Coronal alignment parameters of the knee predict osteoarthritis development : a Coronal Plane Alignment of the Knee...

Area of Science:

• Orthopedics
• Radiology
• Biomechanical Engineering

Background:

• Mechanical alignment is crucial in knee osteoarthritis (KOA) development.
• The Coronal Plane Alignment of the Knee (CPAK) classification's role in KOA pathogenesis requires further investigation.

Purpose of the Study:

• To investigate the association between CPAK classification parameters and KOA development.
• To determine if specific CPAK types or parameter deviations increase KOA risk.

Main Methods:

• Analysis of 2,541 knees from the Multicenter Osteoarthritis Study (MOST) over five years.
• Comparison of baseline CPAK types and parameters between knees that developed KOA (Kellgren-Lawrence grade ≥2) and those that did not.
• Assessment of the association of CPAK type, arithmetic hip-knee-ankle angle (aHKA), and joint line obliquity (JLO) with KOA risk and joint line convergence angle (JLCA) changes.

Main Results:

• Knees developing KOA showed significantly lower JLO and aHKA values.
• JLO was significantly associated with KOA development (OR 1.048), with values under 171.6° increasing risk by 1.36 times.
• aHKA negatively correlated with JLCA change (β -0.139), but CPAK type showed no significant KOA association.

Conclusions:

• CPAK parameters, particularly JLO and aHKA, are significantly associated with KOA development, more so than CPAK types.
• Significant joint line obliquity may be as critical as lower limb alignment in KOA.
• CPAK classification, with adjusted cut-offs, could aid in predicting KOA development and understanding alignment's role in KOA pathophysiology.