Total Knee Replacement

When to consider it

Knee replacement is an operation for pain, not for an X-ray. Plenty of people have knees that look badly arthritic and manage well. Others have moderate changes and cannot get through a night. What usually tips the balance is pain that no longer responds to the simpler treatments and has started to run your life.

The subject usually comes up when several of these are true:

• Pain at rest or at night, not just when you walk
• Physiotherapy, weight management, painkillers and injections have all been given a proper try
• Stairs, squatting or getting up from a chair have become the limiting factor
• The leg has begun to bow inwards or outwards
• You are giving up things you want to do because of the knee

If that does not sound like you yet, the usual advice is to wait and treat the knee pain without surgery. Plenty of patients leave this clinic with exactly that advice. If you have been told you need a replacement and are not sure, a second opinion before a joint replacement is a sensible step. If the wear is only on one side of the knee, a partial replacement may be enough. In a younger patient whose leg has bowed, realigning the shin bone can put a replacement off for years.

What the operation involves

The operation takes one to two hours. Most knee replacements in India are done under spinal anaesthesia: you are numb from the waist down and sedated, but not fully asleep. It generally means less nausea afterwards, and early pain is easier to control.

The worn surfaces are removed. The implant is then sized and positioned so the leg lines up straight and the ligaments are balanced through the full range of movement. Getting that alignment right is most of the operation. It is also where robotic and navigation assistance help most, particularly in a knee with a severe bow.

Dr. Ishan Khanna trained in hip and knee arthroplasty at Lilavati, Sir HN Reliance and Breach Candy Hospitals in Mumbai and at Max Superspeciality Hospital, Mohali. He has experience with both robot-assisted and navigation-assisted technique, and has published research on post-operative pain protocols in knee replacement.

Recovery, week by week

These are typical ranges. Your age, your general health, how stiff the knee was beforehand and how regularly you do the exercises all move them.

• Day 1. You stand and take your first steps with a walker, usually the next morning.
• Week 1 to 2. Hospital stay is generally two to four days. Walking indoors with support, working on straightening the knee fully and bending it past 90 degrees. Stitches or clips come out around day 12 to 14.
• Week 3 to 6. Most people move from a walker to a stick, manage stairs, and return to desk work if they have it. Swelling is still normal at this stage.
• Week 6 to 12. Walking unaided, driving again once you can brake safely, back to routine daily activity.
• 3 to 12 months. Strength and stamina keep improving. Some swelling and warmth around the knee can last for most of a year. This is expected and does not mean anything is wrong.

The physiotherapy is not optional, and it starts straight away. The work you do in the first six weeks does most to decide how much movement you keep.

Exercises to start at home

These four begin in hospital, usually the day after the operation, and carry on once you are home. They keep blood moving through the leg, which helps prevent clots, and they rebuild the thigh muscle and the knee's movement. Your physiotherapist will set how many to do and how often.

Straightening matters as much as bending. A knee that will not go fully straight leaves you with a limp, so do not skip the towel exercise because it is uncomfortable. The American Academy of Orthopaedic Surgeons exercise guide has more for the weeks that follow.

If the calf becomes painful or swollen, the wound starts to leak, or you develop a fever, call the clinic the same day instead of carrying on.

What it will not do

A replaced knee is a very good knee, not a young one. Kneeling is often uncomfortable, and for some people it stays that way. Deep squatting and sitting cross-legged on the floor are usually limited. Running and jumping sports are not advised, because they wear the implant.

Modern implants commonly last fifteen to twenty years or more. They do not last forever, and a younger, heavier or more active patient will wear one out faster. This is one of the things that decides when to operate.

Risks

Serious complications are uncommon, but no operation is free of them. The ones that matter most are infection, blood clots in the leg or lung, stiffness needing further treatment, ongoing pain, injury to nerves or vessels, and loosening or wear of the implant over the years. Blood thinners, antibiotics and early walking are all used specifically to reduce these risks.

You will be told which of these apply more to you before anything is decided. Your general health, diabetes control, weight and smoking all change the numbers.

Common questions

Not sure this is your problem?

These pages start from the symptom. They cover what else can cause it and what is usually tried first.