Influence of cementless femoral stems inserted in varus on functional outcome in primary total hip arthroplasty.

INTRODUCTION: Historically, cemented total hip arthroplasty (THA) femoral stems inserted in varus have yielded poor clinical results. Few studies to date have addressed the question of the effects of varus alignment on cementless stems. We conducted a retrospective review of 125 uncemented THA femoral stems implanted by a single surgeon from 1994 to 1999.
METHODS: We conducted a retrospective radiographic review of 125 cementless primary THA femoral stems implanted by a single surgeon who used the Watson-Jones approach; we identified 16 stems implanted in varus, defined as >or= 5 degrees and thus analyzed the effect of varus alignment on functional outcome. We matched varus stems to a cohort of 16 nonvarus cementless stems and measured radiographic signs of loosening and subsidence, defined as > 2 mm.
RESULTS: At 4 years postsurgery, there was no significant difference in range of motion or in Harris Hip Score (p > 0.5), and no cases showed evidence of radiographic loosening or subsidence (p = 0.226).
CONCLUSIONS: Study results suggest there is no consequence of varus femoral alignment in the cementless stems. Although it is not recommended to implant stems in varus, there were no apparent radiographic or clinical consequences observed at up to 4 years postoperative in this small case series.