Proximal ingrowth components.

Abstract

The advantage of using a proximal ingrowth hip revision component is restoring physiologic load to the revision femur. Although first generation components had limited survivorship and diminished clinical outcomes, subsequent designs have proven much better with rates of aseptic loosening of 2% to 5%, and good clinical scores. Titanium is the favored substrate metal for these components because of its bone affinity and low modulus of elasticity. A series of 107 consecutive revisions of standard stems is presented using a calcar replacement long stem design with an overall 92.7% 11-year survivorship. Bone ingrowth was achieved in all but two components. Radiographic stress shielding was seen in 11.4% with 42.6% having some calcar healing. These implants can be used in most revision situations, but require sufficient proximal metaphysis of the femur to provide support of the component. Supplemental allograft may need to be used. These implants require a tight fit in the isthmus of the femur and fill of the proximal femur. Modularity makes achieving this easier, but monoblock designs also can be successful.