The most common indication for impaction grafting is the stove-pipe Paprosky type IV femur in a younger patient.

Other indications include an ectatic femur over a distal diaphyseal blockade prohibiting press-fit fixation (a long diaphyseal cement plug, a long stemmed revision total knee arthroplasty component, old fracture deformity, etc.)

Femoral impaction grafting follows 5 steps: diaphyseal stabilization, diaphyseal grafting, metaphyseal fixation, metaphyseal grafting, and cementation of implant.

Intraoperative and postoperative femur fractures are not uncommon with this technique. Longer cemented implants may mitigate the risk of postoperative fracture when diaphyseal defects can be bypassed.

An extended trochanteric osteotomy for implant removal is not a contraindication to femoral impaction grafting.

Plates or struts for diaphyseal stabilization

Wires or cables per surgeon preference

Wire mesh if desired for metaphyseal stabilization

Cement restrictor with wire suited for cannulated impactors

Bone chips of varying sizes (3-8 mm is preferred)

Femoral impaction system: distal impactors, phantom implants, square-end impactor, half-moon impactor

Cement

Polished tapered stem designed for cementation with the taper-slip philosophy

The posterior approach most commonly is used because of ease of access to femoral canal and extensile nature.

The anterolateral approach can be used as well.

Extended trochanteric osteotomy or Wagner-type osteotomy can be performed as well if needed for implant removal. Very secure subsequent fixation of the osteotomy is needed before impaction grafting.

Templating is important to plan for an implant that (1) recreates appropriate length and offset and (2) bypasses area of bony deficiency.

Determine whether extended trochanteric osteotomy is likely to be needed for prior stem removal.

Assess deficiencies to determine whether a plate, strut, or mesh will be required for reconstruction.

Following implant removal, the femoral canal is debrided of all fibrous material to establish a fresh bone bed for subsequent grafting.

If diaphyseal defects are present, expose them for reconstruction while maintaining vascularity of the femur.

The diaphysis is stabilized in the areas of deficiency as needed. If a full-thickness defect is present, an allograft strut or mesh may be used to close the defect (Figure 32.1A). If no defect is present, cerclage wires can be enough to protect the weakened femur from fracture during the impaction process. If a distal defect is present that will not be bypassed adequately by the stem (2 cortical diameters), a plate may be used to protect the femur.