Introduction
Anatomy
Cause
Symptoms
Diagnosis
Non-surgical treatment
Surgical treatment
Rehabilitation
Prevention
There are many diseases that may require an amputation surgery. The limb may be involved as part of the primary pathology, or as a complication of other diseases. In certain very critical moments, amputation surgeries have to be performed to save lives.
Amputation usually refers to the excision of part of or the entire upper or lower limb with a defined surgical approach. It is named and classified accordingly to the region and the level of amputation. Lower limb amputation is more common that upper limb because of the nature of the pathology and the disease. Types of lower limb amputations include:
1) Hemipelvectomy, also called hindquarter amputation, which involves the excision of part of the pelvic bone
2) Hip disarticulation, which is the amputation of the limb at the hip level
3) Transfemoral amputation, also named “above knee” amputation
4) Knee disarticulation
5) Transtibial amputation, also called “below knee” amputation
6) Syme amputation, a form of amputation at the level of the ankle joint, where the heel pad is preserved to provide a platform for weight bearing
7) Amputation of the foot: If amputation is performed at the mid-foot, it is called a Chopart; amputation near the metatarsal is called a Lisfrance; and amputation through the metatarsal bones is called a Transmetatarsal amputation
An amputation would be required if the limb is damaged beyond reasonable reconstruction, or if the limb has to be sacrificed because it is part of a serious pathology. Indications of amputation include:
1. Deficiency of blood supply in the toes or feet due to peripheral vascular disease, causing inadequate blood flow to the limbs and jeopardizing its viability. This is commonly found in elderly patients or patients with diabetes.
2. Chronic venous insufficiency may be another cause that affects the blood circulation and results in chronic wound and amputation.
3. Uncontrollable infection of the foot, which is common among diabetic patients. It is also one of the commonest causes of amputation.
4. Malignant conditions such as skin, soft tissue, bone or joint tumors.
5. Trauma with a mangled extremity or a very severe open fracture. It may also be due to the complications related to the fracture, including damage of blood vessels, nerves or other soft tissues, which make the residual limb non-functional.
6. Other congenital conditions including congenital deficiency of a limb. A revision amputation surgery would be required to improve the function.
Symptoms include pain, bluish discoloration, swelling or persistent discharges from the foot or the toes. The involved digits might be dried up and turned black due to the loss of circulation. There may be purulent, foul-smelling discharge from the ulcer, or there is a collection of pus or dirty fluid under the sole. The whole leg may be affected with redness, swelling and increase in local temperature. Patient may run a fever and developed generalised malaise.
An orthopaedic surgeon would examine the patient’s limbs and look for any related pathology. General conditions, including the status of the underlying disease, e.g. diabetes, and the patient’s nutritional status, would need to be considered. The orthopaedic surgeon would assess the status of blood circulation and the function of the remaining soft tissue to determine the level of amputation. Some investigations may help to plan the operation, and that may include an X-ray of the limb to rule out any underlying bony infection, an ultrasound Doppler test to determine the blood flow, or an angiogram to quantify the status of the related blood vessel. The psychological make-up and the patient’s acceptance of the subsequent prosthesis, together with the patient’s future occupational and recreational requirements would also need to be looked into.
Please refer to the section on "Rehabilitation".
Before an amputation surgery, the doctor would decide the most appropriate level of amputation that would result in the best possible functional recovery and the most optimal healing. The longest length of the limb would be preserved, which will help facilitate the recovery of normal, day-to-day function, yet saving the energy for using the prosthesis.
During the operation, a variety of tissues would be transected and due consideration would be taken so that the remaining tissue would heal subsequently and provide proper function. The next step would be to reconstruct the limb and the wound to facilitate healing. The surface of the stump could then provide a stable and durable platform for the fitting of prosthesis.
Rehabilitation of an amputation patient would involve multidisciplinary care. A rigid plaster dressing could be applied post-operatively to control swelling. Plaster dressing can also allow the patient to be trained in standing and walking with a temporary prosthesis early on.
The early stage of rehabilitation would include the control of any pain in the amputated limb. Physical training should start right away to promote and maintain the function of the other healthy body parts, including the opposite limb. Walking could be resumed after the first week if condition allows, while the prosthetists would tailor-make permanent prostheses for the patients’ long-term use.
There are different components to every prosthesis, which are designed according to the patient’s different functional needs. The prosthetists will regularly review the clinical progress of the patient and make fine adjustments to the prosthesis.
During the later stage of the training, therapists would focus on the patients’ adaptation to the new prostheses. Besides walking and maintenance exercises, treatment could also be designed to suit the patients’ different functional and occupational needs. A typical in-patient rehabilitation programme usually takes around four to eight weeks.
After the appropriate rehabilitation, patients can then regain a normal social life. Many of them eventually return to gainful occupation. Orthopaedic surgeons would follow up with patients, assess their clinical conditions and check the status of the prostheses. Normally a standard prosthesis could last for three years with regular maintenance. There are occasions when the patients’ functional needs have changed and a new prosthesis needs to be fabricated. Some patients may be keen to return to sporting activities, and may benefit with a biomechanically more efficient prosthesis. Advancements in technology have resulted in different varieties of prostheses to suit different patients’ needs.
In summary, with the advances in orthopaedic care and the development of prosthetic technology, together with a comprehensive rehabilitation programme, amputation surgery is no longer a debilitating surgery as what people used to think. Patients who have undergone limb amputation would find themselves well-adapted to their normal daily functions and occupations. They could even consider engaging in sporting activities with the use prostheses. This opens up an even wider range of opportunities for patients after amputation surgeries.
Please refer to the section on “Diabetic Foot”.
Dr. KWOK, Hau-yan