[ NEWS - FEATURE ]
What did they find ? Extraordinarily low rates of revision or removal . Of 2,141 patients , a mere 1.26 % ( 27 ) returned for implant revision or removal — mostly for removal ( only 3 representing 0.14 % of the total returned for a revision of their implant .
As study co-author Dr . Richard Guyer explained to OTW , “ I think the most important finding of this paper is the fact that the longevity of the lumbar artificial disc far exceeded what we thought when we first started doing these over 24 years ago ( first one being done in March 2000 ). We used to tell patients — much like total hips and total knees — that we were hoping to get 10 years out of these discs before a revision . And then they kept going and going . With our 20-year follow up we had a 1.2 % revision rate which included 40 % of them attributed to our learning curve of the 1st 25 cases of each of the three primary surgeons ( myself , Dr . Scott Blumenthal , and Dr . Jack Zigler ) giving less than a 1 % revision rate .”
The principal cause of removal was migration and / or loosening .
“ Repeat anterior exposure is obviously very , very challenging and it ’ s one that we try to avoid unless there are no other alternatives ,” said Dr . Guyer , fellowship director and codirector of the Center for Disc Replacement at TBI . “ For example , if there is infection or in a very , very rare event , a fracture at the replacement level , we may have to carry out a revision anterior exposure . One needs to have a very experienced anterior access surgeon because of the scarring of the great vessels that is the aorta , and more importantly , the vena cava .”
“ Special precautions and pre-op imaging studies are needed to help make this surgery as safe as possible . At L5 / S1 a revision exposure is possible and a little bit easier than L4 / 5 , but it is still fraught with difficulty due to the scarring of the vessels . In general , if there are not mitigating circumstances requiring an anterior approach , we will utilize a posterior fusion depending on the indications .”
“ The three revisions were for core repositioning ( technique error ), device repositioning after displacement , and core replacement due to wear / failure . With respect to timing , 37.0 % of removals / revisions occurred within one-month postimplantation . Of note , 40.7 % of removals / revisions occurred in the first 25 TDR cases performed by individual surgeons . There was one significant vascular complication occurring in a patient whose TDR was removed due to trauma . This was also the only patient among 258 with ≥15-year follow-up who underwent removal / revision .”
“ This is consistent with Dr . Marney from France who found in his 21-year follow up a revision rate of less than 1 %. When one looks at the data of the 20-year follow up with total hips and total knees the revision rates are 15 % and 10 %, respectively . What this proves to me is that the stresses on the lumbar disc are very different from the hips and knees and that we can safely tell our patients that unless there was a fracture from severe trauma or infection , which is extremely rare , the likelihood of them needing a revision at that particular disk level is very , very rare up to 20 years !”
“ As further work , we need to continue to follow these patients and begin to look at different groups of patients as we have started to do . Such as , how do patients over the age of 60 fare ? What are the ideal groups candidates ? Previous surgery , etc . I recently presented on these topics at the International Society for the Advancement of Spine Surgery .” ♦
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