Above the Knee Amputations (AKA)


Article Author:
Mitchell Myers


Article Editor:
Brad Chauvin


Editors In Chief:
Dustin Constant
Donald Kushner


Managing Editors:
Avais Raja
Orawan Chaigasame
Carrie Smith
Abdul Waheed
Khalid Alsayouri
Trevor Nezwek
Radia Jamil
Patrick Le
Anoosh Zafar Gondal
Saad Nazir
William Gossman
Hassam Zulfiqar
Hussain Sajjad
Steve Bhimji
Muhammad Hashmi
John Shell
Matthew Varacallo
Heba Mahdy
Ahmad Malik
Sarosh Vaqar
Mark Pellegrini
James Hughes
Beata Beatty
Beenish Sohail
Nazia Sadiq
Hajira Basit
Phillip Hynes


Updated:
7/13/2019 5:06:15 PM

Introduction

Above-the-knee amputations (AKA) involve removing the leg from the body by cutting through both the thigh tissue and femoral bone. This procedure may be necessary for a wide variety of reasons, such as trauma, infection, tumor, and vascular compromise. There are several known physiologic and psychologic complications that are associated with this procedure. However, an interprofessional approach to caring for these patients may decrease the rate of these complications.

Anatomy

The thigh divides into three compartments: anterior, posterior, and medial. These compartments surround the only bone in the thigh, the femur. The anterior compartment contains the vastus lateralis, vastus intermedius, vastus medius, rectus femoris, and genu articularis. Branches of the femoral nerve lie within the anterior compartment and innervate the musculature. A cutaneous nerve, the saphenous, arises from the femoral nerve and innervates the medial skin of the thigh and leg. The iliotibial band runs along the lateral border of the thigh, superficial to the vastus lateralis. The sartorius muscle is in the anterior portion of the thigh more proximally and in the medial portion more distally as it travels from the anterior superior iliac spine to its insertion on the anteromedial aspect of the proximal tibia as part of the pes anserinus. The medial compartment of the thigh contains the adductor magnus, adductor longus, adductor brevis, and gracilis. These muscles receive their innervation from the obturator nerve, except for the adductor magnus, which also receives innervation from the sciatic nerve. The medial compartment also contains the femoral artery and vein, which pass posteriorly after going through the adductor hiatus.[1] Proximally, the femoral artery divides into superficial and deep branches, with the deep branch providing blood flow to the muscles of the thigh and the femoral shaft. The great saphenous vein runs superficially along the medial aspect of the thigh. The posterior compartment contains the long and short head of the biceps femoris, semitendinosus, semimembranosus, and sciatic nerve. Branches of the sciatic nerve innervate the musculature of the posterior compartment.

Indications

Above-the-knee amputations may be necessary for many reasons. These can include trauma to the lower leg, which results in a non-viable leg at or near the level of the knee. Below-the-knee amputation may adequately address a more distal injury. Many studies have attempted to create algorithms to help physicians decide when to reconstruct versus amputate. One of these is the Mangled Extremity Severity Score (MESS), which takes into account skeletal/soft tissue injury, limb ischemia, shock, and patient age.[2] Other indications include infection which has compromised the entire lower leg and is unresectable. Etiologies may include non-healing diabetic wounds, necrotizing fasciitis, or cases of immunocompromised patients. Tumors that are unresectable or whose resection would render the distal aspect of the limb non-usable are yet another indication for this procedure. Vascular compromise, whether from injury or disease, which cannot be corrected, can also necessitate an AKA. Additionally, congenital disabilities that render a limb non-usable can indicate the need for this amputation.

Contraindications

Once all other non-amputation treatment options have been exhausted, there are few contraindications to above-the-knee amputation. An example is if the patient is not medically stable enough to survive the anesthesia and/or surgery. However, it merits consideration that the condition of the patient’s limb may be the cause of their medical instability.

Equipment

In addition to standard operating room set-up, table, and sterile drapes, other needed equipment will vary by surgeon preference but typically includes an orthopedic set with retractors, clamps, etc. An oscillating saw or Gigli saw, a scalpel, and drill will also be needed. Variable sutures and ties of the surgeon's preference are another necessity for tying off vessels. A suction drain is typically used as well, a device of the surgeon’s preference for wound closure. Additionally, some surgeons may choose to use a sterile tourniquet to reduce blood loss.  Radiology is not routinely necessary, but if needed intraoperatively, one must make sure the patient is on a radiolucent bed. 

Technique

Patient placement is supine on the operating room table with the buttock of the surgical side elevated on a stack of blankets. The operative leg gets prepped and draped in a sterile fashion. Planned skin incisions are marked. Some surgeons prefer anterior and posterior skin flaps for a fishmouth type closure with a slightly longer anterior flap, while others prefer medial and lateral flaps. In a traumatic setting, flaps may be dictated by what tissue remains viable. An optional sterile tourniquet is then applied to reduce blood loss. Incisions are then made along the planned lines, and electrocautery is used to control bleeding. Dissection is performed through the underlying fascia. Depending on the level of the amputation, muscle groups are identified and transected with electrocautery. Muscle groups should be transected approximately 1-2 inches longer than the planned bony cut to allow for musculature coverage of the bony end and myodesis. The femoral artery and vein are identified, dissected, ligated, and transected. A similar procedure is performed if encountering any other large vessel branches. Next, the sciatic and saphenous nerves are identified and dissected. Gentle traction is applied, and the nerves are sharply transected to reduce the risk of neuroma formation. A similar procedure is performed for any other nerves encountered, depending on the level of the amputation.

Transection of the femur is typically 12cm proximal to the joint line, but other factors may dictate the level.[3] A Gritti-Stokes amputation involves cutting the femur at the level of the adductor tubercle and arthrodesis of the patella to the end of the cut femur for improved end-bearing. Care must be taken to remove the synovium to avoid post-operative effusion. The bony cut is made with an oscillating saw, and a rasp is used to smooth the edges. Drill holes are made in the lateral and posterior aspects of the distal portion of the remaining femur. The adductor magnus tendon is then sewn to the lateral aspect of the femur with nonabsorbable suture with the leg held in 5 to 10 degrees of adduction. The quadriceps musculature the then brought over the distal end of the femur and sewn with nonabsorbable suture to the posterior aspect of the femur while holding the hip in full extension. The posterior musculature may undergo myodesis to the posterior aspect of the adductor magnus complex. The fascia lata then gets sutured to the medial fascia. An optional drain may be placed deep to the fascial layers to reduce hematoma. The fascia, subcutaneous tissue, and skin are sutured closed in a layered fashion. Care must be taken not to overtighten the skin suture so as not to cause necrosis. Sterile soft dressings are then applied. An optional splint or cast can then be placed over the remaining stump. 

Complications

Complications following above-the-knee amputation include muscle atrophy, surgical site wound infections, dehiscence, and wounds from prosthetic wear. One can minimize the complications from skin breakdown when they are caught early by checking the skin daily, especially in patients who have an insensate stump. Additionally, certain pre-operative measures may be used to predict a patient's ability to heal an amputation. Albumin over 3.0g/dL, total lymphocyte count greater than 1500/mm^3.[4] and ankle-brachial index greater than 0.45 has been shown to improve wound healing. Abduction and flexion contractures may also occur as a complication. One study found that 4 of 8 patients who did not have their iliotibial band fixed to the femur, to avoid developing an abduction contracture, ended up developing a hip flexion contracture; this is believed to have occurred because the gluteus maximus, a hip extensor, inserts in part onto the iliotibial band.[5] The risk of flexion contracture is reducible by having the patient intermittently lie prone post-operatively. Also, myodesis of the quadriceps with the hip in a fully extended position in the OR can reduce this risk. Abduction contracture risk can be decreased by properly performing a myodesis of the adductors to the femur. Phantom-limb pain is another complication of an AKA and has been estimated to affect up to 80% of patients who undergo a limb amputation.[6] Post-traumatic stress disorder (PTSD) and depression are known as psychologic complications of amputation. Elderly patients with chronic pain and those who undergo a traumatic amputation demonstrate a higher prevalence of these disorders. Patients who undergo an AKA as a result of chronic illness have lower rates of PTSD.[7]

Clinical Significance

Above-the-knee amputations can have a significant clinical impact on the lives of patients. Many patients do not have the resources to obtain a prosthesis and may have to continue using a wheelchair following the procedure. For those who do get a prosthesis, their mobility is significantly affected. One study showed that patients with a unilateral transfemoral amputation had a self-selected walking speed 8.6% slower than that of their non-amputee counterparts.[8] Another study showed a 49% increase in oxygen consumption during ambulation in patients with an above-the-knee amputation.[9] Approximately 65% more energy expenditure is required to ambulate in above-the-knee amputees when compared to patients without an amputation.[10] This number can be increased to 100% when the amputation is performed due to vascular compromise, as compared to trauma. This increased energy expenditure and decreased mobility may ultimately affect both the personal and professional lives of these patients.

Enhancing Healthcare Team Outcomes

An above-knee amputation is associated with enormous morbidity; unlike a below-knee amputation, fitting a prosthesis for an above-knee stump is difficult. In fact, most patients cannot adapt to an above knee prosthesis and eventually succumb to a wheelchair to get around. This leads to other complications like pressure sores, inability to perform daily living activities and depression. When possible, clinicians need to avoid an above knee amputation because of the high morbidity; if the procedure is elective, presurgical education of the patient is important. Both the pre and postoperative management of an above knee amputation is best managed by an interprofessional team because there are functional and physical issues that need to be dealt with.

An interprofessional approach is essential in caring for patients who have undergone an amputation. Aside from the physician performing the procedure, specialists in other fields of medicine can play a role in improving a patient's outcome. Internal medicine physicians can control and treat comorbid conditions, which may otherwise slow a patient's progress. Nurses are essential to monitoring vital signs, assisting the patient with daily activities, and delivering medication. The wound care nurse is vital to ensure that the stump is healing; unless the wound has healed, a prosthesis cannot be fitted. 

Pharmacists help with prescribing appropriate medications to control pain, prevent thrombosis, and decrease infection risk. Physical therapists guide the patient in rehabilitation protocols to restore muscle function and regain mobility in the absence of a limb. Prosthetists ensure the patient has an appropriate, well-fitting prosthetic. Psychologists and psychiatrists can be a valuable asset of the treatment team if the patient develops symptoms of PTSD or depression. One study, which reviewed 233 patients over 5 years, showed that a team approach to the care of amputees could decrease inpatient stay by 20 days, increase the number of patients discharged with a prosthesis by five-fold, and increase the effectiveness of rehabilitation in the long term setting by threefold.[11] [Level 3]

The outcomes of patients with an above knee amputation depend on the reason why the surgery was necessary. For those with peripheral vascular disease, the outcomes are guarded; many also have associated heart disease which often leads to death. For those undergoing amputation for trauma, the prognosis is good.

In summary, caring for patients with above the knee amputation requires an interprofessional team approach, including physicians, specialists, specialty-trained nurses, physical and occupational therapists, and pharmacists, all collaborating across disciplines to achieve optimal patient results.[12] [Level V]


Interested in Participating?

We are looking for contributors to author, edit, and peer review our vast library of review articles and multiple choice questions. In as little as 2-3 hours you can make a significant contribution to your specialty. In return for a small amount of your time, you will receive free access to all content and you will be published as an author or editor in eBooks, apps, online CME/CE activities, and an online Learning Management System for students, teachers, and program directors that allows access to review materials in over 500 specialties.

Improve Content - Become an Author or Editor

This is an academic project designed to provide inexpensive peer-reviewed Apps, eBooks, and very soon an online CME/CE system to help students identify weaknesses and improve knowledge. We would like you to consider being an author or editor. Please click here to learn more. Thank you for you for your interest, the StatPearls Publishing Editorial Team.

Above the Knee Amputations (AKA) - Questions

Take a quiz of the questions on this article.

Take Quiz
A 56-year-old malnourished male with diabetes is scheduled to undergo a right lower extremity amputation in the next week due to complications from wounds he has developed on the leg. He undergoes a pre-operative evaluation which shows his serum albumin to be 2.7g/dL, ankle-brachial index (ABI) to be 0.5, and total lymphocyte count (TLC) to be 1700/mm3. What of the following statements is true regarding this patient's wound healing capabilities?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
A 36-year-old female patient with diabetes has no sensation at the distal end of the stump of an above-the-knee amputation. She has proper daily hygiene habits and keeps the stump clean and dry. What other habits should be encouraged in this patient to prevent future complications?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
A 33-year-old female with diabetes has a left above-the-knee amputation due to complications from vascular compromise. Her husband is concerned about how tiring it will be for her to ambulate once she begins using a prosthesis. Which of the following responses is true?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
A 27-year-old male undergoes a left Gritti-Stokes amputation following a motor vehicle collision which leaves his lower leg unsalvageable. Post-operatively, he continues to have recurrent swelling in the distal aspect of the stump. His incision is well healed. There is no surrounding erythema. He denies any new trauma and has not been having any fever or chills. What is the most likely cause of the swelling?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
A 45-year-old female patient who underwent a left above-the-knee amputation two weeks ago presents to the clinic with a 20 degree left hip flexion contracture. She has been compliant with daily prone stretches and exercises, but the contracture has persisted. What nerve innervates the muscle group that was likely myodesed with the hip in flexion during the surgery?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
A 43-year-old male patient has a left above-the-knee amputation. He presents to the clinic two weeks later for suture removal. It is noted that he has developed a twenty-degree flexion contracture of the left hip. What could have been done in the immediate post-operative phase to prevent this contracture from developing?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up

Above the Knee Amputations (AKA) - References

References

Sawyer E,Tadi P, Anatomy, Bony Pelvis and Lower Limb, Popliteal Vein 2019 Jan;     [PubMed]
Higgins TF,Klatt JB,Beals TC, Lower Extremity Assessment Project (LEAP)--the best available evidence on limb-threatening lower extremity trauma. The Orthopedic clinics of North America. 2010 Apr;     [PubMed]
Jaegers SM,Arendzen JH,de Jongh HJ, Changes in hip muscles after above-knee amputation. Clinical orthopaedics and related research. 1995 Oct;     [PubMed]
Flor H, Phantom-limb pain: characteristics, causes, and treatment. The Lancet. Neurology. 2002 Jul;     [PubMed]
Bhuvaneswar CG,Epstein LA,Stern TA, Reactions to amputation: recognition and treatment. Primary care companion to the Journal of clinical psychiatry. 2007;     [PubMed]
Gottschalk F, Transfemoral amputation. Biomechanics and surgery. Clinical orthopaedics and related research. 1999 Apr;     [PubMed]
Russell Esposito E,Rábago CA,Wilken J, The influence of traumatic transfemoral amputation on metabolic cost across walking speeds. Prosthetics and orthotics international. 2018 Apr;     [PubMed]
Huang CT,Jackson JR,Moore NB,Fine PR,Kuhlemeier KV,Traugh GH,Saunders PT, Amputation: energy cost of ambulation. Archives of physical medicine and rehabilitation. 1979 Jan;     [PubMed]
Traugh GH,Corcoran PJ,Reyes RL, Energy expenditure of ambulation in patients with above-knee amputations. Archives of physical medicine and rehabilitation. 1975 Feb;     [PubMed]
Kay SP,Moreland JR,Schmitter E, Nutritional status and wound healing in lower extremity amputations. Clinical orthopaedics and related research. 1987 Apr;     [PubMed]
Ham R,Regan JM,Roberts VC, Evaluation of introducing the team approach to the care of the amputee: the Dulwich study. Prosthetics and orthotics international. 1987 Apr;     [PubMed]
Komelyagina EY,Volkovoy AK,Sanbanchieva NI,Zaichikova MF,Maksimov NV,Antsiferov MB, [MULTIDISCIPLINARY TEAM APPROACH FOR DIABETIC FOOT PATIENTS IN AN OUT-PATIENT CLINIC]. Klinicheskaia meditsina. 2016;     [PubMed]

Disclaimer

The intent of StatPearls is to provide practice questions and explanations to assist you in identifying and resolving knowledge deficits. These questions and explanations are not intended to be a source of the knowledge base of all of medicine, nor is it intended to be a board or certification review of Surgery-Podiatry Cert Medicine. The authors or editors do not warrant the information is complete or accurate. The reader is encouraged to verify each answer and explanation in several references. All drug indications and dosages should be verified before administration.

StatPearls offers the most comprehensive database of free multiple-choice questions with explanations and short review chapters ever developed. This system helps physicians, medical students, dentists, nurses, pharmacists, and allied health professionals identify education deficits and learn new concepts. StatPearls is not a board or certification review system for Surgery-Podiatry Cert Medicine, it is a learning system that you can use to help improve your knowledge base of medicine for life-long learning. StatPearls will help you identify your weaknesses so that when you are ready to study for a board or certification exam in Surgery-Podiatry Cert Medicine, you will already be prepared.

Our content is updated continuously through a multi-step peer review process that will help you be prepared and review for a thorough knowledge of Surgery-Podiatry Cert Medicine. When it is time for the Surgery-Podiatry Cert Medicine board and certification exam, you will already be ready. Besides online study quizzes, we also publish our peer-reviewed content in eBooks and mobile Apps. We also offer inexpensive CME/CE, so our content can be used to attain education credits while you study Surgery-Podiatry Cert Medicine.