Here's my .02 cents on this topic as I just went through this.
Over the last several years I have ridden with different types of "knee guards / shin guards". All of which have done the job and one of the days I chose not to where them, I ended up with some damage to my shin. Small puncture and small fracture....NOT fun!
Anyways, fast forward a tick from that incident and I end up blowing my knee out out on the side of the mountain riding, with "knee guards" on. After a surgery, rehab and having to take a season off, I was like that sucked!!! After getting back on the machine I had that injury on my mind and it bugged me to say the least. I did NOT want to go through that again and after researching what would be the best option to providing protection to my knee, shin AND provide stability to the knee, I ended up with POD knee braces.
I ended up going through my doctor and ultimately getting a prescription for the affected knee. I worked with the clinic and we went back and forth on what to try but ultimately I ended up going with the POD Knee Brace. What's nice is that the POD is a "medical certified device" and my insurance will end up covering at least 80% of the cost of the one.
I just got setup with these and I have no real time feedback yet but I can say they are comfortable, lightweight and will provide plenty of protection to the knee cap, shin while also providing stability to the joint thus avoiding another catastrophic failure of the joint.
There is a ton of information out there on knee braces and I would highly suggest doing some research on these type of braces. "IF" I would have had a set of these on, I could have avoided a damaged knee, surgery, rehab and time off from the sport!!! It's not always fun to spend money on the "what if" equipment but again, it could have saved me a huge headache!!!
Here's what I'm running,
https://podactive.com/product/k8-forged-carbon-knee-brace/
These also can be used without the knee cap guard and can be used for summer sports like motocross and even water skiing.
Good luck!!