Patellar tendon–Hoffa fat pad interface: From anatomy to high-resolution ultrasound imaging

Aim: To propose a standardized, high-resolution ultrasound (US) protocol to assess the patellar tendon–Hoffa fat pad interface (PTHFPI) in patients with (proximal) patellar tendinopathy (PPT). Methods: Using a high-frequency transducer and a high-level machine, we matched the cadaveric and histological microarchitecture of the PTHFPI with multiple sonographic patterns of patients with PPT. Likewise, high-sensitive color/power Doppler assessments were also performed to evaluate the microcirculation of the soft tissues beneath the patellar tendon. Results: Modern US equipment allows for detailed assessment of the potential pain generators located inside the PTHFPI in patients with PPT. They include anterosuperior portion of the Hoffa body and the loose connective tissue of the deep paratenon with its microvascular plexus. Conclusions: In patients with PPT, accurate sonographic assessment of the PTHFPI can be performed using adequate technological equipment. Accordingly, tailored ultrasound-guided interventions can also be planned if/when clinically indicated.