Total and partial knee artroplasty (tka & pka)
When is this procedure indicated?
This surgical procedure is indicated in cases of: osteoarthritis (OA) of the knee joint (of the medial compartment, lateral compartment anterior "patello-femoral" compartment): Primary OA, Post-traumatic OA, Reumatic OA (no PKA), Post-infective OA; osteonecrosis of the medial and/or lateral femoral condyle; special indications in acute fractures of distal femur and proximal tibia.
How is it performed?
Total or Partial Knee Artroplasty or Replacement is done by removing the damaged articular cartilare and bony tissue (including the new-formed eccessive bony tissue called osteophyte), replacing it with an artificial joint usually made of a metal alloy, ceramic or plastic "Polyethylene" that covers the distal femur, proxiaml tibia and/or the patella "knee cap", with an intermiediate "disc" in plastic "Polyethylene" between the femoral and the tibial component, the prosthetic components are fixed into bone either using a special glue called bone cement or applying a direct so-called press-fit meccanical stability; if needed synovial membrane can be partially or totally removed; joint capsule release or reinforcement is perfomed when needed too. This surgical procedure provides also the correction of defotmities and the abnormal ligament laxities around the knee joint; this can be achieved through the release, tentioning or even the simultaneous riconstruction di lacking ligaments. The end result will be a new "artificial" joint that provides a normal, or almost normal, pain-free range of motion with a correct alignment and ligament balance of the knee joint that will guarantee a normal and pain-free function of the operated knee joint, this permits the patient to return to normal life style without significat physical or functional impairment.
Hospitalisation may last from 2 to 5 days. No knee brace is needed. The patient start to walk the day after surgery with the aid of cruthes and weight-bearing is allowed. A period of rehabilitation is needed in order to regain muscle and movement of the knee joint and to "learn" how to walk using the new knee joint; rehabilitation starts the day after surgery and should be continued applying an in-hospital or out-patient regabilitation regimen. The duration of rehabilitation can vary according to the severity of joint limitation and deformity before surgery and according to the physical capacity of the patient.
Short-term complications are generally not frequent, they include: bleeding that necessitates blood transfusion, early local infection, deep vein thrombosis (DVT) and pulmonary embolism (PE), surgical wound opening "dehiscence", wound necrosis, neurovascular injuries, bone facture and ligamentous tear around the knee joint, malpositioning or malalignment of the prosthetic components. Malalignment of the lower limb (varus or valgus deformity of the knee joint). Most of short-term complications have an incidence that can vary according to the standardisation of the surgical procedure and the expertise of the whole surgical, operating room and in-hospital ward equipe and not only of the first surgeon alone. This can be achieved only applying the principle of teamwork throughout all phases of patient management. It's worth to say that Partial Knee Artroplasty (PKA) being a shorter and less invasive procedure is considered to be associated to a less percentage of complications than Total Knee Arthroplasty (TKA).
Long-term complications are again not frequent, they include: late local infection, loosening of the prosthetic components (which can be due to an infection "sceptic loosening", due to a mecchanical malalignment or malpositioning or the prosthetic components, due to a biological reject or lack of integration between the host bone and the prosthetic components themselves), wear of the prosthetic components, breaking of the prosthetic components, knee joint disclocation, limitations in range of motion of the knee, varus or valgus deformity of the knee (which can occur in the long term due to "sinking" or "detachment" of the prosthetic components from the host bone. Mostly long-term complications brings the need to a "Revision Knee Artroplasty" surgery which can be performed in one-stage or two-stage procedure (passing through a provisional bone cement spacer phase in case of sceptic loosening), in some rare cases a complete fusion procedure of the knee joint caslled "Arthrodesis" is recurred to.