Patient-Specific Lattice Implants for Segmental Femoral and Tibial Reconstruction (Part 1): Defect Patterns, Fixation...

Area of Science:

• Orthopedic surgery
• Biomaterials science
• Medical device engineering

Background:

• Large segmental defects in the femur and tibia present significant reconstruction challenges.
• Computed Tomography (CT)-based, additively manufactured (AM) porous implants offer a patient-specific solution.
• Current approaches utilize lattice implants, architected cages, and modular constructs with engineered porosity.

Purpose of the Study:

• To review the application of CT-based AM porous implants for femur and tibia reconstruction.
• To analyze how defect characteristics influence fixation and mechanical performance.
• To identify current limitations and future directions for clinical translation.

Main Methods:

• Comprehensive literature review of studies employing CT-based AM porous implants for long bone reconstruction.
• Analysis of defect classification, implant design, fixation strategies, and reported outcomes.
• Evaluation of simulation (Finite Element Analysis) and mechanical testing data.

Main Results:

• Outcomes are strongly influenced by defect morphology and local biology.
• Implant stiffness, micromotion, and fatigue are controlled by lattice architecture, relative density, and fixation.
• A significant gap exists between simulation/bench testing and in vivo validation, with limited reporting of biological endpoints.

Conclusions:

• CT-based AM porous implants show potential for segmental bone defect reconstruction.
• Standardization of defect descriptors, fixation reporting, and outcome metrics is crucial.
• Bridging the validation gap through integrated datasets and harmonized protocols is essential for clinical translation.