REVISION TKRA – HOW I DO IT

Abstract

The result of the revision TKRA relies upon the causes of failure, method of operation and surgical skill of the surgeon. For the success of the revision, surgeon should do his best from surgical planning to rehabilitation program. I have experienced more than 100 cases of revision TKRA and here I would like to share my surgical techniques of revision surgery in aseptic failure of the primary TKRA. An approach, implant selection, bony reconstruction and fixation methods used are just the same with the principles of other surgeons.

I will describe my surgical tips in removal of the implant, preservation of the joint line and morselized bone graft application.

For removal of implants, I used microsaw instead of Gigli saw. This is because microsaw has advantages of preserving the bone by easy approach to notch and posterior condylar area and less contamination risk.

After partial separation of bone and implant interface by microsaw, I would not remove the implant immediately. Instead I will tap medial and lateral condylar portion alternately with mallet repeatedly until I can see the movement of the prosthesis, and then I will gently remove the prosthesis. By this maneuver, the prosthesis is easily removed with less bony defect.

Before removal of femoral prosthesis, for joint line preservation, I will mark 5–6 cm proximal to the joint line on the femoral metaphyseal area with drill bit. In most revision cases, as the height of femoral prosthesis is maintained, this mark can be good landmark for the joint line insert of the trial prosthesis later at that level, thus the joint line can be preserved.

I also have special tips in morselized cancellous graft. After impaction of morselized bone, the bony fragments are easily dispersed and to prevent this phenomenon, some surgeons apply temporary cement coating over the bone. However, when using cement, the cement can intervene between bony fragment resulting in delay or failure of incorporation. Another disadvantage of cement coating is that the surface may be irregular and interfere with tight fitting of the prosthesis. My methods is by using haematoma to coat on the morselized bone followed by inserting the trial prosthesis in situ, and with knee deflate the torniquette. In most of the revision operation, 2 torniquette times is needed. It means that I deflate the torniquette a little earlier than 1st torniquette time. I do not irrigate for 10 ~ 15 min. After inflation of torniquette, gently remove the trial prosthesis and you can see beautiful shape of morselized graft which is well aggregated with haematoma. In this state, we do not need cement precoating on the morselized graft until the real prosthesis is implanted.