Leg - Transtibial Amputation

This course provides you the practical knowledge for an individual surgical procedure.

After this course, you have :
  • a clear understanding of the steps to be taken to execute the procedure;
  • seen an example of how the procedure is executed;
  • a clear understanding of all anatomical structures encountered during the procedure;
  • seen an example of how the anatomical structures look within the setting of the procedure.
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Step by step

Skin incision

Skin

Mark

Mark the medial joint line, the patella, the tibial tubercle and the lateral joint line. Then mark the skin both lateral and medial about 15 cm under the joint line (10 cm from tibial tubercle). The length of the posterior flap should be half the circumference of the limb from the heretofore mentioned marking + 3 cm. Mark the medial and lateral endpoints of the posterior flap distally. Then draw a line from medial to lateral connecting the two incision marks. Finally connect the two marking points on the lateral and medial side longitudinally .

Incise

Incise the skin following the previously made markings.

Length posterior flap

Make the posterior flap slightly longer than necessary so that it may be trimmed at the time of closure.

Subcutaneous tissue

Incise

Incise the subcutaneous tissue to the level of the muscle fascia to expose the anterior and lateral compartment muscles.

Great saphenous vein

Identify

Identify the great saphenous vein, which is positioned on the medial side and anterior to the deep fascia.

Transect

Transect the great saphenous vein.

Saphenous nerve

Identify

Identify the saphenous nerve running in close proximity to the great saphenous vein.

Transect

Transect the saphenous nerve.

Transection of a nerve

Transect a nerve as proximal as possible while keeping it under traction. This reduces the chance of neuromas and pain development.

Anterior and lateral compartments dissection

Fascia of anterior compartment

Incise

Incise the fascia of the muscles in the anterior compartment.

Anterior and lateral compartment muscles

Identify

Identify the anterior and lateral compartment. The anterior compartment consists of the tibialis anterior, the extensor hallucis longus, the extensor digitorum and the peroneus brevis muscles. Lift the anterior and lateral compartment muscles with a clamp.

Transect

Transect the anterior and lateral compartment muscles.

Superficial peroneal nerve

Transect

Transect the superficial peroneal nerve.

Anterior neurovascular bundle

Identify

Identify the anterior neurovascular bundle. It consists of the anterior tibial artery and vein and the deep peroneal nerve.

Anterior neurovascular bundle identification

The anterior neurovascular bundle can always be identified by dissecting between the tibialis anterior muscle and the extensor hallucis longus muscle.

Transect

Transect the anterior tibial artery and vein. The deep peroneal nerve should be isolated and transected.

Vessel separation

Dissect and separately ligate the large arteries and veins. This prevents the development of arteriovenous fistulas and aneurysms.

Fibula and tibia transection

Interosseous membrane

Transect

Transect the interosseous membranes between the fibula and tibia for a few centimeters.

Fibula

Transect

Transect the fibula 1 cm proximal to the level of the tibia.

Skin irritation prevention

Cut the fibula bone at least 1 cm proximal to the tibial bone to avoid decubitus. A higher level may result in a conically shaped stump with an over-prominent tibia what could make socket fitting difficult.

Periosteum tibia

Dissect

Dissect the periosteum because this is where the fascia of the gastrocnemius will be attached to later on.

Tibia

Transect

Transect the tibia with a sagittal saw at the level, or a little proximal, of the skin. The first centimeter perpendicular to the bone. Now 1-2 cm proximal to this level create a perpendicular precut and subsequently saw in a 45 degree direction to the first cut. Continue with a transverse cut to finalize the transection.

Skin contact

The saw must not be able to come in contact with the proximal skin to avoid skin damage.

Posterior flap dissection

Tibia and fibula

Dissect

Dissect along the posterior side of the tibia and the fibula to the level of the posterior skin incision.

Muscles deep and superficial compartment

Transect

Transect the muscles of the deep and superficial compartments at the level of the skin incision of the posterior flap.

Peroneal vessels

Identify

Identify the peroneal artery and vein running posterolateral.

Transect

Transect the peroneal vessels.

Posterior tibial neurovascular bundle

Identify

Identify the posterior tibial neurovascular bundle posteromedially which includes the posterior tibial artery, vein and tibial nerve.

Transect

Transect the posterior tibial vessels and the tibial nerve as proximal as possible.

Deep posterior compartment muscles

Transect

Transect and remove the tibialis posterior, the flexor digitorum longus and the flexor hallucis longus.

Soleus muscle

Transect

Transect the soleus muscle to the level of the gastrocnemius.

Fascia preservation

The posterior myofascial cutaneous flap can survive very well with the gastrocnemius muscle if its fascia is carefully preserved.

Lesser saphenous vein

Identify

Identify the lesser saphenous vein running posteriorly.

Transect

Transect the lesser saphenous vein.

Sural nerve

Identify

Identify the sural nerve running in close proximity to the lesser saphenous vein.

Transect

Transect the sural nerve as proximal as possible.

Wound closure

Tourniquet

Deflate

(In case a tourniquet is used, deflate tourniquet and check if initial hemostasis is obtained).

Tibia

Rasp

Rasp the tibia to minimize damage caused by sharp edges.

Posterior flap

Check

Check whether the posterior flap length is sufficient.

Drain usage

Use a drain on indication. A stump can be drained by a closed suction drainage positioned deep in the muscle flap and brought out laterally through the skin 10 to 12 cm proximal from the stump.

Gastrocnemius fascia

Approximate

Approximate the fascia to the tibial periosteum with mattress sutures.

Ischaemia prevention

Do not separate the muscle from the fascia to prevent ischaemia of the skin flap.

Subcutaneous tissue

Close

Close the subcutaneous tissue with absorbable braided sutures.

Skin

Close

Close skin with tension-free interrupted monofilament vertical mattress sutures to reduce tension on the skin or surgical staples. Avoid dog ears, and when they do occur a correction should be performed.

Stump

Bandage

Bandage the end of the stump.

Oedema prevention

Leave the bandage on the stump for 3-5 days to prevent oedema.

Objectives

SURGICAL OBJECTIVES

The surgical objectives of the transtibial leg amputation are to completely remove the foot.

Indications for the procedure include severe trauma to the limb, poor blood flow to the limb, severe and ongoing infections, tumors, severe burns or frostbite and loss of function. [1] After severe trauma, a transtibial leg amputation may be advocated to prevent further complications (sepsis, infection, severe bleeding) or in the case of a poor functional outcome following pathology. [2]

Poor blood supply to the leg could cause infarction and/or necrosis, resulting in gangrene of the leg. Both microangiopathy caused by diabetes mellitus or macroangiopathy caused by peripheral atherosclerosis can be the underlying pathophysiology. [3]

Severe and ongoing infections may also be an indication for an amputation. Initially the treatment of infections is tried conservatively,with appropriate wound care and antibiotics. If conservative treatment fails, the infection may spread rapidly, resulting in sepsis. An amputation may be inevitable in this case. [1]

Severe burns or frostbite may result in the damage and death of vital tissue leading to an inevitable amputation, performed above the level of the necrotic tissue.

APPROACHES

If clinically feasible, amputations below the knee are preferred over knee disarticulations or amputations above the knee due to their advanced functional outcomes. There are no conclusive studies on which surgical technique for an amputation below the knee gives the best results regarding the healing of the stump and the prosthesis for maximum rehabilitation potential. [4]

The following approaches for a lower leg amputation can be used:
Long posterior flap approach: a long posterior flap is subsequently brought up and sutured to the anterior tibial side over the transected bone. The long posterior flap approach is the preferred approach.

Skew flap approach: the skin flaps are equally skewed creating an anteromedial and posterolateral flap, with a muscle flap remaining in between. The posterior muscle flap is positioned anteriorly over the bone. The skin flaps are approximated and sutured thus closing the wound.

Sagittal approach: two semicircular flaps are created medially and laterally to the knee and are subsequently sutured over the transected bone.

Medial approach: a long medial flap is created, which is positioned laterally over the transected bone.

GUIDELINES

Preoperative

INSTRUMENTS AND MATERIALS

A basic surgical set is required for this procedure, as well as a sagittal saw/bone cutter. A tourniquet is optional. The benefits of a tourniquet include decreased blood loss during the procedure and a shorter operating time. The disadvantage, however, is that already compromised circulation becomes more compromised.

POSITIONING

The patient is placed in a supine position.

DRAPINGS

Infected or necrotic areas should be isolated using a mechanical barrier, such as a surgical glove, plastic sleeve or adhesive skin drapes preoperatively to minimize the chance of stump infection.

Postoperative

COMPLICATIONS

Besides general complications, specific complications can occur in a transtibial leg amputation, such as stump and wound complications, phantom pain and flexion contractures. Wound healing complications after a transtibial leg amputation are important because in some cases these determine a patient’s ability to walk with a prosthetic limb. [1][2]

Hematoma

A hematoma of the stump acts as a focus for infection. It may cause increased tension in the wound resulting in ischemia of the skin and subsequent delayed wound healing.

Stump edema

Stump edema is usually caused by bandage which is applied too tightly. It may cause pain and could result in delayed wound healing. It is treated by elevating the leg and redressing the wound so it is less tight thereby reducing tension.

Ischaemia

Ischaemia of the skin at the incision line is commonly caused by too much tension on the skin edges or a wrong estimation of the viability of the flaps before the surgery. This can result in wound dehiscence soon after surgery or even skin necrosis in the non-viable areas several weeks postoperatively.

Infection

Surgical site infection is a very common complication postoperatively. Necrosis which has not been completely resected can lead to severe progressive infections. Hypoxic conditions can promote the growth of anaerobes resulting in sepsis.

Phantom pain

Postoperative phantom pain usually improves within the first few weeks after surgery. When pain persists beyond this period it may be a sign of ischemia or ongoing infection of the stump, pressure points, neuroma formation and when all other causes have been ruled out phantom pain may be considered/diagnosed. [3]