Subcutaneous infrapatellar bursa

The subcutaneous infrapatellar bursa is a superficial bursa located anterior to the patellar tendon and beneath the skin. It is one of the two infrapatellar bursae, the other being the deep infrapatellar bursa. The subcutaneous infrapatellar bursa functions to reduce friction between the skin and the patellar tendon, particularly during activities that involve kneeling.

Anatomically, the subcutaneous infrapatellar bursa is situated just below the patella and above the tibial tubercle, lying superficial to the patellar tendon. It is typically smaller and less frequently visualized compared to the deep infrapatellar bursa. The dimensions of the subcutaneous infrapatellar bursa, as observed in cadaveric studies, are approximately 19.5 mm in craniocaudal length, 21.2 mm in mediolateral width, and 2.2 mm in anteroposterior depth.[1]

The subcutaneous infrapatellar bursa may have a thin septum separating its compartments, which was observed in 80% of cases in cadaveric studies.[1] This bursa is prone to inflammation, known as bursitis, often due to chronic microtrauma from activities such as frequent kneeling.[2]

Note: the difference between the subcutaneous infrapatellar bursa and the subcutaneous bursa of tuberosity of tibia remains unclear, as some studies show that subcutaneous infrapatellar bursa extends quite distally, in front of the anterior tibial tuberosity. [2]