[Proximal tibial meniscal slope: a comparison with the bone slope]

Area of Science:

• Orthopedic surgery
• Biomechanics
• Radiology

Background:

• Proximal tibial slope measurements typically exclude cartilage and meniscal thickness.
• Meniscal thickness, particularly the posterior horn, can influence the perceived bony slope.
• Understanding the true articular slope is crucial for accurate knee biomechanical assessment.

Purpose of the Study:

• To measure the proximal tibial slope including cartilage and menisci.
• To compare the meniscal slope with the conventional bony slope.
• To evaluate the clinical relevance of the meniscal slope in knee biomechanics.

Main Methods:

• Nineteen cadaver knee specimens without lesions were analyzed.
• Metallic clamps marked anterior/posterior borders of medial and lateral menisci.
• Lateral plain X-rays were taken to measure bony and meniscal slopes.

Main Results:

• The meniscal slope was significantly less oblique (mean difference -6 degrees) than the bony slope.
• The medial meniscal slope showed a strong correlation with the bony slope.
• No significant correlation was found between bony and lateral meniscal slopes, or between medial and lateral meniscal slopes.

Conclusions:

• The mechanically active meniscal slope is less oblique than the bony slope.
• Medial meniscal and bony slopes are highly correlated, but medial and lateral slopes can differ significantly.
• Knee replacement design should consider the meniscal slope for accurate articular reconstruction.