Bone
Patella
Sesamoid kneecap improving the quadriceps' mechanical advantage
High-yield
This is the body's largest sesamoid bone. Its posterior articular surface glides against the femur; it connects to the tibia by ligament rather than a direct patella-tibia joint.
Overview
The patella sits in the quadriceps tendon in front of the knee and connects below to the tibia through the patellar ligament. Its position holds the extensor mechanism away from the joint axis, improving leverage for knee extension.
Reference facts
- Bone type
- Sesamoid bone within the knee extensor mechanism
- Key landmarks
- Broad superior base, pointed inferior apex and posterior articular surface with medial and lateral facets
- Articulations
- Femur at the patellofemoral articulation
Clinical correlation
Patellar dislocations usually travel laterally. A separate, often superolateral fragment may instead reflect a bipartite patella, a developmental variant that is usually painless but can sometimes become symptomatic.
Frequently asked questions
What type of bone is the patella?
The patella is a sesamoid bone within the knee extensor mechanism bone.
What does the patella articulate with?
The patella articulates with the femur at the patellofemoral articulation.
What are the key landmarks of the patella?
Key landmarks of the patella include the broad superior base, pointed inferior apex and posterior articular surface with medial and lateral facets.