Response from Dr. Jan Ertl and Dr. Will Ertl

Shortly before Thanksgiving, the Drs. Ertl were kind enough to post a lengthy series of reader's comments responding to the series of articles previously published in consecutive Corners. They accepted my invitation to be "guest authors" this month, and have created the following article to expand upon their comments in more detail:

Thank you for continuing to provide information to the amputee community. Information and discussion has been unique and spirited. Regarding the ongoing discussion concerning the Ertl procedure, there are several inconsistencies and errors that need to be highlighted and hopefully corrected as this discussion progresses.

Dr. Johann Ertl developed the osteomyoplastic surgical amputation, or the Ertl procedure, based on his clinical observations of the regenerative properties of periosteum. The technique combines the effects of an osteoplasty and a myoplasty to gain an optimal residual extremity. An optimal residual extremity can be viewed as one that can accept a prosthesis in a painless fashion and allow the patient to be functional. One can argue that this is the goal of any amputation technique. Many patients do gain some level of functionality with a well-done amputation. However, with the Ertl procedure, the fibula is stabilized to the tibia via an osteoplasty. Classically, osteo-periosteal sleeves are elevated from residual bone, the distal portion of the bone is resected and the flaps are sutured together to complete the osteoplasty. In some cases, fibula, iliac crest, and rib have been utilized to augment the bridge. Periosteum, being a tissue source of bone forming cells, then provides an arena for bone formation. The tibia and fibula are transected at equal levels. A greater surface area for end bearing is created versus a small area that will occur with the tibia alone. Stabilization of the fibula also occurs and may also prevent compression of the posterior tibial nerve. When performed as a secondary reconstruction procedure, only 2-3 centimeters of bone needs to be resected from the tibia and fibula to attain enough periosteum to construct the osteoplasty. The distance between the medial tibial cortex and lateral fibular cortex varies between 3-5 centimeters. As a primary procedure, enough periosteum is elevated to the appropriate level of amputation. The X-ray in October's corner shows an amputation with an adequate bone bridge formed however the fibula is significantly shorter in its relation to the tibia. This may potentially negate any effect that a broader surface area for end bearing would provide. In July's corner, you stated that you had spoken with numerous surgeons around the world concerning the Ertl procedure. Concern was expressed regarding a more complex bony procedure and complications that have been encountered. No mention was made at how a synostosis was constructed, whether a myoplasty was utilized or the number/types of complications. From this you concluded that there was no benefit, although your experience as a prosthetist would say otherwise.

The caption under the picture in October's corner also states that the primary difference between the Ertl procedure and other modern techniques is the bone bridge. This is an incorrect statement as the Ertl procedure also incorporates soft tissue coverage via a myoplasty. The myoplasty is performed to provide distal soft tissue coverage to the residual limb and provide an anchorage for the musculature to maintain muscle function. The myoplasty incorporates the anterior, lateral, and superficial posterior compartment. Soft tissue stabilization and balancing is important in amputation surgery and is recognized by the surgeons performing amputations on a regular basis. However, this is not the norm with in training programs throughout the country. Only at centers that make an emphasis on proper resident training do future surgeons learn the importance of adequate and proper soft tissue handling and balancing. Most amputation techniques describe the use of a myodesis of the posterior muscle group only. The anterior and lateral muscle groups are not included in a myodesis. Maintenance of a length tension relationship of a muscle allows the muscle to remain contractile and functional. Numerous articles, that Jan Stokosa has provided, have demonstrated the beneficial effects of each procedure (osteoplasty and myoplasty) alone and in combination. However, there have been articles published that have incorrectly stated the amount of bone needed to resect from the tibia and fibula to achieve a synostosis and no comment regarding the application nor the surgical technique of a myoplasty is made in review articles. The technique applied to the Valley Forge patients was only the osteoplasty portion of the procedure. The term Ertl osteoplasty is correct; however the application of the Ertl osteomyoplasty to these patients in the October corner discussion is incorrect. We have spoken to several surgeons who participated in that study and they have correlated the use of the osteoplasty alone. Further, Dr. LaNoue reported that when a comprehensive approach was abandoned, the results changed. Only when he instituted a comprehensive therapy approach did the results improve. This may have also been a result in a change of prosthetic socket.

When an osteomyoplastic procedure is performed, the socket of choice should be an end bearing socket design with total surface bearing. This will allow greater axial and vertical loading negating the need for flexion to be built into the socket. When an alternative socket is applied, any benefit that may and should result from an osteomyoplastic procedure may be lost and deemed a failure. Quoting from your July "Corner":

"... These transtibial amputees could all place their full body weight onto the residual limb in this manner; the transfemoral folks could all load my hand at least until my metacarpals hurt! This was substantially more distal end bearing that other amputees I had examined could comfortably tolerate."

I therefore designed the sockets for these patients to emphasize peripheral loading and significant end bearing rather that the focused proximal weight bearing that was fashionable in those days of the PTB theory. As anticipated, shifting a significant percentage of the weight bearing forces to the distal end resulted in a very comfortable socket in these cases, and appeared to offer control advantages similar to other end bearing amputations. In other words, these transtibial amputees could be fitted almost as if they had Syme ankle disarticulations; the transfemoral amputees almost as if they had knee disarticulations. Although there was no practical method to quantify the amount of end bearing in those days, I would estimate that all those patients tolerated 50% or greater end bearing long term.

In addition, these residual limbs were well muscled and remained so over the several years that I followed these cases..."

This should reinforce the need for intimate communication between a surgeon and a prosthetist to optimize the function of a prosthesis with the surgical technique utilized. As a standard technique (long posterior flap) cannot be end bearing, alternative loading of the residual limb is required. You also alluded to the fact that these patients maintained volume of their residual limb and this has been studied and described by Loon in his papers out of the University of California-San Francisco. In an ongoing study assessing volume maintenance in osteomyoplastic patients, our early results are reaffirming what Loon had seen in his group of patients even after they are utilizing a prosthesis. These are early, short term results at this time.

Recently, Paul Dougherty, M.D., has published an article reviewing the outcomes of Vietnam War veterans from the Valley Forge Center amputee center in Pennsylvania. His goal was to assess long-term follow-up of patients who required an amputation due to a battlefield injury. He did a comprehensive review and utilized the SF-36 scoring system to assess and judge a patient's outcome. Within that group of amputees, some did receive an osteoplasty, but no myoplasty was performed. As a main outcome from his paper, patients who sustained multiple injuries along with an amputation (group II patients) performed lower on their assessment score than patients with an amputation only (group I patients). Each group was sub-divided in to Ertl osteoplasty and non-Ertl osteoplasty amputees. His review of the results stated "no difference" between Ertl osteoplasty and non-Ertl osteoplasty amputees. However, his review of the data is flawed. As presented in his paper, group I and II Ertl osteoplasty amputees were grouped together and group I and II non-Ertl osteoplasty amputees were grouped together. A comparison was made with these combined groups to come to the conclusion that there was no statistical difference between Ertl osteoplasty and non-Ertl osteoplasty amputees, although all Ertl osteoplasty patients had higher scores in all categories. Patients who had an additional injury may have skewed the data, as one would expect multiply injured amputees to perform lower on their assessment scores. To correctly compare Ertl osteoplasty versus non-Ertl osteoplasty patients, group I Ertl osteoplasty amputees should have been compared to group I non-Ertl osteoplasty amputees. The same should have been done for group II patients. Combining the groups only clouds the analysis.

In the November corner, you review the paper that was presented in 1997 at the American Academy of Orthopaedic surgeons meeting in San Francisco. To date, this is the largest review of patients who had undergone an above knee osteomyoplastic amputation or a below knee osteomyoplastic amputation, Ertl procedure. There was a wide distribution of patients based on their initial indication for an amputation. I would not characterize the number of dysvascular patients as disproportionately low; only that this was the number of patients in the study. The scoring system utilized was modeled after other scoring systems accepted with in the published literature, essentially serving as a model for our scoring system. We would agree that it was not validated at the time. However, at the start of this study, other scoring systems were in the process of being validated and had not been used in amputation research. The scoring system developed included parameters that were felt to be important to assess amputee outcome: edema, pain, ability to ambulate, ability to utilize a prosthesis and radiographic review. As with any scoring system, we attempted to tabulate the information into useful objective data to measure any clinical change that was observed. Further, it was implied that we utilized this system to determine the need to perform a revision surgery. This is incorrect as the scoring system was to be utilized as a measurement tool. Clinical judgment and examination to determine if surgical intervention would benefit a patient are utilized to select patients for surgery. Every patient is unique in their complaints and this requires a thorough and complete assessment of the patient, including their goals and the capabilities of the surgeon. This cannot and is not done by simply tallying up a score sheet.

Pain in an amputee can be mutli-factorial in etiology and potentially can be neurogenic, psychogenic, dermatologic, osteogenic, angiogenic, infectious, and prosthetic in nature. In the series we reported on, several patients with a vascular etiology had a result that was characterized as being fair to poor overall, although they improved in other categories. This select group of patients is a challenge to manage as they may have had continued vascular symptoms even after amputation revision was performed. The challenge is to be able to discern this pre-operatively amongst the other clinical findings that are present. Overall, the patients we reported on benefited from reconstruction surgery of their amputation.

The osteomyoplastic amputation, Ertl procedure, for above and below knee amputations is a useful technique that provides the patient a functional residual extremity, is able to accept a prosthesis and returns the patient to the community. There has been considerable misconception regarding the terminology, the application of the terminology, and the surgical procedure itself. With in this forum, as with peer-reviewed publications, care should be taken to provide accurate information. We hope we have been able provide some clarity regarding the osteomyoplastic amputation procedure. Further, when done correctly, a well-performed amputation should be able to provide a patient with a functional limb. However, the Ertl procedure provides a balanced, cylindrical, end bearing residual limb with good physiologic function. Various aspects of the technique have been supported by both animal and clinical research. Clinicians should be aware of its application and value for the amputee population.

Thank you for your time.

Reader Comments: Read all user comments ertl procedure Please help! After 3 failed total ankle replacement surgeries (along with a subtalar fusion) I am exploring the option of a bka in the hope of getting on with my life. I have been trying to do as much research and be as informed as possib... read more - robyn hanek   9/13/2004 Need referral I need a referral to a doctor that performs the ertl procedure in either Kern County, Tulare County, or Kings County. Bakersfield, Porterville, Visalia or Fresno. Please respond. Thanks, Sharon LaScala (559) 784-3604 - Sharon LaScala   1/13/2004 Re: Need referral I think the most updated source for such information is the Ertl web site at www.ertlreconstruction.com. Since Dr. Jan Ertl is in Sacramento, you may wish to speak with him. --John Michael CPO - John Michael   1/13/2004 Need to find out about limb extention    I have not heard from any doctor yet, so I am going to put my self out on all the medical sites I can find, and maybe just maybe, I can get someone who will be willing to help me reach my goal.  I can wear my leg to do stuff around th... read more - George L. Velazquez   1/10/2004 Re: Need to find out about limb extention If I understand correctly, you are interested in learning whether you are a candidate for surgical limb lengthening. You will need to meet with an orthopedic surgeon with experience in this technique. I'm not aware of any lengthenings for... read more - John Michael   1/10/2004 Feliz Navidad y Prospero Año Nuevo 2004. Ciudad de Mexico 24 de Diciembre, 2003. Estimado John Michael, CPO: le enviamos un afectuoso saludo con motivo de esta Navidad y le deseamos lo mejor para el proximo año 2004. Muchas gracias por su arduo trabajo de informacion, en favor de... read more - Alberto E. Castillo Moreno O.P.   12/23/2003 Re: Feliz Navidad y Prospero Año Nuevo 2004. Thank you, Sr. Castillo, for these kind words of encouragement. Despite the ongoing work required to keep this forum timely, I am honored by the scope of readers worldwide who share my passion for P&O information. As we end another year, ... read more - John Michael   12/24/2003 The Ertle Procedure As a physical therapist and athletic trainer, who has focused on comprehensive rehabilitation following limb amputation, I find this interaction regarding surgical technique very exciting. I have had the privilage of training Paralympic at... read more - David A. Lawrence   12/9/2003 ertl controversy Greetings; in my exploration of the Ertl Procedure, I've found much positive commentary on the results. However, on a few occasions I've seen reference to a controversy around the procedure, although there was no information regarding said... read more - Robert Mercereau   12/6/2003 Re: ertl controversy Robert, I know all the ins and outs of the Ertl because I'm an Ertl amputee myself. My surgery was 6/3/03 in Columbus, Ohio so it's all still very fresh in my mind. The pros for me were (and still are) numerous--I can walk, jump, jog, bike,... read more - AJ Johnson   12/9/2003 Re: Re: ertl controversy AJ....I posted a message on this site but have not gotten any feedback yet so I'm hoping you have some info on my questions about the ertl procedure...1) why aren't there more surgeons who perform it since it seems to be a better amp proced... read more - robyn hanek   9/14/2004 Re: ertl controversy Why the use of the word controversy? Before John Michael’s columns the only other place I could find the word used in connection with the Ertl Procedure was for presentations at the annual meeting of the American Academy of Orthopedic Surge... read more - Vicki Anderson   12/9/2003 Re: ertl controversy The previous Corners on this topic are archived and represent my best effort to present the available information without either excessive hype or blatant prejudice. The Drs. Ertl's clarifications and comments are posted this month. Start... read more - John Michael   12/6/2003 Re: ertl controversy Robert, you can get a lengthy review at the newly launched Ertl website www.ertlreconstruction.com . I agree, you are certainly entitled to look at ALL available options. In my mind, having personally witnessed the procedure performed in ... read more - Anthony T. Barr / President of the Barr Foundation   12/6/2003 REQUESTING ADVISE DRs, BOTH OF MY SHOES HAVE SHOWN SIGNS OF UNEVEN/EXCESSIVE WEAR ON THE OURSIDE OF THE HEEL--MY FEET BEND OUTWARD. I HAVE TRIED TO CORRECT THE MISALIGNMENT PROBLEM BY WEARING A PRODUCT CALLED "PHASE 4 ORTHOTICS." I HAVE LITERALLY BROKEN... read more - RONALD BIDERMAN, MS, LADC, ICADC   12/3/2003 Re: REQUESTING ADVISE Thank you for this question. You don't need a different product until you are evaluated by someone who knows something about the biomechanics of foot orthoses. Once an office exam has established the biomechanical reason why your shoes we... read more - John Michael   12/6/2003