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Updated: Mar 12, 2026
Pedicle Screw Placement Using an Augmented Reality Head-Mounted Display in a Porcine Model
Published on: May 24, 2024
Are Patient-Specific 3-Dimensionally Printed Instrumentations a Viable Solution to Safe Cortical Bone Trajectory
Mark Ehioghae1, Jonathan P Japa1, Kevin Yoon1
1Department of Orthopedics, MedStar Washington Hospital Center, Washington, DC, USA.
Background:
Cortical bone trajectory (CBT) screw fixation has emerged as a promising alternative to traditional pedicle screw techniques, particularly for patients with compromised bone quality. The higher technical demands of CBT have driven interest in patient-specific instrumentation (PSI) to improve screw placement accuracy and safety. Despite rapid clinical adoption, the evidence supporting PSI in CBT remains limited. This study aimed to assess the safety and effectiveness of PSI with CBT screws.
Methods:
A systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed and Embase were searched for articles published before July 2025 evaluating PSI or custom 3D-printed guides for CBT screws. Eligible studies included cadaveric and clinical designs reporting on accuracy, safety, or clinical outcomes. Risk of bias was assessed using validated tools. Data were synthesized narratively and summarized descriptively.
Results:
Eighteen studies, 7 cadaveric and 11 clinical, met our inclusion criteria. Clinical studies included 620 patients and more than 2800 screws. Across study types, PSI-guided CBT screw placement demonstrated high accuracy, with screw containment rates generally above 90% and breach rates below 4%. Comparative studies showed PSI significantly lowered breach rates compared with freehand techniques. Clinical studies reported low complication and revision rates, with favorable outcomes for pain, neurological status, and fusion. PSI was especially beneficial in complex anatomy and for novice surgeons by reducing operative time and radiation exposure.
Conclusions:
This review has limitations. Most studies were small, single-center, or case reports with heterogeneous patient populations and limited samples, reducing generalizability and increasing bias. PSI and 3D-printed guides for CBT screw fixation consistently improve placement accuracy and safety. PSI may help democratize access to technically demanding CBT fixation and standardize outcomes.
Clinical Relevance:
PSI may offer decreased operative time and reduce radiation exposure LEVEL OF EVIDENCE: 3.
