HTO & DFO Guides: Taking the Guesswork Out of Knee Osteotomy

Corrective osteotomy around the knee has a simple principle and unforgiving execution: the correction angle planned on the long-leg radiograph must be reproduced on the bone, degree by degree. Overcorrection converts a varus knee into an uncomfortable valgus one; undercorrection fails to relieve the overloaded compartment.

The digital plan

Planning starts with a full-length weight-bearing radiograph and CT. The mechanical axis is drawn, the target chosen (a common HTO target lands the axis at Fujisawa's zone, 62–65% of plateau width), and the osteotomy simulated digitally — hinge position, wedge geometry, plate position, patellar height and posterior slope all checked before anything is cut.

What the guide does

• Landmark-keyed seating: single correct orientation, no measuring
• Pre-planned pin trajectory defines the hinge axis
• Saw slots bounded in depth to protect posterior structures
• Plate preview holes: fixation drilled before the cut, not after

Accuracy and recovery

Comparative studies report correction within ±1–2° of plan in the large majority of guide-assisted osteotomies — and in osteotomy, the scatter is the complication. Upload the long-leg films and CT via the How It Works page; guide design, simulation and quotation arrive as one package.