Amputees and Their Prostheses
Elizabeth J Davies. M.A. * Barbara R. Friz, M.S. * Frank W. Clippinger, M.D. *
Information on 8,698 amputations was
collected during a period of approximately two years, ending June 30, 1967. This
information was extracted from case-record forms provided by 44 prosthetics
facilities in 30 states. The case-record form used was initially developed and
standardized by the Conference of Prosthetists of the American Orthotic and
Prosthetic Association. Its purpose was to encourage prosthetists in the
accurate recording of pertinent information relating to the amputee and his
prosthesis. Duplicate copies of the case-record forms were submitted to the
Committee on Prosthetic-Orthotic Education (CPOE), National Research
Council, in order that significant data could be identified and
reported.
"The Facility Case Record Study: A
Preliminary Report" and "Children with Amputations", both reporting
findings emerging from this study, have been published previously.
Data analyzed in the study included those
related to age, sex, level and cause of amputations, reamputations,
stump length and contractures, work status of
amputees, referrals, months to delivery of prosthesis, age of replaced
prosthesis and reason for replacement, components most frequently prescribed for
upper- and lower-extremity prostheses, and source of payment for
prostheses.
Methods
Each of the 44 facilities submitted case
record forms on amputees as they were seen. Three forms were utilized, one for
the amputee's medical history, one for the lower-extremity prosthesis, and one
for the upper-extremity prosthesis. In cases where the meaning of the data was
uncertain, follow-up forms were sent to the prosthetics facilities to clarify or
add to the information provided.
A coding system was devised, and
information was transferred from the case-record forms to coding sheets and then
to IBM cards and magnetic tape. Selection of pertinent data for retrieval was
determined by an ad hoc group and the staff of CPOE.
In order to make comparisons between
different areas of the country, the states represented in the study were
arbitrarily grouped into five geographical regions Fig. 1.
Subjects
The study included 8,323 amputees with a
total of 8,698 amputations. Statistics in this study refer only to patients
fitted with a prosthesis; amputees not fitted are not included. Table 1
indicates the types of cases included in the study.
Amputees or amputations being fitted for
the first time were considered "new" cases. Amputees or amputations
being fitted with replacement prostheses were
considered to be "old" cases. There was a total of 4,034 "new" amputations and
4,664 "old" amputations Table 2. Amputations in males accounted for 6,848
amputations, and amputations in females, 1,850-a ratio of 3.7:1.
Findings
Aage of Amputees
Table 3 shows the age of amputees fitted
in prosthetics facilities during the two years covered by this study. The
incidence of amputations for males peaked in the fifth decade; for females, the
peak was reached in the seventh decade. Forty-eight per cent of the amputees
were 51 years of age or older, 30 per cent were over 61 years, and 12 per cent
were over 71 years. The fact that 23 per cent of the amputees were fitted with
either a new or a replacement prosthesis after 65 years of age has Medicare
implications. (It should be noted that Medicare was in effect during only the
second year of data collection.)
Level of Amputations
Amputations of the lower extremity
accounted for 86 per cent of the total number of amputations Table 4. Of
these, 53 per cent were at the below-knee level. In
the upper extremity, 57 per cent of the amputations were at the below-elbow
level.
There was no significant difference in
the incidence of left- and right- side amputation in either the upper or lower
extremities. A total of 4,386 left-limb and 4,312 right-limb amputations was
reported. The right upper extremity was involved slightly more than the left,
605 to 573, and the left lower extremity fractionally more than the right, 3,813
to 3,707.
Cause of Amputation
Causes of amputation were considered in
four categories: congenital, tumor, trauma, and disease. Cases of
infection, gangrene, or osteomyelitis resulting from
trauma were classified under "trauma." Cases of trauma associated with vascular
disease were classified under "disease."
Causes of amputation were analyzed by age
group and level. Of the 8,698 amputations reported in this study, the cause was
known for 8,487 cases; both cause and age were known for 8,394 cases. Fifty per
cent of all amputations were caused by trauma, 37.3 per cent by disease, 8.4 per
cent were of congenital origin, and 4.3 per cent were due to tumor. Table 5
shows the relative incidence of amputation by cause and level.
In Fig. 2 the total number of
amputations by cause of amputation and age is indicated. Amputees most
frequently fitted or returning for replacement in the first
ten years of life were those with congenital limb deficiencies. Amputations for
trauma led all other categories fitted or returning for replacement between the
ages of 11 through 50. In the third, fourth, and fifth decades, this group
accounted for 76 per cent, 82 per cent, and 72 per cent, respectively, of all
cases fitted or returning. Of those fitted in the sixth decade of life, the
incidence was almost equally distributed between traumatic amputations and
amputations due to disease. After age 60, the latter group led all other
categories by a ratio of more than 2:1.
"New" Cases by Cause
Analysis of all amputations entered in
the study gives an overview of the type of amputee being seen and fitted in
prosthetics facilities, as reported above. Analysis of those being fitted for
the first time, however, provides a picture of persons
amputated during the two-year period of data collection and gives a better
current indication of cause related to age, sex, and level of
amputation.
It is probable that the statistics on age
are slightly distorted, since age was reported as of the time of fitting. Age at
the time of amputation, therefore, would be less, and to a variable
degree.
In the group of "new" amputees, cause was
reported for 3,963 cases, and both cause and age for 3,920. Fig. 3 indicates
the incidence of amputation by age. Of the "new" cases, 60.2 per cent of
amputations were caused by disease, 29.1 per cent by trauma, 5.9 per cent by
tumor, and 4.8 per cent were of congenital origin.
The predominance of trauma as the cause
of amputation in the overall amputee population of the study Fig. 2 is in
striking contrast to the predominance of disease as a cause of amputation when
only new patients are considered Fig. 3. In the overall picture, the ratio of
trauma to disease is 1.3:1, whereas in new patients the ratio is reversed, and
disease as a cause of amputation outnumbers trauma 2:1.
Thus, the total sample data obviously
includes a considerable number of traumatic amputees who lost their limbs at an
earlier age and survived to require replacement prostheses. However, the
noteworthy finding is that, in the period surveyed, disease-caused amputations
were occurring at double the rate of those attributable to trauma.
Congenital. In the 191 reported n males, 86 in females Table 6. Of this number, 137 did not require amputation
surgery, while 54 did. This surgery presumably involved the conversion of
anomalous limbs to stumps that were more suitable for the fitting of a
prosthesis. Eighty-three amputations occurred in the lower extremity, of which
44 were at the below-knee level. Of 108 upper-extremity amputations, 78 were at
the below-elbow level. Thirty-two per cent of congenital amputations were not
fitted until after 11 years of age.
Tumor. Of 235 "new" amputations
caused by tumor, 206 (88 per cent) were of the lower extremity Table 7. There
were 120 amputations at the above-knee level, accounting for 58 per cent of the
lower-extremity amputations. An additional 27 per cent were at a level
higher than above-knee, i.e.,
hip-disarticulation or hemipelvectomy. Males outnumbered females 130 to
105.
The highest incidence of tumor (66 cases
or 29 per cent) occurred in the second decade of life. Within this decade, no
particular pattern of incidence is discernible Table 8. These data are
somewhat at variance with those reported by Taft and Fishman from a study
conducted by the staff of New York University Child Prosthetic Studies. This
study, which involved a larger sampling (278 children whose amputations were
caused by tumor), showed a gradual increase in incidence beginning about the 6-8
year period and peaking in the 14-16 year group. Unfortunately, the age
groupings are slightly different from those of our study, so an
exact comparison cannot be made. However, both studies agree that tumor occurs
most frequently in the second decade by a wide margin.
Trauma. Of the 1,156 new cases of
amputations resulting from trauma, amputations in males accounted for a total of
1,050, and those in females for 106, a ratio of approximately 10:1 Table 9.
The highest incidence of trauma-related amputations occurred in the third decade
(250 cases), followed closely by that in the fourth decade (216 cases). The
number of amputees in these two decades accounted for 41 per cent of all new
cases where age was known. The incidence of amputations in females varied only
slightly in each decade between the ages of 11 and 60. The incidence of
amputations in males exhibited a sharp rise through the second and third
decades, and then receded gradually.
In every decade the involvement of the
lower extremity exceeded that of the upper. Actually, the lower extremity was
involved 1.9 times as often as the upper, 753 times as opposed to
403.
Disease. Sixty per cent (2,381
cases) of all new amputations were caused by disease Fig. 13. Although males
outnumbered females by more than 2:1 in this category, the relative percentages
of males and females in each age group were closely parallel, e.g., 980 or 61
per cent of males were over the age of 61 years, while 464
or 62 per cent of females were also over the age of 61. After 40 years of age, a
sharp rise in the incidence of amputations caused by disease was noticeable.
Approximately one-third of the amputations occurred in the seventh decade.
Eighty-five per cent of all new amputees in the disease category were over the
age of 51 years, and 49 per cent were in the Medicare age group.
In disease-caused "new" amputations,
involvement of the lower extremity greatly exceeded that of the upper, the ratio
being 73:1.
Comparison with Amputee
Census
The Glattly study, reported in
1964 and commonly referred to as the "Amputee Census," included only "new"
amputees. It is of interest to compare the findings of that study with the
present one. Findings of our study relating to the sex and age of new amputees
and the cause, side, and level of amputations closely parallel the findings of
the Glattly study. Comparative data of the two studies are depicted in Fig. 4, Fig. 5, Fig. 6, and Fig. 7, and Table 11.
In our study, newly fitted amputees 51
years of age and older accounted for 60.2 per cent of the total, as compared
with 58.8 per cent in the Amputee Census Fig. 4. In both studies, the highest
incidence of amputation was in the seventh decade. Because many geriatric
amputees are not fitted with prostheses, the incidence of amputation in the older age groups would
presumably be even higher if statistics on nonfitted amputees were
included.
In both studies, male amputees exceeded
female amputees by approximately three to one Fig. 5.
The distribution of right- and left-side
amputations was almost equal in both studies, and lower-extremity amputations
still accounted for about 85 per cent of all new fittings Table 11. In Fig. 6 a higher incidence of below-knee amputations and a lower incidence of
above-knee amputations were evident in the more recent study. Among new patients
in this study, there was a total of 3,254 above-and below-knee amputations. Of
these, 50.9 per cent were above-knee.
The relative incidence of trauma as a
cause of amputation decreased by four per cent from the Glattly to the present
study, and the incidence by cause in other categories increased, but by
relatively small amounts Fig. 7.
Original Level of Amputation for
Disease Correlated with Geographical Area and Age
The original level of amputation for
disease was examined for 2,242 new cases whose amputations were at either the
above- or below-knee level. Comparisons were made between below- and above-knee
as the choice of amputation level in each of the five geographical areas Table 12. Below-knee appeared to be the site of choice in less than half the total
number of cases. The South led the other geographical areas in percentage of
amputations at the below-knee level (54 per cent), followed in order by the
Midwest (51 per cent), New England (48 per cent), East Central (46 per cent),
and the West (45 per cent).
A look at the site of the original
disease-related amputation for new patients 41 years of age and above revealed
some interesting statistics Table 13. In the fifth decade, below-knee was
selected in preference to above-knee in 58 per cent of the cases. This
percentage gradually decreased over the next two decades to a low of 43 per cent
in the seventh decade. After the seventh decade, there was an increase to 47 per
cent in the eighth decade and to 50 per cent after the eighth decade. For all
new amputations for disease in patients 41 years of age and above, above-knee
was selected in 52 per cent of the cases, below-knee in 48 per cent.
The lack of a consistent pattern in these
data is intriguing. A progressive decrease in the proportion of below-knee
amputations with increase in age might logically be anticipated. Surgeons, for example,
might wish to be more sure of obtaining healing in older patients and elect to
amputate at the above-knee level. However, other factors than age of patient
obviously enter into the selection of amputation level.
Specific Causes of Traumatic
Amputations
Trauma was listed as the primary or
precipitating cause of 4,306 amputations ("old" and "new" cases). As noted
earlier, some of this number were classified in categories other than trauma,
since trauma was not considered the primary cause of amputation; hence, the
number 4,306 exceeds the number of cases actually coded in the trauma category.
Of these 4,306 instances where trauma was mentioned, there were 392 cases where
the type of trauma was unknown, so, for purposes of this analysis, reference
will be to the 3,914 cases where type was known.
Fig. 8 summarizes the causes of
traumatic amputations. In this category, men were affected ten times as
frequently as women: 3,561 to 353. In males, cars, industrial accidents, and war
each accounted for approximately 20 per cent of the cases. On the other hand,
automobiles were by far the outstanding cause of traumatic amputations in women
(49 per cent), with no other cause approaching this in frequency. It is
noteworthy that the ratio of male to female automobile-caused amputations was
in the order of 4:1, in contrast to the 10:1 overall ratio. Since it is not
known whether these female victims were predominantly drivers or riders, the
full significance of these data is not clear.
Table 14 relates cause of trauma to sex,
side, and level of amputation. Involvement of the right upper extremity in males
was greater than the left. This preponderance was especially evident in farm and
industrial accidents and is doubtless related to handedness. In car accidents,
the left upper extremity was involved significantly more than the right for both
males and females, 62 per cent as compared with 38 per cent. One can speculate
that this incidence might be attributable to the fact that many motorists ride
with the left elbow extending beyond an open window. In the small sample of
train accidents, the involvement of the left upper extremity in males was also
considerably greater than the right but, because of the small number, this
probably was without significance.
The left lower limb was involved slightly
more than the right in males, and the right and left limbs almost equally in
females.
Table 15 compares causes cited for "new"
traumatic amputations in males with those given for "old" traumatic amputations.
Twenty-six per cent of the amputations of "old" cases were due to war injuries,
whereas only 2 per cent of the new cases were due to this cause. At the time of
this study, the Vietnam War had not yet exerted its full impact. The greatest
increase in trauma-caused amputations was seen in the industrial-accident
category. Industrial accidents caused 29 per cent of the "new" traumatic
amputations, but only 15 per cent of the "old" amputations. Elimination of war
cases from the total number avoids distortion of the data due to the
preponderance of old war injuries, and thus presents a somewhat
truer comparative picture of other traumatic causes. With war injuries
eliminated, industrial accidents accounted for 29 per cent of the "new"
amputations and 20 per cent of the "old" amputations, which still reflects an
increased incidence of amputations caused by industrial accidents. Industrial
accidents exceeded all other categories as the cause of amputation in new
patients.
Reamputations of the Lower
Extremity
Reamputations were studied in relation to
cause, original level of amputation, and present level. Level was reported for
396 reamputations of the lower extremity. Some members of this group had second
reamputations, but for the purposes of this study, only the original and present
level of amputation were considered. An attempt was made to exclude simple
revisions that involved no shortening of bone.
In reviewing the figures presented here,
it should be remembered, again, that only those patients fitted with prostheses
at the time of the study are considered. Despite this limitation, analysis of
the available data is thought-provoking. Of 396 reamputations reported, 189 were
in the disease-related category involving a total of 3,122 cases Table 16, and
182 were in the trauma-caused group with 3,387 total cases Table 17. Thus,
reamputations in the first group ran a shade
over 6 per cent, those in the second group a shade under 6 per cent. Stated in
reverse, approximately 94 per cent of the cases in both groups did not require
re-amputation. The statistics for specific levels are also quite fascinating. In
disease-related below-knee amputations, approximately 6 per cent required
reampu-tation versus approximately 5 per cent in the like trauma group. In the
above-knee group, the comparative proportions are 1 per cent versus 0.6 per
cent. At the Syme's level, comparative figures are 25 per cent versus 28 per
cent, and for partial feet 96 per cent versus 25 per cent. The reasons for the
sharp increase in reampu-tations at the last two levels are worthy of further
study. It would also be of interest to know whether partial foot amputations,
for example, were or were not successfully performed on many patients who were
never fitted with prostheses.
For the 189 (48 per cent) reamputations
due to disease, Table 16 gives the final as compared to the original level. Of
93 below-knee amputations requiring ream-putation, 22 (24 per cent) remained in
the same segment, 67 (72 per cent) were converted to an above-knee level, 3 to a
knee-disarticulation, and 1 to a hip-disarticula-tion level. Of the 15 original
above-knee amputations, 9 were reamputated in the same segment and 6 became hip
disarticulations.
Of the 11 Syme's reamputations reported,
2 were reamputated to an above-knee level and 9 to a below-knee level. Of the 67
reamputations at the partial foot level, 22 were converted to an above-knee, 41
to below-knee, and 4 to a Syme's level.
Causes of reamputation for patients in
the disease category were indicated for 181 of the 189 reamputations. In some
instances, two causes of reamputation were cited. In each instance where a cause
was mentioned, it was counted as contributing to the reamputation. The total
number of contributing causes to reamputation in the disease category therefore
was 192 Table 18. "Recurrence of the original cause of amputation" accounted
for almost half (48 per cent) of the reasons cited for reamputations. This
generalized response is interpreted as meaning a continuance of the original
vascular problem responsible for the initial amputation. Specific causes cited
were a nonhealing wound (18 per cent), gangrene (12 per cent), infection (5 per
cent) stump breakdown (3 per cent), and "other" (14 per cent).
Most reamputations in the disease
category occurred very shortly after the original surgery, 49 per cent occurring
in less than 1 1/2 months, and 60 per cent occurring in less than 2 1/2 months.
Eighty-two per cent occurred in the first year following the
amputation.
In the category of traumatic amputations,
levels for 182 reamputations of the lower extremity were reported. Of the 114
amputations at the below-knee level requiring reamputation, 57 per cent (65
amputations) remained at the below-knee level, a percentage considerably higher
than was the case for reamputations due to disease. Forty-five amputations were
converted to above-knee levels and 4 were converted to knee disarticulations.
There were 29 Syme's reamputations, of which 23 were converted to below-knee, 3
to above-knee, and 3 remained at the Syme's level. Of the 22 partial foot
reamputations, 14 were converted to below-knee levels, 7 to Syme's and 1 to
above-knee.
Causes of reamputation were known for 157
of the trauma cases. As with reamputations in the disease category, every
instance where a cause was mentioned was counted. There were 165 contributing
causes to reamputations Table 19. In 71 instances (43 per cent), "other" was
coded as the cause of reamputation. Included in the "other" category were causes
that could not be readily classified, such as "stump not satisfactory for
prosthesis," "shorten bone and remove neuroma," "painful stump." The median
number of months between amputation and
reamputation was six.
There were 16 reamputations for
congenital amputees and 6 for patients whose amputations were caused by tumor.
Three of the latter were reamputated because of recurrence of the tumor.
Reported reasons for reamputations in congenital amputees were too diverse for
classification, except that 4 reamputations were because of bony
overgrowth.
Table 20 summarizes the total number of
reamputations for each level and includes the percentage of reamputations
converted to a higher segment or remaining in the same segment.
Bony overgrowth was cited eight times as
a reason for reamputation: four tibial overgrowths, two fibular overgrowths,
and two not specified. All of these
reamputa-tions were performed on children, with the exception of one on a
27-year-old amputee. While not implicit in the data, it is conceivable that this
27-year-old had had bony overgrowth for a long time prior to reamputation (his
first amputation occurred at age 10).
Stump Length and Contractures
There were 2,602 above-knee amputations
for which the presence or absence of contractures of the hip was reported. Of
this group, 1,345 had either no flexion contracture or a contracture of less
than 5 deg, and are not included in this analysis, other than the notation that
they comprised over half of the group reported. Stumps with 5+ deg of
contracture ranged in length from 2 - 2 1/2 inches to 14 - 15 1/2 inches. Three stumps had flexion contractures of more than 60 deg.
Hip-flexion contractures were greatest in the very
short stump. The average contracture at the above-knee level fell in the 5-9 deg
range.
There were 3,781 below-knee amputations
for which the presence or absence of knee contractures was reported. Of this
number, only 12 per cent were reported as having contractures of 5 deg or more.
In general, the shorter the stump, the more severe the contracture. Considering
only those cases reporting contractures of 5 deg or more, stumps averaging more
than 7 1/2 in. in length had average contractures of between 5 and 9 deg;
for stumps between 4 and 7 1/2 in. long, contractures averaged between 10
and 14 deg; and for stumps 3 1/2 in. and less in length, contractures averaged
15 to 19 deg. The average contracture, excluding those of less than 5 deg, was
10-14 deg. Three stumps had contractures of 60 deg or more.
Work Status
The work status of "old" male amputees
between the ages of 21 and 64, with 2,694 amputations, was reported. "New"
amputees were not studied, since the majority of the group had not yet had time
to return to employment. Eighty-four per cent of the "old" amputees in the cited
age group were employed, the highest employment rate (89 per cent) occurring in
the 41- to 50-year-old age group Fig. 9. In each of the age groups studied, a
higher rate of employment was reported for upper-extremity than for
lower-extremity amputees. It should be noted here that only 6.4 per cent of
amputees between the ages of 21 and 64 were reported as not being gainfully
employed. The remainder of the group (9.3 per cent) were students, retired, or
fell into some other category. This percentage of unemployment is a little
higher than that reported for the national average for the
years 1965, 1966, and 1967 (4.5, 3.8, and 3.8 per cent respectively).
The rate of employment in relation to
each upper- and lower-extremity amputation level appears in Fig. 10 and Fig. 11.
Work status was reported for 383 female
amputees between the ages of 21 and 64. Of this number, 200 were housewives, 148
were gainfully employed, and only 18 were not gainfully employed. Seventeen had
either retired or reported their work status in some other category.
Referrals
The majority (58 per cent) of cases
fitted at prosthetics facilities were referred by amputee clinics; 26 per cent
were referred by physicians; 16 per cent were not referred. Of the "new" cases,
5 per cent were not referred to prosthetics facilities by either a clinic or
physician, as contrasted to the 26 per cent of the
"old" cases not so referred.
Months to Delivery of
Prostheses
For "new" amputations, the time from
amputation (or from birth for congenital amputees not requiring surgery) to date
of delivery of the prosthesis was analyzed by level and cause for the five
geographical regions Table 21. The median period to delivery for all
prostheses was 6 months. Comparing geographical areas, the median was 5 months
for New England, the Midwest and West, 6 months for the South, and 7 months for
the East Central region. Of the 3,588 prostheses with times to delivery
reported, 71 were delivered in 1 month or less, 67 were not delivered for 99
months or longer. Thirty-seven of the latter were for congenital amputations not
requiring surgery, i.e., 37 children were not fitted with their first
prosthesis until after the age of eight
years, three months. A comparison of time to delivery by levels indicated that
the median time lapse was 5 months for the below-knee prosthesis and 6 months
for all other levels. Time to delivery of prostheses ranged from a median of 4
months for below-knee prostheses in the New England area and the West to a
median of 10 months for below-elbow prostheses in the East Central region. These
data will provide a basis for later comparisons in areas where programs of
immediate and early prosthetic fitting have been instituted.
Data on months to delivery were analyzed
by cause of amputation and related to geographical regions Table 22. The
shortest median length of time for delivery was 3 months for congenital amputees
who had had surgery. The longest time was for congenital amputations without
surgery, where the median was 31 to 36 months; however, it should be
recognized here that this median also represents the median age of congenital
amputees not requiring surgery who were being fitted for the first time. Median
time to delivery for amputations caused by tumor was 4 months; by trauma, 5
months; and by disease, 6 months.
Age of Replaced Prostheses and Reasons
for Replacement
The average age of replaced prostheses
for all patients was 6.1 years. For children up to 21 years of age, it was 2.5
years, and for adults, 6.7 years.
Comparisons of the ages of replaced
prostheses for above- and below-elbow and above- and below-knee amputees in
relation to the age of the patient (by decade) are shown in Table 23. In almost
every instance, the "life" of the prosthesis increased with the age of the
patient. The average life of above-elbow prostheses for 124 amputations was 9.2
years. The range was from 2.5 years for the child through the age of 10 years to
16.7 years for amputees over the age of 61. The average age of below-elbow prostheses for
349 amputations was 6.5 years, ranging from 2.5 years for the child through age
10, to 10.3 years for amputees over age 51. The average age of above-knee
prostheses for 1,269 amputations was 6.2 years, with a range from 2.2 years for
the child in the first decade, to 8.1 years for amputees over age 71. The
below-knee prosthesis had the shortest life, averaging 5.8
years for 2,201 amputations, and ranging from an average of 1.7 years for the
child through age 10, to 8.6 years for amputees over 71 years of age.
In comparing ages of replaced prostheses
by cause of amputation and the sex of the amputee, it is found that prostheses
for congenital amputees had the shortest life, averaging 3.5 years, and
prostheses for traumatic amputees had the longest life, averaging 6.8 years
Table 24. The growth rate of children in the congenital group undoubtedly
accounts for the more frequent replacements of prostheses evident here.
Replacement of prostheses for patients in the disease category occurred, on
average, every 5 years, and there was very little difference between
replacements for males and females. The life of prostheses for tumor patients
also averaged 5 years; however, prostheses for males in this category needed
more frequent replacement, lasting 4.5 years as compared with an average 5.6
years for females.
It is interesting to note that the age of
replaced prostheses for males averaged 6.2 years, and that of females 5.4 years.
The large number of males in the trauma category may account for this
difference, inasmuch as the average life of prostheses in this category is
longer than in others.
Table 25 indicates the reason for
replacement of prostheses. The majority of prostheses were replaced because they
were worn out. "Worn out" was listed as the sole or contributing cause of
replacing a prosthesis in 58 per cent of the cases.
It was the leading reason for replacing prostheses of persons whose amputations
were caused by tumor (50 per cent), trauma (67 per cent), and disease (44 per
cent). As would be expected, the primary reason for replacing prostheses of
congenital amputees was that the prosthesis was "outgrown." In 52 per cent of
replacements for congenital amputees, the prosthesis was outgrown; in 33 per
cent of the cases it was worn out.
"Unsatisfactory" was cited as the reason
for replacement in four per cent of the cases. However, it should be noted that
although the "unsatisfactory" category was meant to include only those cases in
which problems arose relating to fabrication or patient tolerance, it was often
cited for other reasons which rendered the prosthesis unsatisfactory. Had this
item been interpreted correctly, the
percentage undoubtedly would have been lower.
The average age of all "worn out"
prostheses that were replaced was 7.6 years Table 26. This exceeds the average
age of prostheses replaced for any reason (6.1 years) by a year and a half. This
higher age undoubtedly reflects the longer life of the prostheses of traumatic
amputees reported above, since "worn out" was the sole or contributing factor
for 67 per cent of the replacements in the trauma category. Additionally, the
lower average age of all the replaced prostheses was affected by the inclusion
of children's prostheses, which had shorter lives.
Ccomponents for Upper-Extremity
Prostheses
The components most frequently used for
upper-extremity prostheses at the above- and below-elbow levels are depicted in
Fig. 12a,Fig. 12b. The voluntary-opening hook was used with 87 per cent (201 instances)
of the above-elbow prostheses and 90 per cent (517 instances) of below-elbow
prostheses. The preference for this type of hook was reflected in all areas
except the West, which showed a preference for the voluntary-closing hook with
below-elbow prostheses. New England was the only area that did not prescribe the
voluntary-closing hook at all.
The hand-type terminal device was
utilized to a limited extent, being prescribed 309 times as opposed to the
hook-type device which was prescribed 806 times. Many amputees for whom hooks
were prescribed were also equipped with hands. Where hand-type devices were
reported, the voluntary opening hand was prescribed for above-elbow prostheses
40 per cent of the time (36 cases) and for below-elbow prostheses 36 per cent of
the time (79 cases). Both the East Central and Midwest areas preferred
voluntary-closing hands for use with above-elbow prostheses. The East Central
and Western areas preferred voluntary-closing hands for below-elbow prostheses.
New England showed a preference for the passive hand with the below-elbow
prosthesis.
The simple friction wrist unit was
overwhelmingly preferred to quick-change types in all geographical areas, being
used with 83 per cent of above-elbow and 85 per cent of below-elbow
prostheses.
Although the triceps pad was used with 56
per cent of the below-elbow prostheses, its use ranged from 35 per cent in the
South to 94 per cent in the New England area. The South preferred the half cuff.
Plastic laminate was the cuff material of choice in 61 per cent of the total
cases, although the East Central and Western areas preferred leather to the
extent of 54 per cent and 55 per cent respectively.
The double-wall socket was used in 89 per
cent of the above-elbow and 77 per cent of the below-elbow prostheses.
Pre-flexed sockets, some of which also had double walls, were used in 11 per
cent of the below-elbow prostheses. Sixty-one per cent of the preflexed sockets
were utilized by children.
In 98 per cent of the upper-extremity
prostheses, the sockets were made of plastic.
The elbow unit with internal lock was the
item of choice for above-elbow prostheses in all geographical areas, being used
in 78 per cent of all fittings. Seventeen per cent of all elbow units had
spring-flexion assists. Sixty-four per cent of the elbow hinges used in
below-elbow prostheses were flexible, the range being from 44 per cent in the
West to 92 per cent in New England. The Midwest showed almost equal preference
for the single-pivot (47 per cent) and the flexible hinge (50 per
cent).
Dual-control systems were used in 80 per
cent of above-elbow and single control in 96 per cent of the below-elbow
prostheses.
Eighty-three per cent of the harnesses
for above-elbow prostheses were of the figure-eight type, the majority of this
group (55 per cent) being equipped with the Northwestern University harness
ring. The East Central area and the West showed a preference for the
figure-eight harness without the ring. Of the 14 cases with reported type of
harness in the West, none used the ring with the figure-eight. The South used
the ring to the greatest extent for above-elbow prostheses.
Ninety-two per cent of the below-elbow
harness were of the figure-eight type, 59 per cent of these being equipped with
rings. The East Central, South, and Midwest areas showed greatest preference for
the ring figure-eight harness; the New England and Western areas used the
figure-eight harness without the ring almost as often as with it.
Components for Lower-Extremity
Prostheses
Components most frequently used for
above- and below-knee prostheses appear in Fig. 13a,Fig. 13b. The various geographical
areas showed more consistency in prescription of lower-extremity than
upper-extremity components. In most instances, only the percentage varied, not
the type of component.
The SACH foot was prescribed for 55 per
cent of the above-knee and 73 per cent of the below-knee prostheses. In area
comparisons, the South showed the greatest usage of the SACH foot, and the
Midwest the lowest. For the above-knee prosthesis, prescription of the SACH foot
rose from 76 per cent in the first to 83 per cent in the second decade, and then
gradually declined with advancing amputee age. In the below-knee group, the SACH
foot was prescribed 96 per cent of the time for children under 10 years of age;
the percentage declined steadily to a low of 56 per cent in the eighth decade,
then rose to 63 per cent for the group of amputees 81 years of age and
over.
Wood was used as the shank material in 95
per cent of the above-knee and in 90 per cent of the below-knee
prostheses.
The most frequently used knee component
for above-knee prostheses was the single axis, with friction being used in 74
per cent of the fittings. Twelve per cent of the knees were single axis with
manual locks. Eight per cent of the knees were hydraulic, with the West showing
the greatest preference (17 per cent) and the Midwest the least (4 per cent). In
instances where metal joints were reported for below-knee prostheses, the lap
joint was specified in 48 per cent of the cases and the clevis joint in 22 per
cent. The type of joint was not specified in 30 per cent of the
cases.
For above-knee amputees, the
quadrilateral socket was used in 85 per cent of the prostheses. It was the
overwhelming choice in each of the geographical areas.
The socket of choice for below-knee amputations was the patellar-tendon-bearing.
Preference for this socket averaged 58 per cent, the South and West showing
greatest utilization, 79 per cent and 82 per cent respectively, and the New
England and Midwest areas the least utilization, 44 per cent and 47 per cent
respectively.
Wood was used most often for above-knee
sockets, averaging 57 per cent, although the South showed a preference for
plastic, using it for 55 per cent of all sockets. Below-knee sockets were most
often (55 per cent) fabricated in plastic. New England showed a preference for
leather sockets, and the Midwest preferred wood (41 per cent) to either plastic
or leather.
The pelvic belt was the preferred method
of suspension (56 per cent) for above-knee prostheses. Only in the West
did the use of suction, either alone or in combination with other suspension,
exceed the use of the pelvic belt. In correlating methods of suspension with
age, it was noteworthy that during the second, third, and fourth decades,
suction alone was preferred to all other types of suspension. In all other
decades, the pelvic belt was preferred.
In considering types of suspension
reported for all below-knee prostheses, the knee cuff alone was the choice of
suspension in 36 per cent of the cases. It was least used in the Midwest (22 per
cent). The South and West utilized the knee cuff alone most frequently (55 per
cent). When type of suspension for the patellar-tendon-bearing prosthesis is
analyzed by age group, it is found that, while the knee cuff alone was used for
62 per cent of all
the prostheses, greatest usage occurred
in the second decade (73 per cent) and next greatest in the third decade (71 per
cent). Least use of the knee cuff alone occurred in the very young child (48 per
cent), but the inclusion of cases where a waist belt was used in conjunction
with the knee cuff raised this percentage to 68.
Sources of Payment
Table 27, Table 28, and Table 29 indicate the
sources of payment for prostheses. More than one source was sometimes listed, in
which case they are reported under "combinations of the above "or" "other".
Medicare had been in operation only one year prior to the conclusion of this
study and presumably would rank considerably higher as a source of payment at
the present time. As mentioned earlier, over 23 per cent of the amputees in this
study were in the Medicare age bracket.
Source of payment was given for 8,631
prostheses Table 27. The greatest contributors to defraying the costs of
prostheses were State Bureaus of Vocational Rehabilitation (22.5 per cent) and
the patient himself (22.8 per cent). Next in order were the Veterans
Administration (14.3 per cent), welfare (10.8 per cent) and insurance (9.9 per
cent).
The Children's Bureau paid for 46.5 per
cent of the prostheses for children up to the age of 21. Through the
wage-earning years, 21 to 64, State Bureaus of Vocational Rehabilitation paid
for 31.9 per cent of the prostheses, the amputee for 24.3 per cent, and the
Veterans Administration for 19.3 per cent. During the retirement years, 65 and
over, the amputee alone paid for 29.9 per cent of the prostheses, Social
Security and Medicare for 19.5 per cent, and welfare for 15.3 per
cent.
A further analysis of sources of payment
relating to the wage-earning years yields some interesting facts Table 28. The
Veterans Administration paid for 30 per cent of replacement prostheses, but
only 10 per cent of new prostheses. This
statistic doubtless reflects the continuing supply of prostheses to veterans of
World War II and the Korean War and a decreased
number of fresh cases. More "new" male amputees were supported by insurance or
compensation than "old" male amputees, 24 per cent as opposed to 8 per cent.
This may reflect the policy of some insurance companies to pay for the first
prosthesis only. On the other hand, it may indicate an increase in opportunity
for insuring oneself against disability and a greater awareness of the values of
health insurance. In comparing source of payment for males and females in this
age group, one notices the higher level of support by the amputees themselves
and the Bureaus of Vocational Rehabilitation for the female group, and also the
very low percentage of females supported by insurance or
compensation.
In correlating source of support with
occupation, only "old" amputees were considered, since in most instances "new"
amputees had not yet returned to work at the time the data forms were submitted.
Amputees were studied in three categories: those gainfully employed, those not
gainfully employed, and those who were students, housewives, or retired Table 29.
Of the 3,055 "old" cases included above,
only 187, or 6 per cent, were reported as not being gainfully employed. The
Bureaus of Vocational Rehabilitation paid for 35 per cent of the prostheses for
the gainfully employed group, the Veterans Administration for 28 per cent, and
the amputee for 25 per cent. For the group of amputees not gainfully employed,
the Bureaus of Vocational Rehabilitation were the source of payment for 28 per
cent of the prostheses, the Veterans Administration for 27 per cent, and welfare
for 24 per cent. In the 468 amputations of students, housewives, or retired
amputees, 31 per cent of the prostheses were paid for by the amputee, 28 per
cent by the Bureaus of Vocational Rehabilitation,
and 17 per cent by the Veterans Administration.
Discussion
In recent years, there has been
increasing interest in defining the characteristics of the amputee population,
and also in providing amputees with functional stumps and prostheses. Much
progress has been made in understanding the amputee and his problems, and in the
fabrication of improved prosthetic components. This study has sought to document
some of the characteristics of the amputee and his prosthesis during a
particular period in time-the approximately two years ending June 30,
1967.
Certain characteristics of amputees,
namely sex and age, and the cause, side, and site of amputation, were well
established in Glattly's study of 12,000 new amputees for whom data were
collected over a two-year period, ending in 1963. In the present study of over
8,000 amputees, 4,034 of whom were new, data were likewise collected over a
two-year period which ended in 1967, four years later. Unless some catastrophic
event had occurred immediately before or during either of the two periods, it
would be expected that in large samples such as these, the sex and age of the
amputee and side and cause of the amputation would be relatively constant. Such
was indeed the case, indicating that the sample in the latest study was a valid
cross-section of the amputee population. As noted before, neither the Medicare
Act nor the conflict in Vietnam had exerted a significant impact on this study.
Although medical advances over a number of years have been largely responsible
for the increasing age of the amputee, with a resulting shift from trauma to
disease as a predominant cause of amputation, such changes would not be expected
to exert a significant difference in as short a period as four years.
In amputations caused by disease, the
site of amputation can be influenced by medical judgment at a particular time. In
the vast majority of cases where amputation is categorized as disease, the
amputees had vascular insufficiency. For this condition, amputation at a level
above the knee had been widely advocated for many years because it was felt that
this procedure facilitated healing. It has been found, however, that amputation
may be performed at a below-knee level, with primary healing occurring in the
majority of cases. By preserving the knee joint, amputation at this level
greatly enhances the rehabilitation potential of the patient.
Burgess has reported that most below-knee
amputations for ischemia heal primarily, and with proper prosthetic care do not
break down. Lim reports that 92 per cent of below-knee amputations were
successful when a popliteal pulse was present, and 75 per cent were successful
when pulse was absent. He also reports a lower mortality rate for below-knee
amputees, 16 per cent as opposed to 35 per cent for above-knee amputations.
Tracy cites a 90 per cent successful healing rate for below-knee amputations for
ischemic gangrene.
Although the increase in the percentage
of below-knee amputations in our study, as compared with the Glattly study, is
relatively small in view of the potential increase, it is nevertheless an
encouraging trend, and it is to be hoped that a dramatic increase will be
reflected in future surveys as the results of ongoing educational programs take
effect.
Although the incidence of amputations due
to trauma appears to have declined, as far as percentage of the total amputee
population is concerned, this does not necessarily imply a decrease in the
overall incidence of traumatic amputations. Actually, the increasing age of
amputees, with its corollary of increasing incidence of amputations due to
disease, is certainly partly responsible for the decline in percentage of trauma
cases. In the younger age groups, trauma continues as the major cause of
amputations. The Public Health Service report published in 1964
shows that "absence of major extremity,"
classified as an accident "while at work," occurred almost three times as often
as amputation caused by "moving motor vehicles." In the present study, the ratio
was closer to 1:1 than 3:1, i.e., moving vehicles as a cause of traumatic
amputations was almost equal to that of industrial accident. A higher percentage
of auto accidents than industrial accidents occurred in the female group, a
pattern which is typical of other reported findings. These results may indicate
improved safety controls in industry, or may underscore the soaring rate of
automobile accidents, or both. The large number of amputations resulting from
trauma continues to have strong implication for improved accident-prevention
programs and more effective human-factors engineering. The need for greater
safety of design, particularly in cars and industry, continues to be
great.
It is of interest to note that prosthetic
prescription varied among the geographical areas, some areas having a greater
tendency than others to incorporate newer prosthetic techniques. It might be
expected that the latest prosthetic developments would be incorporated into
prosthetic practice in those areas which were near the prosthetic-orthotic
educational centers (New York, Chicago, and Los Angeles) or in areas of greatest
concentration of prosthetic facilities (California, Pennsylvania, New York, and
Illinois), or amputee clinics (New York, Pennsylvania, California, and Texas).
With the exception of the West, where newer developments were used in a high
percentage of cases, there appeared to be no relationship between the nature of
prosthetic services provided and the factors cited above. Both the South and the
West showed a more consistent use of newer techniques than did the other
areas.
The provision of prosthetic services
reported in the study indicates that much improvement is to be desired as far as
length of time for delivery of the prosthesis is concerned. The time
between the date of amputation (or reamputation)
and delivery of the prosthesis was inordinately long, ranging from a median of
four months for patients whose amputations were caused by tumor to six months
for patients with vascular disease. The provision of temporary prostheses and
immediate postsurgical fitting of prostheses would help shorten this time
lag.
The finding that a relatively high
percentage of congenital amputees (32 per cent) were not fitted until after
their eleventh birthday is distressing. Since current philosophy is to fit
congenital amputees at a very early age, it would be interesting to know the
reason for this reported delay. Whether the fault lies with amputee clinics, or
with parents who are either reluctant to take their children to clinics or are
ignorant of the prosthetic opportunities available to them, is not evident from
the present analysis. The implication is that more needs to be done at the
educational level. The growth and implementation of dynamic treatment programs
would surely result in a much more optimistic picture.
A composite picture of amputees reported
in this study would present the following profile:
- The congenital amputee seen in
prosthetic facilities was a male under 10 years of age with involvement at the
below-knee level.
- The amputee whose amputation was
caused by tumor was a male between 11 and 20 years of age whose amputation was
at the above-knee level.
- The traumatic amputee was a male
now between the ages of 41 and 50 years who had received his amputation between
the ages of 21 and 30 years. His amputation was at the below-knee level and was
most likely received as a result of a car accident, industrial accident, or war
injury.
- The amputee whose amputation was
caused by disease was also a male, between the ages of 61 and 70 years, who was
amputated during these same years. His amputation was as likely to be at
the above-knee level as at the below-knee
level.
Summary
- This study, which extended over
a two-year period ending in June 1967, presents data on 8,323 amputees with
8,698 amputations, all of whom were fitted with prostheses.
- Of the "new" amputations
seen in prosthetic facilities, 60 per cent were caused by disease, 29 per cent
by trauma, 6 per cent by tumor, and 5 per cent were of congenital
origin.
- Of all amputations, "new" and
"old," being fitted in prosthetic facilities, 50 per cent were caused by trauma,
37.3 per cent were caused by disease, 8.4 per cent were of congenital origin,
and 4.3 per cent were caused by tumor.
- The greatest incidence of
disease-caused amputations occurred in the seventh decade, those of trauma in
the third decade, and those of tumor in the second decade.
- Males outnumbered females
in every category, the ratio for "new" amputations of males to females being
approximately 2:1 for disease, 10:1 for trauma, and 1.2:1 for both congenital
causes and tumor.
- Eighty-six per cent of the total
number of amputations were of the lower extremity, with 53 per cent of this
group being at the below-knee level.
- Although automobile accidents
were cited as the single greatest cause of all traumatic amputations, war
injuries, industrial accidents, and automobile accidents were cited almost
equally for male amputees.
- Forty-eight per cent of all
reampu-tations were in the disease category, 60 per cent of these occurring
within two and one-half months of the original amputation. The reamputation rate
for below-knee amputations caused by disease was not significantly higher than
that for trauma-caused amputations-approximately 6 per cent in both
instances.
- Degree of contracture reported
at both hip and knee varied inversely with the length of the stump. Excluding
contractures of less than 5 deg, the average hip flexion contracture for
above-knee amputations was in the 5-9 deg range; the average knee flexion
contracture for be-low-knee amputations fell in the 10-14 deg range. Fifty-two
per cent of those cases reporting presence or absence of contractures had either
no contracture or one of less than 5 deg.
- Unemployment rate for "old"
male amputees between the ages of 21 and 64 was 6.4 per cent, slightly higher
than the national average for the years covered by the report.
- Fifty-eight per cent of
patients were referred to prosthetic facilities by amputee clinics, 26 per cent
by physicians, and 16 per cent were not referred.
- The median time from amputation
to delivery of a prosthesis was six months, the below-knee prosthesis being
delivered in the shortest length of time. Congenital amputees who required
surgery received prostheses in a median time of three months postsurgery.
Patients in the disease category waited the longest time- six months.
- Prostheses had an average life
of 6.1 years, with the life of the prosthesis increasing with the age of the
patient. Below-knee prostheses generally and prostheses for congenital amputees
had the shortest life. Prostheses for males lasted longer than those for
females. "Worn out" was the primary reason given for replacing a
prosthesis.
- Prosthetic prescription varied
in the geographical areas, some regions demonstrating a greater tendency than
others to incorporate newer prosthetic techniques. Generally, as the age of the
amputee advanced, there was a tendency to use the older types of components,
e.g., pelvic hands, articulated ankles.
- The Children's Bureau was the largest
single source of financial support for the purchase of prostheses for children,
and the State Bureaus of Vocational Rehabilitation provided the greatest
financial support for amputees during the wage-earning years. The Veterans
Administration paid for a high percentage of prostheses for males who were in
the "old" category. In all, the federal government paid entirely for 48 per cent
of all prostheses and provided partial support for another 3 per
cent.
Acknowledgments
Grateful appreciation is extended to the
44 facility owners and their staffs who provided the data on which this study is
based.
References:
- Burgess, Ernest M., The below-knee amputation, Bull. Pros. Res., 10-9:19-25, Spring 1968.
- Davies, E. J., B. R. Friz, and F. W. Clippinger, Jr., Children with amputations, Inter-Clinic Inform. Bull., 9:3:6-19, December 1969.
- Friz, Barbara R., and Frank W. Clippinger, Jr., The facility case record study: a preliminary report, Orth. and Pros., 23:1:8-17, March 1969.
- Glattly, H. W., A statistical study of 12,000 new amputees, Southern Med. J., 57:1373-1378, November 1964,
- Lim, R. C, Jr., et al.. Below-knee amputation for ischemic gangrene, Surg. Gynec. Obstet., 125: 493-501, September 1967.
- Sarmiento, A., and W. D. Warren, A re-evaluation of lower extremity amputations, Surg. Gynec. Obstet., 129:799-802, October 1969.
- Taft, C. B., and S. Fishman, Survival and prosthetic fitting of children amputated for malignancy, Inter-Clinic Inform. Bull., 5:5:9-28, February 1966.
- Tracy, G. D., Below-knee amputation for ischemic gangrene, Pacif. Med. Surg., 74:251-253, September-October 1966.
- U. S. Department of Health, Education, and Welfare, Public Health Service, Impairments due to injury by class and type of accident, United States, July 1959-June 1961, Washington, D.C., 1964.
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