Uncemented femoral revision arthroplasty using a modular tapered, fluted titanium stem

Abstract

Background and purpose —Due to the relative lack of reports on the medium- to long-term clinical and radiographic results of modular femoral cementless revision, we conducted this study to evaluate the medium- to long-term results of uncemented femoral stem revisions using the modular MRP-TITAN stem with distal diaphyseal fixation in a consecutive patient series.Patients and methods —We retrospectively analyzed 163 femoral stem revisions performed between 1993 and 2001 with a mean follow-up of 10 (5–16) years. Clinical assessment included the Harris hip score (HHS) with reference to comorbidities and femoral defect sizes classified by Charnley and Paprosky. Intraoperative and postoperative complications were analyzed and the failure rate of the MRP stem for any reason was examined.Results —Mean HHS improved up to the last follow-up (37 (SD 24) vs. 79 (SD 19); p < 0.001). 99 cases (61%) had extensive bone defects (Paprosky IIB–III). Radiographic evaluation showed stable stem anchorage in 151 cases (93%) at the last follow-up. 10 implants (6%) failed for various reasons. Neither a breakage of a stem nor loosening of the morse taper junction was recorded. Kaplan-Meier survival analysis revealed a 10-year survival probability of 97% (95% CI: 95–100).Interpretation —This is one of the largest medium- to long-term analyses of cementless modular revision stems with distal diaphyseal anchorage. The modular MRP-TITAN was reliable, with a Kaplan-Meier survival probability of 97% at 10 years.

Outcome of a modular tapered uncemented titanium femoral stem in revision hip arthroplasty

“…In contrast, our revision rate using the MRP-TITAN stem is 6.8 %, with a Kaplan-Meier survival rate of 85.6 % after 9.75 years. These promising results were supported by findings of Wirtz et al [5], showing a 15-year survival of 85 %, with a revision rate of 6 %. Many authors reported up to 10 % axial migration with subsidence as the main reason for revision stem failure [1].…”

“…A study from Gravius et al [16] reported no corrosion or fretting at all modular interfaces using the MRP stem because of a specific manufacturing process of the Morse taper junctions [17]. These data were supported by the findings of Wirtz et al [5]. Also, we could not detect any osteolysis around the modular connections of the stem.…”

“…The subsidence rate for the MRP stem is lower with a mean of ca. 4 % migrations [5,14,15]. Nevertheless, we could not find any stem subsidence or axial migration after a mean follow-up of 55 months.…”

“…1) has excellent short-and longterm results in a number of studies, with low mechanical failure rates and high overall survival rates. Most of the reports with higher patient numbers are multicentre-designed, have different exclusion criteria and use different stem lengths with or without additional distal fixation [3,5,6]. Because of these shortcomings, we investigated the clinical and radiological outcomes, of femoral revision arthroplasty with the 200-mm curved MRP-TITAN stem in a retrospective, monocentric and consecutive study.…”

CORR Insights®: Nonmodular Tapered Fluted Titanium Stems Osseointegrate Reliably at Short Term in Revision THAs

“…Further, sizing and placement of the distal fixation part is rendered independent in modular designs. The reported mid-term results are encouraging [3,15].…”