Amputation and Limb Deficiency

 

Overview

In the United States there are approximately 150,000 amputations performed annually. Those numbers are even higher for Mexico and Canada, leaving an estimated 2.5 million amputees living in North America alone. Ischemia from vascular disease, usually due to complications from diabetes, is the most common cause of amputation. Only 3% of the U.S. population is afflicted by diabetes, however diabetics make up 51% of the total amputations performed annually1. Other causes of amputation can be just as devastating.  The other 50 % of amputations are caused by massive trauma, infection, or tumors.  These causes are more frequent in people under the age of 45. 50 % of the estimated amputees in North America are between the ages of 21 and 651.  This has left the field of prosthetics with a great demand for high-level prostheses for athletics. 

 

Transtibial

Nearly 40,000 transtibial amputations are performed annually in the United States.  Transtibial amputation is the most common major limb amputation in the U.S., U.K. and Australia.  Surgeons performing the amputation procedures must evaluate the vascularity and infection level of the lower limb. When the decision to amputate is made, the surgeon’s goal becomes to leave a cylindrical shaped well- padded residual limb. Most surgeons will create a muscular flap using the gastrocnemius and soleus muscles.  These muscles are essentially wrapped under the remaining tibia and secured to the anterior tibia by suture. The rehabilitation process starts soon after surgery.  For most cases the patient will only participate in range of motion for the first week post-op.  After that, the patient will undergo a gradual weight-bearing program for the residual limb and if all goes well the amputee will have full activity capacity of the residual limb in 4 to 6 weeks.

 

Transfemoral

In 1997 alone, 35,000 transfemoral, or above-knee amputations were performed in the United States2. Much like transtibial amputees, after amputation the transfemoral amputee begins a large rehabilitation process that will involve his surgeon, prosthetist and therapist.  But the surgeon has the first and most immediate responsibility, to perform a good amputation.  That involves leaving as much residual limb as possible, preservation of the adductor muscles, and effective suturing of the remaining soft tissue.  It has been shown that the length of the residual femur is inversely related to the energy consumption in walking with a prosthesis3.  According to Gottschalk4, the goal of surgery should be the creation of a dynamically balanced residual limb with good motor control and sensation.  Because abduction of the femur is a common problem amongst transfemoral amputees affecting both their gait and energy consumption, preservation of the adductor (to balance the abductor) is important.

 

Upper Extremity

Upper extremity amputations are not as common as lower extremity amputations, however they present unique challenges to the surgeon, prosthetist, and amputee.  There are approximately 6,000-10,0005 of these amputations each year in the United States. In addition to amputees, people with deformities of congenital defects make up a large portion of those who utilize upper extremity prostheses.  The following lists the most common etiologies necessitating an upper extremity prosthesis.

           


Amputation causes

  • trauma
  • tumors - osteosarcoma
  • deformities -  dysmelia
  • shortened limb - phocomelia
  • absence of upper limb – amelia

 

Congenital disorders are most common indication in the 0-15 age bracket6. Amputation due to trauma is the prominent indication in the 15- 45 age bracket6. Overall 70 percent of upper extremity amputations occur in individuals under the age of 646.  That leaves a large number of still very active people with an upper limb deficiency. 

 

There are several defined levels of amputation for upper extremities (Click here or scroll down for a picture of the relevant bony anatomy). 

  1. Wrist disarticulation – through carpal bones from radius and ulna 
  2. Transradial (57%) – through radius and ulna
  3. Elbow disarticulation – through elbow between radius/ulna and the humerus (in children)
  4. Transhumeral (23%) – through humerus, often divided into long and short
  5. Shoulder disarticulation – through arm leaving 30% or less of humerus
  6. Forequarter – distal end of the clavicle and scapula, and partial trunk musculature

 

The cost and rehabilitation time associated for all new prostheses is widely variable. A non-automated sport specific prosthesis alone could cost $15,000.  Although, myoelectric automated upper extremity devices can cost considerably more.  The non-automated sport specific prosthesis typically have a one to two year lifespan under heavy athletic use.  Protective sleeves for the residual limb could add another $1,000 per year.   Depending on the level of re-training that is necessary for the patient to return to their sport, rehabilitation services could add another $5,000 to $15,000 in the first year and another $2,000 to $5,000 annually.  Annual medical (physician visits, MRI and CT, medication, various therapies, etc…) costs an average of about another $5,500.  If necessary, pain treatment programs can cost an additional $4,000 to $6,000 per year.  Overall, the cost of maintaining a sports prosthesis and being a competitive athletic amputee can cost $20,000 to $35,000 per year.

 

References

  1. Smith, DG, Fergason, J; Transtibial Amputations  Clinical Orthopaedics 1999; 1999: 108
  2. Detailed diagnoses and procedures, National Hospital Discharge Survey (1997)  and Lower extremity amputation rates, progression and utilization.  67, 2000.
  3. Michael, J.W. New Developments in Recreational Prostheses and Adaptive Devices for the Amputee.  Clinical Orthopaedics and Related Research.  July: 256, 1990.
  4. Gottschalk, F.  Transfemoral Amputation: Biomechanics and Surgery.  Clin Orthop.  361:15, 1999.
  5. Twala Maresh. Department of Physical Therapy, University of Central Arkansas. February, 2003.
  6. National Center for Health Statistics: US Department of Health and Human Services. Current Estimates From the National Health Interview Survey, 1990.

 

 

Relevant Bony Anatomy

For relevant bony anatomy, click here.

 

 

Back to the top…

 

 

Why Athletics?

Individuals who had undergone amputation at or above the knee about 20 years ago were said to have had an overall mortality rate 1.4 times as great as non-amputees and a mortality rate from cardiovascular diseases almost 1.7 times as large1.  It is believed that the sedentary lifestyle not uncommon to many amputees at the time was a contributing factor.  This was one of many reasons that doctors and prosthetists came to believe that athletics were very important for amputees.  Michael2 said that participation in sports was also responsible for improved strength, cardiopulmonary endurance, muscle coordination, and balance in amputees.  Additionally, competitive sports were said to be responsible for the improvement of coping behavior, cognitive abilities, mood, psychological well-being, self-confidence and self-esteem.  

 

Over the years, a large number of organizations have evolved to encourage amputee participation in competitive sports.  In addition to the reasons suggested above, many of these groups were motivated by amputees who were athletes prior to amputation and did not want to stop participating in their sport.  The most notable of athletic competitions for disabled athletes is the Paralympics.  Started in 1960 in England for spinal cord injury patients, the Paralympics evolved in 1976 to include other disabilities, and namely ambulated limb deficient athletes - athletes with prostheses.  The Paralympics are coordinated with the Olympics in time and place and include athletes from over 120 countries.

 

1.        Webster, J. et. al. Sports and Recreation for Persons with Limb Deficiency.  Arch Phys Med Rehabil.  82 Suppl 1:S38-44, 2001. 

2.      Michael, J.W. New Developments in Recreational Prostheses and Adaptive Devices for the Amputee.  Clinical Orthopaedics and Related Research.  July: 256, 1990.

 

Back to the top…

 

 

Glossary

 

Bilateral – amputation of the same limb on both sides

Gait -  pattern of walking

Gastrocnemius - the most substantial and superficial muscle of the calf. It arises by two heads, which are connected to the condyles of the femur by strong, flat tendons.

Ischial – the lowest of the major bones of the pelvis, see figure

Prehensile – grasp

Pronation – rotation of the hand or forearm so that the palm faces down or back

Supenation – rotation of the hand or forearm so that the palm faces up or forwards

Proprioception – the detection of body position and movements

Prosthesis - An artificial replacement for a body part
Prostheses - The plural of prosthesis
Prosthetist: - The practitioner who deals with prescribing, fitting and adjusting prostheses
Prosthetics - The profession of artificial limbs
Transfemoral - Amputation above the knee

Range of motion- the total amount the articulating portions of the prosthesis can move

Residual limb -: The remaining part of the limb after amputation (the stump)

Soleus - a broad flat muscle situated immediately in front of the Gastrocnemius. It arises by tendinous fibers from the back of the head of the fibula.  Together with the Gastrocnemius it forms the “calf” muscle.

Shock absorption- the amount of ground reaction force that is dissipated by a prosthesis   and therefore not transmitted through the prosthesis and to the native limb.

Stiffness (Young’s Modulus)- the ratio of stress to strain for a given substance. The strain is proportional to stress, and therefore the ratio of the two is a constant that is commonly used to indicate the elasticity the substance.

Unilateral – amputation on only one side

Terminal device – distal portion of prosthesis, often replacing hand function or appearance

 

Back to the top…