IPP-Fat Pad Complex

Written by Dr Sheila Strover on March 14, 2025

The IPP-Fat Pad Complex is the anatomical connection of the infrapatellar plica and the fat pad. Page updated December 2023 by Dr Sheila Strover (Clinical Editor)

IPP-fat pad complex
This illustration shows how, because of its tethering at both ends, the IPP-fat pad complex is deformed during flexion and extension.

In many patients - although not all - the infrapatellar plica or ligamentum mucosum is intimately connected to the Hoffa fat pad behind the patella and both are put on stretch when the knee is extended.

Because the Hoffa fat pad is richly endowed with nerves, distortion of this structure can cause pain in the front of the knee.

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"AKP is not well correlated with location around the knee because it is physically linked to the widespread innervation of these central, pain-sensitive structures..."

Thomas Victor Smallman et al

Ligamentum mucosum, Fat pad syndrome, IPP, Fat pad, Anterior knee pain

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