Revision Knee Replacement Surgery

The average life of an artificial knee or hip joint is anywhere between 15 to 25 years. This depends on quality of bone in which the parts are fixed, the quality of surgery, and complication like injury or infection in the implanted joint.

The surgery of revision is more demanding than the first surgery, because in revision scenario, the quality of the bone is usually poor, with large gaps that may need filling up. Also the ligaments may be damaged beyond repair, requiring specialized implants.

Following are specialized implants and their use in various special situations.

  • Rods
    When the bone needs additional support, one may use long rods. As in case of fracture in the tibia that needs additional support
  • Wedges or augments
    when the bone on one side is more damaged, one may need wedge or augment to support the defect
  • Sleeve or cone
    when there is big defect in the bone, one may need a sleeve or cone to fill it up
  • Rotating hinge
    a special kind of joint that is needed when ligaments can no longer support the regular implant.

Case 1

This lady had her primary knee replacement done using simple implant
This failed and hence the surgeon used wedge and rod to fill up the bone defect
This too failed

At this stage she came to our centre

On detailed analysis we found that her upper tibial bone was completely missing

We opted for sleeve reconstruction which is ideal for such a massive bone loss

x-rays after sleeve reconstruction and complete stabilization of joint

Case 2

The usual life of artificial knee joint is close to 20 years. But in some instances, the implant may separate from the bone, may be due to mismatch in the elasticity of bone and metal. This condition is called “Aseptic loosening” meaning loosening without infection (sepsis)

In such a situation one needs to do re surgery and change the implant. And usually the bone is soft and deficient so one needs revision implant

The x-ray shows right knee joint implant is loose and there is bowing of the knee joint
Since one needs to plan the exact angle of deformity, a special full length x-ray is taken
X-rays after revision using sleeve in tibia

Case 3

Why does an implant become loose

An implant may become loose either because of infection. In which case it is called Septic loosening.
When it loosens without infection, it is called aseptic loosening

Sepsis : Means infection

An implant can become loose without infection for following reasons

  • If initial bond between cement and bone does not happen
  • If the bone underneath the implant dies
  • If the implant is not inserted in correct axis
  • Over load on the implant
  • Sometimes the wear particles of plastic or metal cause weakening of bone and loosening
  • Injury
  • Osteoporosis
Here are two more cases of aseptic loosening