Lower limb

Infrapatellar fat pad (Hoffa's fat pad)

Corpus adiposum infrapatellare

Origin

Lies in the anterior compartment of the knee, directly below the patella and behind the patellar ligament

Insertion

Extends to the tibial tuberosity and the margins of the synovial membranes of the knee

Function

No muscular function: the fat pad fills the space between the patellar ligament and the joint capsule, cushions impact and reduces friction during knee movement

Innervation

Sensory innervation by branches of the femoral and tibial nerves; no motor innervation as it is not muscle tissue

Movement & chain

Deforms dynamically during knee flexion and extension to cushion and reduce friction between patellar tendon and anterior tibia.

Palpation

Directly palpable on either side of the patellar tendon in the anterior joint line; feels like a soft, resilient cushion.

Clinical

Hoffa's disease (Hoffitis): inflammation, hypertrophy, and impingement of the infrapatellar fat pad between femur and patella during knee hyperextension.

Segmental innervation

L3–L4 (femoral / saphenous nerve)

In clinical practice

Used as an anatomical landmark during arthroscopic access to the anterior knee, since it lies just below the patellar ligament.

Region in the model

Lower limb