Four alignment philosophies
Femoral valgus setting 0°
Tibial varus setting 0°
Ideal reference calculation
F = 90° − mLDFA; T = 90° − mMPTA. These calculated targets assume ideal mechanical reference axes. They are not measurements of the atlas or predictions of achieved mHKA.
How one degree changes the plan Increase F by 1°: mLDFA falls by 1° and aHKA moves +1° toward valgus. Increase T by 1°: mMPTA falls by 1° and aHKA moves −1° toward varus. Decreasing either setting reverses its effect.
Original CPAK JLO = mMPTA + mLDFA. The sum is an index, not the physical tray tilt to the floor. Measured HKA uses the acquired hip–knee and knee–ankle axes and remains separate.
Sagittal tibial slope demonstration 3°
The sample KA/rKA comparison uses an illustrative native target, with femoral valgus 2° and tibial varus 6°. Presets illustrate intent and boundaries, rather than measure this atlas. They are not patient prescriptions.
Freedom: which instrument changes what?
Distal femoral coronal angle DFCG angle block / R–L rail adapter. Measure the anatomical–mechanical angle (AMA) before converting the mechanical target to the IM reference. For the usual valgus geometry: IM setting = AMA + F. With an illustrative AMA of 6°, F 0° gives 6° and F 2° gives 8°. A higher setting adds femoral valgus if the rod direction is unchanged. R10 lists marked 3°–9° adapters; confirm the supplied tray and rod trajectory.
Original Maxx Freedom R10, page 8 · distal femoral IM guide Tibial coronal angle and slope The EM ankle-clamp M/L adjustment orients the coronal reference; the alignment rod checks it. The EM tower quick-release adjusts sagittal orientation. R10 specifies a 3° posterior-slope cutting slot: account for that slot offset and the guide orientation when interpreting the final plane. There is no universal millimetres-per-degree knob movement.
Original Maxx Freedom R10, page 10 · EM tibial guide Femoral axial rotation and resection depth The universal A/P sizer offers 0°, 3° or 6° external rotation to PCA. 3° → 6° adds 3° ER; 3° → 0° removes 3°. Cross-check AP anatomy and surgical TEA. The distal block ±2 mm positions and the 2/9 tibial stylus change depth references, not degrees.
Original Maxx Freedom R10, page 9 · universal A/P sizer Freedom R10: pages 6–11 and instrument list page 16 . Confirm the achieved cut and reconstruction after a change.
PAS definitions · Published rKA protocol Femoral rotation Reference the posterior condylar axis (PCA), cross-check the surgical TEA and AP anatomy.
External rotation relative to PCA 3°
0° 3° 6°
Freedom A/P guide options: 0°, 3° or 6° relative to PCA (R10, p. 9). Selection depends on the reconstruction and observed anatomy.
The axes shown on this atlas are schematic reference lines. The angle control rotates the demonstration line; it does not identify a surgical TEA or prescribe tibial slope.
Official technique STAGE 01 / 18
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Femoral rotation to PCA 3°
Atlas bones with generic instruments and implant surfaces. Educational stage animation; no tissue mechanics, cutting-force model, patient-specific planning or validated surgical-training simulation. Operative order varies.
Freedom R10 surgical technique