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The Importance of Amputation & Surgery in Prosthetic Fitting - The Ertl Procedure


How the amputation is performed is crucial.  How bone, nerve, blood vessel, fascia, muscle, and skin are treated during surgery have a profound impact on your comfort and function - both with prosthesis on and off.

With the advent and ease of internet research, many people who are faced with the possibility of amputation have researched amputation techniques and have read about the Ertl Procedure.  Research shows it offers the most biological, physiologically sound method of amputation.  Many people in their research find my name associated with the Ertl Procedure and will ask me to see them before they have surgery to discuss and learn about how the surgery is important to the fitting of the prosthesis, and the overall outcome from a comfort, functional perspective. I have had the privilege and honor to work with John Ertl, MD, Bill Ertl, MD, Jan Ertl, MD, William Ertl, MD, and Christian Ertl, MD over the past 30 years and can attest to the superior result of the “ERTL PROCEDURE” at all levels of amputation. It results in the most physiologic, biologic outcome.


The “Ertl Procedure”, as it is now known, refers to the primary and secondary reconstruction of lower extremity amputations. This procedure has withstood the test of time, as its foundation and advantages are based on solid biological and regenerative principles. These principles are utilized to recreate a limb with active participation and ambulation, combating what we have termed the inactive stump syndrome. Inactive stump syndrome consists of physical stump pain, bone and soft tissue atrophy, non-physiologic motion of bone and soft tissue all leading to inactive participation of the residual limb.

The Ertl Procedure utilizes biologic principles in attempts at recreating a physiologic harmony (studies state) between bone and soft tissue. The primary foundation of this procedure is based on the flexible Ertl bone graft, which is based on osteoperiosteal dissection, and has also been applied to spinal fusion, surgery and bony reconstruction of jaw and skull defects. The advantages of the Ertl Procedure are based on biologic principles as well as 70 years of experience, results, and patient satisfaction. In the below knee amputation attention is initially directed toward bone and a flexible bone graft harvested. This is utilized to create a bridge between the tibia and fibula. This step produces a synostosis providing a bony framework which recreates a heel type structure with weight-bearing capabilities.

Secondly, this bony framework secures the fibula, preventing it from separating from its tibial relation on weight-bearing or pulled by its tendinous attachments. Without this stabilization the fibula may separate from the tibia causing excessive and unnecessary motion leading to irritation of the soft tissues and nerves. This non-physiologic state in turn leads to further weakening to the already compromised durability of the lower extremity stump.​

Thirdly, the bony bridge prevents excessive rotational motion of the below-the-knee stump within its socket, thereby creating additional stability in the rotational axis of the patient's limb.

The fourth advantage is the recreation of the normally existing closed bone marrow cavity. This is automatically completed on creation of the synostosis, i.e., bony bridge between the tibia and fibula. This closure of the bone marrow is similarly accomplished in the above-the-knee amputations by osteoperiosteal flap closure. This is the work horse of the Ertl Procedure and its principles have been studied and supported through biomechanical laboratory experiments at UCSF providing evidence for its necessity. The bone marrow cavity is normally a closed system with its own blood supply. In conventional amputation techniques the bones are transected exposing the medullary cavity. With the bone marrow cavity exposed, abnormal vascular tissue will proliferate from the bone ends. This, in turn, leads to vascular connections between blood vessels outside the bone, causing arteriovenous fistulas which are abnormal. These arteriovenous fistulas lead to circulatory insufficiency, pain and dysfunction, all contributing to a disorganized and non-physiologic mass at the bone end. In the above knee amputations, osteoperiosteal closure of the bone marrow cavity also prevents crown sequestration. These crown sequestrations are caused by endosteal and periosteal stripping resulting in a 1.5 to 2.0 cm ring of necrotic bone at the amputation site. With reestablishment of a closed bone marrow cavity, physiologic circulatory dynamics are restored.

Once the bony foundation has been established attention is directed to the motor function, i.e., the muscles. A myoplasty is performed which reestablishes a length-tension relationship of the muscle by suturing opposing muscle groups together. The myoplasty is performed in both below knee as well as above knee amputations, the difference being the level of amputation and number of muscle groups requiring reconstruction.

The myoplasty serves a second purpose by reestablishing the pumping action of the skeletal peripheral heart. The peripheral heart refers to the muscles pumping action in the lower limbs during ambulation providing the return of venous blood back to the heart.

This advantage should be emphasized for its assistance in cardiac output which improves the amputee's ambulatory performance and may decrease some of the energy requirements.

Special attention is also given in dissection of the arteries, veins, and nerves. These structures are identified and isolated from its surrounding attachments as well as from each other. The arteries and veins are separately ligated and allowed to retract, preventing communication between the two. The nerves are handled with great care. In primary amputation, nerves are transected under tension and allowed to retract into their soft muscular bed where no tension or traction can be applied.

In stump reconstruction, nerves are commonly found adherent to localized scar tissue as well as to the skin itself. This scarring restricts the normal gliding motion of the nerves leading to pain. The neurolysis is performed and the nerve is transected under tension allowing it to retract to its soft muscular bed regaining its gliding properties. Lastly, the skin is approached and flaps contoured to the shape of the underlying muscle. A smooth surface is constructed to facilitate the fitting of full contact weight-bearing prosthesis. The smooth contour assists in decreasing air leaks at the extremity socket interface.

Soft drains are placed to evacuate any residual hematoma and are removed on the first or second postoperative day. At six to eight weeks, the wound is mature enough to accept final fitting of a prosthesis. The fitting of the appropriate prosthesis is important. In contrast to the frequently used PTB (patellar tendon-bearing) prosthesis, the patellar tendon-bearing prosthesis utilizes the patella and femoral condyles for prosthesis suspension, with the weight being borne on the patellar tendon. Within this prosthesis, the amputated stump becomes inactive acting only as a lever for the extremity. The residual limbs, bone and soft tissue undergo disuse atrophy and may become ulcerated from chronic irritation, eventually an inactive part of the body. Emphasis is placed on full contact and weight bearing properties. The weight bearing capabilities assist in reestablishing the proprioceptive modalities of the lower extremity, increasing the patient's stability, confidence and endurance.

The ERTL Procedure benefits the amputee in the following ways:

  • Prevention of excessive fibular motion by bony bridge (synostosis) stabilization in below knee amputations.

  • Reconstruction of the medullary canal with reestablishment of intramedullary pressure and prevention of arteriovenous connections at the bone ends in both above knee and below knee amputations.

  • Prevention of crown sequestrations in above knee amputations by medullary canal closure.

  • Improved venous return to the heart by myoplasty, i.e., reconstruction of the peripheral muscle pumping activity assisting in cardiac output.

  • Prevention of nerve adhesions by restoring the gliding properties of the nerve.

  • Improve prosthesis fitting with removal and prevention of unstable scars and creating a smooth contoured interface for prosthetic fitting.

  • Decreasing osteoporosis due to disuse atrophy by providing end bearing potential and reinstitution of physiologic bone loading.

The Ertl Procedure was developed and applied in 1920 in Hungary by Professor Janos Ertl, Sr., M.D. The indications for applying his regenerative principles in surgery of the amputated limb are to reestablish active extremity participation and function from an inactive stump. This reconstruction then allows for improved prosthesis fittings and biomechanics. Drs. John Ertl, M.D. and William Ertl, M.D. assisted in the development and continue to apply and modify these surgical principles. Through their efforts and those of their proponent, Jan Stokosa, the Ertl method became popular in the United States with the publication of “Whole Again” by Lee Whipple. This publication is also found in condensed form in the January 1980 issue of Reader's Digest.

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