Total Knee Replacement Surgery

Before surgery, a thorough medical evaluation is conducted to assess the patient’s overall health status. This includes a detailed medical history, a physical examination, and an assessment of the knee’s condition. The orthopaedic specialist will also review any existing medical conditions, such as diabetes or heart disease, which may affect the surgery or recovery.

Various tests are performed to ensure the patient is fit for surgery. These may include:

• Blood Tests: Blood tests help determine the patient’s blood count, kidney and liver function, and electrolyte levels.
• Imaging Tests: X-rays and possibly MRI scans of the knee are taken to provide detailed images of the joint’s structure. These images help the orthopaedic specialist plan the procedure.
• Cardiovascular Evaluation: For patients with a history of heart disease or those at risk, a cardiovascular evaluation may be needed to ensure the heart can withstand the stress of surgery.

Educating the patient about the procedure, recovery process, and what to expect is important to preoperative preparation. This includes:

• Preoperative Instructions: Patients are given specific instructions on preparing for surgery, including fasting requirements and medication adjustments.
• Postoperative Care Plan: Information about pain management, physical therapy, and activity restrictions after surgery is provided to help patients understand the recovery process.
• Home Preparation: Patients are advised to prepare their homes for a safe and comfortable recovery. This involves arranging for assistance, setting up a recovery area, and ensuring everything they need is within easy reach.

The patient will be given anaesthesia to ensure they are comfortable and pain-free during the surgery. General anaesthesia induces sleep, while spinal anaesthesia numbs the lower body, allowing the patient to remain awake but pain-free.

To access the knee joint, a surgical incision is made on the front of the knee. The incision length can vary, but it is usually 6 to 10 inches.

The orthopaedic specialist carefully removes the damaged cartilage and a small amount of underlying bone from the thigh bone (femur), shin bone (tibia), and kneecap (patella).

Once the damaged tissue is removed, the orthopaedic specialist places the artificial components to recreate the joint’s surface. This process involves several steps:

• Femoral Component: A metal piece is shaped to fit the end of the femur. The orthopaedic specialist secures this component to the bone using either bone cement or a press-fit technique.
• Tibial Component: This component has a metal base plate and a plastic spacer. The metal base plate is attached to the top of the tibia, and the plastic spacer is placed on top of this base plate to provide a smooth, gliding surface for the femoral component.
• Patellar Component: A dome-shaped plastic piece is attached to the back of the kneecap. This component helps the kneecap smoothly over the femoral component during knee movements.

The orthopaedic specialist tests the new joint by bending and rotating the knee to ensure proper alignment and function. Adjustments are made as required to achieve a smooth and stable movement.

Once the implants are in place and functioning correctly, the orthopaedic specialist closes the incision with sutures or staples. A sterile bandage is applied to protect the wound.

Pain management methods include:

• Medications: Pain relievers such as opioids, non-steroidal anti-inflammatory drugs (NSAIDs), and acetaminophen may be prescribed to manage pain. These help reduce inflammation and ease discomfort.
• Regional Anesthesia: Nerve blocks or epidural injections may be used to numb the area around the knee. This can provide effective pain relief immediately after surgery.
• Ice Therapy: Applying ice packs can help reduce swelling and relieve pain. Ice should be applied to the knee for 20-30 minutes every 2-3 hours during the first 48 hours post-surgery.

Physical therapy plays an important role in the recovery process by helping patients regain strength, flexibility, and mobility in the knee. A typical physical therapy plan includes:

• Range of Motion Exercises: These exercises help improve knee mobility. Heel slides involve sliding the heel up and down while lying on the back, which helps bend and straighten the knee. Knee flexion exercises, done by bending the knee as much as possible while sitting or lying down, also improve flexibility.
• Strengthening Exercises: Specific exercises are designed to strengthen the muscles around the knee. Quadriceps sets and straight leg raises involve tightening the thigh muscles while keeping the leg straight, which helps build strength. Ankle pumps, involving moving the foot up and down, improve circulation and could help prevent blood clots.
• Walking and Gait Training: Patients are encouraged to walk with a walker or crutches initially, progressing to independent walking as strength and confidence improve. Proper gait training helps ensure correct walking patterns and reduces the risk of falling.

Certain activities may be restricted during recovery to ensure proper healing and prevent complications. These restrictions typically include:

• Weight-Bearing Limits: Initially, patients may be advised to put only partial weight on the operated leg. The orthopaedic specialist will provide specific instructions based on the patient’s progress.
• Avoiding High-Impact Activities: Running, jumping, or twisting should be avoided to protect the new knee joint. These activities can place excessive stress on the implant and surrounding tissues.
• Excessive Strain on the Knee: Patients should avoid sudden or excessive strain on the knee. This involves starting with light activities such as walking or light housework and slowly progressing to more demanding tasks.