Isolated ganglions of the anterior cruciate ligament.

We report three athletes with symptomatic isolated ganglion of the anterior cruciate ligament. The symptoms consisted of anteromedial knee pain, worse when changing direction while running, and on squatting. All gave a history of repeated minor knee trauma without a single episode of serious injury. At day-case arthroscopy, a unilobulated cystic mass arising from a clinically and arthroscopically intact anterior cruciate ligament was noted and removed in each case. No further intra- or extra-articular knee lesion was seen. Histology revealed a cystic ganglion in each case. With early physiotherapy, the patients could start gentle training 3 wk after arthroscopy, and, at 6-month review, were fully asymptomatic. A review of the literature shows that an isolated ganglion arising from the anterior cruciate ligament is exceedingly rare, with only three such ganglia having been previously reported.