SUNSHINE HOSPITALS TOTAL KNEE ARTHROPLASTY
SUNSHINE HOSPITALS TKA is one of the most successful surgeries performed with excellent 15–20-year survivorships routinely reported in large series by multiple surgeons. It is widely used in the treatment of severe knee osteoarthritis, Inflammatory arthritis, rheumatoid arthritis, gout and other general arthritic conditions.
When the medical treatments antalgic and anti-inflammatory medications, heel wedges, off-loading knee braces, weight reduction, activity modification, the use of ambulatory aids , intra-articular corticosteroid or viscosupplementation injections, physiotherapy have failed, time is coming to implant a prosthesis to relieve pain and to restore knee function.
Prosthesis Components
The devices are composed of :
- a fixed femoral and
- a fixed tibial plateau these components articulate by the intermediary of :
- a polyethylene insert replacing the two damaged articular surfaces.
The patellar surface is not always damaged and in that case the surgeon doesn’t resurface it.
One successful design concept that has evolved over the last 3 decades is the use of mobile-bearing TKA : it allows unimpeded freedom of the polyethylene inserted between the femur and tibia to rotate around a central post on a highly polished, cobalt-chrome tibial surface.
Kinematics of The Prosthesis
Kinematicaly, the native knee joint is much more complicated than a simple “hinge” joint. TKA attempts to recreate the complicated sagittal and rotational plane kinematic motions that occur during range of motion in the normal knee.
The mobile-bearing TKA allows increasing implant conformity and substantially increases contact area, reduces contact stresses, and lowers polyethylene wear. This is supported by in vitro testing and the excellent long-term clinical results with minimal loosening reported in numerous studies.
It improves control of anteroposterior translation with reduced paradoxical anterior femoral translation and self- aligning behavior to maintain large, centrally located surface contact areas at the femorotibial articulation during both flexionextension and axial rotation of the knee which is much more difficult to achieve in fixed-bearing TKA designs.
The rotational freedom provided by rotating-platform TKA designs assists in maintaining self-alignment of both the patellofemoral and femorotibial articulations throughout knee flexion, lessens polyethylene surface stresses, and reduces polyethylene wear by decoupling multidirectional motions to more monodirectional motion patterns at 2 differing interfaces, thus reducing cross-shear stresses and wear.