How Patient-Specific Guides Can Ease the Learning Curve of Cortical Bone Trajectory: A Retrospective Study

Area of Science:

• Spine surgery
• Orthopedic surgery
• Surgical instrumentation

Background:

• Lumbar fusion procedures utilize various screw fixation techniques.
• Cortical bone trajectory (CBT) offers an alternative fixation method.
• Patient-specific instrumentation (PSI) aims to improve surgical accuracy and efficiency.

Purpose of the Study:

• Compare operative time, blood loss, length of stay, and complications between CBT lumbar fusions using PSI versus freehand.
• Evaluate the learning curve and economic impact of PSI in CBT fusions.

Main Methods:

• Retrospective review of 247 CBT lumbar fusions performed by a single surgeon (2018-2025).
• Comparison between freehand and CT-guided PSI-assisted approaches.
• Propensity matching for patient demographics and fusion levels.

Main Results:

• PSI use correlated with a 33-minute reduction in operative time (P=0.003) and 75 mL lower EBL (P=0.026).
• Significant decrease in infection and reoperation rates for two-stage procedures (35.7% to 7.5%, P<0.001).
• Overall efficiency per fused level improved by 18%-25% (P=0.02).

Conclusions:

• PSI in CBT lumbar fusion is safe and effective, reducing operative time and blood loss.
• PSI facilitates increased surgical volume and consistency, potentially smoothing the learning curve.
• Improved operating room efficiency with PSI may lead to practical cost savings.