Load a TKA radiograph to start measuring
Click “Open image” or paste (Ctrl/⌘+V) from PACS
Click “Open image” or paste (Ctrl/⌘+V) from PACS
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Case (Study ID)
Film type
Pre-op → saves value as Planned / target (native alignment) · Post-op → saves as Achieved for the selected observer
Observer (for ICC)
Select observer before saving (applies to Post-op). Measured value goes to that observer’s Achieved field.
Angle measurement (click “Measure”, then click points on the image)
Auto-calculated (from MPTA & LDFA)
Parameter
Planned
Achieved
Deviation
aHKA = MPTA − LDFA
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JLO = MPTA + LDFA
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CPAK type
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aHKA: negative = varus, positive = valgus (±2°) · JLO: <177° apex distal, 177–183° neutral, >183° apex proximal · CPAK 9 types per MacDessi 2021 (Achieved = mean of observers)
Demographics & surgery
Outlier thresholds: MPTA/LDFA ±2° · aHKA/JLO ±3° · slope ±3° · angles are scale-invariant (no calibration needed)
© Research aid — always verify each measured value before analysis
© Research aid — always verify each measured value before analysis