In a recent study, University of Oxford researchers state that nearly 8% of components used in primary hip replacements in 2011 were implanted without readily identifiable evidence of clinical effectiveness. The researchers report that at the start of the study, they sought to confirm the number of hip replacement joints that exhibit no readily available evidence of clinical effectiveness to support their use—and how many are being implanted in clinical practice.
According to BMJ-British Medical Journal, the researchers used data from the National Joint Registry (NJR) of England and Wales to identify implants used in hip replacement surgery in 2011 that were rated “unclassified” or “pre-entry” by the orthopedic Data Evaluation Panel (ODEP). The medical literature was then reviewed to establish the level of evidence available for these implants.
The results suggest that 10,402 or 7.6% of the 136,593 components used in primary hip replacements in 2011 were implemented without readily identifiable evidence of clinical effectiveness. Additionally, the study indicates that these comprised 157 cemented stems (0.5% of those implanted), 936 uncemented stems (2.8%), 1,732 cemented cups or 7.1%, and 7,577 uncemented cups or 17.1%.
The study’s results are a cause for concern, researchers say, “particularly in light of the widespread publicity surrounding recent safety problems with regard to some resurfacing and other large diameter metal-on-metal joint replacements.”
The researchers add that an underestimation of the issue likely exists, “as much of the evidence that does exist for the other unrated prostheses is of low quality or relates to short-term outcomes only.” The scarcity of good quality evidence in this area, the researchers emphasize, may be linked to the expansion in the number of devices introduced into the market during the past 2 decades, as demand for hip replacement surgery increases worldwide and in light of the difficulty in conducting high quality randomized controlled trials with orthopedic implants.
In the conclusion of the study, the researchers state that the work indicates a need still exists for an improved and more rigorous approach to regulation of devices to avoid devices with no available evidence of being used in a widespread and uncontrolled manner.
[Source: BMJ-British Medical Journal]