From the Guidelines
A step-wise approach to total knee arthroplasty (TKA) begins with preoperative planning, which includes obtaining weight-bearing radiographs, assessing the patient's anatomy, and selecting appropriate implants, as recommended by the most recent guidelines 1. The procedure starts with patient positioning in supine position with a tourniquet applied to the proximal thigh. After sterile preparation and draping, a midline skin incision is made, followed by a medial parapatellar arthrotomy to expose the knee joint.
- The surgeon then resects the distal femur perpendicular to the mechanical axis, typically removing 9-10mm of bone, followed by anterior and posterior femoral cuts to size the femoral component.
- The proximal tibia is cut perpendicular to its mechanical axis, removing about 8-10mm of bone.
- After these bone cuts, the surgeon performs soft tissue balancing to ensure equal flexion and extension gaps.
- Trial components are placed to assess alignment, stability, and patellar tracking.
- Once satisfied with the trial, the definitive components are cemented in place, typically starting with the tibial component, followed by the femoral component, and then the polyethylene insert.
- The patella may be resurfaced depending on its condition and surgeon preference.
- The wound is thoroughly irrigated, a drain may be placed, and closure is performed in layers. Postoperatively, patients begin physical therapy within 24 hours, focusing on range of motion exercises and progressive weight-bearing.
- Deep vein thrombosis prophylaxis is essential, using either low molecular weight heparin, factor Xa inhibitors, or mechanical compression devices for 2-4 weeks, as supported by recent studies 1.
- Pain management typically includes multimodal analgesia with acetaminophen, NSAIDs, and opioids as needed, with consideration of the patient's individual needs and medical history, as discussed in the literature 1. This systematic approach to TKA aims to restore knee function, relieve pain, and improve the patient's quality of life by creating a stable, well-aligned knee joint, with consideration of the latest evidence and guidelines 1.
From the Research
Preoperative Planning
- Preoperative planning is crucial in total knee arthroplasty (TKA) as it helps the surgeon envision the operation and minimize the risk of premature implant failure 2
- A thorough preoperative analysis includes obtaining a thorough history, physical examination, and standard radiographs to evaluate the integrity of the soft tissues, neurovascular status, range of motion, limb deformity, and the status of the collateral ligaments 2
- Preoperative planning also involves templating to plan the bone cuts, tibial slope, implant size, and position at the time of surgery 2
Surgical Approach
- A well-planned surgical approach is essential in TKA, including the removal of components, adequate reconstruction of the joint line and posterior condylar offset, and the use of offset stems 3
- The choice of surgical approach and the use of constrained implants, metal augments, and bone grafts are critical in achieving good outcomes in TKA 2, 3
Patient Education and Management
- Patient education is an important aspect of TKA, and a multidisciplinary approach to patient education can improve functional outcomes and reduce the need for walking devices 4
- Preoperative patient education, preoperative planning, and perioperative management are all critical components of a successful TKA 5