Tuberculosis (TB) of the knee is treated like TB of the lungs, with anti-TB medications. However, the area on the knee does need to be checked to be sure that it is a TB lesion and there is nothing else wrong.
For this reason, the knee area should have a biopsy. After this, the surgeon would likely clean out the area in the knee that was affected by the TB, as well as prescribing anti-TB medication.