Lateral unicompartmental replacement: a road less traveled.

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Knee Arthroplasty

Background:

• Lateral unicompartmental knee replacement (UKA) is performed significantly less often than medial UKA, with a ratio of approximately 10:1.
• Lateral UKA presents unique technical challenges compared to medial UKA, necessitating specific surgical considerations.

Purpose of the Study:

• To delineate the technical differences and critical considerations for performing lateral unicompartmental knee replacement.
• To provide guidance on optimizing surgical technique for improved outcomes in lateral UKA.

Main Methods:

• Detailed description of surgical technique modifications for lateral UKA.
• Emphasis on patellar management to prevent impingement.
• Recommendations for femoral and tibial component selection and positioning.
• Consideration of surgical approaches and tibial slope management.

Main Results:

• Lateral disease often presents with posterior wear patterns, potentially leaving residual cartilage on the distal femoral condyle.
• Specific techniques are required to address patellar impingement, including careful recessing and potential anterior undersizing of the femoral component.
• Conservative initial tibial resection and strategic component placement (femoral lateral, tibial medial) are advised for optimal congruency and stability.

Conclusions:

• Lateral UKA requires meticulous attention to specific technical details, particularly regarding patellar management and component positioning.
• Adherence to conservative resection and strategic alignment can mitigate risks and enhance functional outcomes in lateral unicompartmental knee arthroplasty.