A keen runner presents at your clinic with right knee pain. Keith is a 26 year old male who has been jogging for many years but who has been in specific training for the Melbourne marathon for the last 6 months. 2 weeks ago he entered a cross country 10 km event to vary his training. During the event he landed awkwardly on his right leg while going over a jump obstacle. He states that he landed and twisted inwards and now he is experiencing pain inside the knee when changing direction suddenly and he has moderate swelling around the knee.
From the presenting history what would be your primary differential diagnosis?
Select one:
a. Patella tendinopathy
b. LCL sprain
c. Infrapatella bursitis
d. All of these answers are correct
e. ACL sprain