboru, Hasegawa},
 issue = {11},
 journal = {Journal of Orthopaedic Research},
 month = {Nov},
 note = {Currently, no evaluation method assesses intraoperative pedicle screw fixation (PSF) strength to determine the success of added support to a spinal fusion. Herein, we have established a laser-based resonance frequency analysis (RFA) system with high-speed, non-contact, quantitative measurements of PSF to evaluate implant fixation strength for future investigation of surgical failure risk of implants. We investigated the characteristics of the laser RFA by comparison with conventional methods.
Pedicle screw was inserted in the vertebral pedicle of dissected human cadaver or artificial bone, followed by screw pull-out, peak torque, the implant stability quotient (ISQ) value obtained by magnetic dental RFA system and fixation strength of laser RFA. We compared outcomes using best-fit linear or logarithmic approximations.
For the model bone study, the resonance frequency (RF) versus the conventional methods showed strong correlations (logarithmic: peak torque: R = 0.931, vs pull-out force (POF): R = 931, p < 0.001) and (liner: peak torque: R = 0.842, vs POF: R = 0.840, p < 0.001). RF strongly correlated with the ISQ value using linear approximation (R = 0.981, p < 0.001). For the cadaveric vertebrae study, the correlation coefficients between RF and the conventional methods were significant regardless of approximation method (peak torque: logarithmic: R = 0.716 vs linear: R = 811, p < 0.001) (POF: logarithmic: R = 0.644, vs linear: R = 548, p < 0.05).
Thus, our findings revealed a constant correlation between RFA and the conventional methods, as a measurement validation, predicting its favorable support of intraoperative PSF.},
 pages = {2474--2484},
 title = {Laser resonance frequency analysis of pedicle screw stability: a cadaveric model bone study},
 volume = {39},
 year = {2021}
}