56M p/w R knee pain and swelling x4 days after prolonged kneeling
- What structure corresponds to label A?
- Patellar tendon (patellar ligament) since it attaches from the patella to the tibial tuberosity. The quadriceps tendon would be a continuation of the quadriceps muscle and attaches to the superior aspect of the patella which we do not see in these images.
- Which bursa corresponds to label B and is it abnormal?
- Superficial infrapatellar bursa. Note the small anechoic collection here indicating bursitis. `
- Which bursa corresponds to label C and is it abnormal?
- Deep infrapatellar bursa. Note the larger anechoic collection here indicating effusion/bursitis.
- If an infectious etiology is not clinically suspected, what is the diagnosis and how is it treated?
- Infrapatellar bursitis (also known as Clergyman’s knee) with effusion. This is very similar to prepatellar bursitis (Housemaid’s or Carpenter’s knee) which would be inflammation of the bursa just superficial to the patella. It is important to first distinguish from septic bursitis/arthritis. If no infectious component, management is supportive typically with NSAIDs, rest, compression bandages, elevation, and warm compresses. Fluid aspiration is sometimes performed for symptomatic relief however is controversial due to increased risk of infectious complications.