Knees are only meant to bend forward and backward. If a knee pops and locks up with major pain, something serious is going on there, and it's most likely an ACL injury.
The injuries often need surgery to reconstruct the ligament, followed by therapy to help rehabilitate the knee.
It does not lower pain, protect from reinjuring the knee or improve the stability of the knee. Rather, braces add an unnecessary expense to the recovery.
Vitamins and other supplements also don't help in the healing process.
Beginning physical therapy shortly after surgery, ideally within a few days after, can bring great outcomes for patients.