Fig. 2

Schematic drawing of the bone region parameters of the supra-fibular-head space (A). The actual measurement of the technique to measure the bone region parameters on the 3D CT image (B, C). The blue pin indicates the superior border of the articular surface of the fibular head (M); the green pin indicates the vertical intersection of the blue pin to the lateral margin of the articular surface of the tibial plateau (B); the red pin indicates the anterior border of the articular surface of the fibular head (N); and the purple pin indicates the vertical intersection of the red pin to the lateral margin of the articular surface of the tibial plateau (C). I indicates region I; II, region II; and III, region III. The black pin indicates the centre of the leading edge of the tibial plateau (E); the grey pin indicates the centre of the trailing edge of the tibial plateau (D); the brown pin indicates the centre of the tibial intercondylar eminence (F). α indicates the thickness of articular cartilage. Green pentagram, caput fibulae; White pentagram, lateral condyle femur; Red pentagram, articular cartilage