biostudies-literatureLee SMinistry of Trade, Industry and EnergyMinistry of Science, ICT and Future Planning769-780https://www.ebi.ac.uk/biostudies/studies/S-EPMC6037596biostudies-literatureUnknown59(6)<h4>Purpose</h4>The intraoperative version of the femoral component is usually determined by visual appraisal of the stem position relative to the distal femoral condylar axis. However, several studies have suggested that a surgeon's visual assessment of the stem position has a high probability of misinterpretation. We developed a computed tomography (CT)-based navigation system with a patient-specific instrument (PSI) capable of three-dimensional (3D) printing and investigated its accuracy and consistency in comparison to the conventional technique of visual assessment of the stem position.<h4>Materials and methods</h4>A CT scan of a femur sawbone model was performed, and pre-experimental planning was completed. We conducted 30 femoral neck osteotomies using the conventional technique andYonsei medical journalCT-based Navigation System Using a Patient-Specific Instrument for Femoral Component Positioning: An Experimental in vitro Study with a Sawbone Model.PMC6037596R-20170419-00154810052980Lee SBaek SHKim SYKim JYHong JfalseCT-based Navigation System Using a Patient-Specific Instrument for Femoral Component Positioning: An Experimental in vitro Study with a Sawbone Model.<h4>Purpose</h4>The intraoperative version of the femoral component is usually determined by visual appraisal of the stem position relative to the distal femoral condylar axis. However, several studies have suggested that a surgeon's visual assessment of the stem position has a high probability of misinterpretation. We developed a computed tomography (CT)-based navigation system with a patient-specific instrument (PSI) capable of three-dimensional (3D) printing and investigated its accuracy and consistency in comparison to the conventional technique of visual assessment of the stem position.<h4>Materials and methods</h4>A CT scan of a femur sawbone model was performed, and pre-experimental planning was completed. We conducted 30 femoral neck osteotomies using the conventional technique and2018-01-01T00:00:00Z2018 Aug2025-04-21T19:28:31.275Z2019-03-26T23:48:56ZS-EPMC60375962997861410.3349/ymj.2018.59.6.769