Abstract
Background: The principal aims of this study were to examine
functional outcomes following trauma-related lower-extremity amputation and to
compare outcomes according to the amputation levels. We hypothesized that
above-the-knee amputations would result in less favorable outcomes than would
through-the-knee or below-the-knee amputations. A secondary aim was to examine
the factors, in addition to amputation level, that influence outcome,
including the type of soft-tissue coverage, selected patient characteristics,
and the technological sophistication of the prosthetic device.
Methods: A cohort of 161 patients who had undergone an
above-the-ankle amputation at a trauma center within three months following
the injury was followed prospectively at three, six, twelve, and twenty-four
months after the injury. The Sickness Impact Profile, a self-reported measure
of functional status, was used as the principal measure of outcome. Secondary
outcomes included pain; degree of independence in transfers, walking, and
climbing stairs; self-selected walking speed; and the physician's satisfaction
with the clinical, functional, and cosmetic recovery of the limb. Longitudinal
multivariate regression techniques were used to determine whether outcomes
differed according to the level of amputation after we controlled for
covariates.
Results: There was no significant difference in the scores on the
Sickness Impact Profile between the patients treated with above-the-knee and
those treated with below-the-knee amputation. However, patients with a
below-the-knee amputation performed better than did patients with an
above-the-knee amputation on the timed test for walking speed (p = 0.04).
Patients with a through-the-knee amputation had worse regression-adjusted
Sickness Impact Profile scores (p = 0.05) and slower self-selected walking
speeds (p = 0.004) than did patients with either a below-the-knee or an
above-the-knee amputation. Differences according to the level of amputation
were most pronounced for physical function. In general, physicians were less
satisfied with the clinical, cosmetic, and functional recovery of the patients
with a through-the-knee amputation. Except for problems encountered with
insufficient gastrocnemius coverage of the stump in many patients with a
through-the-knee amputation, neither the soft-tissue coverage nor the
technological sophistication of the prosthesis correlated with outcome.
Conclusions: Severe disability accompanies above-the-ankle
lower-extremity amputation following trauma, regardless of the level of
amputation. Clinicians should critically evaluate the need for a
through-the-knee amputation in patients with a traumatic injury. The results
of this study also underscore the need for controlled studies that examine the
relationship between the type and fit of prosthetic devices and functional
outcomes.
Level of Evidence: Prognostic study, Level I-1
(prospective study). See Instructions to Authors for a complete description of
levels of evidence.
Lower-limb amputations secondary to trauma typically are performed in young
patients without the medical comorbidities often associated with nontraumatic
amputations. However, in order to preserve limb length, trauma-related
amputations are often performed in or near the zone of injury, resulting in
atypical wound closures, the use of skin grafts or flaps to achieve good
coverage, and a residual limb that is often less than ideal. There is debate
regarding the functional outcomes following amputation as few prospective
studies have been conducted with the use of well-validated and broadly based
measures of outcome. The few studies that have been performed have largely
focused on return to work as the single
metric1-13.
The principal aim of the present study was to examine a range of two-year
functional outcomes following trauma-related amputation and to compare
outcomes according to the level of amputation—i.e., above the knee,
through the knee, and below the knee. We hypothesized that above-the-knee
amputations would result in less favorable outcomes than would either
through-the-knee or below-the-knee amputations. A secondary aim of the study
was to examine the factors, in addition to the level of amputation, that
influence outcome, including the type of soft-tissue coverage, characteristics
of the patient, and the technological sophistication of the prosthetic device
being used at the time of the outcome assessment.
Study Population
The study population consisted of 161 patients treated with an
above-the-ankle amputation within three months after sustaining high-energy
trauma below the distal femoral level. These individuals were participants in
the Lower Extremity Assessment Project (LEAP), a multi-institutional,
prospective study designed to examine the differences in outcome following
reconstruction or
amputation14.
Previous publications have described the overall similarity between the
outcomes following reconstruction and those following
amputation15. The
present analysis was conducted to determine whether outcomes differed among
subgroups of patients with an amputation. To be eligible for participation in
the parent LEAP study, a patient had to be between eighteen and sixty-nine
years of age and have one or more of the following injuries to the lower
extremity: a
Gustilo16
Grade-IIIB or IIIC fracture, a Grade-IIIA fracture with certain
characteristics (Grade-IIIA fracture requiring a hospital stay of more than
four days, requiring two or more surgical procedures, and associated with two
or more of the following: severe muscle damage, associated nerve injury, or
major bone loss or bone injury), a dysvascular limb (a knee dislocation, a
closed tibial fracture with a pulseless foot, or a penetrating wound with
vascular injury), a major soft-tissue injury to the tibia (a degloving or
severe crush/avulsion injury), or a severe foot or ankle injury (an open pilon
or Grade-IIIB ankle fracture or a severe hindfoot or midfoot injury). Criteria
for exclusion included a moderate-to-severe brain injury (a score of <15 on
the Glasgow Coma
Scale17 at
twenty-one days after the lower-limb injury or at the time of discharge), a
spinal cord deficit, a prior amputation of the leg or foot, or a third-degree
burn on the injured lower limb. Also excluded were patients who had been
transferred to the participating center more than twenty-four hours after the
injury, those who did not speak English or Spanish, those with a documented
psychiatric disorder or mental retardation, and those who were on active
military duty or who lived outside the hospital's catchment area and for whom
follow-up was deemed impossible. Patients were recruited into the study from
eight level-I trauma centers over a forty-month period (March 1994 through
June 1997).
A total of 161 patients met the LEAP study criteria and had had a
unilateral amputation within three months after the injury. (Ten LEAP patients
who had undergone bilateral amputation were excluded from this analysis.) Of
the 161 patients with a unilateral amputation, thirteen had an intact lower
limb at the time of discharge from the hospital where they had received their
initial acute care but were readmitted for a delayed amputation within three
months after the injury. Within three months after the injury, 109 study
patients had an amputation below the knee; thirty-four, above the knee; and
eighteen, through the knee. One patient had a revision to a higher level
subsequent to the three-month evaluation. Most injuries had resulted from a
motor-vehicle (20%), motorcycle (25%), or pedestrian-motor vehicle (17%)
collision. The majority of the patients were men (84%); the mean age (and
standard deviation) of the entire group of patients was 35.2 ± 13.3
years, with a range of eighteen to sixty-eight years.
Procedures
The study participants were evaluated at baseline (before hospital
discharge) and at three, six, twelve, and twenty-four months after the injury.
At each time-point, the patients were evaluated by an orthopaedic surgeon to
ascertain complications and limb status, by a physical therapist to ascertain
impairment and functional performance, and by a research nurse to assess the
patient's perception of the functional outcome. At twelve and twenty-four
months after the injury, permission was obtained from the patient to contact
his or her prosthetist or prosthetists for detailed information about the type
of prosthesis. Of the 161 study patients, 143 (88.8%) were followed at three
months; 141 (87.6%), at six months; 139 (86.3%), at twelve months; and 124
(77.0%), at twenty-four months. Patients with incomplete follow-up were more
likely to be male, nonwhite, and without a high-school education (p <
0.05). The study was approved by the institutional review boards at the
coordinating center and at each study site. Written informed consent was
obtained from all study participants.
Measures of Outcome
Functional outcome was measured with use of the Sickness Impact Profile
(SIP)18. The SIP is
a multidimensional measure of self-reported health status, consisting of 136
statements about limitations in twelve categories of function: (1) walking,
(2) mobility, (3) body care and movement, (4) social interaction, (5)
alertness, (6) emotional behavior, (7) communication, (8) sleep and rest, (9)
eating, (10) work, (11) home management, and (12) recreation and pastimes.
Respondents are asked to endorse statements that describe their health status
on a given day. Scores were calculated for the overall instrument, for each of
the twelve categories listed above, and for two major dimensions of health
(physical health summarizing limitations in the first three categories, and
psychosocial health summarizing limitations in the second four categories).
The SIP has been well tested for reliability and
validity19,
including with regard to the assessment of postinjury
outcomes20. Overall
SIP scores range from 0 to 100 points. An SIP of >10 points represents
substantial disability, and differences of 2 or 3 points reflect meaningful
differences in function. Overall SIP scores range between 2 and 3 points for
the general
population21.
Secondary outcomes included two performance measures: degree of
independence in transfers, walking, and climbing stairs (defined by the
Functional Independence Measure
[FIM]22) and
walking speed as measured with a 100-ft (30.48-m) timed
test23. Both
performance measures were administered by a physical therapist at each
follow-up visit. Intensity of pain was measured with use of a visual analogue
scale24. Before the
examination by the physical therapist, patients were asked to place a mark on
a 100-mm line that best described their present level of pain. The line was
anchored with the descriptors "no pain at all" on one end (0) and
"unbearable pain" on the other end (100). A continuous score was
derived by measuring the distance of the mark (in millimeters) from the lower
end of the scale. Finally, because of concerns that the Sickness Impact
Profile may not adequately capture difficulties in performing tasks requiring
advanced functional capabilities, three questions were added to the interview
to assess the respondent's ability to walk without help on uneven ground or a
slope, outdoors in bad weather, and while carrying an object. The physician's
satisfaction with the clinical, functional, and cosmetic recovery of the lower
limb was recorded at each visit with use of a 10-point scale ranging from 1
(not at all satisfied) to 10 (completely satisfied).
Factors Influencing Outcome
Factors, in addition to the level of amputation, that were hypothesized to
influence outcome included (1) characteristics of the injury leading to the
amputation as well as injuries sustained in association with the specific limb
injury, (2) characteristics of the amputation and post-acute-care
complications, (3) characteristics of the patient including preexisting
medical conditions and health habits, and (4) the technological sophistication
of the prosthetic device being used at two years after the injury.
All injuries were prospectively characterized according to the type and
extent of osseous damage, extent of soft-tissue injury, initial pulse
assessment, and plantar
sensation25.
Associated injuries were classified with use of the Abbreviated Injury Scale
(AIS)26, the Injury
Severity Score
(ISS)27, and two
scores denoting the maximum AIS severity of contralateral and ipsilateral
(non-study) lower-limb and pelvic injuries. Shock was defined as systolic
blood pressure of <90 mm Hg prior to the initiation of
resuscitation28.
Amputations were classified according to their timing (immediate, not
immediate but during the initial hospitalization, and postdischarge but within
the first three months after the injury) and the type of closure (either a
typical elective amputation skin flap or an atypical, best possible skin
coverage, including the use of split-thickness skin grafts and free tissue
transfers). Also recorded at the time of the amputation was whether a myodesis
or myoplasty was performed, whether the joint above the amputation was
immobilized, the number of days from the amputation to the wound closure, and
whether a temporary prosthesis was fitted following the amputation. To account
for the impact of complications on recovery, a variable was constructed to
indicate rehospitalization because of a complication associated with the
lower-limb injury and/or amputation and included the need for a stump revision
and treatment of a major infection.
Patient characteristics that were hypothesized to influence treatment
assignment or outcome were described in detail in a previous
publication14. They
include age, gender, race/ethnicity, education, preinjury poverty status
(defined by relating total household income to household size)29
and insurance status, work status and occupation30, personality
characteristics measured by the NEO Personality Inventory31, social
support measured by a modified version of the Inventory of Socially Supportive
Behaviors (a tool that measures available support in terms of tangible
assistance, directive guidance, and emotional support)32,33, and
self-efficacy34,35 (a measurement of how confident patients are [at
the time of hospital discharge] about their ability to resume their major life
activity). Also hypothesized to influence recovery were self-rated preinjury
health and preexisting chronic conditions; preinjury exercise,
smoking36, and drinking habits37; and compensation
received for the injury and whether legal services were
retained38.
To determine the technical sophistication of the prostheses worn by the
study participants, a panel of two prosthetists and of one orthopaedic surgeon
with more than ten years' experience in amputation surgery and rehabilitation
rated each device as low, medium, or high technology39. These
ratings were based on information obtained from a mailed survey of the
patients' prosthetists and included characteristics of the suspension system;
sockets; knee, foot, and ankle components; exoskeletal and endoskeletal shank
techniques; and whether CAD/CAM technology was used when the prosthesis was
fitted. It should be noted that the sophistication of the device used at
twenty-four months after the injury was known for only 119 (74%) of the
patients. Patients were asked to estimate the number of days between the
amputation and the fitting of their first definitive prosthesis.
Statistical Methods
Overall differences in outcome according to the level of amputation were
initially tested with analysis-of-variance techniques and multiple-comparison
tests for continuous measures (i.e., the SIP scores and the pain scores on the
visual analogue scales) and chi-square analysis for categorical measures
(self-selected walking speed of =4 ft (1.22 m)/sec, independence in
activities, self-reported inability to perform certain activities, and
physician-reported satisfaction with recovery). Longitudinal multivariate
regression techniques40 were then used to determine whether there
were differences in SIP scores and the percentages of patients with a
self-selected walking speed of =4 ft/sec after we controlled for other
factors hypothesized to influence outcome. In modeling SIP outcomes, both
additive and multiplicative regression models were considered, but the
multiplicative model was chosen because we observed that, while SIP scores
continuously improved, the rate of this improvement declined over time.
Longitudinal logistic regression techniques were used to estimate the odds of
walking at a speed =4 ft/sec after we controlled for potential confounders.
Stepwise modeling techniques were used to construct the final multivariate
models that included the level of amputation and all patient, injury, and
device characteristics that remained associated with outcome at p < 0.20.
The extent to which the effect of these variables on outcome varied according
to the time since the injury or the level of the amputation was examined, and
interaction terms were incorporated where indicated. To examine the potential
bias introduced by variable follow-up and incomplete data, two models were
developed. The first model was based on data from only individuals for whom
complete twenty-four-month follow-up data were available. The second model was
based on data available on all patients who were followed for at least three
months and used pairwise deletion to estimate the parameters of the model.
Similar results were obtained with use of the two approaches; thus, the
results based on all available data are reported.
Course of Hospital Treatment and Clinical Status at Twenty-four
Months
The average stay in the hospital for initial acute care was T17.7 days
(Table I). The duration of the
initial hospitalization was longest for the patients treated with a
through-the-knee amputation (23.7 days) (p = 0.08). More than one-quarter
(29.8%) of all patients were rehospitalized at least once because of a
complication, with 14.5% requiring a stump revision. Rates of
rehospitalization were similar across the subgroups. On the average, the
patients spent a total of 20.5 days in the hospital as a result of their
injury and had 2.3 surgical exposures (i.e., the number of times they received
general anesthesia related to the LEAP injury). The percentage of patients who
had a myodesis was significantly higher in the above-the-knee amputation group
than it was in the below-the-knee or through-the-knee amputation group (p =
0.01), and the percentage of those who had a myoplasty was significantly lower
in the through-the-knee amputation group than it was in the below-the-knee or
above-the-knee amputation group (p = 0.01). The mean number of days until
wound closure was significantly higher for the patients with a
through-the-knee amputation than it was for those with a below-the-knee or
above-the-knee amputation (p = 0.01).
A modest proportion of patients had not fully recovered by the time of the
twenty-four-month assessment, as indicated by unhealed soft-tissue injuries
(in 6.5% of the patients) and an anticipated need for additional surgery (in
4.8% of the patients). There were no significant differences between groups
with regard to the percentage of patients with an unhealed soft-tissue injury
(p = 0.16) or the percentage requiring additional surgery (p = 0.13).
The mean number of days from the amputation to the fitting of the first
prosthesis (excluding the temporary prosthesis) was 101 days, with no
difference among the three groups of patients (see Appendix). Approximately
three-quarters of the prostheses worn at twenty-four months after the injury
were judged to be of medium technological sophistication (53.8% of the
prostheses) or high technological sophistication (17.7%).
Outcomes by Level of Amputation
Overall, and across most dimensions of the SIP, patients with a
through-the-knee amputation had the highest SIP scores
(Table II and Appendix). Those
with a below-the-knee amputation had somewhat higher mean scores than those
with an above-the-knee amputation, although the differences were more modest.
However, none of the differences among the three amputation groups was
significant at the p < 0.05 level.
The mean overall SIP scores for all three amputation groups indicated
substantial disability. Forty-three percent of all patients, 44.4% of those
with an above-the-knee amputation, 60.0% of those with a through-the-knee
amputation, and 39.2% of those with a below-the-knee amputation had an overall
SIP score of =10 points. For all dimensions except eating and
communication, the SIP scores at twenty-four months after the injury were
significantly higher than published population norms or preinjury scores
(mean, 2.6 points) (p <
0.01)20,21.
Subscores that reflected limitations in the amount and kind of work that could
be performed (including the inability to work at all) were particularly high;
only 54.4% of patients who were working prior to the injury had returned to
work by two years after the injury.
Poorer outcomes following through-the-knee amputation compared with those
following below-the-knee or above-the-knee amputation were reflected by the
secondary measures examined in this study
(Table II). Patients with a
through-the-knee amputation had significantly worse scores for the objective
performance measures of self-selected walking speed (p = 0.01) and
independence in transfers, walking, and stair-climbing (p = 0.05). A higher
percentage of patients with a through-the-knee amputation also reported
needing help with two of the three physically demanding tasks (walking on
uneven ground and walking outdoors in bad weather) (p < 0.05). Although
patients with a through-the-knee amputation reported a lower average level of
pain, it was not significantly different from the pain levels reported by the
other two groups. Patients with a below-the-knee amputation had a faster
walking speed than those with an above-the-knee amputation, and a smaller
percentage of patients with a below-the-knee amputation indicated that they
needed help with walking on uneven ground or while carrying an object. These
differences between the below-the-knee and above-the-knee amputation groups
did not achieve significance.
The relatively poor twenty-four-month outcomes of through-the-knee
amputations compared with the outcomes of below-the-knee and above-the-knee
amputations is underscored by the differences in the percentage of cases in
which the physician was satisfied or very satisfied with the recovery.
Although subjective in nature, these ratings suggest that physicians were less
satisfied with both the clinical and the cosmetic recovery of the patients
with a through-the-knee amputation (p = 0.05). They were also less
satisfied with their functional recovery, although this difference was not as
large and was not significant (Table
II).
Adjusted Differences in Outcomes by Potential Confounders
The differences observed in the SIP scores according to the level of
amputation persisted after we controlled for selected potential confounders.
Specifically, the regression-adjusted SIP scores for patients with a
through-the-knee amputation were 37.0% higher than those for patients with a
below-the-knee amputation (p = 0.05) (Table
III). These differences in scores were largely due to differences
in physical, as opposed to psychosocial, function. There were no measurable
differences in the SIP scores between the below-the-knee and above-the-knee
amputation groups. Differences in walking speed also persisted after
controlling for potential confounders. Specifically, the adjusted relative
odds of having a walking speed of =4 ft/sec was 0.03 for the
through-the-knee amputation group compared with the below-the-knee amputation
group (p = 0.004) and 0.22 for the above-the-knee amputation group compared
with the below-the-knee amputation group (p = 0.04). Thus, when compared with
the patients who had a below-the-knee amputation, those who had a
through-the-knee amputation had significantly worse outcomes as demonstrated
by both a self-reported measure of disability and a performance-based measure
of walking speed. Furthermore, although the SIP scores did not differ
significantly between the below-the-knee and above-the-knee amputation groups,
the walking speed of the patients with a below-the-knee amputation was
significantly faster than that of the patients with an above-the-knee
amputation.
In addition to the level of amputation, factors that were significant (p
= 0.05) predictors of a poor overall SIP score included a preexisting
medical condition, smoking, an ipsilateral limb injury, less than a college
education, low self-efficacy, and nonwhite race
(Table III). The effect of an
ipsilateral injury and a previous medical condition on the overall SIP scores
was largely due to their impact on physical, as opposed to psychosocial,
function, whereas a higher educational level appeared to affect psychosocial
function more than physical function. Marginally significant predictors of a
poor SIP score (p < 0.15) include poverty, an age of less than fifty-five
years, and an ISS score of >13 points. Predictors of poor outcome were the
same for all levels of amputation. We found no significant differences in
outcome on the basis of the timing of the amputation, the type of soft-tissue
coverage, the muscle-anchoring techniques, or the technological sophistication
of the prosthetic device. The only significant predictor of walking speed (in
addition to the level of the amputation) was gender; women were 0.16 times as
likely as men to achieve a speed of =4 ft/sec (p = 0.02).
To better understand why patients with a through-the-knee amputation had
poorer outcomes, three of us reviewed the operative reports, the
anteroposterior and lateral radiographs, and the appearance of the wound on
admission and at the time of soft-tissue coverage for all eighteen patients
who had undergone a through-the-knee amputation. The through-the-knee
amputation was in the zone of injury in all but one patient. Twelve of the
eighteen patients did not have gastrocnemius muscle coverage over the femoral
condyles, as this tissue was not available. Management of the distal part of
the femur varied. The condyles were contoured in ten of the patients. The
patella was removed in nine of the patients, and it was fused to the distal
end of the femur in one.
Although rates of major lower-limb amputation secondary to trauma have
declined in recent years, the annual number of hospital discharges following
trauma-related amputation in the United States remains high, at approximately
350041,42. Most of
the amputations are performed in adolescents and young adults, yet little is
known about the impact of the amputations on functional outcomes and quality
of life. Even less is known about the factors associated with post-amputation
recovery. With very few exceptions, the outcome studies that have been
published were limited by their retrospective design, small sample size, and
lack of standardized measures of
outcomes1-13.
Clinical experience suggests, however, that the type and quality of the
soft-tissue coverage, preservation of the knee joint, residual limb length,
and design of the prosthesis are important factors leading to good
outcomes43.
In this study, the functional outcomes at twenty-four months were poor.
These results are generally in agreement with those of
others1-13
who have reported high rates of physical disability following amputation
despite substantial advances in amputation surgery and in the development of
prostheses made of lightweight and strong materials that incorporate
technologically sophisticated energy-returning foot and ankle modifications.
However, to our knowledge, the high rates of psychosocial (in addition to
physical) disability have not been reported before. The two studies in which
this aspect of outcome was evaluated with standardized assessment
techniques1,3
showed no significant deficits in scores measuring mental health and emotional
function. Both of those studies, however, were retrospective, with assessments
made at variable points in time ranging from two to ten years after the
injury. In the present study, the rates of psychosocial disability were high
at three months and remained high, with little improvement, over the
twenty-four-month follow-up period.
Interestingly, and contrary to our hypothesis, patients who had undergone
an above-the-knee amputation reported functional outcomes (as measured with
the SIP) that were similar to those reported by patients with a below-the-knee
amputation. However, the walking speeds of the patients with a below-the-knee
amputation were significantly better than those of the patients with an
above-the-knee amputation. Other studies have shown below-the-knee amputation
to have an advantage over above-the-knee amputation with regard to measures of
energy consumption involved in
walking24,44.
The results of the present study suggest that better lower-limb function per
se (as measured by walking speed) may not necessarily translate into overall
improvement in daily life (as perceived by the individual and measured with
the SIP). As discussed below, several factors influence SIP scores; the extent
of impairment of lower-limb function is only one of these factors. Regardless
of the level of the amputation, all patients experienced similar frustrations
and challenges that may overwhelm the actual degree of impairment of
lower-limb function.
Through-the-knee amputations, however, resulted in two-year outcomes, as
measured by both walking speed and self-reported measures of disability, that
were significantly worse than those following either below-the knee or
above-the-knee amputation. These results stand in contrast to those found in
the amputation literature. Studies have shown improved self-selected walking
velocity and maximum walking velocity as well as extended durations of
prosthetic wear for persons with a through-the-knee amputation compared with
those with an above-the-knee
amputation44-48.
Those studies, however, were based primarily on the experience of elderly
persons who had undergone elective amputation because of dysvascular
disorders. In the performance of an elective through-the-knee amputation, the
gastrocnemius muscles are employed to form a well-padded layer over the end of
the femur. In the case of a trauma-related through-the-knee amputation, long
posterior flaps containing the gastrocnemius muscles are often not available,
as the amputation is being performed in or near the zone of
injury49. Of our
eighteen patients with a through-the-knee amputation, seventeen underwent the
amputation in the zone of injury and twelve had no remaining gastrocnemius
muscle. We believe that our data bring into question the wisdom of performing
a through-the-knee amputation in patients who have sustained high-energy
trauma, especially when the knee is included in the zone of injury.
Only 10.4% of our patients were fitted for a prosthesis immediately
postoperatively. This probably reflects the management of the soft tissues in
the zone of injury. The use of skin grafts or free tissue transfer does not
appear to affect the outcomes of below-the-knee amputations. The mean SIP
scores (and standard deviation) were 13.2 ± 12.7 and 13.5 ± 13.6
points for patients with typical and atypical flaps, respectively.
We also found that the technological sophistication of the prosthetic
device did not appear to have an impact on outcome. The results of our
analyses do not support the contention that outcomes measured in the first two
years following amputation are improved by the provision of a more
technologically sophisticated and expensive device. Given the subjective
nature of the assessments of the devices used in this study, these findings
must be interpreted with considerable caution. At a minimum, however, they
underscore the need for controlled trials to better delineate the relationship
between device characteristics and functional outcomes. It will be important
to measure not only the component characteristics of the device but also the
quality of the fit, alignment, and extent to which the specifications of the
device match the needs of the patient.
Several factors in addition to the level of the amputation were
significantly associated with poor SIP scores. There were particularly strong
correlations between race and outcome. Nonwhites had overall SIP scores that
were 60% higher than those of whites. Although race appears to correlate with
outcome over and above socioeconomic status, it is likely that it is measuring
an aspect that is not captured by educational level, poverty status, and
insurance coverage alone. These relationships between race and functional
outcome have been documented for other
conditions50. It
will be important in future studies to investigate the reasons for these large
disparities in outcome.
Our study also confirms the previous observation that low self-efficacy is
an important determinant of poor outcome. Self-efficacy is the belief that one
is able to perform specific tasks or activities. Persons with low
self-efficacy are more likely to disengage from the coping process because
they expect to
fail51. These
patients often feel a strong desire to resume activities that they enjoyed
prior to the injury but hesitate to do so out of fear they will be unable to
perform component tasks. Self-efficacy can be both taught and
improved52, and
modification of self-efficacy through cognitive-behavioral interventions has
been
demonstrated53.
More research is needed to develop and evaluate these interventions for
individuals facing the challenges of postinjury recovery.
The results of this study must be interpreted in light of its limitations.
Although it is one of the larger prospective studies of post-amputation
outcomes, the numbers of through-the-knee amputations and above-the-knee
amputations were relatively small. Follow-up rates were high, although
complete twenty-four-month outcome data were missing for 23% of the patients
initially enrolled in the study. Patients with missing data tend to be of
lower socioeconomic status, suggesting that our results regarding poor overall
levels of functional recovery may underestimate the extent of the problem. In
addition, the generalizability of the results beyond level-I trauma centers is
uncertain. The clinical outcomes observed in this study may well represent
better-than-average results, given the injury volume and experience at the
participating clinical centers.
It is also important to emphasize that the results presented here are based
on functional outcomes observed at two years. A small number of patients had
not recovered completely by this point in time, as evidenced by the percentage
in whom the soft tissue had not healed and the percentage requiring additional
surgery. Continued modification of the fit of the prosthesis and increasing
comfort with and confidence in the prosthetic device could also improve the
long-term function of patients with an amputation. Long-term follow-up of
these patients is imperative, and a seven-year outcome assessment is under
way.
On the basis of the results of this study, we advise clinicians to
critically evaluate the need for a through-the-knee amputation in a patient
who has sustained a traumatic injury of the lower limb. The results also call
into question the advisability of fitting patients with the more sophisticated
(and expensive) prostheses, given that the low-tech devices appeared to yield
equivalent outcomes. However, more research that takes into account the fit
and alignment of the prosthesis must be conducted before definitive
recommendations can be made.
Tables showing details of the prosthetic application and sophistication and
mean SIP scores at twenty-four months after injury are available with the
electronic versions of this article, on our web site at
(go to the article citation and click on "Supplementary Material")
and on our quarterly CD-ROM (call our subscription department, at
781-449-9780, to order the CD-ROM).
Note: The authors acknowledge the efforts of the
coinvestigators, study coordinators, and physical therapists at each of the
eight LEAP study sites. Their dedication to the study's objectives and their
commitment to quality data collection were essential to the success of the
study. They include Julie Agel, ATC; Jennifer Avery, PT; Denise Bailey, PT;
Wendall Bryan; Debbie Bullard; Carla Carpenter, PT; Elizabeth Chaparro, RN;
Kate Corbin; Denise Darnell, RN, BSN; Stephanie Dickason, PT; Thomas
DiPasquale, DO; Betty Harkin, PT; Michael Harrington, PT; Dolfi Herscovici,
DO; Amy Holdren, RNC, ANP, MSN; Linda Howard, PT; Sarah Hutchings, BS; Marie
Johnson, LPN; Melissa Jurewicz, PT; Donna Lampke, PT; Karen Lee, RN; Marianne
Mars, PT; Maxine Mendoza-Welch, PA; J. Wayne Meredith, MD; Nan Morris, PT;
Karen Murdock, PT; Andrew Pollak, MD; Pat Radey, RN; Sandy Shelton, PT; Sherry
Simpson, PT; Steven Sims, MD; Adam Star, MD; Celia Wiegman, RN; John Wilber,
MD; Stephanie Williams, PA; Philip Wolinsky, MD; Mary Woodman, BA; and Michele
Zimmerman, RN.
Pezzin LE, Dillingham TR, MacKenzie
EJ. Rehabilitation and the long-term outcomes of persons with
trauma-related amputations. Arch Phys Med Rehabil.2000;81:
292-300.81292
2000
[PubMed][CrossRef]
Matsen SL, Malchow D, Matsen FA
3rd. Correlations with patients' perspectives of the result of
lower-extremity amputation. J Bone Joint Surg Am.2000;82:
1089-95.821089
2000
[PubMed]
Smith DG, Horn P, Malchow D, Boone
DA, Reiber GE, Hansen ST Jr. Prosthetic history, prosthetic charges, and
functional outcome of the isolated, traumatic below-knee amputee. J
Trauma.1995;38:
44-7.3844
1995
[CrossRef]
Walker CR, Ingram RR, Hullin MG,
McCreath SW. Lower limb amputation following injury: a survey of long-term
functional outcome. Injury.1994;25:
387-92.25387
1994
[PubMed][CrossRef]
Millstein S, Bain D, Hunter GA. A
review of employment patterns of industrial amputees—factors influencing
rehabilitation. Prosthet Ortho Inst.1985;9:
69-78.969
1985
Legro MW, Reiber GD, Smith DG, del
Aguila M, Larsen J, Boone D. Prostheses evaluation questionnaire for
persons with lower limb amputations: assessing prosthesis-related quality of
life. Arch Phys Med Rehabil.1998;79:
931-8.79931
1998
[PubMed][CrossRef]
Curley MD, Walsh JM, Triplett RG.
Some adjustment indices of oralmaxillofacial war casualties, limb amputees,
and non-injured veterans. Mil Med.1982;147:
572-4.147572
1982
[PubMed]
Kishbaugh D, Dillingham TR, Howard
RS, Sinnot MW, Belandres PV. Amputee soldiers and their return to active
duty. Mil Med.1995;160:
82-4.16082
1995
[PubMed]
Kegel B, Carpenter ML, Burgess
EM. Functional capacities of lower extremity amputees. Arch
Phys Med Rehabil.1978;59:
109-20.59109
1978
Melchiorre PJ, Findley T, Boda W.
Functional outcome and comorbidity indexes in the rehabilitation of the
traumatic versus the vascular unilateral lower limb amputee. Am J
Phys Med Rehabil.1996;75:
9-14.759
1996
[CrossRef]
Pierce RO Jr, Kernek CB, Ambrose TA
2nd. The plight of the traumatic amputee.
Orthopedics.1993;16:
793-7.16793
1993
[PubMed]
Purry NA, Hannon MA. How
successful is below-knee amputation for injury?
Injury.1989;20:
32-6.2032
1989
[PubMed][CrossRef]
Pozo JL, Powell B, Andrews BG, Hutton
PA, Clark J. The timing of amputation for lower limb trauma. J
Bone Joint Surg Br.1990;72:
288-92.72288
1990
MacKenzie EJ, Bosse MJ, Kellam JF,
Burgess AR, Webb LX, Swiontkowski MF, Sanders RW, Jones AL, McAndrew MP,
Patterson TM, McCarthy ML. Characterization of patients undergoing
amputation versus limb salvage for severe lower extremity trauma. J
Orthop Trauma.2000;14:
455-66.14455
2000
[CrossRef]
Bosse MJ, MacKenzie EJ, Kellam JF,
Burgess AR, Webb LX, Swiontkowski MF, Sanders RW, Jones AL, McAndrew MP,
Patterson BM, McCarthy ML, Travison TG, Castillo RC. An analysis of
outcomes of reconstruction or amputation after leg-threatening injuries.
N Engl J Med.2002;347:
1924-31.3471924
2002
[PubMed][CrossRef]
Gustilo RB, Mendoza RM, Williams
DN. Problems in the management of type III (severe) open fractures: a new
classification of type III open fractures. J Trauma.1984;24:
42-6.2442
1984
Teasdale G, Jennett B. Assessment
of coma and impaired consciousness. A practical scale.
Lancet.1974;2:
81-4.281
1974
[PubMed][CrossRef]
Bergner M, Bobbitt RA, Carter WB,
Gilson BS. The Sickness Impact Profile: development and final revision of
a health status measure. Med Care.1981;19:
787-805.19787
1981
[PubMed][CrossRef]
de Bruin AF, de Witte LP, Stevens F,
Diederiks JP. Sickness Impact Profile: the state of the art of a generic
functional status measure. Soc Sci Med.1992;35:
1003-14.351003
1992
[PubMed][CrossRef]
Jurkovich G, Mock C, MacKenzie E,
Burgess A, Cushing B, deLateur B, McAndrew M, Morris J, Swiontkowski M.
The Sickness Impact Profile as a tool to evaluate functional outcome in trauma
patients. J Trauma.1995;39:
625-31.39625
1995
[PubMed][CrossRef]
Gilson BS, Bergner M, Bobbitt RA,
Carter WB.The Sickness Impact Profile: final development and
testing. Seattle: Department of Health Services, University of
Washington School of Public Health and Community Medicine;
1979.
1979
Granger CV. The emerging science
of functional assessment: our tool for outcomes analysis. Arch Phys
Med Rehabil.1998;79:
235-40.79235
1998
[CrossRef]
Waters RL, Hislop HJ, Perry J, Thomas
L, Campbell J. Comparative cost of walking in young and old adults.
J Orthop Res.1983;1:
73-6.173
1983
[PubMed][CrossRef]
Scott J, Huskisson EC. Graphic
representation of pain. Pain.
1976;2:
175-84.2175
1976
[PubMed][CrossRef]
MacKenzie EJ, Bosse MJ, Kellam JF,
Burgess AR, Webb LX, Swiontkowski MF, Sanders R, Jones AL, McAndrew MP,
Patterson B, McCarthy ML, Rohde CA; LEAP Study Group. Factors influencing
the decision to amputate or reconstruct after high-energy lower extremity
trauma. J Trauma.2002;52: 641-9.
Erratum in: J Trauma. 2002;53:48.52641
2002
[PubMed][CrossRef]
Association for the Advancement of Automotive
Medicine.The abbreviated injury scale. 1990
revision. Des Plaines, IL: Association for the Advancement of
Automotive Medicine; 1990.
1990
Baker SP, O'Neill B, Haddon W Jr,
Long WB. The injury severity score: a method for describing patients with
multiple injuries and evaluating emergency care. J
Trauma.1974;14:
187-96.14187
1974
[CrossRef]
Johansen K, Daines M, Howey T, Helfet
D, Hansen ST Jr. Objective criteria accurately predict amputation
following lower extremity trauma. J Trauma.1990;30:
568-73.30568
1990
[PubMed][CrossRef]
Dillingham TR, Pezzin LE, MacKenzie
EJ. Limb amputation and limb deficiency: epidemiology and recent trends in
the United States. South Med J.2002;95:
875-83.95875
2002
[PubMed]
Pinzur MS. Amputations in trauma.
In: Browner BD, Jupiter JB, Levine AM, Trafton PG, editors.
Skeletal trauma: basic science, management and reconstruction. 3rd ed, vol 2. New York: WB Saunders;
2003. p 2613-26.22613
2003
Pinzur MS, Gold J, Schwartz D, Gross
N. Energy demands for walking in dysvascular amputees as related to the
level of amputation. Orthopedics.
1992;15:
1033-7.151033
1992
[PubMed]
Hagberg E, Berlin OK, Renstrom P.
Function after through-knee compared with below-knee and above-knee
amputation. Prosthet Orthot Int.
1992;16:
168-73.16168
1992
[PubMed]
Bowker JH, San Giovanni TO, Pinzur
MS. North American experience with knee disarticulation with use of a
posterior myofaciocutaneous flap: healing rate and functional results in
seventy-seven patients. J Bone Joint Surg Am.2000;82:
1571-4.821571
2000
[PubMed]
Pernot HF, Winnubst GM, Cluitmans JJ,
De Witte LP. Amputees in Limburg: incidence, morbidity and mortality,
prosthetic supply, care utilisation and functional level after one year.
Prosthet Orthot Int.2000;24:
90-6.2490
2000
[PubMed][CrossRef]
Pinzur MS, Bowker JH. Knee
disarticulation. Clin Orthop.1999;361:
23-8.36123
1999
[PubMed][CrossRef]
Yaremchuk MJ, Brumback RJ, Manson PN,
Burgess AR, Poka A, Weiland AJ. Acute and definitive management of
traumatic osteocutaneous defects of the lower extremity. Plast
Reconstr Surg.1987;80:
1-14.801
1987
[CrossRef]
Smedley BD, Stith AY, Nelson AR,
editors.Unequal treatment: confronting racial and ethnic
disparities in health care. Washington, DC: National Academies
Press; 2002.
2002
Buckelew SP, Huyser B, Hewett JE,
Parker JC, Johnson JC, Conway R, Kay DR. Self-efficacy predicting outcome
among fibromyalgia subjects. Arthritis Care Res.1996;9:
97-104.997
1996
[PubMed][CrossRef]
Bandura A.Social
foundations of thought and action: a social cognitive theory.
Englewood Cliffs, NJ: Prentice-Hall; 1986.
1986
Lorig KR, Mazonson PD, Holman HR.
Evidence suggesting that health education for self-management in patients with
chronic arthritis has sustained health benefits while reducing health care
costs. Arthritis Rheum.
1993;36:
439-46.36439
1993
[PubMed][CrossRef]