Revision Knee prosthesis operation

What exactly is it?

Current data shows that the large majority of patients who undergo knee prosthesis surgery live a comfortable life. However, the prosthesis that was implemented in the first surgery may lose its functionality due to many reasons, and a second surgery may be required. Revision knee prosthesis refers to the procedure that replaces the area where the first prosthesis was implanted.

The main goal of the revision knee prosthesis operation is, just like with the first knee prosthesis, to reduce pain and gain function. However, the procedure to be performed is completely different.

When and why will we require it?

Revision surgery is performed due to two main problems: mechanical and infectious. Infectious reasons can be described as the current prosthesis being infected. Mechanical reasons are mentioned in cases such as deterioration of the integration of the primary prosthesis and bone (loosening), wear of metal and/or plastic prosthesis parts, and instability (abnormal movement).

Revision knee prosthesis that performed due to infection

Infection is a potential problem that may occur after all surgical procedures. We can define prosthetic infection as the appearance of bacteria in the prosthetic parts and/or the surrounding bone. Infection occurring in the first 6–8 weeks after surgery is called the “early period,” while infection occurring after this period is called the “late period.” Treatment is planned according to this classification.

In early-stage infections, debridement and limited component replacement (insertion) are usually performed. Cultures taken around the prosthesis during this surgery determine the antibiotic treatment to be applied in the next period. In addition, artificial joint parts are washed with special solutions. Antibiotic treatment after surgery is permitted and allowed to be effective.

In late-stage infections, there is a factor that causes infection in artificial joint parts and adjacent bones. Usually, a single or two-stage surgical procedure is performed, which will require the replacement of all artificial joint parts.

In a single-stage surgical procedure, the primary prosthesis is removed in the same operation and the adjacent bone is mechanically cleaned. Cleaning is the removal of dead tissue. The remaining bones and joint space are washed with special solutions, and a new prosthesis is placed. Antibiotic treatment is started according to the microbes produced as a result of cultures taken from the prosthesis and bone. Follow-up is done with the infection parameters in the blood.

In two-session revision surgery, the bone is debrided after the infected prosthesis is removed. A temporary prosthesis made of antibiotic bone cement is placed to fill the gap. Appropriate antibiotic therapy is given against the causative microorganisms. By monitoring the infection parameters in the blood values, it is decided when the second surgery will be performed. This period varies between six and eight weeks. When suitable conditions are met, the temporary prosthesis is removed and a revision knee prosthesis is attached. An average of six months of antibiotic therapy may be required after this surgery.

Revision surgery due to relaxation and corrosion:

The factors causing loosening may change according to the technological condition and the technique of the first-placed prosthesis. Depending on these factors, the deterioration of the attachment of the primary knee prosthesis to the bone is called loosening. The disruption of the knee prosthesis’ grip on the bone is called relaxion. The micro movements that occur as a result of relaxation cause pain and bone corrosion.In some cases, the microfragments that are sourced from plastic material at the environment of friction of prosthesis parts cause the activation of the immune system by gathering around the prosthesis. This reaction may affect the bone around the prosthesis, and bone loss called osteolysis may develop. This loss means the relaxation of the connection between the prosthesis and bone. In revision surgery, due to loosening and wear, mostly all artificial joint parts are replaced. However, in cases where the bone has lost volume and is weak, additional implants, apparatus, and bone grafts can be used to attach the revision prosthesis to the bone.

Instability:

For the knee prosthesis to function properly, the ligaments surrounding the knee must be in the proper tension and balance. Disruption in this balance disrupts the harmonious movement between the parts, causes pain, and wears out the polyethylene insert. The deterioration of the harmonious movement between the prosthetic parts is called instability. Revision surgery is performed in cases of instability that cannot be treated conservatively.

Joint Stiffness 

Sometimes adequate range of motion cannot be achieved after total knee replacement surgery. Joint stiffness occurs as a result of covering the tissues around the prosthesis with an extremely tight connective tissue (scar). In such a case, joint mobilization is first performed under anesthesia. If this procedure is not successful, revision surgery is needed.

A periprosthetic fracture is the loss of bone around a prosthesis caused by trauma.The revision surgery is subject to change based on the prosthesis’ grip on bone and the geometry of the fracture.If the connections with the bones of the prosthesis are not damaged, then bone detection methods without replacing the prosthesis (plate, screw, wire, etc.) are applied.