|ESSR 2019 / P-0069|
|Unusual neurovascular compressive lesions around the knee: A pictorial review of key anatomy and imaging findings|
Cystic, cystic-like and solids lesion are often encountered around the knee and can be a diagnostic dilemma if one is not familiar with the radiological findings. These lesions comprise of a diverse group of entities ranging from simple benign processes to more complex diseases. Due to the relative close compartment of the knee, neurovascular structures are prone to compression. It is therefore important for the radiologist to be familiar with the characteristic MR and ultrasound features with particular regard to the involvement of the neurovascular structures. This pictorial review highlights the key neurovascular anatomy at the knee joint and describes unusual presentations of compressive lesions around the knee with its associated involvement of the neurovascular structures. The specific anatomic location of these compressive lesions often permits the correct diagnosis, thus avoiding the need for additional imaging.
Neurovascular anatomy at the knee joint and its compartments:
Neurovascular compressive lesions are relatively uncommon but can often be visualised on routine MRI sequences. The peroneal nerve, popliteal artery and popliteal vein, including their branches have a specific course at the knee joint despite variant anatomy. We initially focus on the relevant anatomy of the peroneal nerve and popliteal vessels and describe some of the pathological mechanisms they can get compressed by.
Most of the lesions in the knee are benign and are often related to tendon/ligament ganglia, bursal fluid distension or synovial herniation from the joint. MRI and ultrasound are the most useful imaging modalities in evaluating these lesions around the knee. MRI is favourable in delineating the specific anatomic location of lesions in addition to determining if the lesion is purely cystic, cyst-like or solid. The normal anatomic bursae are cystic spaces containing synovial fluid. The bursae characteristically do not connect to the joint space thus distinguishing them from synovial cysts and normal joint recesses.
Thematically related posters
ESSR 2019 / P-0115
Migratory loose bodies from the ankle joint to the flexor hallucis longus tendon sheath – Imaging features