A comparison of modular tapered versus modular cylindrical stems for complex femoral revisions.

Abstract

The effect of distal geometry in modular stems in revision THA remains unclear. The purpose of this study is to compare femoral revisions with modular tapered versus modular cylindrical stems in high-grade defects. A multicenter review of 105 femoral revisions with Paprosky III/IV defects using modular titanium stems (61 tapered; 44 cylindrical) was performed with an average follow-up of 5 years. Demographic data was comparable between groups. The tapered group had more IIIB and IV defects (51% vs. 20%; P < .01). The failure rate for component osseointegration was 1.6% in the tapered group and 15.9% in the cylindrical group (P = <.01). The rate of femoral component re-revision for any reason was 4.9% in the tapered group and 22.7% in the cylindrical group (P = .013). Modular tapered stems were associated with lower rates of stem failure and improved bone ongrowth compared to cylindrical stems despite being used in femurs with greater defects.