Oooops! I should have noticed that the above space wasn't for questions but continuing a conversation. Sorry about that.
I have had tendonitis in my knee for slightly more than a month during the summer and had gone for physical therapy in August & part of September. My physical therapists got the swelling in my knee down enough to be not seen or felt with sonagrams and stretching excersizes. Now I'm "recovering" but it does't feel like it. I feel pain radiating down the side of my right leg when I'm sitting and sometimes when I'm walking. Does this mean the tendonitis is coming back? Will my knee swell again?
It might be some muscle flexors pain. Lateral side of your thigh you have some muscles like iliacus, Psoas major, Psoas minor which help in flexion if you have some injury or damage to some fibres then you might have this, Orthopaedician is the best person and muscle damage is difficult to find out in X-Ray. Take some anti inflammatory drugs to relieve the pain. Take care!