Osteomyoplastic transtibial amputation: technique and tips
© Taylor and Poka; licensee BioMed Central Ltd. 2011
Received: 28 October 2010
Accepted: 7 March 2011
Published: 7 March 2011
Treatment of severe lower extremity trauma, diabetic complications, infections, dysvascular limbs, neoplasia, developmental pathology, or other conditions often involves amputation of the involved extremity. However, techniques of lower extremity amputation have largely remained stagnant over decades.
This article reports a reproducible technique for transtibial osteomyoplastic amputation.
Amputation osteomyoplasty, or bone bridging, is a technique developed in 1920 to better correct the residual limb to a normal physiological status . Proponents of this technique state that the bone bridging between the tibia and fibula creates a larger and more stable end-bearing construct as well as preventing the fibular instability that occurs secondary to loss of the ankle mortise [2–7]. Vascularity of the residual limb is improved by sealing the intramedullary canal, which has been shown in angiographic studies to reestablish intramedullary pressure, improve medullary blood flow comparable to healthy volunteers and increase the blood flow to the residual limb [3, 8–10]. The myoplasty or myodesis component of the procedure recreates the normal length-tension of the muscles [2, 4, 7], increases and stabilizes the surface area available for prosthetic fitting, normalizes muscle function as viewed with EMG testing , and improves both the arterial and venous circulation of the residual stump [8, 13, 14].
The patient is placed in the supine position and a general anesthetic administered. A pneumatic tourniquet is placed on the proximal thigh and a bump under the ipsilateral buttock is helpful to control rotation of the limb.
Incision site and flap creation will depend on location of scars, deformities, wounds, or previous amputations. Approximately twelve to fifteen centimeters of residual tibia should be the goal in an average patient; distal third amputations should be avoided due to poor soft tissue coverage. Seventeen to twenty-two centimeters between the end of limb and the ground is required for the use of most modern integrated high-impact foot and pylon shock-absorbing systems. Preoperative discussion with the patient's prosthetist is recommended to integrate the fitting needs into the surgical plans.
A periosteal flap is created from the anteriomedial and anterolateral surfaces of the tibia from distal to proximal; this is elevated to a level just proximal to the desired tibial cut. If no substantial periosteum is seen, an osteoperiosteal flap can be created with use of an osteotome to lift 1-2 mm of cortical bone on its limited attachment. Proximal attachment of this periosteal flap is desired to ensure maintenance of vascular supply. The tibia is then sectioned with the fibular cut being made approximately three centimeters distal to the level of the tibial cut. The distal tibial piece is then levered anteriorly as the posterior tibia and fibula are released to the level of the posterior flap incision. The nerves and vessels are again individually ligated and divided, and the posterior incision is then carried through in a full-thickness manner.
The efforts of creating a distal bone bridge and the osteomyoplasty does add time and potential morbidity to the transtibial amputation procedure, but is directed at creating a more functional and physiological residual extremity. Patient reported outcomes from this procedure are encouraging and generally higher than that for traditional transtibial amputees, with improved rate of return to work as well as patient-reported outcomes [1, 2, 7, 15].
Indications for this procedure include acute trauma as well as sequelae from tumor, trauma, previous surgery, and congenital deformities. Although traditional thought is that diabetic or dysvascular patients should not undergo this procedure, several reports of these patients included in larger groups reveal that they can undergo this procedure successfully but may not perform as well on functional testing [1, 2, 4, 6, 7].
The foot is a very unique end-bearing organ, and the removal of the distal limb creates several difficulties. Traditional transtibial amputation creates a smaller and possible less stable area for weightbearing with surrounding soft tissues that are not designed to resist the compressive and shearing forces of weightbearing. This procedure was developed to help create a more enhanced and physiological weightbearing platform.
Written informed consent was obtained from the patient for publication of this report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.
We would like to thank John Hays, the prosthetist for many of these patients, for contributing to their care and providing photography for the technique described above.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.