Lengthening over nails using the double plate system ONAS-DPS

Area of Science:

• Orthopedic surgery
• Biomedical engineering
• Bone regeneration

Background:

• Lengthening over nails (LON) can be challenging due to limited bone stock and infection risks from Schanz screw placement.
• Direct contact between Schanz screws and intramedullary (IM) nails in standard LON increases infection spread from skin to the IM nail.

Purpose of the Study:

• To introduce a new device for bone lengthening that overcomes the limitations of traditional LON procedures.
• To reduce the risk of infection associated with Schanz screw placement in LON.

Main Methods:

• Development of the Over Nail Angle Stability-Double Plate System (ONAS-DPS).
• The ONAS-DPS utilizes two overlaying plates for Schanz screw fixation, avoiding direct bone penetration.
• Plate fixation to the bone is achieved using four angle stability screws.

Main Results:

• The ONAS-DPS eliminates the need for Schanz screws behind the IM nail.
• Schanz screws are fixed to the plates, not directly through the bone, mitigating infection transmission.
• The system provides stable fixation at a chosen angle for screw positioning through cortical bone.

Conclusions:

• The ONAS-DPS offers a safer and more stable alternative for bone lengthening over IM nails.
• This system effectively addresses the challenges of Schanz screw insertion and associated infection risks in LON procedures.