A 14-year-old girl with an unremarkable medical history presented to the family medicine clinic with a 6-month history of right knee pain (episodic locking and anterior pain). Physical examination of the knee ligaments revealed that the knee was stable and pain-free in the frontal and sagittal planes. There was no intra-articular effusion, the joint spaces were not painful, and range of motion was normal.
Palpation of the knee elicited pain, notably when the physician rolled his fingers over a “cord” above the internal parapatellar compartment. X-rays of the knee were normal. In light of the patient’s chronic pain, magnetic resonance imaging (MRI) was performed (FIGURE 1).