KNEE SURGERY

Revision of knee prosthesis

Despite remarkable advances in orthopaedic surgery, a knee prosthesis can, over time, wear out or develop complications that require replacement. 
Revision of a knee prosthesis is a highly technical procedure designed to replace the worn prosthesis with a new one in order to restore joint function, relieve pain and improve quality of life.

The operation can also be used for joint reconstruction if the bone damage is extensive.
Knee replacement surgery requires specific know-how and experience. Some specific implants have been designed for knee replacement, such as semi-constrained or constrained prostheses. 


knee picto

Why can a knee prosthesis wear out?

The quality of knee prostheses has evolved considerably over the last 40 years, thanks to:

  • A design for implants improved to better reproduce the natural anatomy of the knee, in particular the patellofemoral joint.
  • More efficient materials:the quality of the polyethylene between the femur and the tibia.
  • To more modern installation techniques:these include better-adapted ancillary equipment, navigation and robotics.

Despite this progress, the prosthetic joint is still subjected to daily stress when walking, going up and down stairs, and during physical and sporting activities...

In the long term, these constraints lead to a wear and tear but slowly and progressively. 

Other events may also lead to the need to change the prosthesis.

prothèse totale de genou de reprise de type %22charnière%22 (contrainte)

Hinge-type revision total knee prosthesis (constraint).

Here are the situations in which a prosthesis may need to be replaced:

  • Loosening of the prosthesis (due to wear) In general, loosening is the result of wear and tear of the part between the tibia and the femur. This wear leads to the formation of a granuloma with wear particles. However, loosening can also be the result of a problem with the initial fixation of the implant. The implant then becomes abnormally mobile in relation to the bone. This may involve the femoral or tibial part of the prosthesis moving. It is this loss of adhesion between the prosthesis and the bone that causes the pain. 
  • Instability Ligament loosening: this is abnormal mobility of the prosthesis. The ligaments are relaxed and the prosthesis is not stable. This can cause pain, a feeling of insecurity and repeated effusions. This situation is rare.   
  • Infection In case of infection of the prosthesis, it may be necessary to change the whole prosthesis. Simply washing the prosthetic joint with antibiotics is not always sufficient. Infection usually occurs within a year of the prosthesis being fitted, but sometimes later. 
  • A fractured tibia or femur Fracture: a fracture of the femur or tibia, if it is close to or in contact with the knee prosthesis, may cause it to break. It may then be necessary to change the prosthesis when the fracture is repaired.
  • Chronic pain, stiffnessTotal knee replacement is an operation that works well in 70 to 80 % of cases. Nevertheless, in a small percentage of cases, the knee may remain painful and stiff, without the diagnosis of loosening or infection being made. The cause of the pain is not very clear in these cases. Sometimes the knee is too tight. Whatever the case, it may be decided to replace the prosthesis as a last resort.

The post-operative course of a revision knee prosthesis is longer than that of a first intention prosthesis.

What are the signs of wear on a knee prosthesis?

The wear mainly concerns the polyethylene part between the tibia and the femur. 

It will lead to:

  • Wear debris polyethylene forming a granuloma
  • Inflammatory reaction in the joint
  • Progressive deterioration of the bone in contact with the prosthesis
  • Loosening: the prosthesis is no longer firmly attached to the bone and begins to move abnormally.

For the patient, this means:

  • From pain increasing joint pain
  • A feeling instability
  • A swelling knee (effusion)
  • Sometimes a progressive deformation of the leg.
nexgenr

Three examples of revision knee prostheses according to level of complexity.

revision knee prosthesis 2

Front and side partial knee prosthesis with wear in the other compartments

How long does a knee replacement last?

The lifespan of a knee prosthesis is very satisfactory:

  • According to published series 90 to 98 % of prostheses have no loosening of more than 15 to 20 years monitoring 
  • The rare cases of loosening or significant wear generally occur after 15 years.

However, factors such as age, activity level, weight and bone quality can influence this duration.

What are the indications for revision knee replacement?

There are two main indications for revision knee replacement:

  • Prosthetic loosening responsible for pain and abnormal knee mobility.

The loosening will be confirmed by radiographic examinations and possibly a CT scan. 

On the X-ray and CT scan, the surgeon highlights a border,this is an abnormal space between the prosthesis and the bone. 

There has also been a mobilisation of the prosthesis which is no longer in its normal axis. The part of the femur or tibia is tilted. This mobilisation of one of the implants is responsible for a deformity of the knee, often varus or valgus.

  • Infection of the prosthesis not controlled by antibiotic therapy and joint lavage. 

Early infection can often be treated by washing the joint and prosthesis and treating with antibiotics. 

However, if the infection occurs four to five weeks after the prosthesis has been fitted, then this treatment is often not sufficient. It is often recommended that the entire prosthesis be replaced, along with washing and antibiotics.

  • As we saw earlier, there are other situations in which the prosthesis may need to be changed: a fracture around the initial prosthesis or the totalization of a partial prosthesis.

The latter situation is characterised by wear and tear in the knee compartments that were not operated on when a partial prosthesis was fitted. Osteoarthritis of the knee has therefore progressed, affecting compartments that were initially intact. The partial prosthesis has played its role for a while, but it is now advisable to remove it and fit a total prosthesis.

revision knee prosthesis

Front and side partial knee prosthesis with wear in the other compartments

partial knee replacement

Revision knee prosthesis with external wedge.

How does the takeover work?

Revision of a prosthesis is a more complex operation than initial implantation. It requires :

  • A new incision:the surgeon generally takes over the scar whenever possible. It is sometimes necessary to make another incision.
  • Withdrawal of the old prosthesis: this is a delicate, meticulous stage that must not be neglected. Even if the implant is loosened or partially loosened, great care must be taken to remove only the worn prosthesis and preserve as much of the patient's bone as possible. In some cases, there may be significant adhesion despite the loosening. The soft tissue must be preserved, i.e. the muscles, tendons, etc. This important stage can take a long time to complete.
  • A bone reconstruction if necessary: if there is bone damage related to wear, bone tissue must be reconstructed where possible. A bone graft is used.
  • The installation of a specific revision prosthesis: in knee replacement surgery, it is sometimes possible to reposition a primary prosthesis known as a "sliding prosthesis". On the other hand, it is sometimes necessary to use a semi-stressed prosthesis or, more rarely, a stressed (hinged) prosthesis if the ligaments are damaged. These prostheses provide greater stability in the frontal plane.

How do you prepare for a return to surgery?

The revision of a knee prosthesis is a more complex operation that requires planning and preparation:

  • An in-depth clinical assessment with the surgeon and anaesthetist.
  • A complete and appropriate complementary imaging work-up (CT scan, MRI, scintigraphy): a radiographic work-up is often supplemented by a CT scan, and sometimes by an MRI. This imaging work-up enables us to assess the displacement of the prosthesis, its wear and tear, and any bone damage to the tibia and femur.
  • Biological work-up if infection is suspected: the joint is usually punctured to analyse the fluid for bacteria. A blood count and CRP are taken. 
  • A cardiological opinion is sought. It is sometimes necessary to complete this assessment with more specific tests (scintigraphy, cardiac echography, etc.).

As each case is unique, the surgeon will adapt the surgical strategy to your situation.

partial knee replacement 2

Revision knee prosthesis with external wedge.

Post-resumption recovery and rehabilitation

The revision of a knee prosthesis involves a longer period of re-education and recovery:

  • Progressive mobilisation supervised by a physiotherapist
  • Personalised post-operative instructions 
  • Support instructions and a time limit for regaining full walking ability adapted to each situation
  • Muscle strengthening work focused on the quadriceps
  • The initial hospital stay is often slightly longer than after a first-line prosthesis.

Good patient involvement (compliance with the instructions given by the surgeon) is essential to ensure the success of the operation.

Where to have an operation in Paris?

Our teams work in a number of leading establishments in Paris:

For consultations:

  • Espace Médical Vauban
  • IMSS - Institut Médical Sport Santé
  • ARAGO Clinic

For interventions:

  • ARAGO Clinic

You will be cared for by recognised specialists: Dr Kerboull, Dr Sailhan and Dr Zilber, experts in hip surgery.

clinical entrance

Revision knee replacement is a specialised surgical procedure designed to restore joint stability and provide lasting pain relief. An experienced team and personalised care are essential to the success of the operation.

Don't wait to regain your mobility: contact us to assess your situation and consider a suitable solution.

Contact us for a consultation