Conventional joint Replacement is a very successful procedure for the treatment of arthritis. The main complication with any joint replacement using polyethylene is that the polyethylene gradually wears, eventually reaching a point where the replacement joint no longer functions properly. The other problem is that although the plastic itself is inert, tiny particles of the plastic are worn away when the metal rubs against the plastic. This plastic debris can cause an inflammatory reaction and can cause the surrounding bone to be absorbed by the body, leading to loosening of the artificial joint.
Revision Total Knee Replacement is a procedure in which the surgeon removes a previously implanted artificial knee joint, or prosthesis, and replaces it with a new prosthesis. Knee revision surgery has three major purposes: relieving pain in the affected knee; restoring the patient's mobility; and removing a loose or damaged prosthesis before irreversible harm is done to the joint. Knee prostheses can come loose for one of two reasons. One is mechanical. The second reason for loosening of a knee prosthesis is related to the development of inflammation/infection in the knee joint. In most cases, increasing pain, stiffness, and loss of mobility in the knee joint are early indications that the patient may benefit from revision surgery.
Infected Total Knee Replacement:
Though total knee replacement is a very successful procedure there is a small risk of infection of about 0.5 to 1%. Infection can be classified depending on the chronology of occurrence as,
- Acute - within 6 weeks
- Sub acute- 6 weeks to 3 months
- Chronic- more than 3 months.
Acute infection is confirmed by clinical findings, aspiration and culture of the joint fluid.
Acute infection can be treated with intravenous antibiotics and joint lavage with exchange of insert and retention of the prosthesis. One or two attempts at retention of prosthesis may be successful. Intermittent short course suppressive antibiotic therapy is also helpful in preventing recurrence.
Sub- acute or chronic infection or failure to salvage in acute infection can be treated by two staged revision of the prosthesis. Initial debridement after discontinuation of all antibiotics for a few weeks with multiple intra operative cultures, fixation of antibiotic laden articulating spacer, short course of appropriate antibiotic intravenously followed by oral antibiotics for 8 to 12 weeks followed by second stage revision at present one of the successful protocols.
Two-Stage Revision Knee Arthroplasty
Infection remains another complication in hip replacement. We perform a two-staged procedure for these cases with the initial stage comprising of a thorough debridement and antibiotic-impregnated cement spacer application followed by a second procedure involving a redebridement and the insertion of the definitive prosthesis.