Physiotherapy After Knee Replacement: What Recovery Involves

Had a knee replacement and wondering what recovery should actually look like? You’re not alone. It’s one of the most common surgeries for advanced knee arthritis — but the rehab afterwards is where a lot of the progress really happens.

Here’s what you need to know.

What is a knee replacement?

A knee replacement, also called a total knee replacement or total knee arthroplasty, is surgery where the worn joint surfaces of the knee are replaced with artificial components.

Most people have it because of advanced knee osteoarthritis. In simple terms, the smooth cartilage inside the knee has worn down, making the joint painful, stiff and harder to use.

The surgery can reduce joint pain, but the new knee still needs to regain movement, strength and control.

That’s where physiotherapy comes in.

How do people get to the point of needing one?

Most people need a knee replacement after years of gradual joint degeneration.

Common contributing factors include:

• Knee osteoarthritis

• Previous knee injuries

• Meniscus tears

• ACL injuries

• Previous knee surgery

• Age-related joint changes

• Genetics

• Inflammatory arthritis

• Long-term joint loading

• Reduced strength or altered lower limb mechanics

  
  

Not everyone with arthritis needs surgery. It’s usually considered when pain, stiffness and reduced function are significantly affecting walking, stairs, sleep, exercise or quality of life.

Common signs and symptoms

Before surgery, common symptoms include:

• Knee pain with walking or stairs

• Morning stiffness

• Swelling around the knee

• Grinding, clicking or catching

• Difficulty bending or straightening the knee

• Reduced walking distance

• Pain standing from a chair

• Reduced confidence loading the knee

  
  

After surgery, it’s normal to have swelling, bruising, stiffness, weakness and discomfort in the early stages.

The key is that things should gradually improve.

If you notice increasing redness, wound discharge, fever, sudden worsening pain, significant calf swelling, shortness of breath or chest pain, seek medical review.

What does physio focus on?

Physiotherapy after knee replacement is about more than just doing exercises.

We look at:

• Swelling and pain management

• Restoring knee range of motion

• Getting the knee fully straight

• Improving knee bend

• Rebuilding quadriceps strength

• Strengthening the glutes, hamstrings and calves

• Walking and gait retraining

• Balance and confidence

• Stairs and functional movement

  
  

One of the biggest early goals is restoring full knee extension. If the knee doesn’t straighten properly, it can affect walking mechanics and place extra load through the hip, back and opposite leg.

Strength is also a major focus. After surgery, the quadriceps often become inhibited — meaning the thigh muscle doesn’t switch on properly. In technical terms, this is called arthrogenic muscle inhibition.

In normal terms, the quad needs to be retrained.

How long does recovery take?

Most people notice meaningful improvement in the first 6 to 12 weeks, but recovery continues for months.

A general guide:

• Weeks 1–2: Pain, swelling, walking aids and basic movement

• Weeks 2–6: Improving knee range, walking tolerance and early strength

• Weeks 6–12: Strengthening, stairs and functional exercise

• Months 3–6: Building strength, endurance and confidence

• Months 6–12: Continued improvement in higher-level function

  
  

The biggest mistake is stopping rehab as soon as walking feels easier. The knee may be replaced, but the muscles still need to be rebuilt.

What else could be causing pain?

Not all pain after knee replacement is just normal recovery.

Other things we consider include:

• Joint stiffness or scar tissue

• Infection

• Deep vein thrombosis

• Patellofemoral pain

• Tendon irritation

• Hip or lower back referral

• Prosthesis-related issues

  
  

A physiotherapy assessment helps work out whether your symptoms are expected for your stage of recovery, or whether something else needs to be checked.

When should you see a physio?

Ideally, physiotherapy starts early after surgery and continues through the main stages of recovery.

If your knee is still very stiff, swollen, weak, painful, or you’re limping, struggling with stairs or unsure whether you’re progressing properly, come in to Urban Physiotherapy for a review.

We can assess your range of motion, strength, walking pattern and function and help guide the next stage of your knee replacement rehab.