As knee arthritis gets worse over time, patients’ pain when moving — whether simply flexing, walking, or stepping up stairs — also gets worse. Medications can help, as can moderating your activity level and using walking supports, but sometimes none of these aids help enough. That’s when it’s time to consider total knee replacement surgery.

When you remove the worn-down and damaged knee tissue, and replace it with a prosthesis, you can decrease pain dramatically, correct deformities in your leg, and also boost your activity level again. The results are outstanding, thanks to huge improvements in the materials and surgical techniques. Nearly 581,000 knee replacements now happen in the U.S. each year — one of the most common orthopedic surgical procedures.



You rely on your knees for most of your daily actions, yet you probably only think about it if you’re in pain. To understand what can go wrong, let’s take a closer look at the anatomy…

Your knees are your biggest joints in your body, made up of your thighbone’s lower end (femur), which rotates on your shin bone’s upper end (tibia). Your kneecap (patella) slides into a groove at your femur’s tip. Strong ligaments attach your femur to your tibia for stability, with long thigh muscles giving your knee strength.

Knee Anatomy

As you can see in the diagram, articular cartilage covers the joint surfaces where the femur, tibia, and patella connect, proving a smooth cushion for the bones to move easily.

These parts normally work without a second thought. But damage from injury or disease can can cause weakness, decreased function, and pain. Again, that’s when knee replacement surgery may be a good option.



healthy knee damaged knee
A healthy knee. You can see the joint space between the tibia and femur. A damaged knee. Notice the worn cartilage and bone spurs.


Since arthritis is the most common cause of chronic knee pain, it’s helpful to know the different types that can cause dysfunction.

Osteoarthritis is the first kind, which is most often seen in people aged 50+ years, especially when it runs in the family. Osteoarthritis causes the cartilage cushioning the knee bones to soften and wear away. That, in turn, causes the knee bones to grind against each other, causing chronic pain and stiffness.

Rheumatoid arthritis is a little different. Still resulting in cartilage loss, the initial cause is the synovial membrane thickening and inflaming, which then stimulates excess synovial fluid production. Once the joint space overflows, the conditions are again in place for cartilage damage.

On the other end of the spectrum, traumatic arthritis is caused by injury. For example, let’s say you fall, causing a knee fracture or tears in one or more of your knee ligaments. If left untreated, that damage can wear down your articular cartilage over time, causing the same bone friction and pain mentioned above.

Rheumatoid arthritis and traumatic arthritis are the most common forms, but definitely consult with a doctor to verify which one you have.

Knee Replacement


Is Total Knee Replacement for You?

Only you can ultimately decide to have total knee replacement surgery, but your orthopedic surgeon, family physician, and your own family can all help you to decide. After all, any such decision requires a clear picture of the technical benefits and risks, plus also the lifestyle impacts.

Los Angeles knee replacement surgeon, Dr. Samimi, is happy to fully evaluate you, explain your results in non-technical language, and cover potential treatment options — including physical therapy, injections, medications, and other orthopedic surgical procedures. Knee replacement surgery is just one path, but Dr. Samimi will help you understand how much it may ease your pain and bolster your knee function vs. the risks.


Self-Reflection Questions When Considering Knee Replacement

  • Does your knee pain limits your day-to-day activities, including walking, climbing stairs, sitting down, and getting up again? If you have trouble walking more than a few blocks without serious pain, consider trying a cane or walker for now.
  • Knee pain even while resting? How bad is it?
  • How often is your knee inflamed?
  • Does your knee appear deformed (e.g, bowing in or out)?
  • Can you fully bend and straighten your knee? How stiff does it feel?
  • How much do anti-inflammatory drugs — like aspirin and ibuprofen — help? They’re often the most effective for the early phases of arthritis, and their effectiveness varies hugely from person to person for dulling knee pain.
  • How well can you tolerate pain medications? Any complications from taking them?
  • Have you tried other treatments, like physical therapy, cortisone injections, or other surgeries? How much did they help?

To give you some more background, the average age range for knee replacement is 60 to 80. Of course, you may require it a much younger age because of trauma, arthritis, or other reasons. Our Los Angeles orthopedic surgeons thoroughly evaluate each patient individually. We’ve performed total knee replacements successfully across a wide age range, from a young teenager who had juvenile arthritis to an elderly patient who had degenerative arthritis.


Realistic Expectations About Knee Replacement Surgery

Before you decide on total total knee replacement surgery, make sure you’re clear on what the procedure can’t do for you:


Of course, you’ll notice most of the no-nos are unusually high-impact. We’ll advise you to avoid some of them for life, while other activities you may be able to work up in time. We’ll help you gauge what safe boundaries are for you based on your recovery progress and physiology.

The immediate benefit for ~90% of people who have knee replacement is being able to do the “normal” things they no longer could. The pain doesn’t paralyze them anymore (there may still be some, but it’s usually minimal).

Since every knee replacement is mechanical, it will develop some wear in its plastic cushion. Knee replacements can still last for many years though, as long as you moderate your activity as we advise.


Your Surgery

On the day of your surgery, the hospital will admit you, to first be evaluated by someone from the anesthesia team.

There are various kinds of anesthesia you may get, depending on your preference and what’s necessary. The most common are general anesthesia, which lets you sleep through the surgery, and spinal (epidural) anesthesia, which lets you stay awake while only your legs are anesthetized. You’ll also get an injection of numbing (“nerve block”) medication during anesthesia, to drastically reduce any post-op pain.

The procedure itself only takes about 2 hours. Your orthopedic surgeon will first remove the damaged cartilage and bone, and then position the new metal / plastic joint surfaces to realign your knee for proper function.

Knee Replacement

While there are several kinds of materials and designs used in total knee replacement surgery, almost all of them consist of these three components:

  1. a femoral component (made of a strong metal that’s been highly polished)
  2. the tibial component (made from a highly durable plastic, usually held in a metal tray)
  3. the patellar component (also plastic)

After your surgery, you’ll go to the the recovery room for 1 to 2 hours while you’re monitored as you awaken from the anesthesia-induced sleep. Once you’re awake, you’ll go back to your hospital room.

Woman with walker
Your Stay in the Hospital

You’ll likely stay in the hospital for up to 3 days. You’ll also feel some pain after surgery, but Dr, Samimi and his staff will give you medication and actively help you manage pain throughout your recovery.

Remember that walking and knee movement in general are important to your recovery, so a physical therapist will help you start doing exercises the day after your surgery.



Most people don’t have any major complications from knee replacement surgery. Infections in the knee joint, for example, happen in less than 2% of patients. Blood clots in the leg veins are the most common issue, so your orthopedic surgeon will give you a prevention program.


After Surgery – The Long Term

Continue regularly — but lightly enough to prevent falls and injuries — exercising to maintain your knee’s strength and mobility. If you have a fracture, you may require more surgery.

Also, make sure to let your dentist know about your knee replacement. As a precaution, you’ll need antibiotics before oral surgery from now on.

And, of course, come see your friendly orthopedic surgeon at least once a year for a routine checkup, which a follow-up exam and x-rays.