PLoS ONE (Jan 2021)

Survival and reasons for revision of the uncemented Symax hip stem: A Dutch Arthroplasty Register study.

  • Dennis S M G Kruijntjens,
  • Sander M J van Kuijk,
  • Liza N van Steenbergen,
  • Liesbeth M C Jutten,
  • J J Chris Arts,
  • René H M Ten Broeke

DOI
https://doi.org/10.1371/journal.pone.0248483
Journal volume & issue
Vol. 16, no. 3
p. e0248483

Abstract

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AimsPrevious studies have already shown early proximal ingrowth, fast osseous integration, and a stable fit of the uncemented Symax hip stem, with excellent clinical and radiographic performance. Aims were to evaluate cumulative revision rates and reasons for revision of the Symax hip stem using Dutch Arthroplasty Register (LROI) data and to assess possible associations between patient characteristics and revision rate of the Symax hip stem.Patients and methodsAll total hip arthroplasties with the uncemented Symax hip stem registered in the LROI between 2007 and 2017 were included (n = 5,013). Kaplan-Meier survival analysis was performed to assess the cumulative 1, 5 and 7-year revision percentages. Cox proportional hazard regression analysis was performed to assess the association between patient and procedural characteristics, and revision arthroplasty of the stem.ResultsCumulative 1, 5, and 7-year revision rates (with 95% confidence interval (CI)) for revision of any component were 1.5% (CI 1.2%-1.8%), 3.2% (CI 2.7%-3.7%), and 3.8% (CI 3.1%-4.4%) respectively. Cumulative 1, 5, and 7-year stem revision rates of the Symax hip stem were 0.9% (CI 0.6%-1.1%), 1.5% (CI 1.1%-1.9%), and 1.7% (CI 1.3%-2.1%) respectively. Periprosthetic fractures (n = 35) and loosening of the stem (n = 30) were the most common reasons for revision of the stem. Revision of the stem was associated with acute fracture as primary diagnosis (Hazard Ratio (HR) 2.4 (CI 1.3-4.3)), or history of a previous surgery to the affected hip (HR 2.7 (CI 1.4-5.2)).ConclusionThis population-based registry study shows revision rates for the Symax hip stem comparable to those for best performing uncemented total hip arthroplasties in the Netherlands. Primary diagnosis of an acute fracture, and history of previous surgery on the affected hip, were significantly associated risk factors for revision of the Symax hip stem, and we discourage the use of the Symax hip stem in these patients.