Abstract
Introduction
Cemented stems have given good results with no difference in outcome when comparing taper slip and composite beam designs in short-term randomised trials. We aimed to ascertain differences in outcome between the different cemented design philosophies using a large-scale registry analysis.
Materials and Methods
A retrospective cohort study of National Joint Registry of England and Wales (NJREW) was conducted. The study population included all primary total hip operations performed in the UK from 1 April 2003 to 31 September 2012. All cemented stems were identified and categorised as taper slip (polished) or composite beam (non-polished).
Results
Non-polished stems accounted for 16.6% of all primary cemented hip replacements with polished stems making up the remainder. Mean age for non-polished stems was 73.0 years and 71.8 for the polished group (p<0.001) suggesting selection bias. There was a statistically significant increased chance of revision in the non-polished group compared with the polished group (p<0.001).
Reasons for revision by fixation type:
| Reason for revision | Total | Polished n=253667 | Non-polished n=50661 | ||||||
| N | % | n | % | ||||||
| Aseptic loosening stem | 532 | 300 | 0.12 | 232 | 0.46 | ||||
| Infection | 965 | 735 | 0.29 | 230 | 0.45 | ||||
| Stem lysis | 149 | 99 | 0.04 | 50 | 0.10 | ||||
| Cup lysis | 156 | 125 | 0.05 | 31 | 0.06 | ||||
| Malalignment stem | 114 | 86 | 0.03 | 28 | 0.06 | ||||
The risk of aseptic loosening, stem lysis, malalignment and infection were several magnitudes higher for non-polished stems than for polished varieties (p<0.05).
Discussion
Theoretical concerns are reflected in clinical practice with an increased incidence of revision for non-polished stems for all indications recorded.
Conclusions
Incidence of revision is higher in cemented non-polished stems compared with polished designs.
