Below the knee amputation

Below-knee amputation (BKA) is the surgical removal of the distal lower leg (tibia and fibula) ankle joint and foot including the soft tissues and serves as a life-saving procedure.

Indications

Generally, below-knee amputation is preferred over above-knee amputation, as the former has better rehabilitation and functional results ^1,2.

There are three large categories of indications for proceeding with the below-knee amputation, including the following cases ¹:

• necrotizing infections or hemorrhagic injuries where source control outweighs limb preservation

• trauma cases with serious or complete neurovascular compromise, irreparable soft tissue defects or full-thickness burns to the majority of an extremity

• elective below-knee amputation in certain circumstances such as

  • non-septic patients suffering from extensive nonhealing tissue loss

  • multiple distal to mid-foot amputations with persistent infection

  • irreparable vascular insufficiency with a nonhealing ulcer, or lack of distal foot/ankle function with refractory pain

Contraindications

The most important contraindication for a below-knee amputation is vascular insufficiency at the planned amputation site.

Also, in extreme situations such as acute major organ failure, sepsis, blood loss and cardiac arrest, every attempt should be made to stabilize the patient before starting the surgical procedure (an exception to this is uncontrolled, spreading necrotizing infection, in which source control is often life-saving).

Procedure

After taking written informed consent, the procedure is done in an emergency or elective non-emergency condition.

Technique

There are several ways to perform a below-knee amputation, one of the most significant differences being guillotine versus completed amputation.

Complications

Acute complications

• uncontrolled bleeding possibly

• infection

• acute postoperative pain

• stress-induced cardiac ischemia

• anemia

Chronic complications

• painful neuromas from transected nerves ³

• phantom limb pain, or the perception of pain or troubling sensation in the missing limb