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Individualized Stem-positioning in Calcar-guided Short-stem Total Hip Arthroplasty
Published on: February 27, 2018
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Dual-Modular Versus Single-Modular Stems for Primary Total Hip Arthroplasty: A Long-Term Survival Analysis
Samo K Fokter1, Nejc Noč2, Vesna Levašič3
1Department of Orthopaedics, University Medical Centre, 2000 Maribor, Slovenia.
Medicina (Kaunas, Lithuania)
|February 25, 2023
Summary
Dual-modular femoral stems in primary total hip arthroplasty showed lower survivorship than single-modular stems. This study found no benefit to stem modularity in primary hip replacements, suggesting it should be avoided.
Area of Science:
- Orthopaedic Surgery
- Biomaterials Engineering
Background:
- Dual-modular (DM) femoral stems in primary total hip arthroplasty (THA) have shown increased revision rates due to modular-neck breakage and adverse local tissue reactions (ALTRs).
- Some DM stem designs have been recalled, yet long-term studies on specific DM stems have not consistently shown inferiority compared to standard single-modular (SM) stems.
- A direct head-to-head comparison of DM versus SM stems in primary THA is lacking.
Purpose of the Study:
- To compare the survivorship and complication rates of a specific dual-modular (DM) femoral stem design against a similar single-modular (SM) stem in primary total hip arthroplasty (THA).
Main Methods:
- A multicentre cohort study included 807 patients (882 hips) undergoing primary cementless THA between January 2012 and November 2015.
- 377 hips received a Zweimüller-type DM stem THA system, while 505 hips received a comparable SM stem THA system, both with modern press-fit acetabula.
- Kaplan-Meier survivorship analysis and complication rates were compared with a median follow-up of 9.0 years.
Main Results:
- The 9-year survivorship for the DM stem THA system was significantly lower (92.6%) compared to the SM stem THA system (97.0%).
- No significant differences were observed in revision rates for septic loosening, dislocation, or periprosthetic fractures between the groups.
- The primary reason for revision in the DM stem group was aseptic loosening of components, with isolated cases of ceramic inlay and Ti-alloy modular neck breakage.
Conclusions:
- The dual-modular (DM) stem THA system demonstrated inferior survivorship compared to the similar single-modular (SM) stem THA system in a comparable clinical setting with long-term follow-up.
- The findings suggest that stem modularity offers no advantage in primary total hip arthroplasty (THA).
- There is no current rationale for utilizing stem modularity in primary THA procedures.
