Abstract
Introduction
Austin Moore cervicocephalic prostheses have been a therapeutical option for femoral neck fractures in patients with a reduced general condition for many years. Since treatments other than total hip arthroplasties have also been included in National arthroplasty registers during the last decade, adequate reference data for comparative analyses have recently become available.
Materials and Methods
Based on a standardised methodology, a comprehensive literature analysis of clinical literature and register reports was conducted. On the one hand, the datasets were examined with regard to validity and the occurrence of possible bias factors, on the other hand, the objective was to compile a summary of the data available. The main criterion is the indicator of Revision Rate. The definitions used with respect to revisions and the methodology of calculations are in line with the usual standards of international arthroplasty registers.
Results
Publications of clinical studies since the year 2000 have been found to significantly underestimate revision rates, on average by a factor of 2.15 as compared to register data. With 2 revisions per 100 observed component years, the revision rate in registers clearly exceeds the comparative values for total hip arthroplasty.
The medium-term outcome of treatment with Austin Moore implants shows statistically significantly worse values than the use of total hip endoprostheses, bipolar implants or modular cervicocephalic prostheses. This may be rated as a hint that, in particular cases, there is potential for improvement as regards the indication for cervicocephalic implants.
In the datasets of a single National register of a country such as Australia, with a population of just over 21.7 million, approximately 3 times as many cases have been documented within a period of 9 years than in all clinical studies that have been published in Medline-listed journals since the year 1960.
Since these data are much more homogeneous, they allow for markedly more accurate evaluations and statements of higher validity. The period of time by which sufficient data are available for a well-founded recommendation is considerably shorter in a register.
Conclusion
The results of a meta-analysis of clinical literature deviate conspicuously from data from a National arthroplasty register. The medium- and long-term revision rates after treatment with Austin Moore implants are significantly higher than for treatment with total hip prostheses or modular implants. There is evidence that more stringent indications for monobloc implants could improve the outcome of surgery.
