Intra-articular cysts and ganglia of the knee: a report of nine patients.

Completely intra-articular cysts and ganglia of the knee are rare. They have been found in various locations such as on the anterior or posterior cruciate ligaments, in the infrapatellar fat pad, on the posterior wall of the posteromedial compartment and (very rarely) in connection to the menisci. We analyzed nine patients with intra-articular cysts or ganglia found in a series of 2,400 consecutive arthroscopies. In four patients, the cyst or ganglion was found attached to the anterior part of the ACL, in two patients it was located between the ACL and the PCL, and in the remaining three cases it was found in connection with the meniscus. In three out of the nine patients there was either no or very minor additional pathology found in the knee besides the cyst or the ganglion. We believe that intra-articular cysts and ganglia of the knee can be symptomatic, and excellent or good results after cyst removal can be expected especially when there is little additional pathology.