JOA - 2026-04-01 - Journal Article; Systematic Review; Meta-Analysis
The Role of Stem Shape and Geometry in Revision and Complication Risk Following Primary Total Hip Arthroplasty: A Systematic Review and Meta-Analysis.
De C, Tahir M, Kumar RS, Solovos EM, Al-Dahan T, Pierce TP, Patel N
Topics
Key Takeaway
Anatomic femoral stems carry the highest overall revision rate (3.9%) in primary THA, while single-wedge stems demonstrate the lowest relative revision risk (RR 0.31) and periprosthetic fracture risk (RR 0.21) compared to anatomic designs.
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Summary
This systematic review and meta-analysis compared revision and complication rates across four femoral stem geometries in primary THA using studies published 2015–2025. Anatomic stems had the highest revision rate (3.9%) and periprosthetic fracture incidence (1.4%), while single-wedge stems showed the lowest relative risk for revision (RR 0.31), instability (RR 0.15), and periprosthetic fracture (RR 0.21). Paradoxically, PJI risk was lowest with anatomic stems (0.22%) and highest with taper wedge designs (RR 2.52 vs. anatomic).
Key Limitation
The analysis does not account for indication-driven stem selection bias—anatomic stems are disproportionately used in dysplastic or deformed femora (e.g., Crowe DDH), which independently elevate complication risk and confound the between-group comparisons.
Original Abstract
BACKGROUND
Primary THA may be performed with femoral stems that differ in shape and geometry. The purpose of this meta-analysis was to evaluate the revision and complication risks of the following stem designs: (1) anatomic; (2) single-wedge; (3) single-taper; and (4) taper wedge.
METHODS
A comprehensive search of four electronic databases (PubMed, CINAHL Plus, EMBASE, and SCOPUS) was performed for all articles pertaining to this topic from January 2015 to January 2025. A total of 18 studies were selected for inclusion. There were: (1) 12,969 anatomic; (2) 17,115 single-taper; (3) 19,326 single-wedge; and (4) 1,965 taper wedge stems.
RESULTS
The revision rate was highest within the anatomic stem cohort (3.9%; 95% confidence interval [CI], 3.6 to 4.2), with lower rates being found in single-taper (relative risk [RR], 0.38; 95% CI, 0.34 to 0.43; P = 0.0001), single-wedge (RR, 0.31; 95% CI, 0.27 to 0.35; P = 0.0001), and taper wedged stems (RR, 0.52; 95% CI, 0.4 to 0.68; P = 0.0001). Periprosthetic joint infection risk was 0.22% (95% CI, 0.15 to 0.31) within anatomic stems and was higher in single-taper (RR, 2.12; 95% CI, 1.5 to 2.98; P = 0.0002) and taper wedge cohorts (RR, 2.52; 95% CI, 1.27 to 5.01; P = 0.004). Aseptic loosening rate with anatomic stems was 0.65% (95% CI, 0.52 to 0.79), and the single wedge was lower (RR, 0.72; 95% CI, 0.56 to 0.92; P = 0.014). The risk of instability in anatomic stems was 0.44% (95% CI, 0.33 to 0.56) with a much lower rate in single-taper (RR, 0.7; 95% CI, 0.51 to 0.94; P = 0.025) and single-wedge stems (RR, 0.15; 95% CI, 0.09 to 0.25; P = 0.0001). Periprosthetic fracture incidence in anatomic stems was 1.4% (95% CI, 1.2 to 1.6). The rates were much lower in single-taper (RR, 0.74; 95% CI, 0.63 to 0.87; P = 0.001) and single-wedge cohorts (RR, 0.21; 95% CI, 0.16 to 0.27; P = 0.0001).
CONCLUSION
Anatomic stems had a higher risk of revision, instability, and fracture. The risk of periprosthetic joint infection was highest in taper wedge stems. Future research should focus on comparative studies that further investigate any potential increased risk of certain complications following primary THA based on various construct designs. Revision risk was highest in the anatomic stem cohort.