Apr 28, 2022
Holding Pressure AKA/BKA Shownotes
Name of Surgery: Above Knee Amputation/Below
Knee Amputation
Authors:
Dominique Dockery, MS3, Alpert Medical School of Brown
University
Robert Patterson, MD, FACS, Alpert Medical School of Brown
University/Providence Surgical Care Group
Editor:
Yasong Yu
Reviewer:
Ryan Meyer
Core Resources:
- Rutherford's Vascular and Endovascular Therapy 9th Edition
Chapters 104, 105, 111, 112
- Anson and McVeigh’s Surgical Anatomy
Additional Resources:
Underlying disease featured in episode: Peripheral arterial
disease (PAD)/chronic limb threatening ischemia (CLTI)
- Pathophysiology/etiology
- Blockage of the arteries supplying blood to the lower limbs
usually secondary to atherosclerosis
- Affects an estimated 8-12 million Americans
- Associated with smoking, diabetes, hypertension, obesity
- CLTI is more severe form of PAD (up to 20% of PAD patients)-
associated with rest pain, ischemia ulceration, or gangrene
- Patient presentation
- Varies based on disease progression and prior intervention
- Ranges from asymptomatic to major tissue loss
- Often have patients with intermittent claudication, rest pain,
or wounds/ulceration
- Patients can be classified using Rutherford scale or WIfI
classification
- Diagnosis
- Ankle-brachial index is diagnostic (<0.9 or >1.3)
- Often obtain CTA with run-off to visualize vessels prior to
angiogram
- Angiogram to plan intervention
- Surgical treatment
- Revascularization: either endovascular (angioplasty vs
stenting) or open (bypass based on targets with either vein or
graft)
- Amputation: after failed revascularization or
irreversible/severe ischemia with no revascularization options
- Minor (toe/foot) vs major (below knee/through knee/above
knee)
Indications for surgery:
- acute ischemia: for irreversible ischemia, for severe ischemia
with no revascularization options, or following unsuccessful
attempts at revascularization
- chronic ischemia: failure of revascularization, lack of
suitable conduit or target arteries, severe patient comorbidities,
poor functional status, or extensive gangrene or infection such
that foot salvage is not possible
- foot infection
- severe traumatic injury
- lower extremity skeletal or soft tissue malignancy
Preop Preparation: linking the patient with a prosthetist prior
to surgery is ideal and helps with surgical planning, addressing
patients’ fears and concerns, determining level of amputation
(pulses/blood flow, level of infection, etc.)
Surgical steps with relevant images:
Below the knee amputation (posterior flap technique):
- Create a hemi-circular incision anteriorly (generally about 1
handbreadth below the tibial tuberosity that goes from just
anterior to the fibula to an equidistant portion of the other side)
and a long posterior flap
- Cut through the muscles of the anterior compartment (muscle
bundle on the lateral side of the tibia) and expose the anterior
tibial artery and vein- ligate and suture ligate
- Using a periosteal elevator, which is something like a chisel,
strip the periosteum proximally from the tibia and divide the tibia
with an oscillating saw. Then strip the periosteum and attachments
of the fibula at this level and divide either with the saw or a
bone shear.
- Use an amputation knife to create the posterior flap along the
skin and fascia incision lines (fashion it to make sure it will
reach anteriorly without muscle bulk/tension). The remaining tibial
vessels are then identified and individually suture ligated.
Identify the tibial nerve, bluntly dissect it quite proximally and
divide it with electrocautery.
- After hemostasis has been established, remove a wedge of bone
from the anterior portion of the tibia so that that doesn’t provide
a pressure point on the prosthesis and resect the fibula 1-2
centimeters above the line of tibial transection with a rib cutter
to be sure that the fibula doesn’t wear against the prosthesis
laterally and create an ulceration or painful protrusion.
- Loosely approximate the posterior flap to the anterior fascia
with several interrupted Vicryl sutures and then carefully
re-approximate the skin with vertical mattress sutures of Prolene
using a Keith needle to avoid traumatizing the skin with
forceps.
Above knee amputations (Callander technique): Does not cut
across any muscle bellies but is purely dividing all muscular
attachments through the tendinous insertions. It is similar to a
through the knee amputation, but it involves dividing the femur
immediately above the flare of the condyle with curved anterior and
posterior fish mouth type flaps that again allow division without
the trauma of muscular transection.
Postoperative care: knee immobilizer post-operatively after BKA
to reduce risk of contractures, non–weight bearing on the stump
until the fitting of a prosthesis 4 to 6 weeks after surgery, close
follow up with vascular surgeon
Complications: primary healing fails in 20% to 30% of patients
and approximately 1 in 5 patients undergoing BKA need a
higher-level amputation due to wound problems
Top Asked Questions:
- What ankle-brachial index is diagnostic of peripheral arterial
disease?
Less than 0.9, severe PAD is less than 0.4. An ABI greater
than 1.3 or 1.4 is considered non-diagnostic and further workup is
indicated.
- What is the Rutherford classification for peripheral arterial
disease?
0- asymptomatic, 1- mild claudication, 2- moderate
claudication, 3- severe claudication, 4- ischemic rest pain, 5-
minor tissue loss, 6- major tissue loss
- Which amputation level requires more energy to ambulate with a
prosthesis?
Above knee amputations require 50-70% more energy than below
knee amputations
- What are the compartments of the lower leg, and which major
vessels and nerves are in each compartment?
Anterior- anterior tibial artery and vein, deep peroneal
nerve
Lateral- superficial peroneal nerve
Deep posterior- posterior tibial artery and vein, peroneal
artery and vein, tibial nerve
Superficial posterior- mostly musculature