Abstract
We maintain a database on 1000 femoral revisions using extensively porous-coated stems. Using femoral rerevision for any reason as an endpoint, the survivorship is 99 ± 0.8% (95% confidence interval) at 2 years, 97 ± 1.3% at 5 years, 95.6 ± 1.8% at 10 years, and 94.5 ± 2.2% at 15 years. Similar to Moreland and Paprosky, we have identified prerevision bone stock as a factor affecting femoral fixation. When the cortical damage involved bone more than 10 cm below the lesser trochanter, the survivorship, using femoral rerevision for any reason or definite radiographic loosening as an endpoint, was reduced significantly, as compared with femoral revisions with less cortical damage.
In addition to patients with Paprosky type 3B and 4 femoral defects there are rare patients with femoral canals smaller than 13.5 mm or larger than 26 mm that are not well suited to this technique. Eight and 10 inch stems 13.5 mm or smaller should be used with caution if there is no proximal bone support for fear of breaking. Patients with canals larger than 18 mm may be better suited for a titanium tapered stem with flutes. While a monolithic stem is slightly more difficult for a surgeon to insert than a modular femoral stem there is little worry about taper junction failure.
