Fibular hemimelia is the most frequently occurring congenital
deficiency of the long bones11,18.
Primary treatment options include (1) Syme or Boyd amputation with
early prosthetic fitting and (2) tibial lengthening. There appears
to be little consensus as to which option is best4,6,11,13,15,23.
Numerous studies have documented the success of both early amputation1,3,5,9,10,12,19,24,25 and lengthening
techniques2,7,16,21,22. The decision
regarding which treatment to implement is very difficult. Understandably,
the parents have a great deal of apprehension regarding such a permanent
and important decision14. Frequently,
the parents are not comfortable with an amputation; conversely,
lengthening often requires multiple procedures and a long treatment course.
The choice between amputation and lengthening is made more difficult
by the fact that there have been few comparisons of the two treatment
modalities. Two research groups directly compared the results of
amputation and lengthening9,17.
However, in one of these studies functional outcome parameters were
not evaluated, and in the other study lengthening was performed
primarily through the femur and the Wagner technique was used exclusively;
thus, comparisons are difficult.
The purpose of our study was to compare the results of amputation
and tibial lengthening in children with fibular hemimelia. Specifically,
we addressed activity restrictions, pain, satisfaction, complications,
number of procedures, and cost.
All patients with fibular hemimelia treated with either an amputation
or a lengthening procedure at our institution from 1970 to 1995
and followed for at least two years were studied. Thirty limbs in twenty-five
patients were evaluated. Fifteen patients (nineteen limbs) underwent
amputation (nine Syme and ten Boyd amputations) and are referred
to as the amputation group. Ten patients (eleven limbs) underwent
lengthening of the tibia (six Ilizarov and five Wagner lengthenings)
and constitute the lengthening group. The mean age at the time of
amputation was 1.2 years (range, seven months to 2.3 years), and
the mean age at the time of initial lengthening was 9.7 years (range,
5.5 to 18.3 years). The mean duration of follow-up was 6.9 years
(range, 2.1 to fourteen years) in the amputation group and 7.1 years
(range, two to 15.4 years) in the lengthening group. There were
seventeen right limbs and thirteen left limbs in eleven female and
fourteen male patients.
Functional results, including assessment of activity level, level
of pain, and satisfaction (yes or no), were determined for twenty
of the twenty-five patients. The activity score reflected the activity
level on a scale of 0 to 3 points, and the pain score reflected
the level of pain on a scale of 0 to 4 points (Table I).
The complication rate was determined by dividing the total number
of complications by the number of limbs for each group.
For each patient, the number of procedures and the cost were
determined from a review of the medical records. A cost analysis
was performed for all patients with use of cost data (hospital costs
in United States dollars as of 1997) from identical or similar procedures
performed for patients with the diagnosis of fibular hemimelia.
We did not include the cost of prosthetics or orthotics.
Preoperative radiographic and clinical data were used to compare
the degree of severity of the fibular hemimelia between the amputation
and lengthening groups. The percent shortening of the affected limb
(in sixteen of the twenty patients with unilateral involvement),
the percent shortening of the fibula compared with the ipsilateral
tibia (in twenty-three of the thirty limbs), and the number of rays
in the foot (in twenty-six of the thirty limbs) were recorded. The
final limb-length discrepancy was determined for the patients who
underwent limb-lengthening.
The Wilcoxon signed-ranked test was used to determine significance.
A p value of less than 0.05 was considered significant. StatMost
32 software (DataMost, Sandy, Utah) was used for the statistical
analysis.
The results are summarized in Table II.
Functional Results
The patients in the amputation group had less pain, were able
to perform more activities, and were more satisfied than the patients
in the lengthening group.
None of the patients in the amputation group had any activity
restrictions (mean activity score, 0 points), and all participated
in sports. In contrast, five of the ten patients in the lengthening
group complained of moderate activity restrictions (an activity
score of 2 points); the lengthening group had a mean activity score
of 1.2 points (p < 0.05).
Three patients in the amputation group complained of mild discomfort
after strenuous activity (mean pain score for the group as a whole,
0.2 point), whereas five patients in the lengthening group complained
of pain (mean pain score for the group as a whole, 1.2 point) (p
= 0.091).
All patients interviewed in the amputation group were satisfied
with the procedure, whereas only five of the ten in the lengthening
group were satisfied (p < 0.05).
Complications Related to the Procedure
There were significantly more complications (p < 0.05) in
the lengthening group (complication rate, 1.91) than in the amputation
group (complication rate, 0.37). There were five complications related to
pain or sensitivity at the stump site in the amputation group. In
addition, two patients, both with a Boyd amputation, had an asymptomatic
nonunion.
There were twenty-one complications in the lengthening group.
These included tibial angulation in six limbs; pin-site infection
in five; retained hardware in two; equinus deformity in two; and knee
flexion contracture, recurrent ankle valgus angulation, hematoma
requiring drainage, premature closing of a corticotomy site, decreased
sensation in the foot, and bone-graft dislodgment in one each.
Number of Procedures and Resulting Cost
Lengthening required more procedures. Patients in the amputation
group underwent a mean of 1.9 procedures, whereas those in the lengthening group
underwent a mean of 7.0 procedures (p < 0.05). The mean hospital
cost in the amputation group was $7016 compared with $26,900 in
the lengthening group (p < 0.05).
Degree of Severity
All of the preoperative clinical parameters were more severe
in the amputation group. On the average, the length of the fibula
was 6 percent of the length of the tibia in the amputation group
(it was shortened 80 percent in one limb and was absent in the rest)
and it was 59 percent (range, 0 to 100 percent) of the length of
the tibia in the lengthening group (p < 0.05). The mean number
of rays was 3.3 (two, three, or four) in the amputation group compared
with 4.6 (four or five) in the lengthening group (p < 0.05).
The length of the affected limb averaged 86 percent (range, 82 to
94 percent) of the length of the unaffected limb in the amputation group
and 90 percent (range, 82 to 93 percent) of the length of the unaffected
limb in the lengthening group (p = 0.18).
In general, the lengthening was successful in equalizing limb
lengths. The mean lengthening of the eight limbs that were assessed
was 4.6 centimeters (range, two to 7.1 centimeters), and the mean
length discrepancy of the nine limbs that were assessed was 0.7
centimeter (range, zero to 1.4 centimeters) at the time of the latest
follow-up. No patient in the lengthening group subsequently underwent
an amputation.
This study demonstrated that children who undergo early amputation
for the treatment of fibular hemimelia are more active, have less
pain, are more satisfied with the result of the treatment, have
fewer complications, undergo fewer procedures, and incur less cost
than those who undergo lengthening. This is true even though good
results can be obtained with lengthening procedures and most patients
achieve limb-length equality, are able to walk, have minimal pain,
and are quite active.
Many studies have concluded that early amputation and prosthetic
fitting provide satisfactory results1,3,5,9,10,12,19,24,25,
but several others have shown that lengthening can reproducibly
equalize limb length and result in a functional extremity2,7,16,21,22. However, none of these
authors compared their results with those of amputation, and only
a few collected outcome data5,9,21.
Two studies directly compared the results of amputation and lengthening.
Naudie et al.17 reported more
complications and longer and more frequent hospital stays for patients
who had lengthening, but the follow-up was short (less than two
years for the lengthening group) and no functional outcome data
were collected.
Choi et al.9 evaluated forty-three
patients, thirty-two of whom had early amputation and eleven of
whom had lengthening. They also found that the amputation group
had a higher percentage of satisfactory results (88 percent) than
the lengthening group (55 percent). Unlike the patients in our series,
most of their patients had lengthening of the femur (only four tibiae
were lengthened) and all limbs were lengthened with the Wagner technique;
thus, comparison with the results of the Ilizarov technique is difficult.
The long-term results of lengthening can be unpredictable. Sharma
et al.20 showed that tibiae that
underwent lengthening because of a congenital deficiency subsequently
had a decreased growth rate. Cheng et al.8 found
that substantial progressive angular (osseous) deformities can occur
after lengthening for the treatment of fibular hemimelia.
We examined our lengthening group in detail to determine which
preoperative factors were associated with a good result. A ball-and-socket
ankle does not seem to preclude a good result, as we had four very
active patients with a ball-and-socket ankle, three of whom were
satisfied with the result. Valgus angulation of the ankle joint
did seem to be a predictor of a poor result. Of the four patients with
ankle valgus, three were not satisfied and all four had pain and/or
activity restrictions. No patient in either group required walking
aids.
The cost analysis did not include the cost of prosthetics, which
can be quite high throughout a patient's lifetime. We primarily
used the cost analysis as a measure of the duration and complexity
of the treatment and do not believe that cost should play a deciding
role in determining the treatment plan.
The choice of treatment of fibular hemimelia can be difficult
for the family and the physician7,14.
The condition of the foot, the presence of associated anomalies,
bilaterality, the desires of the family, and cultural differences
must be considered when choosing between amputation and lengthening.