Total Knee Replacement : 61 years female, Rheumatoid

61 years female. Rheumatoid. Bilateral Total Knee Replacement 4 yrs ago. Fell down 6 months post surgery and injured left knee. Since then global instability in left knee and inability to walk.
X-ray left knee AP and lateral shows subluxation with fixed implant. Revision TKR done with RHK (Rotating Hinge Knee) to substitute for deficient collateral ligaments. Post op X-ray shows good alignment with well fixed component . Patient is comfortable and walking pain free with full weight bearing.