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The Elite-Plus stem migrates more than the flanged Charnley stem
Thord von Schewelov1, Lennart Sanzén, Jack Besjakov
1Department of Orthopedics, Lund University, Malmö University Hospital, Malmö, Sweden.
Acta Orthopaedica
|April 7, 2010
Summary
The Charnley Elite-Plus stem shows good survival rates, but migration patterns indicate that careful monitoring is needed, especially with inferior cement techniques in total hip replacement patients.
Area of Science:
- Orthopedic surgery
- Biomedical engineering
- Radiology
Background:
- The Charnley Elite-Plus stem was introduced as an advancement over the original Charnley stem.
- This study initiated in 1996 aimed to evaluate the migratory behavior of the Elite-Plus stem.
Purpose of the Study:
- To investigate the migration patterns of the Charnley Elite-Plus femoral stem.
- To assess the long-term survival and stability of the Charnley Elite-Plus stem in total hip replacements.
Main Methods:
- Radiostereometry (RSA) was used to measure migration and wear in 114 patients undergoing primary total hip replacement.
- Follow-up averaged 6.5 years, with radiographic evaluation focusing on cementing technique and stem migration.
- Patient cohort included individuals with osteoarthritis, with a mean age of 64 years at operation.
Main Results:
- Stem survival rates were 98% at 7 years and 92% at 10 years.
- Mean migration was observed: 0.35 mm medially, 0.51 mm distally, and 1.1 mm dorsally, with a mean total point motion of 1.7 mm.
- Migration stabilized after 5 years but continued slight subsidence; inferior cementing techniques correlated with increased migration.
Conclusions:
- The Charnley Elite-Plus stem demonstrates favorable long-term survival.
- Inferior implantation techniques, such as cement mantle defects, are associated with increased stem migration.
- Patients with the Charnley Elite-Plus stem and evidence of suboptimal implantation require vigilant clinical monitoring.
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