3D-Printed Orthopedic Cast Enables Minimally Invasive Distal Radius Osteotomy

Overview

This cadaveric study demonstrates a novel 3D-printed cast system that facilitates minimally invasive corrective osteotomy of distal radius malunions. The system allows percutaneous pinning through the cast and accurate placement of an external cutting guide, minimizing soft tissue dissection and improving surgical precision.

Background

Distal radius malunion often requires corrective osteotomy to restore bone alignment. Traditional patient-specific instruments (PSIs) require extensive soft tissue dissection for accurate placement, which can delay recovery and worsen outcomes. Minimally invasive approaches using external cutting guides mounted on percutaneous pins may reduce soft tissue damage. This study proposes a 3D-printed cast that enables reproducible arm positioning, percutaneous pin insertion, and guided osteotomy with minimal invasiveness.

Data Highlights

The study included five fresh-frozen cadaver arms scanned in a reproducible Closed-Pack Position (CPP) with wrist in maximal ulnar deviation and fingers/elbow flexed at approximately 45°. The cast and external cutting guide were designed from CT images and 3D printed. The workflow involved arm insertion into the cast, percutaneous pinning through integrated drilling pillars, cast removal, and placement of the cutting guide over the pins for osteotomy. Image analysis and 3D printing required approximately 24 hours.

Key Findings

• The 3D-printed cast allowed reproducible positioning of the radius in the CPP, critical for accurate surgical navigation.
• Percutaneous pinning through the cast drilling pillars was feasible, enabling minimally invasive fixation without large incisions.
• The external cutting guide slid over the pins after cast removal, guiding the osteotomy saw precisely along the planned cutting plane.
• The system minimized the need for extensive soft tissue dissection compared to traditional PSIs, potentially improving recovery and functional outcomes.
• Accuracy and precision of virtual pin placement and osteotomy transfer were evaluated, supporting the method's reliability.

Clinical Implications

This 3D-printed cast system offers a practical minimally invasive approach for corrective osteotomy of distal radius malunions, reducing soft tissue trauma and potentially enhancing postoperative recovery. Surgeons can achieve accurate osteotomy guidance through percutaneous pins without large incisions, facilitating the use of patient-specific implants. Adoption of this technique may improve surgical precision and patient outcomes in distal radius corrective procedures.

Conclusion

The proposed 3D-printed cast and external cutting guide system enables accurate, minimally invasive distal radius osteotomy with reproducible arm positioning and percutaneous pinning. This approach may represent a valuable advancement in corrective osteotomy techniques by reducing soft tissue disruption while maintaining surgical accuracy.

References

1. Distal radius malunion and corrective osteotomy context
2. Use of 3D pre-operative planning and patient-specific instruments
3. Minimally invasive navigation and percutaneous pinning techniques
4. Closed-Pack Position for reproducible forearm positioning