3D-Printed Guides in Bone Tumor Resection: Studying Their Error and Determining a Safety Margin for Surgery

Area of Science:

• Orthopedic Oncology
• Biomedical Engineering
• Surgical Accuracy

Background:

• 3D-printed guides are emerging in orthopedic oncology for improved bone resection accuracy.
• Inaccuracies in current 3D-printed guides can lead to critical errors like positive tumor margins.
• Quantifying the margin of error is crucial for enhancing the safety and efficacy of these guides.

Purpose of the Study:

• To quantitatively investigate the margin of error associated with various 3D-printed jig types.
• To determine a "safety margin" for 3D-printed jig design to minimize positive tumor margins.
• To provide guidance for surgeons and jig engineers in developing safer 3D-printed cutting guides.

Main Methods:

• Simulated wide resection of distal femoral bone sarcoma on Sawbone specimens using various 3D-printed jigs.
• Ten participants with no prior expertise in cutting guides performed the resections.
• A mathematical model based on kinematic theory was developed to define a safety margin for 98% likelihood of avoiding positive margins.

Main Results:

• The mean deviation in placing cutting guides ranged from 2.86 mm to 6.54 mm across four jig types.
• A safety margin of 4.8 mm is recommended for standard guides.
• A safety margin of 8.65 mm is recommended for gusset guides to account for human error in placement.

Conclusions:

• Established safety margins are essential for 3D-printed jig design to mitigate risks associated with human error in guide placement.
• The findings provide critical data for optimizing 3D-printed jig engineering in orthopedic oncology.
• Further research involving cadavers and patients is warranted to validate these findings in clinical settings.