Healthcare News

When should patients seriously consider a knee replacement?

Mr Sam Rajaratnam | March 22, 2023 | Interview

Next available consultation with Mr Sam Rajaratnam:

Mr Sam Rajaratnam discusses knee pain, treatment options and timing, and explains when knee replacement surgery is necessary.

In answer to the question ‘at what point should I seriously consider knee replacement surgery to be the best option, and when is it necessary?’, Compare my Care put the following questions to leading knee replacement surgeon, Sam Rajaratnam.

  • What are the typical signs that knee replacement surgery may be required?
  • Why do the symptoms of knee degeneration vary so much?
  • Should surgery always be considered as a last resort?
  • Can you leave surgery for a painful knee too late?
Ultimately, choosing the right time for a knee replacement should positively transform patients’ lives.

What are the typical signs that knee replacement surgery may be necessary?

Sam Rajaratnam: Knee replacement surgery is usually required when the surface of the knee has worn out, with a loss of surface articular cartilage exposing the underlying bone and nerve endings. This process is called osteoarthritis.

Depending on which part of the knee is affected, this condition can cause a combination of pain, instability, deformity and loss of function.

What are the three main patterns of osteoarthritis and their symptoms?

1. The medial or Varus pattern which often leads to a bow legged deformity. Typically this results in pain on walking.

2. The knock-kneed or Valgus pattern resulting in the knee giving way and the feeling of instability. This pattern is slightly more challenging because pain is usually only a late feature, and it is frequently diagnosed when it has already progressed.

3. The Patellofemoral pattern where the wear pattern is at the front of the knee. This typically leads to pain on walking up and down stairs and inclines. Instability may be an issue, but walking on the flat is often quite comfortable.

In many cases there will be combined patterns of OA of the knee. It's therefore important for an accurate diagnosis to be made, and appropriate advice and treatment plans formulated - depending on a patient's unique symptoms, deformity and lack of function.

For an accuarate diagnosis and the best way to improve your symptoms, contact Compare my Care or schedule an appointment.

What imaging is required?

Knee surgeons will often get a series of X-rays to locate the OA and determine the severity of the condition. These should ideally involve four views including: a front-on AP weight bearing view, a lateral view, a Skyline view of the knee cap, and a Rosenberg Schuss view which unmasks subtle patterns of osteoarthritis.

Why do the symptoms of knee degeneration vary so much?

Sam Rajaratnam: The symptoms caused when the surface of the knee wears out vary tremendously from patient to patient. Careful diagnosis is crucial to creating an accurate plan for surgery.

Surface cartilage wear

The surface of the knee should be covered with a beautiful cartilage surface (Hyaline cartilage). In osteoarthritis, this surface layer disappears exposing the underlying nerve endings on the bone. As the exposed bony surfaces rub together, the knee becomes painful - rather like toothache when the surface of the tooth is exposed.

Torn shock absorber

As the surface of the knee wears out, the shock absorber cartilage (ie the meniscus) can also be ground away and ejected from the joint (called a degenerate meniscal tear with meniscal extrusion).

This can lead to some pain from the unstable degenerate edge of the meniscus, and also pain from the soft tissue envelope that is stretched over the ejected meniscus.

Excess Synovial fluid

The synovial lining of the joint often creates synovial fluid to lubricate a normal knee. In a healthy knee, approximately 1 ml of fluid lubricant bathes the surface and keeps the joint healthy.

In a degenerate knee, much more fluid is created and this often forms a pouch or cyst at the back of the knee (called a Baker’s cyst).

Occasionally the Baker’s cyst ruptures causing pain at the back of the knee or in the calf, and occasionally with swelling in the ankle. This is often confused with the symptoms of a deep vein thrombosis (DVT), but the two are generally unrelated.

Loose bodies in the knee

Occasionally the disintegrating surface can form cartilage or bony loose bodies, which in-turn can jam the joint and cause sharp pains within the knee, as well as true locking of the knee joint.

Symptom variation, frequency and severity

Given the tremendous variation in the degenerative process, it is understandable that all of the above issues will cause greater or lesser amounts of pain and discomfort in the knee - and will vary from person to person.

Frequently, in the early stages of osteoarthritis, the symptoms may be occasional but they become more frequent and severe in intensity as the deformity progresses.

The symptoms may be occasional but they become more frequent and severe in intensity as the deformity progresses.

Should knee replacement surgery always be considered as a last resort?

Sam Rajaratnam: Getting the timing of surgery right is key to achieving great results after knee replacement surgery.

Rather like “picking grapes at the perfect moment to make wine", an experienced surgeon will help you with choosing if a knee replacement is right for you at a certain moment in time.

Can you leave surgery for an osteoarthritic knee too late?

For the best results, it is often wise not to leave the situation until severe deformity, stiffness and loss of function have set in over the years.
Occasionally I see someone who has a severe deformity in their knee, by ignoring the problem for many years.

Once ligamentous incompetence and stiffness become established in the knee, more complicated surgery needs to be performed, involving soft tissue releases, more advanced and invasive replacements.

Getting advice early is the key.

To discuss your symptoms and the best way to manage them speak to one of our specialists on 020 8064 0875.

How does timing of treatment affect the outcome of a total knee replacement?

Sam Rajaratnam: A knee replacement is more likely to be successful in individuals whose pre-operative range of motion and muscle tone remain good. Surgery should always be considered on a case by case basis, and depends on the severity of the disease process.

How do you choose the right time for a knee replacement?

Sam Rajaratnam: Each case is different and each presentation is unique. Often individuals will have tried conservative treatments and have come to the realisation that these treatments may have helped for a short period of time - but not provided the cure.

If the right moment is chosen when the patients' quality of life is deteriorating based on the progression of their osteoarthritic knee, a knee replacement should positively transform their lives.

The decision to operate and perform a knee replacement is a shared process between doctor and patient.

About Sam Rajaratnam

Mr Sam Rajaratnam is Orthopaedic Director of Schoen Clinic, a specialist private hospital dedicated to orthopaedic and spinal surgery.

Sam is recognised as one of the leading knee surgeons in the UK, with amongst the best results and lowest failure rates on the National Joint Registry. He has performed over 5000 knee replacements and has a particular interest in making knee surgery less painful and promoting a rapid recovery and quicker return to function.

Please call Compare my Care on 020 8064 0875. We are very much here to help and guide you.

Want to see more?

View Mr Sam Rajaratnam's biography...