Symptomatic ganglion cyst in a patient with knee pain.

The patient was a 39-year-old man who was referred to a physical therapist by his primary care physician for a chief complaint of left posterior knee pain. Radiographs of the left knee, which had been previously ordered by the patient's primary care physician, were interpreted as normal. Given the patient's worsening symptoms, no history of trauma or injury, and lack of improvement with prior conservative measures, the patient was referred to an orthopaedic surgeon. Magnetic resonance imaging of the left knee was ordered, which revealed a septated ganglion cyst within the femoral notch that caused moderate displacement of the cruciate ligaments.