Calipered-Kinematically Aligned (KA) Total Knee Replacement

Dr. Sukin introduced calipered kinematic alignment to his patients in 2020 to speed knee recovery after total knee replacement. Unlike ‘mechanical alignment,’ this technique uses intraoperative verification checks and caliper measurements to ensure a perfect fit. Dr. Sukin has collaborated on studies, education, and recently developed an augmented reality (AR)-assisted kinematic alignment technique with a global team of orthopedic surgeons.

The traditional, mechanically aligned (MA) can change the patient’s joint line, causing pain, stiffness, and instability in some. Calipered-kinematic alignment restores the patient’s pre-arthritic joint surfaces, more accurate than robotics and navigation instrumentation. It also has a beneficial effect on function, similar to aligning new tires on a car’s axles.

What does an arthritic knee look like?

The goal is to have bone and cartilage that is removed in every aspect of the knee to be the same thickness as the replacment. The simple caliper is the most crucial tool for kinematic alignment, measuring bone thicknesses and adjusting them to ± 0.5 mm of replacement parts. Recent studies show caliper technique accuracy surpasses robotic surgery in restoring joint lines. Augmented reality now aids surgeons during surgery, providing valuable additional information.

Researchers compared caliper-assisted kinematic alignment to mechanical alignment in many multicenter studies. Patients with caliper-assisted technique had better satisfaction, function, and recovery. They also had fewer ligament releases, improved knee motion, and better overall function compared to mechanical alignment. The forgotten joint score, a measure of patient satisfaction after knee replacement, showed a significantly higher score for caliper-assisted technique than mechanical alignment.

Combining the kinematically aligned knee with the right prosthesis provides ACL- like stability with a medial ball-in-socket prosthesis and normal pre-arthritic anatomy with an unconstrained lateral compartment. This unique design offers both stability and anatomical integrity.

Medial Ball-In-Socket, Unconstrained Lateral

The pre arthritic human knee functions like a ball-and-socket mechanism, pivoting on the same side. A prosthetic that mimics this function is essential for stability and normal knee function. A ball-in-socket design provides ACL-like stability and functions like a normal knee, leading to a more stable and athletic knee. Studies show that combining kinematic alignment with a ball-in-socket prosthesis results in higher function compared to traditional components which function more like a knee without an ACL and meniscus.

  • Same-day discharge is the standard for most.
  • These Implants are also durable, with most patients aged 60 or older having a low probability of needing another operation in the same knee.
  • These implants offer cementless options exist.

For a patient consultations, kindly call 406-586-8029.

*Outside referrals are individually reviewed for failed knee replacements