Distal femoral osteotomy in degenerative knee disease: indications, planning, techniques and complications
Distal femoral osteotomy (DFO) is an established joint-preserving procedure that occupies a clearly defined, though under-utilised, place in the surgical management of unicompartmental degenerative knee disease of femoral origin. By correcting the deformity at its anatomical site, DFO restores a satisfactory mechanical axis without inducing the excessive joint-line obliquity that may follow an isolated tibial correction.
The aim of this review is to provide the practising surgeon with a structured overview of the current indications, preoperative planning, operative techniques and complications associated with DFO. The ideal candidate is a relatively young and active patient with mild lateral or medial femorotibial osteoarthritis, an extra-articular deformity of femoral origin, and an abnormal mechanical Lateral Distal Femoral Angle (mLDFA <85° in genu valgum, >90° in genu varum). Preoperative assessment must combine a bipedal weight-bearing full-length lower-limb radiograph with adequate dynamic and axial views; computed tomography or EOS imaging is recommended when a multiplanar component is suspected or when patient-specific cutting guides are envisaged. Planning aims for moderate overcorrection in varus and restoration to a normal mechanical axis in valgus, while keeping the mLDFA within the physiological range.
The principal techniques—medial closing-wedge and lateral opening-wedge osteotomy for genu valgum, and lateral closing-wedge (favoured) and medial opening-wedge osteotomy for genu varum—are described step by step, with emphasis on the biplanar cut, the position and protection of the hinge, and reliable fixation with a locking compression plate. Postoperative management is dictated by the chosen technique, with earlier weight-bearing permitted after closing-wedge procedures. The most relevant complications—correction errors, hinge fracture, delayed union and non-union, vascular injury, stiffness and hardware-related discomfort—are reviewed, together with practical strategies for their prevention and management. Patient-specific cutting guides currently appear to be the most promising adjunct for improving reproducibility and meeting the demanding operative requirements of DFO.
