PATELLA AND ITS APPLIED ANATOMY

PATELLA AND ITS APPLIED ANATOMY

• Patella is the largest sesamoid bone in the human body.

• It is situated within the tendon of quadriceps femoris in front of the knee joint.

• It plays a crucial role in knee extension and joint mechanics.

SANSKRIT REFERENCE

• In Ayurvedic texts, the bones of the body are classified under अस्थिस्थूलानि and the region of the knee is referred as जानु प्रदेश.

• The Patella may be correlated with जानुककुद् अस्थि mentioned in सुश्रुत संहिता.

सुश्रुतसंहिता शारीरस्थान ५/४७

यदस्ति जानुनो मध्ये स्थूलं च तद्विशेषतः।
जानुककुदिति ख्यातं स्थूलं तदस्त्यसंश्रयम्॥

FEATURES OF PATELLA

• Type of Bone: Sesamoid bone (develops within a tendon).

• Shape: Triangular, with apex directed downwards.

• Location: Anterior to the knee joint, embedded in the quadriceps tendon.

• Articulations: Articulates with the femoral condyles (patellar surface of femur).

• Surfaces:

  • Anterior Surface: Rough, subcutaneous, covered by fascia and skin.

  • Posterior Surface: Smooth, articulates with the femoral condyles, covered by articular cartilage.

• Borders:

  • Superior border (base): Attached to quadriceps tendon.

  • Inferior border (apex): Attached to patellar ligament.

  • Medial and lateral borders: Provide attachment to retinacula.

OSSIFICATION

• Ossification begins from a single center during the 3rd to 5th year of life.

• Complete ossification by puberty.

ATTACHMENTS

• Tendons and Ligaments:

  • Superiorly: Quadriceps femoris tendon.

  • Inferiorly: Patellar ligament (continuation of quadriceps tendon).

• Retinacula:

  • Medial and lateral patellar retinacula maintain patellar alignment and stability.

FUNCTIONS OF PATELLA

• Increases the leverage of quadriceps muscle.

• Protects the anterior aspect of the knee joint.

• Prevents friction of quadriceps tendon over the femoral condyles.

• Centralizes the pull of quadriceps femoris on the tibia.

APPLIED ANATOMY

• Patellar Fracture: Caused by direct blow or sudden contraction of quadriceps.

• Patellar Dislocation: Usually lateral dislocation; common in young females due to a wider pelvis and increased Q-angle.

• Chondromalacia Patellae: Softening and degeneration of cartilage under patella; common in athletes.

• Patellectomy: Surgical removal of patella; results in weakened knee extension.

• Jumper’s Knee: Inflammation of patellar tendon (Patellar tendinitis).

• Prepatellar Bursitis (Housemaid’s knee): Inflammation of the bursa anterior to patella due to prolonged kneeling.

CLINICAL EXAMINATION AND DEMONSTRATION

• Surface Marking: Patella is easily palpable and visible on anterior aspect of knee joint.

• Mobility Test: In extension, patella is freely movable transversely. In flexion, it becomes fixed in the intercondylar groove.

• Reflex Testing: Patellar tendon reflex (L2-L4 nerve roots) tested by tapping the patellar ligament.

MODERN CORRELATION (AS PER BD CHAURASIA'S HUMAN ANATOMY)

• Volume 2 (Lower Limb):

  • Patella is described in detail under the chapter “Knee Joint”.

  • Details include: morphology, ossification, attachments, functions, and clinical anatomy.

• Figures and Diagrams: Demonstrate patellar surface anatomy, relation with femur, and muscular attachments.

• Clinical Notes:

  • Emphasize conditions like dislocation, congenital anomalies (bipartite patella), and fractures.

  • Orthopedic surgical relevance in knee replacements and trauma cases.