Total and partial knee arthroplasty implants that maintain native load transfer in the tibia.

Area of Science:

• Biomaterials engineering
• Orthopedic biomechanics
• Surgical innovation

Background:

• Knee replacement surgeries like unicompartmental (UKA) and total knee arthroplasty (TKA) are effective for osteoarthritis.
• However, traditional solid metal implants can alter natural bone stress distribution, potentially leading to bone loss and revision complications.

Purpose of the Study:

• To investigate if titanium lattice UKA and TKA implants can preserve natural load transfer in the proximal tibia.
• To compare the mechanical environment created by lattice implants versus conventional solid implants.

Main Methods:

• Cadaveric knee specimens (n=8) underwent UKA and TKA with both conventional solid and titanium lattice tibial implants.
• Bone-implant interface stress was measured and compared to the native, pre-operative state.

Main Results:

• Titanium lattice implants effectively replicated the native tibia's mechanical environment for both UKA and TKA.
• Conventional solid implants significantly reduced bone stress (by 10x) and caused substantial underloading (>70% of bone surface).

Conclusions:

• Titanium lattice implants maintain natural tibial loading post-arthroplasty, unlike conventional solid implants.
• This represents a promising advancement for preserving bone health, though further evaluation of fatigue and micromotion is necessary for clinical application.