In a Knee Replacement, the knee joint is accessed through an incision on the front of the knee. The arthritic parts of the Femur (thigh bone), Tibia (shin bone) and often the Patella (knee cap) are shaved off and replaced by the prosthesis.
The artificial Knee Prosthesis comprises of a metal femoral component, a metal tibial component, a plastic insert between the two and a plastic button for the knee cap. The femoral and tibial component are fitted onto the respective bones like a ‘crown on a tooth’, often with cement. The insert clips in between and the movement happens between the femoral component and the plastic insert. Unlike Hip Replacements, the bearing surface in Knee replacements are uniformly Metal on Plastic.
The operation is performed under a general or a spinal anaesthetic. Depending on the time of the operation, the patients are up walking (with a frame) the same day or the next day. Patients often stay 1-3 days in hospital and then may spend a week or so in a rehabilitation hospital where the focus is on physiotherapy. Alternatively, patients may get discharged home directly and see a physiotherapist in the community few times a week. There are no hard and fast rules about this as long as one works hard the first month to restore your movement range and strength. Return to work would depend on the type of work being undertaken but for most occupations this can be expected by 6-8 weeks.
Unlike hip replacements though, Knee replacement require significantly more motivation and effort on the part of the patient, especially in the first month after surgery. Patient motivation in rehabilitation has been identified as the single most important factor in getting a good result.
Overall recovery may take a year (till all healing comes to a plateau) but functional recovery can be expected by 4- 6 weeks. Some aching pain and swelling can remain for many months but as long as everything is gradually improving, this is all expected. These symptoms often wash away over 6-12 months.
Knee Replacement Videos
Advances in Knee Replacement Surgery
For people who are suffering with arthritis but are too young and high demand to consider a Knee Replacement, a Realignment of the knee can be considered. The purpose of this is to unload the diseased part in order to delay the need for a Knee Replacement.
Consequences of Patellar Maltracking
Patellar Maltracking can cause problems ranging from instability (Knee Cap popping out) on one hand, to an increased pressure behind the patella causing pain often referred to as ‘Anterior Knee Pain’ on the other. Whilst instability or Patellar dislocation can cause major cartilage damage even in one instance, these pressure changes cause slower early wear of the cartilage surface (Chondromalacia Patellae).
All of these culminate in ongoing damage to the cartilage i.e., Arthritis.