Optimizing patellar positioning during total knee arthroplasty: an anatomical and clinical study

Area of Science:

• Orthopedic Surgery
• Biomechanical Engineering
• Anatomical Studies

Background:

• Patellar component positioning in total knee arthroplasty (TKA) is critical for surgical success.
• Current practice often relies on empirical placement of the patellar component.
• Evidence-based guidelines for optimal patellar component positioning are lacking.

Purpose of the Study:

• To anatomically quantify the optimal location for patellar component placement.
• To establish reference points for positioning the prosthetic patella relative to the native patellar cut.
• To provide data for evidence-based guidelines in TKA surgery.

Main Methods:

• Anatomical study involving intra-operative measurements of 129 TKA patellar cuts.
• Measurement of the distance between the optimal center of the prosthetic patella (OCPP) and the center of the patellar cut.
• Analysis of measurements along both the vertical (proximal-distal) and horizontal (medial-lateral) axes.

Main Results:

• Significant morphological differences in patellar cuts were observed between males and females (P < 0.0001).
• The OCPP was located superiorly and medially to the patellar cut center in 89% of cases.
• Other locations included inferiorly and medially (9.4%) and laterally and superiorly (1.6%), with no cases laterally and inferiorly.

Conclusions:

• Patellar component placement in TKA is highly variable between individuals.
• Defining the optimal center of the prosthetic patella (OCPP) on a patient-specific basis allows surgeons to replicate native patellar anatomy.
• This patient-specific approach can potentially improve functional outcomes in TKA.