Long-term comparison of the Charnley, Muller, and Trapezoidal-28 total hip prostheses. A survival analysis

Area of Science:

• Orthopedic Surgery
• Biomaterials Science
• Medical Device Engineering

Background:

• Total hip arthroplasty (THA) is a common procedure to alleviate hip pain and improve function.
• Evaluating long-term prosthesis survival is crucial for patient outcomes and healthcare planning.
• Different THA designs may exhibit varying performance characteristics over time.

Purpose of the Study:

• To compare the long-term survival rates of three distinct total hip arthroplasty prostheses: Charnley, Muller, and Trapezoidal-28 (T-28).
• To identify factors influencing the success and failure of these prostheses in a large patient cohort.
• To analyze specific modes of failure, such as aseptic loosening and component fracture.

Main Methods:

• Survival analysis was applied to data from 791 total hip arthroplasties performed between 1969 and 1980.
• Follow-up data was obtained for the vast majority of patients, minimizing selection bias.
• Multivariate regression analysis was used to identify significant predictors of prosthesis survival and failure.

Main Results:

• At 10 years, projected survival rates were 91% for Charnley, 88% for T-28, and 80% for Muller prostheses.
• The Muller acetabular cup demonstrated significantly higher rates of premature loosening compared to Charnley and T-28.
• Muller femoral stems also showed inferior performance compared to Charnley stems.
• Despite 10 fractures, T-28 femoral stems showed no significant difference in success rates compared to the other designs.
• Female sex and older patient age were associated with significantly higher success rates.
• Radiolucency at bone-cement interfaces and acetabular cement fractures were significant predictors of failure.

Conclusions:

• The Muller prosthesis exhibited a higher failure rate, particularly concerning acetabular component loosening.
• While T-28 femoral stems experienced fractures, their overall survival did not differ significantly from other designs in this cohort.
• Patient demographics (female, older age) and specific radiographic findings (radiolucency, cement fracture) are critical factors influencing total hip arthroplasty outcomes.