Anatomic alignment of the patellar groove

Area of Science:

• Orthopedic surgery
• Biomechanical analysis
• Anatomical variation

Background:

• The patellar groove's alignment is crucial for knee function.
• Previous studies have not fully characterized the variability of the natural patellar groove.
• Understanding this variability is important for improving total knee arthroplasty outcomes.

Purpose of the Study:

• To quantify the variability in the orientation of the natural patellar groove relative to key femoral anatomical axes.
• To assess the reliability of common femoral axes as references for patellar groove positioning.
• To investigate the potential link between patellar groove variability and total knee arthroplasty complications.

Main Methods:

• Utilized 15 cadaveric femurs for anatomical assessment.
• Acquired multi-planar radiographs (coronal, sagittal, transverse).
• Employed electronic digitization to create 3D representations and measure groove orientation relative to distal, mechanical, transepicondylar, and transcondylar axes.

Main Results:

• Demonstrated profound variability in patellar groove orientation in coronal and transverse planes (11-16 degrees range).
• The transepicondylar axis showed the closest average alignment in the coronal plane, but with extensive individual variation.
• No tested anatomical axis reliably predicted the natural patellar groove's position.

Conclusions:

• The natural patellar groove exhibits significantly greater anatomical variability than previously recognized.
• Current femoral component designs may not adequately account for this variability.
• Failure to accommodate patellar groove variability could be a key factor in patellar component complications during total knee arthroplasty.