Surgical Technique: Primary Total Knee Replacement
Surgical Steps for Primary Total Knee Replacement:
A Midline Skin incision of about 10 cm is taken over the Knee. Subcutaneous Tissue and Fascia are cut to expose the muscle and patella.
The Midvastus Muscle is then split vertically and the Knee Joint is exposed by retracting the patella to the lateral side.
Once the Knee Joint is opened, a special positioning device (a cutting guide) is placed on tibia. This guide is used to cut the tibia in the correct alignment.
Next the surface of the femur is prepared. Another type of cutting guide is placed at the lower end of the femur.
These cutting guide are used to ensure that the bone is cut in the proper alignment to the leg's original angles, even if the arthritis has made the Limb Bow Legs or Knock Knees. With the help of these cutting guides, the surgeon cuts several pieces of bone from the end of the femur. The Artificial Knee will replace these worn surfaces with a metal surface.
Then the articular surface of the patella is removed. This is again replaced by polyethylene plastic.
The Knee is given a thorough wash with pulse lavage so as to clear all debris. The Knee is then dried up and prepared for cementing.
Cement mantle is pressurised on the femoral cut surface and the femoral component is then placed and hammered so as to fix it on the femur.
Cementing is then done for the tibia and the metal component is then fixed and hammered on to the tibia.
A trial insert is put and the knee is then extended to replace the patella component. After cementing the patella, the component is then held in its place by a patella clamp.
It takes about 10 minutes for the cement to set, after which all excess cement is removed and the stability of the joint is assessed. A final insert is then mounted on the tibial tray. The knee is then reduced and is closed in layers after putting in a drain. Skin is the approximated and stapled so as to give a clean scar. compression dressing is then applied to the knee.
This surgery last for about one and a half hour with a total of tourniquet time of 45 minutes.