Infection of a knee replacement prosthesis is a serious and potentially disabling complication. Early infections occur within the first four weeks after knee replacement surgery. Late infections are those that occur after the first postoperative month. Treatment for a knee replacement infection depends on when the infection occurs, the species of bacteria responsible for the infection, and the patient's medical condition and treatment goals. Treatment options range from antibiotic therapy to amputation.
Antibiotic Suppression
Curing an infection of a knee replacement prosthesis requires surgery and possible replacement of the infected artificial joint, report orthopedic surgeons David Jacofsky and Mark Campbell in a 2006 article published in "Hospital Physician." In certain cases, however, the risks of additional surgery outweigh the potential benefits. Among a highly selected group of patients for whom surgery poses a higher risk than keeping the infected prosthesis, long-term antibiotic treatment to suppress the infection may be advised. This course of treatment is unusual, but may be appropriate for some patients.
Surgical Debridement
Patients with early postoperative infections or late infections diagnosed within a few weeks of the onset of symptoms may be candidates for surgical debridement without removal of the prosthesis, notes the online orthopedic reference website Wheeless' Textbook of Orthopaedics. Surgical debridement involves opening the knee, removing all infected tissue, thoroughly cleaning the operative site and replacing the plastic surfaces of the knee prosthesis. A prolonged course of antibiotic therapy accompanies this treatment approach. Jacofsky and Campbell report that surgical debridement without prosthesis replacement proves successful in approximately 18 to 24 percent of patients.
Knee Prosthesis Replacement
Removal and replacement of the knee prosthesis is the most common form of treatment for an infection of the artificial joint. A two-stage approach involves removal of the prosthesis followed by several weeks of antibiotic therapy to ensure clearance of the infection. Upon cure of the infection, surgeons implant a replacement knee prosthesis. Some surgeons use a one-stage treatment approach with removal of the infected device and replacement in a single operation. Overall, the two-stage approach proves more successful in curing infection than a one-stage procedure, report Dr. Esa Jämsen and colleagues in a 2009 article published in "Acta Orthopaedica."
Knee Arthrodesis
Arthrodesis involves removal of the infected knee prosthesis and permanent fusion of the thighbone to the lower leg bones. Knee arthrodesis typically proves successful in curing the infection and alleviating pain. The ability to bend the leg at the knee, however, is lost. This uncommon approach may be appropriate for people who have undergone previous unsuccessful attempts to replace an infected joint or who have an infection with a difficult-to-treat species of bacteria, explains Wheeless' Textbook of Orthopaedics.
Amputation
Although rare, infection of a knee replacement prosthesis may require an above-the-knee amputation. This approach may prove necessary if the patient is critically ill because of the infection or all other treatment approaches have failed, according to Jacofsky and Campbell.
References
- "Hospital Physician"; The Infected Total Knee Arthroplasty Part 2: Management Options; David J. Jacofsky, M.D., Mark D. Campbell, M.D.; February 2006
- Wheeless' Textbook of Orthopaedics: Infected Total Knee Joint
- "Acta Orthopaedica"; Outcome of Prosthesis Exchange for Infected Knee Arthroplasty: The Effect of Treatment Approach, A Systematic Review of the Literature; Esa Jämsen, M.D., et al.; 2009
- "The New England Journal of Medicine"; Infection Associated with Prosthetic Joints Jose L. Del Pozo, M.D., Ph.D., Robin Patel, M.D.; August 2009
