Ernest M. Burgess

Amputations of the Leg for Peripheral Vascular Insufficiency

From July 1964 to July 1970, 193 major lower-extremity amputations were performed on 177 consecutive patients for ischemia by the Prosthetics Research Study team. Of these amputations, 101 were performed in diabetic patients; eighty-three in non-diabetic patients; and four in patients with Buergers disease. The initial levels of amputation were above-the-knee in twenty-eight, below-the-knee in 157, Syme in two, and knee disarticulation in three. The final levels were above the knee in forty, knee disarticulation in three, below the knee in 145 (two bilateral) and Syme in two (one bilateral). Selection of the level for amputation, the technique of below-the-knee amputation, the rigid dressing, immediate postsurgical prosthetic regimen, the procedure for weight-bearing and ambulation, and the method of follow-up are described. The results in terms of rehabilitation of the patients to a functional status are analyzed. Only nine of the 132 below-the-knee and Syme amputees and eight of the thirty-one above-the-knee and knee-disarticulation amputees who were fitted with a definitive prosthesis failed to gain independence out of the home. Seventy-four of the eighty-one below-the-knee and Syme amputees, who were sixty years old or older, were fitted with a definitive prosthesis and gained full independence out of their homes. Twelve below-the-knee amputations failed to heal and reamputation above the knee was required. Of these failures, seven could be attributed to incorrect selection of the level and five to inadequate postoperative management. It is concluded that with strict adherence to the precepts outlined with respect to the selection of the level, surgical technique, and postsurgical management. consistently high rates of healing and rehabilitation can be achieved after below-the-knee amputation for vascular insufficiency.

Segmental transcutaneous measurements of PO2 in patients requiring below-the-knee amputation for peripheral vascular insufficiency.

An accurate method is needed to quantitate the healing potentials of the possible sites of amputation in dysvascular limbs. We evaluated the segmental transcutaneous measurements of PO2 in thirty-seven patients who required below-the-knee amputation because of peripheral vascular insufficiency. The fifteen patients with below-the-knee transcutaneous PO2 values of forty millimeters of mercury or more had no delay in healing of the below-the-knee amputation. Seventeen of nineteen patients with values of more than zero but less than forty millimeters of mercury had healing at the below-the-knee level, in two after local revision. The three patients who had below-the-knee values of zero required re-amputation above the knee.

Transcutaneous oxygen tension as a predictor of success after an amputation.

We measured local transcutaneous oxygen tension at the foot and proximal and distal to the knee in 162 patients who then had 206 amputations. When the values for oxygen tension at the foot and distal to the knee were compared with the success or failure of healing after an amputation of the foot or distal to the knee, respectively, a clearly increasing probability of failure was correlated with decreasing transcutaneous oxygen tension. However, even at a tension of zero the probability of failure was not 100 per cent. The results were similar for diabetic and non-diabetic patients. Preoperative values for transcutaneous oxygen tension were a much more consistent predictor of success or failure of healing after an amputation of the foot or distal to the knee than were measurements of systolic blood pressure at the ankle, but neither was predictive of the outcome after an above-the-knee amputation.

Interface shear stresses during ambulation with a below-knee prosthetic limb.

Shear stresses on a residual limb in a prosthetic socket are considered clinically to contribute to tissue breakdown in below-knee amputees. When applied simultaneously with normal stresses, they can cause injury within the skin or can generate an abrasion on the surface. To gain insight into shear stresses and parameters that affect them, interface stresses were recorded on below-knee amputee subjects during walking trials. On the tibial flares, resultant shear ranged from 5.6 kPa to 39.0 kPa, while on the posterior surface it ranged from 5.0 kPa to 40.7 kPa. During stance phase, anterior resultant shears on a socket were directed toward the apex while posterior resultant shears were directed downward approximately perpendicular to the ground. Waveform shapes were usually double-peaked, with the first peak at 25% to 40% into stance phase and the second peak at 65% to 85% into stance. Application of these results to residual limb tissue mechanics and prosthetic design is discussed.

Clinical measurement of normal and shear stresses on a trans-tibial stump: Characteristics of wave-form shapes during walking

Stresses on the surface of a stump within a prosthetic socket during walking can potentially traumatise stump tissues. To gain insight into stresses and design parameters that affect them, normal and shear interface stresses were measured on three unilateral trans-tibial amputee subjects during walking trials. During stance phase repeated characteristics in wave-form shapes from different subjects were apparent. They included “loading delays”, “high frequency events (HFEs)”, “first peaks”, “valleys”, “second peaks”, and “push-off”. Characteristics did not necessarily occur at the same time from one step to the next but their timings matched well with events in shank force and moment data which were collected simultaneously. For “plantarflexion” and “dorsiflexion” alignment changes, the above wave-form characteristics were still pesent but their timings within the stance phase changed. The physical meaning and relevance of the characteristics to stump tissue mechanics are discussed.

Automated fabrication of mobility aids (AFMA): below-knee CASD/CAM testing and evaluation program results.

In 1988 the Department of Veterans Affairs Rehabilitation Research and Development Service, under the directorship of Margaret J. Giannini, M.D., began a nationally directed computer-aided design and computer-aided manufacturing (CAD/CAM) research program for the Automated Fabrication of Mobility Aids (AFMA). Under this program CAD/CAM research and development centers were established at the Prosthetics Research Study in Seattle, WA; at Northwestern University and the VA Lakeside Medical Center in Chicago, IL; and at the VA Medical Center and New York University Medical Center in New York, NY. These three centers conducted a collaborative program: (a) to introduce CAD/CAM technologies to prosthetists, physicians, therapists, and rehabilitation health care professionals in the United States; (b) to evaluate the feasibility of using CAD/CAM systems in clinical prosthetics settings; (c) to test and evaluate the University College London-Bioengineering Centers and the University of British Columbia-Medical Engineering Resource Units respective systems for the computer-aided design and computer-aided manufacture of prosthetic sockets (CASD/CAM) for below-knee amputees; and, (d) to obtain quantitative data for refinement of the CASD/CAM systems tested, and for the development of new, enhanced, more efficacious, and expedient systems.

Development and preliminary evaluation of the VA Seattle foot.

Most mobility aids for physically handicapped individuals seek to restore and improve function that primarily relates to basic lifestyle needs. This is an appropriate priority. With the lower limb amputee, this objective means stable, bipedal standing, and walking on unobstructed level surfaces . These elementary needs should be accomplished with comfort and with reasonable energy output (7, 19) . Presently available lower limb prostheses effectively satisfy these needs in most instances. However, as the mobility demands of an individual with amputation expand, conventional prostheses in general perform Poorly. This circumstance is most evident whe amputee attempts to run . Incremental inch in speed through fast walking, jogging running rapidly cause gait alterations in whu 9 with increasing speed, the unilateral amputee spends less and less time and weight on the deficient limb, which results in the sound limb largely propelling the body through the gait cycle. This, resulting high-energy consuming, uncomfortable, unstable, and unsightly gait pattern is thus generally avoided . Very few bilateral leg amputees are able to run . For these reasons

Achilles Tendon Tenodesis to Prevent Heel Pad Migration in the Syme's Amputation

In an attempt to prevent migration of the heel pad, 11 patients underwent a combined Symes amputation and Achilles tendon tenodesis between December 1989 and April 1992. Ten patients healed the Symes amputation, and one patient failed to heal the surgical wounds and required a below-knee amputation. In all 10 successful Symes cases, the heel pad has remained stable with no migration, and no skin breakdown at an average follow-up of 18.5 months. Published series of Symes amputations report that the incidence of heel pad migration is between 7.5% and 45%, and occurs primarily in the postoperative or early rehabilitation stage. We believe that tenodesis of the Achilles tendon is a technically easy addition to the Symes amputation, that it keeps tension off of the incision during healing, and that it prevents migration of the heel pad.

The All-Terrain Foot

In the past, people who managed to survive the traumatic loss of a leg or even those born with a major limb deficit required an ambulatory aid for functional mobility. The peg leg was developed under these circumstances and has remained with us throughout history. Since it continues to be used by many amputees regardless of other options they may have, the peg leg remains valuable. Prosthetics Research Study has designed a new lower-limb terminal device called the All-Terrain Foot.

Percutaneous electrical stimulation for clinical tibial fracture repair.

Observations on stress generated electrical currents in bone have stimulated interest in the possible osteogenetic effect of externally applied electrical energy to establish diaphyseal bone defects in animals and man. This report records the observed effects of pulsed electrical energy directed through a metal (Riordan pin) electrode placed in a large proximal tibial shaft dedect in a young man who sustained loss of bone from a gunshot wound. The fixation pin placed directly into the defect provided the cathode (-) electrode. The anode (+) electrode consisted of an aluminum foil band placed on the skin adjacent to the leg. The tibia had 282 consecutive days of electrical stimulation and provided X-ray and clinical evidence of enhanced osteogenetic activity. The degree of osteogenetic response attributable to the electrical stimulation is undetermined because other factors, including cast immobilization, time and minimal touchdown (25 pounds) weight-bearing in the cast during the period of observation, may also have had some influence on the healing response. Circumstantial clinical evidence indicates that the applied electrical energy was of primary importance in the healing process. This theoretically and technically acceptable source of osteogenetic activity merits continued, intensive investigation.