The Ertl Controversy: Discussion

Prior articles have looked at the best of the limited body of written information available regarding the Ertl method of lower limb amputation, starting with the historical accounts and post-war experience of the 1960s and 70s. The only peer-reviewed article that I am aware of, by Dougherty, has been briefly summarized. And, Drs. Jan and Will Ertl were kind enough to contribute a Guest Article last month clarifying their viewpoint on a number of important details.

It is my understanding that Dr. Pinzur in Chicago, Dr. Schon in Baltimore, and Dr. Geddes in Brazil are all currently studying the Ertl in its original or slightly modified form. Hopefully their work will be published in peer-reviewed journals in the coming year to provide more much-needed objective information on this topic. If readers are aware of any additional scientific studies or peer-reviewed papers, please let me know and I will add that information to this forum.

At this point, I am left with far more good questions than solid answers. So, if readers hoped for a simple summary of this complex discussion, you will be disappointed. The best I can hope for is to cut through some of the "noise" surrounding the topic to clarify what we currently know, and perhaps more importantly, what still needs to be objectively demonstrated.

The Facts:

As has always been the case historically, many contradictory opinions regarding the Ertl procedure and its advantages or limitations have been expressed, based on very few hard facts. In the absence of facts, the arguments are often waged on the basis of volume: the loudest subjective opinion tends to prevail in the short run. For what it's worth, I have culled out the following facts from the volume of debate over the past thirty years on this matter:

1. Testimonials by amputees who have undergone the Ertl procedure are strongly positive and sustained.

Although testimonials are generally dismissed because they have been shown to be of very limited value scientifically, my clinical experience has been that sustained positive testimonials are very rare in prosthetic rehabilitation. As the old saw goes, "You can't fool all of the people all of the time..."

Over the decades, I have seen a few instances where amputees and sometimes prosthetists have jumped on a bandwagon for the new "doo-dad du jour", convinced in the short run by clever marketing strategies that this new approach was a panacea. But, in virtually every instance, the cold hard reality of longer term experience soon set in and enthusiasm diminished over the ensuing months and years as it became clear that the panacea failed to deliver on many of the benefits that proponents believed in.

What I find intriguing is that interest in the Ertl keeps reappearing every 15 years or so, and that it is largely driven by amputee enthusiasm and the support of experienced prosthetists. My "gut" tells me that there is almost certainly something of genuine value about the Ertl method, and it is therefore worth the effort to sort through all the chaff to identify those important kernels.

2. Most reported Ertl results are based on revision surgery at the transtibial level.

The preponderance of anecdotal information in support of the Ertl method is retrospective data after revision surgery including patient testimonials. In interpreting these results, it is important to realize that the comparison is to failed prior surgeries of unknown technique among the self-selected population who are so unhappy with their residual limb they will consent to undergo re-amputation. This is clearly not a random sampling of all amputees.

Even though the positive accolades are undoubtedly sincere and accurate, these results don't generalize very well. We can have pretty good confidence that an Ertl TT revision is far better than a poorly done primary amputation. It is not at all clear that this makes it better than another meticulous technique. [Many of the reports on new prosthetic socket designs have the same methodological problems: they compare a new socket concept to an older poorly fitting prosthesis that is ready for replacement. Such results clearly demonstrate that a new, well fitting socket has advantages over an older, poorly fitting one. It does not help establish whether or not one design is superior.]

It is possible that good results at the transtibial level translate directly into equally good results at the transfemoral or other levels. But, in view of the significant musculoskeletal differences between TT and TF anatomy, this is not necessarily the case. To determine the value for transfemoral amputees, it would be very helpful to compare a series of patients who underwent another recognized meticulous TF amputation, such as that advocated by Gottshalk, with a fairly closely matched cohort who had a primary Ertl. If the functional differences between the approaches are substantial, then even a fairly small series might show a distinct advantage. If not, then we might conclude that good amputation surgery is important but that some of the details can vary from surgeon to surgeon. Today, we simply don't know which assumption is correct.

3. The morbidity associated with a more complex procedure, such as constructing a bony bridge, will be higher than with less involved operations.

There is a well-established correlation between time spent in surgery and the risk of complications such as infection, and the longer time required to heal "bone work" slows the pace of rehabilitation in the first months following amputation. So, there is a trade-off between the potential long-term benefits of an Ertl TT or TF and the short-term risks of an infection and the delay in ambulation until the more traumatized bone ends heal fully. From the reports I have heard and read, the overwhelming majority of amputees who have had the procedure would say it is well worth those tradeoffs.

However, many surgeons are very cautious about adopting new methods that carry even slightly increased risk for complications. I suspect this is one of the primary reasons so few have enthusiastically embraced the Ertl concepts to date. Surgeons considering the Ertl approach are confronted with postulated advantages combined with an expected increase in risk of unknown magnitude.

This again points to how helpful it would be to have objective evidence that conclusively demonstrated the functional advantages of the Ertl TT or TF. With such evidence, one could then argue persuasively that the relatively minor increase in morbidity is far outweighed by the proven advantages. I believe that conclusively demonstrating objective benefits from the Ertl procedure will be the key to more widespread utilization of this method of amputation.

Next month: More facts to consider

Reader Comments: Read all user comments continued#3 As for myself, I am an average middle aged Ertl Amputee with load of wonderful antidotal information. My surgery was primary amputation not a revision. 16 months after my surgery, I cycled 3800 miles in 52 day across American to demonstrat... read more - Daniel Sheret   1/12/2004 Re: continued#3 Thanks for sharing your experiences, Mr. Sheret. I wish we had more evidence to rely upon, but documenting individual results is the first step toward sorting out all the potential benefits of this procedure. --John Michael CPO - John Michael   1/12/2004 ERTL/BRIDGE Sir, I work at a manufacturing facility that puts great effort into educating amputees of all ages so they can make wise choices. We work with a wide array of amputees both with and without the ERTL/bridge. While the Ertl may not be a b... read more - Larry Corley   1/16/2004 Re: ERTL/BRIDGE I agree with Larry. Although the "data" may not be out there, why would people choose to ignore what Ertl amputees have to say about the whole deal? I mean, good grief, who better to discuss the procedure with than those who can tell you th... read more - AJ Johnson   1/16/2004 continued #2 I also appreciate your interest and curiosity of The Facts as you put it, that “Ertl keeps reappearing every 15 years or so, and that it is largely driven by amputee enthusiasm and the support of experienced prosthesists.” I cannot speak f... read more - Daniel Sheret   1/12/2004 Ertl Procedure #1 Dear Mr. Michaels, I wanted congratulate you on a well written rebuttal to the information posted the Drs. Ertl on your web corner. I would agree with you that you do leave your reader with more questions than answers. According to your s... read more - Daniel Sheret   1/12/2004 John Michael's "Face #3" I think there is a point you have forgotten in your third "fact." You stated "many surgeons are very cautious about adopting new methods that carry even slightly increased risk for complications" as one of the reasons that surgeons aren't e... read more - AJ Johnson   1/11/2004 Re: John Michael I've heard similar speculation from time to time but have never found any evidence whatsoever to support that opinion. All the surgeons I've worked with have done what they believed was in their patient's best interest regardless of whethe... read more - John Michael   1/11/2004