Fig. 2

Fluoroscopic intra-operative views of a left knee underwent TCVO. a Two guide wires were parallelly inserted at a same horizontal level 3 cm below the joint line, with one positioned at anterior 1/3 and the other at posterior 1/3 of the tibial shaft. Another guide wire was inserted from anteroinferior site of the tibial tubercle and passed towards the tip of the lateral intercondylar eminence. b A spreader was applied to provide valgus force for gradually raising the lateral tibial condyle. c Measurement of opening angle and distance during osteotomy surgery. The distance between the intersections of the osteotomy lines with the medial cortex was defined as opening distance. The angle formed between the margins of osteotomy gap was defined as the opening angle. Application of two prophylactic hollow screws across the intercondylar eminence before fixing the locking plate is essential for protection against fracture under large correction angle