ARTHRODESIS OF THE KNEE AFTER INFECTED TOTAL KNEE ARTHROPLASTY (TKA): COMPARISON OF 3 DIFFERENT ROD SYSTEMS

Abstract

In selected patients, knee arthrodesis is a well-recognised salvage procedure after infected total knee arthroplasty (TKA). Several procedures of arthrodesis have been introduced and should be adapted to the individual situation of the patient. In our center we regularly treat elderly patients after multiple revision operations; in 36% defects of the bone, soft tissue or the extensor mechanisms are present. In these cases we prefer arthrodesis to reimplantation. Because of the high rate of non-unions when using an external fixator, we perform arthrodesis by use of an intramedullary rod system.

The objective of this study was to compare the results of different rod systems for knee arthrodesis after TKA infection.

We reviewed the results of 3 rod systems in 34 patients: cementless system (Brehm; n=9), cement rod usually used in tumor patients (Mutars; n=7) and a regular cement rod system (Link; n=18).

In the group of cementless rods we had to explantate 3 rods because of a relapse of the infection. This is most propably due to the technical design of the system: in poor soft tissue situation the tissue is compressed by the voluminary docking part which causes continuous necrosis. This problem can be avoided by an early tissue flap. Of the Mutars rod system we had to explantate 2 systems; one because of an infection, the other one due to telescoping, which can be avoided by use of a longer stem with the option to interlock. In the group of the Links system no revision was necessary.

In our opinion, arthrodesis of the knee using a rod system is a satisfactory salvage procedure following an infected TKA, especially in elderly patients, and can provide reliable, painless extremity and satisfactory quality of life.