New concepts in revision total knee arthroplasty

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering

Background:

• Revision knee arthroplasty is complex and differs significantly from primary procedures.
• Accurate diagnosis of failure is crucial for successful revision surgery.
• Existing diagnostic methods may not fully capture the complexities of knee joint failure.

Purpose of the Study:

• To establish revision knee arthroplasty as a separate surgical discipline.
• To outline a systematic diagnostic approach for knee arthroplasty failure.
• To present a technical framework for revision knee arthroplasty.

Main Methods:

• Categorization of failure modes: sepsis, extensor mechanism rupture, stiffness, instability, fracture, loosening, osteolysis, patellar complications, breakage, and no diagnosis.
• Consideration of alternative diagnoses when no clear cause is found (e.g., chronic pain, referred pain).
• Description of a three-step technical pathway: tibial platform preparation, flexion gap stabilization (femoral rotation, size, patellar height), and extension gap stabilization.

Main Results:

• A structured diagnostic approach is mandatory for revision knee arthroplasty.
• Revision surgery requires specialized techniques and implant systems, not a repeat of primary procedures.
• A three-step surgical technique focusing on flexion and extension gaps is recommended.
• Stem extensions and porous metal augments offer improved fixation and bone defect management.

Conclusions:

• Revision knee arthroplasty is a distinct specialty demanding a rigorous diagnostic and technical approach.
• Complete revision is often necessary, utilizing specialized implant systems.
• The proposed technical pathway addresses the three-dimensional nature of the knee joint articulation.
• First revision knee arthroplasty may potentially surpass the durability of primary knee arthroplasty, barring specific complications.