Normative data of frontal plane patellar alignment in athletes

Area of Science:

• Biomechanics
• Sports Medicine
• Orthopedics

Background:

• Patellar alignment is crucial for knee function and injury prevention.
• Assessing patellar alignment in athletes is important for understanding sport-specific biomechanics.
• Existing methods for measuring patellar alignment require reliable normative data.

Purpose of the Study:

• To provide normative data for frontal plane patellar alignment using McConnell and Arno angles.
• To verify the association between McConnell and Arno angles.
• To identify patellar rotation differences across various sports.

Main Methods:

• A cross-sectional study involving 230 athletes (460 knees) from volleyball, basketball, gymnastics, and soccer.
• Frontal plane patellar alignment measured via photogrammetry in a standing position.
• Intra and inter-examiner reliability assessed in a preliminary study.

Main Results:

• High reliability (0.85–0.98) for patellar alignment measures.
• Mean McConnell angle: 2.05° (±5.9°); Mean Arno angle: 2.89° (±7.57°).
• Low association (r=0.189) between McConnell and Arno angles; significant sport-specific differences in rotation (p<0.014).

Conclusions:

• The photogrammetric method for measuring McConnell and Arno angles is highly reliable.
• Normative data for patellar alignment in healthy athletes were successfully established.
• Sport-specific differences in patellar rotation exist, highlighting the need for tailored assessments.