The fate of the oblique abdominal muscles after free
TRAM flap surgery
Journal of Plastic Surgery
Ph. N. Blondeel*, W. D. Boeckxt, G. G. Vanderstraetent,
R. Lysens§, K. Van Landoyt*, P. Tonnard*, S. J.
Monstrey' and G. Matton'
Departments of 'Plastic and Reconstructive Surgery,
University Hospital Gent, and Traumatology and Reconstructive
Surgery, University Hospitals Leuven, and Departments
of Physical Medicine and Rehabilitation, f University
Hospital Gent and University Hospitals Leuven, Belgium
SUMMARY: During recent years, clinical research on
the donor site morbidity after free or pedicled transverse
rectus abdominis myocutaneous (TRAM) flap surgery has
been focusing on the reduced flexion capacity of the
abdominal wall. However, the rectus abdominis muscles
have close interactions with their synergists and antagonists
and collaborate with their neighboring muscles. The
purpose of this study was to examine the consequences
of partially resecting the rectus abdominis muscle on
the different muscle groups of the abdominal wall.
Twenty free TRAM flap patients, 12-61 months (mean
32.1 months) after surgery, were clinically examined,
evaluated for curl-up performance and underwent isokinetic
dynamometry for flexion, extension and rotation. The
patients were compared with 20 non-operated controls.
Nineteen patients answered a questionnaire.
Abdominal wall abnormalities occurred in 10 patients:
umbilical asymmetry (n = 3), abdominal wall asymmetry
(n = 4), lower abdominal bulging (n = 2) and hernia
(n = 1). Curl-up performance was less in the TRAM flap
patients (P = 0.001, Mann-Whitney). Isokinetic flexion,
extension and rotation were also less in the TRAM flap
patients (Fisher's exact test).
This study indicates that what has been believed to
be 'limited' surgical damage to the abdominal wall leads
to an important reduction in flexion strength but to
an even more important reduction of rotation strength
due to bilateral displacement and damage of the insertion
of the oblique muscles. Partial compensation by synergists
is variable and unpredictable on an individual basis.
These functional disorders can potentially lead to important
changes in activities of daily life.
Although several surgeons have tried to limit the damage
to the rectus abdominis muscle by selective harvesting
of free transverse rectus abdominis myocutaneous (TRAM)
flaps, TRAM flap harvesting still involves the resection
and denervation of an important part of the rectus muscle
above the arcuate line. Besides the structural changes
inflicted on the abdominal wall leading to abdominal
protrusion, bulging or hernias, the loss of function
caused by interrupting the continuity of the muscle
is at least equally important. Recent studies3-'0 evaluating
the donor site morbidity of TRAM flaps have only been
focusing on the decrease of flexion capacity. Interested
in the consequences of partially resecting one rectus
abdominis muscle on the function of the entire abdominal
wall, i.e. flexion and rotation, we extended our investigations
to the assessment of both the rectus and oblique abdominal
In this study, the flexing and rotating capacity of
the trunk of free TRAM flap patients was evaluated by
their ability to perform curl-ups and by isokinetic
dynamometry and compared to a control group who had
not had TRAM flaps. Patients' opinions of the results
of surgery were assessed by a questionnaire.
Patients and methods
Twenty patients who had undergone a breast reconstruction
with a unilateral free TRAM flap at least
12 months prior to this study (mean 32.1 months, range
12-61 months) by two of the authors (PhB, WB) at the
University Hospitals Leuven were included in this study.
The patients' mean age was 46.8 years (range 29-63 years)
at the time of surgery. Their mean postoperative weight
of 66.5 kg (range 47-92 kg) did not differ significantly
from the mean preoperative weight of 66.2 kg (range
49-90 kg). Patients with tumour recurrence or distant
metastasis were excluded. In 11 patients, a 6-8 cm long
segment of the left rectus abdominis muscle had been
harvested over its entire width above the arcuate line
- TRAM (Left) group. In 9 patients the same dissection
had been performed on the right side - TRAM (Right)
group. Closure of the anterior rectus sheath was reinforced
by synthetic mesh in 18 cases. The control group was
composed by inviting a sister or female friend of the
patient to perform the same tests at the same time.
In this way, a group of 20 healthy non-operated women
with comparable socio-economic background, physical
condition, age (mean 45.4 years; mean 29-68) and weight
(mean 68.7 kg; range 52-97) was formed.
Patients and controls were examined supine and upright
by a physician other than the surgeons. All patients
were inspected for asymmetric positioning of the umbilicus,
abdominal wall asymmetry, lower abdominal bulging and
hernias. Asymmetry of the abdominal wall was dehmed
as a unilateral distension of the lower abdomen. Bulging
was defined as a protrusion of a part of the lower abdominal
wall with palpable edges but without a defect in the
abdominal fascia. A hernia was defined as a defect in
the deep abdominal fascia.
A postoperative CT scan or MRI of the Iower abdominal
wall between umbilicus and pubis was offered to the
patients to evaluate the anatomical changes.
All subjects were asked to perform straight and rotational
curl-ups. In this exercise, subjects have to consecutively
flex and lift the head, shoulders, thoracicand lumbar
spine and finally pelvis. Subjects were placed in a
dorsal supine position, knees and hips flexed and feet
fixed on the table. A higher score was given to a better
curl-up performance following the criteria in Table
1." During the rotational curl-ups, subjects were
asked to turn the upper body and bring the elbow to
the contralateral knee. Left and right rotation were
tested. Sit-ups with a straight upper body were avoided.
Evaluations were done by a physician other than the
The CybexR II isokinetic dynamometer (Cybex, Division
of Lumex, Inc., Ronkonkoma, N.Y.) with stabilization
system for trunk muscle force assessment was used to
objectively evaluate the dynamic flexion, extension
and rotation performance of the trunk. This apparatus
has previously proven to give reliable measurements
in a test/retest design.'2 In the Trunk Extension-Flexion
(TEF) unit, all subjects were positioned according to
the trunk stabilization system.'3'4 Measurements were
done in a standing position. Knees were positioned in
15° of flexion to avoid hamstring strain when performing
trunk flexion. The input axis of the dynamometer's shaft
was aligned at the L5-S1 articulation. A testing trial
consisted of five consecutive flexion/extension repetitions
from 0° to 80° at a speed of 60°/s. In the
Torso-Rotation (TR) unit, subjects were tested in 4
sitting position (Fig. 1). Knees and hips were flexed
in 90° and hips were additionally abducted 10°
to improve stability of the pelvis. Otherwise, fixation
was similar to the TEF unit. Here a testing trial consisted
of five consecutive trunk rotations from 45° right
to 45° left and back, at a speed of 60°/s. The
resting time between both trials was approximately 5
minutes. Before testing, each subject received detailed
instructions and, once positioned, an opportunity was
given to warm up and familiarize with the testing motion.
During testing each subject was strongly encouraged
by the physical therapist conducting the measurements
to maximize her efforts.'5 Peak torque/body weight (pt/bw)
and average power/ body weight (ap/bw) provided by the
Cybex data reduction computer were the parameters used
in this study to compare groups while avoiding the influence
of weight changes.
Figure 1Positioning of the tested subject in
the torso-rotation unit of the Cybex II isokinetic dynamometer.
A self-administered questionnaire was sent to all TRAM
flap patients to assess their opinion about abdominal
strength and complaints, posture, lower back pain and
changes in activities of daily life. Details of the
questionnaire are published elsewhere.'6
To compare the dynamometric results between groups
the Mann-Whitney test was used. To compare the curl-up
scores, Fisher's exact test was used. P < 0.05 was
considered as statistically significant.
Three (15%) patients had umbilical asymmetry and an
additional four (20%) patients had abdominal wall asymmetry.
A: bulging of the lower abdominal wall was found in
two (10%) patients and a hernia in one case. Three persons
in the control group were found to have a small symptom-free
Physical exercise evaluation
A distinct difference in curl-up performance was recorded
for straight flexion and rotatory flexion to the left
and right in both groups (Fig. 2). Sixteen controls
were able to attain a straight curl-up score of 5. Only
seven TRAM flap patients were able to obtain the same
score. Most patients achieved a maximum score of 3 (5
patients) or 4 (8 patients) for straight curl-ups, significantly
more than the number of controls with a maximum score
of 3 or 4 (P = 0.001). Even fewer patients were able
to perform a score 5 rotational curl-up (4 left, 5 right).
Most patients were only able to lift one scapula from
the surface (9 patients). The number of patients with
a maximum score of 3 or 4 was significantly greater
than the number of controls (left P = 0.0004; right
P = 0.001).
Figure 2 - Physical examination. Percentages of subjects
able to achieve muscle power scores of 3,4 or s. (Straight:
Straight curl-up. Left: Left rotational curl-up. Right:
Right rotational curl-up.)
Table 2 Isokinetic dynamometry results of TRAM flap
patients vs. control group for different movements of
the torso at 60°/s and their statistical significance
(pt/bw = peak torque per body weight. ap/bw = average
power per body weight)
Lower mean pt/bw and ap/bw were observed in the TRAM
flap group for extension of the torso but the differences
from the control group were not statistically significant
(Table 2). The mean pt/bw and ap/bw to flex the upper
body were significantly lower for TRAM flap patients
compared to the controls. The mean flexion/extension
ratios were not significantly different. Left rotation
and to a lesser degree right rotation were significantly
less powerful in patients than in controls. The weaker
rotation to the left was once again demonstrated by
the lower mean left/right rotation ratios for TRAM flap
patients but statistical significance was considered
to be borderline.
In TRAM (Left) and TRAM (Right) patients no significant
changes (Mann-Whitney test) were found in the capacity
to rotate the upper body to the left or to the right
at a speed of 60°/s (Table 3).
CT or MRI of the abdominal wall
Only 6 TRAM flap patients presented themselves for
the imaging study. The postoperative follow-up in these
6 patients varied from 19 to 54 months. The rectus muscle
had been replaced by a mixed sheet of fascia, mesh and/or
scar tissue. The midline was deviated to the operated
side and the distance between the midline and the insertion
line of the oblique muscles was reduced. The medial
border of the external oblique muscle and to a lesser
degree the medial border of the internal oblique had
shifted medially. Finally, we observed a reduction in
diameter of all oblique muscles of about 25% compared
to the non-operated side.
Nineteen of the 20 TRAM flap patients filled out and
returned the questionnaire. The results are given in
detail in a second paper in this issue of the Journal.'6
In summary, the patients complained about-decreased
abdominal power (44%), reduced ability to lift heavy
objects (28%), abdominal protrusion (42%), pain in the
lower abdominal wall when the intra-abdominal pressure
was raised (e.g. coughing, Valsalva manoeuvre) (47%)
and difficulties in getting up from a supine position
One of 14 patients in employment before surgery was
not able to continue her job as a housekeeper. Five
patients (26%) had to alter the way they did domestic
activities. Three (30%) of 10 patients were no longer
able to carry on with their favorite preoperative sport.
Two others (20%) hac1 to change to a different sport.
Two (20%) out of 10 patients with an active hobby preoperatively
(gardening), were not able to continue with their gardening.
The normal function of the abdominal muscles
The role of the rectus abdominis muscles in flexion
of the trunk is generally overestimated. Although they
primarily flex the lumbar spine, they are only responsible
for the first 30° of flexion of the upper body as
an initiator of movement. The iliopsoas muscles then
take over and are the strongest flexors responsible
for trunk flexion over the largest part of the trajectory.
In daily life the rectus muscles are hardly ever used
as pure flexors because in an upright position gravity
flexes the upper body. The flexing function of the rectus
muscles is mostly needed to get up from a supine position,
which is done maybe once or twice a day. The rectus
abdominis muscles are far more important in daily life
for stabilization of the upper body. Not only do they
form a dynamic and flexible muscular pillar as a counterpart
of the rigid bony spine but they are also an important
site of insertion for all the oblique muscles. In this
way they assist in rotatory movements and are essential
for normal function of the oblique muscles. Together
with the transverse muscles they are responsible for
raising intra-abdominal pressure, a crucial function
for lifting heavy objects, bowel movements, forced expiration
(coughing, sneezing), etc.
The vertically orientated muscle fibers of both the
internal and external oblique muscles assist in flexing
the trunk, synergistic with the rectus muscles. The
oblique muscle fibers are mainly responsible for lateral
flexion and rotation of the trunk. Unilateral contraction
of the external oblique muscle causes rotation to the
contralateral side supported by the contralateral internal
oblique. The oblique muscles are the strongest rotators
of the trunk. The oblique part of the para-vertebral
muscles and shoulder musculature only assist in the
Table 3 The mean peak torque and average power of left
rotation compared to right rotation in the TRAM (Left)
and TRAM (Right) groups at 60°/s (pt/bw = peak torque
per body weight, ap/bw = average power per body weight).
No differences were statistically significant
Evaluation of the abdominal muscles
The complex interaction of the recti with their surrounding
muscles, specifically the oblique abdominal muscles,
and the influence of synergistic muscles, e.g. the iliopsoas
muscles, and of antagonists, e.g. the hamstrings and
paravertebral muscles, make an isolated clinical evaluation
of the function and strength of the rectus abdominis
muscles very difficult. All reported clinical tests
measure the capacity to flex the upper body by joint
contraction of the rectus abdominis muscles, iliopsoas
muscles and the vertical fibers of the oblique muscles
but do not measure rectus muscle activity independently.
A reduced flexion capacity can be caused by damage to,
or loss of strength of, one or more of these flexing
muscles. The specificity of these tests for the rectus
muscles can be increased by reducing the synergistic
influence of the other muscles, e.g. by flexing the
hips during curl-ups. Even so, results have to be interpreted
1. Clinical examination. Although an asymmetric position
of the umbilicus is probably only an aesthetic problem,
protrusion of the abdominal wall can become hazardous
to abdominal wall function in the long term. Abdominal
asymmetry, bulging and hernias are probably three stages
in a problem with the same aetiology, which is an increasing
laxity and elasticity of the deep abdominal fascia and/or
scar tissue. This laxity can either not occur or not
be apparent, or remain stable or progress into a hernia
over time. Long-term studies will be necessary to prove
if the incidence of hernias will increase in these patients.
2. Curl-up performance. A substantial difference has
to be made between a 'sit-up and a 'curl-up'.
In a 'sit-up the spine is lifted from the surface
but kept straight while the hips are flexed. Flexion
is mainly performed by the iliopsoas muscles, while
the rectus muscles have an isometric stabilizing function.
In the first phase of a 'curl-up', the cervical spine
followed by the thoracic spine is lifted up from the
surface by contraction of the rectus muscles and the
flexing part of the oblique muscles, flexing the lumbar
spine for about 30°. Further flexion by rectus muscle
activity then becomes impossible as shortening of the
rectus muscle has reached its maximum. In the second
phase of a 'curlup', that is over 30° to 45°,
the iliopsoas muscles take over. The static or stabilizing
function of the rectus muscles then slowly decreases
as flexion increases."
To test the rectus muscle as a pure flexor while excluding
any influence of the iliopsoas muscles, the first phase
of the curl-up would probably be the best exercise because
at that point the iliopsoas muscles are inactive. But
the range of motion of 0° to 30° is limited,
making it very difficult to grade performances. In other
concentric flexing tests such as a sit-up or a full
curl-up, the influence of the contraction of the iliopsoas
muscles cannot be avoided. The rectus muscles then act
as strong stabilizers during flexion of the hips to
keep the upper body in an isometric position. If the
rectus muscles were not active and the trunk could not
be stabilized, no sit-up or curl-up could be performed
because the iliopsoas muscles would only be tilting
the pelvis and lower lumbar spine, leaving the upper
We preferred using the 'full curl-tip' to clinically
test the flexing capacity because the rectus muscles
are evaluated in this test as flexors in the first part
and stabilizers in the second part. In this test, the
influence of the iliopsoas muscles can be reduced by
flexing the hips and knees, causing shortening of the
iliopsoas muscles and reduced lordosis of the lumbar
spine. If additionally the feet are not supported, the
test becomes an even more selective test for the rectus
abdominis muscles." This is because the ability
to perform flexion of the trunk is then directly correlated
to the degree of curling up of the upper body and in
a consecutive phase stabilizing the upper body maximally.
The curling up brings the point of gravity of the upper
body as short as possible to the pivot point (the hip
joint), thereby reducing the torque necessary to flex
the upper body. On the other hand, not having foot support
decreases the sensitivity of this test too much. Looking
at the general female population, it has been reported
that only very few non-operated women are able to perform
such a curl-up because the overall strength of their
rectus muscles is too low to execute phase one.49 If
the majority of persons is not able to do the curl-up
preoperatively, it will become very difficult to grade
a decrease in strength postoperatively. For that reason
we preferred to support the feet.
If the hips are flexed and the feet are supported,
almost every woman can perform a curl-up. A decline
in this performance reflects either a weakening of the
iliopsoas muscles, or reduced rectus strength, or both.
The condition of the undamaged iliopsoas muscles can
only be affected by an important change in the patient's
general condition. We considered both groups to have
a comparable general condition because no major differences
were found in extension strength during the isokinetic
dynamometry testing and back muscles are the first to
weaken rapidly if a person's general condition declines.
Therefore a decline of curl-up performance with feet
supported largely depends on reduced rectus muscle strength.
As the rectus muscle is the only one of the flexor group
that has been surgically damaged, we may presume that
the decreased abdominal wall strength is caused by resection
of a part of the rectus muscle. We found that only 35%
of TRAM flap patients were able to reach a score 5 whereas
80% did so in the control group. As 75% of TRAM flap
patients, compared to 95% in the control group, were
able to at least perform a score 4 curl-up, we can deduce
that the flexing movement itself still can be executed
by contraction of the intact contralateral rectus abdominis
muscle and the oblique muscles, but with increasing
work load (score 5) performances decrease drastically
The rotational curl-up is a very specific exercise
for assessing the function of the ipsilateral external
oblique muscle, laterally flexing and rotating the vertebrae.
Almost half of the TRAM flap patients were not able
to complete a full rotational curl-up and only 20% were
able to execute the complete exercise (score 5). The
poor performances (score 3 in 45% of TRAM flap patients)
indicate important damage to the external oblique muscles,
although they are not directly surgically injured during
surgery. Whereas in a straight curl-up the function
of a unilaterally damaged rectus abdominis muscle is
compensated by strong synergistic muscles, the function
of the apparently undamaged external oblique muscle,
dominant in rotational movements, can only be partially
compensated in a rotational curl-up by weak synergists.
This is why a large number of patients was not able
to execute the complete exercise, regardless of the
work load, and why differences with the control group
are even more significant for the rotatory movements,
especially for score 5.
3. Isokinetic dynamometry. This is a method to measure
the force or power exerted over a joint by a group of
muscles at a fixed angular speed.'8 The testing device
will automatically keep the speed constant by increasing
the resistance to the movement if the tested person
increases their efforts. The calculated peak torque
(= force x distance, Nm) represents the maximum muscle
capacity while the average power (= work/time, Watts)
represents the total amount of work a muscle is able
to perform over a certain amount of time. Because movements
of the upper body were made in the same direction as
the vector of gravity, all results were corrected for
the patient's weight. During testing, feet, hips and
knees have to be fixed to be able to measure forges
in a constant and reproducible manner. This means that
the function of the iliopsoas muscles, as in curl-up
testing, can never be excluded and results will always
be influenced by both iliopsoas and rectus muscles.
Isolated testing of the rectus muscles is impossible
with this device. We preferred to test our patients
in a standing position because this is considered to
be the most functional posture, best resembling daily
living activities and providing sufficient amplitude
for movement of the upper body.
Because the general condition of both groups was comparable,
we once again could assume that the strength of the
undamaged iliopsoas muscles was similar in both groups
and that the statistically significant difference in
flexion strength was due to the surgical resection of
a part of the rectus abdominis muscle. Differences became
even more apparent looking at the average power. The
flexion/extension ratio values were lower in TRAM flap
patients but did not differ significantly from the control
subjects. It is unclear at this moment whether this
could be an indicator that the balance between abdominal
and back musculature was disturbed and whether this
can be correlated with a higher number of patients with
postoperative lower back pain as reported in the questionnaire.
Despite the statistically significant reduced rotational
strength measured in both directions in TRAM flap patients,
rotation to the left was slightly weaker than to the
right. This difference, represented by a decreased left/right
rotation ratio, was not statistically significant and
remains unexplained. The side of muscle harvest did
not influence the rotational strength in a particular
direction. Right rotation was slightly stronger in both
the TRAM (Left) and TRAM (Right) groups but differences
were not statistically significant.
Implications for abdominal wall function and strength
The resection of a part of one rectus abdominis muscle
leads to an interruption of the rectus muscle continuity
and thus to the complete loss of function of one of
the rectus abdominis muscles. Theoretically, the strength
of the central muscular pillar of the abdomen is therefore
reduced by 50%. By compensatory mechanisms of the synergistic
muscle groups, the functional loss is limited but a
statistically significant decrease in flexing strength
is unavoidable and permanent. The fact that only a part
or the whole muscle is harvested does not seem to make
Additionally, the resection of a part of the rectus
abdominis muscle causes major functional changes in
the oblique muscles. The loss of strength of the oblique
muscles can only be attributed to the iatrogenic alterations
that took place at its insertion line, because vascularisation
and innervation have been left intact. As seen intraoperatively
and on postoperative imaging, the contralateral rectus
muscle (in case of a unilateral free TRAM) is pulled
over the midline by the tension of the partially resected
and sutured anterior rectus fascia. The decreased width
of the ipsilateral rectus fascia and the decreased distance
between the insertion lines of the oblique muscles of
both sides causes overstretching of the external and
internal oblique muscles on the operated and non-operated
side. In the early postoperative period, this can lead
to an increased resting length of the sarcomeres. As
shown in Brand's'9 sarcomere tension-length curve of
a skeletal muscle (Fig. 3), this could result in a reduction
of the tension capacity. Extreme tension and overstretching
can even lead to areas of permanent fibrosis. In an
intermediate phase, the muscles, held in a 1engthened
position, can add sarcomeres to increase muscle fiber
length, finally restoring the normal resting length.
But in the meantime, the elasticity of the mixed meshscar-aponeurosis
layer that replaced the rectus muscle and fascia may
slowly increase. This can be clinically observed with
the different degrees of laxity of the abdominal wall,
ranging from abdominal asymmetry to bulging. Increased
elasticity is difficult to prove on CT scans or MRI
as patients are lying in a relaxed supine position,
reducing the tension on the abdominal wall. The pulling
of a muscle with increased fiber length on semi-elastic
tissue can be responsible for an important loss of strength
of the oblique muscles.
Besides these physiological changes in the oblique
muscles, the biomechanical changes taking place at the
interface of the oblique muscles with the damaged rectus
muscles are maybe even more important. Each contraction
of the rectus abdominis muscle increases the muscle's
diameter temporarily. The tension on, and the medial
displacement of, the insertion line of the oblique muscles
is necessary for proper function of the oblique muscles.
This mechanism is destroyed on the ipsilateral side
and is damaged on the contralateral side due to the
high passive tension on the anterior and eventually
posterior rectus fascia. Reefing of the contralateral
anterior rectus fascia to obtain symmetry of the umbilical
position will probably only further deteriorate this
Figure 3 - Clinical length-tension curve of a skeletal
muscle. R1 is the resting length of a normal muscle.
R2 is the resting length of a stretched muscle (modified
Additionally, the weakening of the central muscular
pillar after partial muscle resection will reduce its
dynamic rigidity. In non-operated subjects, a rigid
and dynamic central muscular pillar is necessary for
the oblique muscles to be able to exert their forces
without laxity at the insertion line. If the oblique
muscles do not receive sufficient counter-action from
a weakened central pillar containing only the contralateral
rectus muscle (unilateral TRAM) or no muscle at all
(bilateral TRAM), the insertion line will be deflected,
resulting in an improper function of the oblique muscles
and loss of strength.
These physiological and biomechanical changes can express
themselves in a variable degree in each patient. After
surgery, 35% of TRAM flap patients were still able to
perform a full straight curl-up and 25% a full rotational
curl-up. On the other hand, some patients were only
able to partially initiate the movement and suffered
an important loss of strength. In most patients synergists
can take over the functional movement but as the load
increases (e.g. when hands are brought to the neck or
higher) flexion and rotation performances decrease drastically.
Re-examining the questionnaire taught us that patients
with the lowest curl-up and dynamometry score had the
most complaints in daily living activities. They specifically
complained about decreased abdominal power (44%), reduced
ability to lift heavy objects (28%), abdominal, protrusion
(42%), abdominal pain when the intra-abdominal pressure
was raised (47%) and difficulties in getting up from
a supine position (38%). Although these complaints were
seldom incapacitating, adaptations of activities of
daily life were noticed in 31% for professional activities,
30% for sports and 20% for hobbies.
We wish to thank Dr K. Depuydt, Mrs L. Vervaet and
Mrs 1. Didden for their efforts in physically and clinically
evaluating the patients. We also wish to express our
gratitude to Mr G Vanmaele for his statistical work.
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PhiDip N. Blondeel MD, FCCP, Associate Professor,
Department of Plastic and Reconstructive Surgery,
University Hospital Gent
Willy D. Boeekx MD, PhD, Professor, Department of
Traumatology and Reconstructive Surgery, University
Guy G Vanderstraeten MD, PhD, Professor and Chief
of the Department of Physical Medicine and Rehabilitation,
University Hospital Gent
Roeland Lysens MD, PhD, Professor and Chief of the
Department of Physical Medicine and Rehabilitation,
University Hospitals Leuven
Koenread Van Landoyt MD, FCCP, Associate Professor,
Department of Plastic and Reconstructive Surgery,
University Hospital Gent
Patriek Tonnard MD, FCCP, Clinical Assistant Professor,
Department of Plastic and Reconstructive Surgery,
University Hospital Gent
Stan J. Monstrey MD, PhD, FCCP, Professor and Chief
of the Department of Plastic and Reconstructive Surgery,
University Hospital Gent
Guido Matton MD, FACS, Emeritus Professor and former
Chief of the Department of Plastic and Reconstructive
Surgery, University Hospital Gent.
Correspondence to Phillip N. Blondeel, Department
of Plastic and Reconstructive Surgery, University
Hospital Gent, De Pintelaan 185, B-9000 Gent, Belgium.
Paper received 8 November 1996.
Accepted 19 March 1997, after revision.