Popliteal swelling is a common complaint seen in the
practice of orthopaedics. Although imaging is useful to aid in
the diagnosis of popliteal swelling pre-operatively, definitive
diagnosis is often obtained post-operatively through
histopathological report of the swelling. Baker’s cyst arises
medially and hence usually spares the posterolaterally
located neurovascular bundle until it becomes larger in size.
A thrombosed aneurysm can mimic that of Baker’s cyst on
computed tomography (CT) imaging in view of its location
and the absence of contrast within the lesion. Diagnosis of a
popliteal swelling with neural or vascular compression is not
as straightforward and surgeons should be well aware that
intra-operative findings may differ from diagnosis made preoperatively. Meticulous exploration is pertinent in
identifying the origin of the swelling and structures related to
it. MRI imaging of the swelling should be done preoperatively whenever possible.