Learning objectives
1) Review key anatomy of the neurovascular structures at the knee joint.
2) Describe the radiological findings of unusual compressive lesions that involve the neurovascular structures of the knee.
Background
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...
Imaging findings OR Procedure Details
Relevant Anatomy:
Common peroneal nerve anatomy
The common peroneal nerve (CPN) is the lateral division of the sciatic nerve tracking from the posterolateral side of the knee around the fibular head down towards the anterolateral side of the lower leg Fig. 1 .
On MRI the course of the peroneal nerve and important landmarks are best appreciated on the axial T1W imaging Fig. 2 .
They appear as bundles of fascicles surrounded within a thin sheath.
Once the CPN has branched off the sciatic nerve,...
Conclusion
Compressive lesions affecting the neurovascular structures around the knee are more common than one may predict.
In this pictorial review we have reviewed key neurovascular anatomy and have highlighted a few of the more uncommon presentations of these lesions around the knee.
Descriptions of their specific involvement on the adjacent neurovascular structures have also been discussed.
The specific anatomic location of these compressive lesions often permits prompt diagnosis,
thus avoiding the need for additional imaging.
References
1.Van den Bergh FR,
Vanhoenacker FM,
De Smet E,
Huysse W,
Verstraete KL.
Peroneal nerve: Normal anatomy and pathologic findings on routine MRI of the knee.Insights Imaging.
2013;4(3):287–299.
doi:10.1007/s13244-013-0255-7
2.Botchu R,
Shah A,
Jakanani G,
Esler CN,
Rennie WJ.
Parameniscal Cyst - A Rare Cause of Popliteal Artery Compression: Treatment with Ultrasound-guided Decompression.West Indian Med J.
2015;64(2):172–173.
doi:10.7727/wimj.2013.218
3.Garwood ER,
Duarte A,
Bencardino JT.
MR imaging of entrapment neuropathies of the lower extremity.
Radiol Clin North Am.
2018;56(6):997-1012.
doi: S0033-8389(18)30078-2 [pii].
4.Perdikakis E,
Skiadas V....