Table 1 Differences between commonly used personalized Total Knee Arthroplasty techniques
Technique | KA [5] | rKA [6] | Easy rKA | iKA [8] | |
|---|---|---|---|---|---|
Planning surgical steps | Femur first (ext. gap first) | Femur first (ext. gap first) | Femur first (flex. gap first) | Tibia first (ext. gap first) | Femur First (ext. gap first) |
Knee balancing drivers | Tension native ligaments | Tension native ligaments | Slight asymmetry gaps (1–2 mm) | Ligaments Isometry | Ligaments Isometry |
Tools | Caliper (manual) | Robotics recommended | Robotics mandatory | Robotics | Robotics |
Femoral distal cut | Wear determined | Parallel to distal femoral joint line (HKA ± 3°) | DLFA ± 5° | Guided by tibial cut | Parallel to distal femoral joint line (Target: 0°–5°) |
Femoral posterior cut | Parallel PCA | Parallel PCA | Slight asymmetry flex gap | Guided by tibial cut | Surgical TEA |
Tibial coronal cut | Symmetric (base of ACL spine) | Parallel to tibia joint line (HKA ± 3°) | MPTA ± 5° | Safe zone: 6°varus/2°valgus | Perpendicular tibial MA |
Tibial slope | Parallel medial plateau slope | Parallel lateral plateau slope | 5°–7° (MC insert) | Parallel medial plateau slope | Parallel medial plateau slope (0°–3°) |
Tibial rotation | Parallel axis lateral plateau | Matching with femur in extension | Maximum coverage tibial plateau | Parallel axis lateral plateau | Target: Akagi’s line |
Soft tissue releases | Never | Only for extreme preoperative alignments | Occasionally to correct severe deformities | Sometime | Rarely |