Everything You Need to Know About Knee Replacement

What is Knee Replacement?

Knee replacement (also called knee arthroplasty) is a surgical procedure that replaces damaged or worn-out parts of the knee joint with artificial components. It’s usually done when someone has severe arthritis or long-term knee damage that doesn’t improve with other treatments. The goal is to reduce pain, improve movement, and restore function.

An analogy…

Think of the knee like a door hinge that’s become rusty and worn out. When oiling or repairing the hinge no longer works, you replace it with a new, smooth-moving hinge. That’s what a knee replacement does. It swaps out the damaged parts for new ones that move better and hurt less.

What are other names that knee replacement can be called?

Total Knee Replacement (TKR)
Total Knee Arthroplasty
Knee Replacement Surgery
Knee Resurfacing (in some cases)

What causes knee replacement to be needed?

Severe osteoarthritis (most common reason)
Rheumatoid arthritis
Post-traumatic arthritis (after injury)
Knee deformity or instability
Long-term stiffness and limited mobility
Chronic pain that doesn’t improve with physio, medication, or injections

What are the signs and symptoms that might lead to knee replacement?

Constant knee pain, even at rest or during the night
Difficulty walking, standing, or climbing stairs
Stiffness and reduced range of motion
Swelling and inflammation that doesn’t go away
Grinding, clicking, or bone-on-bone sensation
Significant change in leg alignment (e.g. bow-legged or knock-kneed)

What tests are used to diagnose issues that need knee replacement?

X-rays: show joint space loss, bone spurs, and cartilage wear
MRI or CT scan: sometimes used for more detailed images
Physical exam: checks movement, alignment, and joint stability
Patient history: important to determine how symptoms affect daily life and mobility

How long does knee replacement take to heal?

Hospital stay: usually 1–3 days
Walking with a walker or crutches: within days
Returning to light daily activities: 4–6 weeks
Resuming most activities (including driving and walking unaided): 6–12 weeks
Full recovery and strength: often takes 6 months to a year

How does knee replacement happen?

During surgery, the damaged cartilage and bone surfaces of the knee joint are removed and replaced with metal and plastic implants. These components are shaped to mimic the normal movement of the knee. The surgeon ensures proper alignment and stability, then closes the incision. You’ll begin moving the knee with help shortly after surgery.

What treatment can help after knee replacement?

Pain management with medication, ice, and elevation
Physiotherapy to restore movement, strength, and balance
Manual therapy to improve flexibility and reduce scar tightness
Progressive strength exercises for quads, hamstrings, glutes, and calves
Walking with assistive devices
Daily stretching to prevent stiffness
Monitoring for swelling, infection, or wound healing issues

What exercises or stretches can I do for knee replacement?

Ankle pumps and quad sets (immediately post-surgery)
Heel slides to restore knee bending
Straight leg raises to strengthen the thigh
Seated knee extensions
Bridges and step-ups in later rehab
Stationary bike or walking in a pool (as recovery progresses)
Stretching for calves, hamstrings, and hip flexors

What products can help with a knee replacement?

Isometric quads supine

Lie on the bed. Stretch out your leg and press the back of your knee downwards until you feel your thigh muscles tighten.

Seated knee flexion

Sit in a neutral posture, your shoulders back and down. Pull your heel back towards the chair as far as you can go. Relax to the neutral position and switch sides. Pull your heel back and relax.

Straight leg raise long sit

Start in a seated position on a bench with your legs stretched out in front of you. Bend your toes in towards you and push your knee down into the bench. Raise one leg slightly. Hold, and then return to the starting position. Repeat.

Active knee flexion in long sit

Start in a seated position with your legs stretched out. Bend one knee and bring your foot in as close as possible towards your buttocks. Hold, and then return to the starting position.