The P.F.C.® Sigma® TC3 design is the most constrained device available within the P.F.C.® Sigma® Knee System and is indicated for use in cases where collateral ligaments are deficient.

Your knee may keep popping, clicking, crunching, or grinding due to harmless causes, like air bubbles in or around your knee joints. Crepitus is the medical term for the popping sounds or sensations ...