Achieving Ligament Balance with Mako
Despite significant advancements in TKA instrumentation and surgical techniques, properly balancing a knee during total knee arthroplasty continues to be one of the most important challenges facing orthopedic surgeons today. Patients with mal-aligned and unstable knees have consistently reported lower satisfaction scores, and these knees demonstrate a higher incidence of loosening and revision. In contrast, TKA patients with well-aligned and well-balanced knees that function optimally demonstrate longer survivorship and significantly higher patient satisfaction.
The complexity increases further when dealing with knees presenting fixed deformities, severe flexion contractures, or recurvatum—conditions that add substantial difficulty to the joint balancing process. Traditional TKA approaches have historically aimed at placing components in the same position for all patients, irrespective of anatomic differences, relying primarily on classic 2D templating on acetate or digital x-rays for preoperative planning.
The paradigm shift: Functional implant positioning represents patient-specific implant placement determined by both bone structures in the joint and the condition of the ligaments—moving away from one-size-fits-all approaches to individualized surgical planning.
Patient-specific 3D bone models generated from CT scans provide unprecedented accuracy in planning and component size predictability, replacing traditional 2D templating methods.
Real-time assessment of soft tissue tension throughout the range of motion enables surgeons to achieve optimal ligament balance without excessive soft tissue releases.
Submillimeter accuracy in bone preparation ensures the surgical plan is executed with unprecedented precision, consistency, and reproducibility.
Recent clinical research demonstrates that functional alignment with individualized planning leads to superior patient outcomes. In a prospective study of 300 consecutive robotic-assisted functional alignment TKAs, patients who received individualized functional alignment planning showed significantly improved results compared to mechanical alignment approaches.
Patients with constitutional varus reported the greatest improvement with functional alignment techniques (Forgotten Joint Score of 89 versus 65). The study concluded that maintaining joint line obliquity while achieving individualized alignment was associated with improved outcomes at 2 years post-TKA, and that three-dimensional component position and joint line obliquity affect outcomes following TKA independently of coronal limb alignment.
Key Finding: Functional alignment with kinematic planning resulted in higher tibial varus, higher femoral valgus, and higher joint line obliquity—yet maintained the same overall limb alignment while delivering superior patient-reported outcomes.
3000 Edward Curd Ln.
Franklin, TN 37067
