Study of ADR failures

[johnb]

This was presented at the AAOS and I found the conclusions quite informative and thought it might promote some thoughtful discussion. The sample size wasn't huge (which is good when we are talking failures)

I've edited this post to point out that 46% of the failures were facet related and not 46% of the study had facet problems. This group is a subset of the I.D.E. studies. I wanted to be clear about this so no one considering ADR will think they have a 46% chance of facet problems. The study does not conclude this.

2009 Annual Meeting Information Podium Presentations Why Lumbar Artificial Disc Replacements (A.D.R.) Fail - AAOS

Of interest to me is that 46% of the failures were related to facet pathology. These patients came from I.D.E. study groups which, according to all the exclusion criteria I've seen, exclude for facet problems. Why do some people develop facet problems after implantation? Did patients with facet problems get into the study due to improper screening? I hope not though it is evident that facets seem to still present diagnostic problems. I'd like to know the screening methods for the original I.D.E. studies. There is another podium post on cervical facets concluding that MRI was not reliable in diagnosing facet problems. I'd like to see the same study for lumbar facets but I'd bet the conclusions would be similar but I'd like to see the science and not make assumptions. Did the placement cause the problems? It would be interesting if they could further research the facet failure placement with the successes for each disc and glean further info. The study also indicates the rate of success at 2 years was highest for the kineflex, then Maverick, then the charite being the least successful.

For reference, here is the presentation on cervical facet diagnosing with MRI vs. CT 2009 Annual Meeting Information Podium Presentations Comparison of MRI and CT in Predicting Facet Arthrosis in the
Cervical Spine - AAOS