Good luck with your condition. I was diagnosed with this in grade school. Here are some of my thoughts.
While taking time off, hot and cold treatment, and limiting the intensity of exertion alleviated my symptoms I do not feel that the cause was diagnosed. Based purely on my own observations I think that I was placing too much weight on the balls of my feet and not activating my glutes and lower back enough. Even when walking I tended to keep my weight forward. I sort of bounced along instead of pulling myself. I had the feeling at the time that it was easier to push me backward than other people. My first reactive motion forward was a gathering of myself, or a hesitation.
At the time I failed to define this action but my vertical leap was impressive so I ignored the problem and concentrated on what I could do well. I did a disservice to myself by not being in tune with my own biomechanics but it is difficult to recognize an issue that has always been incorrect.
In time I developed a capacity to tolerate the discomfort but prematurely wore my meniscus and skeletal cartilage. It should be mentioned that I had a nerve damaging natal spine surgery in addition to wear and tear issues, but I feel the cause of the Osgood problem was related to my motor recruitment and led to tightness in my posterior chain.
Squat down. Take notice of comfort, balance, heels coming off the ground, tightness in the hip and lower back, and shakiness. Does your balance noticeably improves when you have a barbell with weight on your back but you still feel like you will fall backwards if you straighten your back while keeping your shoulders opened. Regardless of how you hold the barbell doing a front squat do you feel that you never get all your force into the movement because of your balance, hips being out of alignment, and or lower back miscues.
When jumping do you use your glutes and hamstrings much or just your quads. Take notice of your landing with regards to absorbing the impact with a good knee bend and back posture. I noticed that I was landing sort of straight legged and with minimal knee bending and absorbing the landing by bending at the waist too much because my balance was off.
I also kept all my weight on my toes and jumped almost solely by quadriceps contraction. I think keeping all the weight forward might allow for quicker rebounding but it aggravates and wears the knee joint.
If these are problems that you observe then I would recommend getting your glutes, hams, and lower back conditioned to aid in jumping and squatting. It still feels awkward for me to jump and land correctly but I am trying to make it a habit as I feel that it saves my joints.
An exercise that works for me is to stand up straight about one foot from a wall, feet together, lean back and make contact with the wall. Slide down to just before 90 degrees. Maintain contact with your butt and shoulders, while trying to keep your back straight and in contact also. Now take you arms out to your sides making a T with your upper body and keep your shoulders against the wall in addition to your arms and hands. Try to retract your shoulders blades without activating your traps while maintain contact with the wall. Hold in this position for about a minute while concentrating on activating your glutes and lower back, not quads. Alternate from pushing back against the wall with your butt to pushing up more. Now slide down a couple inches against the wall and hold again. And again a few inches lower.
I think that Eric Cressey included this in his Neanderthal No More article with pictures. I use this to get my motor patterns working before jumping or bounding. Do a search for a diagram of a Psoas muscle stretch and try it. I would suggest that you read some of the many articles here addressing lack of flexibility and then concentrate on deads and good mornings, and properly executed depth jumps as your condition allows.
Enough already, good luck.