Below the Knee Amputation
Below the knee amputation (BKA) is surgery to remove all or part of your foot or your leg below the knee cap. A below the knee amputation is a surgical procedure when the bottom part of the leg is removed with an incision below the knee. This is also known as a trans-tibial amputation. This procedure is recommended when a patient has a severely diseased or damaged lower leg that cannot be treated. Below-knee amputation is usually performed for extensive high-grade soft-tissue sarcomas of the lower leg, ankle or foot. Primary bone sarcomas rarely occur in these locations.
Extensive infiltration of tendons and ligaments and around bones in this area may preclude a functional extremity following wide excision. The almost universally good functional outcome of below-knee amputation makes it an even more realistic option. Indication: BKA is indicated in cases of benign and malignant tumor of the foot, peripheral vascular disease (PVD), severe traumatic injury of the lower limb with compromise neurovascular status especially involving tibia bone and various complication of diabetic foot like soft tissue necrosis, osteomyelitis, uncontrollable infection, or intractable pain.
Procedure: This operation can be performed using 2 major techniques. The most common technique is the posterior myoplastic flap (Burgess Technique) where the skin and muscle from the calf are brought forward to cover the shin bones after they have been divided (see below left). The other main technique is the skew flap (Kingsley Robinson technique) in which the muscles of the calf are brought forward in the same way as in the posterior technique but the skin flaps are skewed in relation to the muscle.
There is no proven advantage for one technique, but sometimes it is easier to perform a skew flap amputation if there has been significant skin damage above the ankle. Initially the skin is incised after marking the line of the incision and the incision is then deepened through the subcutaneous fatty tissue to the muscles. Bleeding from superficial veins is controlled and then the muscles are divided initially at the front to expose the two bones of the lower leg – the tibia and fibula. While doing this the major blood vessels in the calf are ligated.
The bone in the lower leg (tibia) is divided about 12-15 cms below the knee joint, the fibula is divided a little higher so that it is well recessed away from the end of the stump. The muscles and skin at the back are then divided low down after separation from the tibia and fibula so that they can be brought forward over the end of the bones to provide cover. To facilitate this coverage much of the muscle must be resected so that the flap is not too bulky. Other blood vessel at the back must also be controlled. The skin edges are then approximated.
This produces a good size stump to which prosthesis can be fitted. Disadvantage: Amputation of a limb or limbs will affect people in different ways. It is a very personal loss and in many patients can feel like bereavement. The emotional loss can be like losing a relative and it will take time to adapt to such a loss. Physically your body will be permanently altered and can affect all areas of your life. How much your amputation affects your life will to some degree depend on the extent of your physical recovery.