slideshow: patella
TRANSCRIPT
The Patella
The Patella is the largest sesamoid bone in the
body
PatellaPatella
A sesamoid bone is a bone that is
embedded in the tendon of a muscle
Anterior view, right knee
PatellaPatella
The Patella lies in the tendon of the
Quadriceps muscle
QuadricepQuadricepss
Patellar Patellar TendonTendon
Anterior view, right knee
The Patella has a wide upper border
Wide upper Wide upper borderborder The lower border is pointed
and is called the Patellar Apex
Patellar ApexPatellar Apex
The Patella has a wide upper border
The ventral surface is convex and ridged
Ventral Ventral surfacesurface
The posterior surface has articular facets that articulate
with the Distal Femur
The Posterior Surface
The Posterior Surface
The upper 2/3rds is smoothand covered in hyaline cartilage
The Posterior Surface
The upper 2/3rds is smoothand covered in hyaline cartilage
It engages with theMedial and Lateral Femoral Condyles
Patella
Quadriceps Muscle
Patellar TendonThe patella engages with the
Medial and Lateral Femoral Condyles
The Posterior Surface
There is a prominent vertical ridge that
divides the posterior articular
surface into medial and lateral facets
The Posterior Surface
The Lateral Facet is larger and gently concave
The Posterior Surface
The Lateral Facet is larger and gently concave Medial Facet
The Posterior Surface
The inferior aspect of the posterior surface is
roughened due, partly, to the attachment of the
patellar tendon
Medial Facet
Patellar Stability
upwards and upwards and outwardsoutwards
The Patella is embedded in the Tendon of the
Quadriceps
upwards and upwards and outwardsoutwards
On contraction, the Quadriceps pulls the Patella upwards and outwards
upwards and upwards and outwardsoutwards
This is counteracted by the action of Vastus Medialis which pulls the Patella inwards
On contraction, the Quadriceps pulls the Patella upwards and outwards
The Patella is embedded in the Tendon of the
Quadriceps
The Lateral Femoral Condyle projects further forward than the Medial Femoral
Condyle and this provides a bony obstacle to lateral movement of the Patella
Lateral Femoral Lateral Femoral CondyleCondyle