Steps of Total Knee Replacement

1. Preoperative planning
   • Confirm indication, clinical deformity, range of motion, ligament stability, and X-rays.
   • Plan component size, alignment, fixation method, and whether to resurface the patella.
   • Give prophylactic antibiotics, anesthesia, and thrombosis-prevention measures.
2. Positioning, preparation, and anesthesia
   • Patient lies supine.
   • Spinal or general anesthesia, often with regional analgesia, is used.
   • The limb is prepared and draped; a tourniquet may be used depending on surgeon preference.
3. Surgical exposure
   • A midline anterior skin incision is made.
   • The joint is entered, commonly through a medial parapatellar arthrotomy.
   • The patella is everted or displaced laterally to expose the knee joint.
   • Menisci, osteophytes, and damaged cartilage are removed.
4. Tibial bone preparation
   • An alignment guide, navigation, or robotic system is used to guide the proximal tibial cut.
   • A measured amount of proximal tibia is resected while maintaining appropriate coronal and sagittal alignment.
   • The tibial surface is sized and prepared for the tibial baseplate.
5. Femoral bone preparation
   • The distal femur is cut using an intramedullary or extramedullary alignment guide, navigation, or robotic assistance.
   • Further femoral cuts prepare the anterior, posterior, and chamfer surfaces for the femoral component.
   • The surgeon restores appropriate limb alignment and femoral rotation.
6. Soft-tissue balancing
   • The medial and lateral collateral ligament tension is assessed in extension and flexion.
   • Selective releases or adjustment of bone cuts are performed if needed to obtain balanced flexion and extension gaps.
   • The posterior cruciate ligament may be retained, sacrificed, or substituted depending on implant design and knee stability.
7. Trial components
   • Trial femoral and tibial components and a trial polyethylene insert are placed.
   • The knee is taken through flexion and extension.
   • Alignment, stability, range of motion, patellar tracking, and insert thickness are checked and adjusted.
8. Patellar preparation, if resurfacing is planned
   • The undersurface of the patella is resected.
   • A polyethylene patellar button is trialed and then implanted.
   • Patellar tracking is reassessed. Patellar resurfacing is selective, not universal.
9. Implantation of definitive components
   • The femoral and tibial components are fixed, most commonly with bone cement, although some implants are press-fit.
   • The definitive polyethylene tibial insert is locked into the tibial tray.
   • The insert forms the smooth bearing surface between the metal femoral and tibial components.
10. Final assessment and closure

• Final alignment, stability, motion, and patellar tracking are confirmed.
• Hemostasis is secured, the wound is irrigated, and the arthrotomy, fascia, subcutaneous tissue, and skin are closed.
• A sterile dressing is applied.

1. Postoperative care

• Multimodal pain control, early mobilization, physiotherapy, antibiotics as indicated, and venous thromboembolism prophylaxis.
• Early goals include safe walking, knee extension, progressive flexion, and wound monitoring.