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Published on: August 17, 2017
Fracture and loosening of Charnley femoral stems. Comparison between first-generation and subsequent designs
D M Dall1, I D Learmonth, M I Solomon
1Hospital of the Good Samaritan, Los Angeles, California.
Insights
First-generation Charnley stems showed higher fracture rates, while later generations had increased loosening. This study compares stem performance over 4-17 years.
Area of Science:
- Orthopedic surgery
- Biomedical engineering
- Materials science
Background:
- Charnley stems are widely used in hip arthroplasty.
- Assessing long-term performance of different stem generations is crucial for patient outcomes.
Purpose of the Study:
- To compare the clinical and radiological outcomes of first-generation Charnley stems versus second- and subsequent-generation stems.
- To investigate the incidence of fracture and stem loosening requiring revision.
Main Methods:
- A 4- to 17-year clinical and radiological follow-up study.
- Comparison of 264 first-generation stems with 402 second- and subsequent-generation stems.
Main Results:
- First-generation stems had a 4.1% fracture incidence versus 0.5% in later generations.
- Stem loosening requiring revision was 3.1% for first-generation and 11.4% for second-generation stems.
- Increased loosening in later stems is hypothesized to be due to increased flexural stiffness from larger cross-sectional areas.
Conclusions:
- First-generation Charnley stems demonstrate a higher risk of fracture.
- Second- and subsequent-generation stems exhibit a higher rate of loosening, potentially linked to design changes.
- Long-term performance data is essential for optimizing hip implant design and surgical techniques.
Abstract:
We report the results of a 4- to 17-year clinical and radiological follow-up of 264 Charnley first-generation stems in comparison with those of 402 second- and subsequent-generation stems. The incidence of fracture was 4.1% in first-generation stems and 0.5% in second- and subsequent-generation stems. The incidence of stem loosening requiring or likely to require revision was 3.1% in first-generation and 11.4% in second-generation stems. We believe that the increased loosening rate in second- and subsequent-generation stems is due to their larger cross-sectional area, which produces an increase in flexural stiffness.
