A case article by Dr. Manjunatha Ganiga Srinivasaiah
There is current debate concerning the most biomechanically advantageous knee implant systems, and there is also currently great interest in improving patient satisfaction after knee arthroplasty. Additionally, there is no consensus whether a posterior-stabilized (PS) total knee device is superior to a more congruent, cruciate-substituting, medially-stabilized device (MS). The primary hypothesis was that the clinical outcomes and specifically the patient satisfaction as measured by the Forgotten Joint Score (FJS) would be better in the MS group.
Kinematic alignment originated from the studies showing that the tibia moves about the femur in a flexion extension axis, which corresponds to the axis of the cylinder that best fits the femoral condyle. The flexion extension axis is parallel to the distal joint line as well as the posterior joint line of the femur. Kinematic alignment restores the joint line through anatomic resurfacing hence, aligning the prosthetic components to the flexion extension axis of the knee.
Osteoarthritis can damage the cartilage layer of the femur and tibia and lead to degeneration leading to varus or valgus alignment which alters the kinematics of the knee and the tension of the collateral ligaments. Kinematic alignment restores the pre-arthritic condition starting from the femur compensating for the cartilage wear to reference the native joint line and cutting exactly the implant fitness on the two condyles both distally and posteriorly. Which resurfaces the femur and aligns the components to the cylindrical axis, once the femoral component is placed the native femoral articular surface is restored. Similar technique is applied to the tibia, a symmetric cut is performed on the medial and lateral side restoring the native anatomical slope, later implants are fixed and native tibial articular surface is restored through anatomic resurfacing with no ligament releases. Kinematic alignment restores the native joint line as well as the limb alignment of the patient for a truly personalized implant placement combined with the unique design features of the implants.
Currently it is documented in Australian Orthopedic Registry that approximately 27% increase in kinematic knee arthroplasty with good FJS.
At Medeor Hospital, Dubai, we had a gentleman (hard manual labourer) with secondary osteoarthritis right knee of Grade IV. He was 45 years and weighed about 106 kilograms. Hence for better function and durability he was planned and performed Kinematic Alignment Right Knee Arthroplasty.
However, to our knowledge it is the first of this kind surgery performed in UAE in a patient for a truly personalized implant placement combined with the unique design features of the MS implants used.
Post – operatively, patient walked around two hours after a Kinematic Alignment Knee Replacement surgery and was discharged after three days.