JOA - 2026-05-20 - Journal Article
Monoblock and Modular Tapered Fluted Stems Versus Proximal Femoral Replacement in Revision Total Hip Arthroplasty: A Survivorship Analysis Using the Paprosky Classification.
Leipman JH, Lam AD, Bido J, Seetharam A, Sherman MB, Krueger CA, Fillingham YA
Topics
Key Takeaway
In revision THA with Paprosky Grade II+ femoral bone loss, proximal femoral replacement demonstrated significantly lower 4-year survivorship (69.8%) compared to monoblock (84.5%) and modular tapered fluted stems (85.8%, P=0.030).
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Summary
This single-institution retrospective cohort compared re-revision-free survivorship of monoblock (n=108), modular (n=198), and proximal femoral replacement (PFR, n=44) stems stratified by Paprosky femoral bone loss grade. Monoblock and modular stems showed equivalent 4-year survivorship across Paprosky Grade I/II versus Grade III+ defects (87.4% vs 83.3%, P=0.540). In Grade II+ bone loss, PFR survivorship was significantly inferior to both tapered fluted stem constructs (69.8% vs 84.5–85.8%, P=0.030), with PJI as the leading re-revision indication.
Key Limitation
Retrospective single-center design with small PFR cohort (n=44) and likely unmeasured confounding in implant selection—surgeons may have chosen PFR for cases with qualitatively worse bone stock within each Paprosky grade, artificially inflating PFR failure rates.
Original Abstract
INTRODUCTION
Periprosthetic bone loss is often challenging in revision total hip arthroplasty (THA). This study compared survivorship of monoblock, modular, and proximal femoral replacements (PFR) across various stages of femoral bone loss.
METHODS
This was a retrospective cohort study of 350 patients who underwent revision THA at a single institution. Patients either received a monoblock stem (n = 108, 30.9%), a modular stem (n = 198, 56.6%), or a PFR (n = 44, 12.6%) during revision THA. Pre-revision radiographs were reviewed to determine the Paprosky classification of femoral bone loss (Grade I, II, IIIA, IIIB, or IV). The primary outcome was implant survivorship free of re-revision between stem types in patients who had femoral bone loss.
RESULTS
There were 115, 162, and 73 cases classified as Paprosky I, II, and III+ (including grades IIIA, IIIB, and IV), respectively. In total, 55 (15.7%) required re-revision and 15 (4.29%) required reoperation. The most common indication for re-revision was periprosthetic joint infection. Monoblock and modular stems classified as Grade I or II showed comparable four-year survivorship free of re-revision to those classified as Grade III+ (87.4% [95% CI (confidence interval) 83.5 to 91.5] versus 83.3% [95% CI 72.0 to 96.4]; P = 0.540). When comparing implants in patients who had Grade II+ femoral bone loss (n = 235), PFRs demonstrated significantly lower four-year survivorship (69.8% [95% CI 57.3 to 84.9]) compared to monoblock (84.5% [95% CI 75.7 to 94.3]) and modular stems (85.8% [95% CI 80.1 to 91.9]; P = 0.030).
CONCLUSION
Monoblock and modular stems demonstrated comparable mid-term survivorship across varying degrees of bone loss, including severe Paprosky III+ defects. PFRs had lower survivorship than non-PFR stems above Grade II. In select cases with advanced femoral bone loss, modular and monoblock stems can be a viable alternative to PFR in revision THA.