Abstract
Background: There is only limited objective
information about functional donor-site morbidity after harvest
of one head of the triceps surae muscles to cover a severe soft-tissue
defect of the leg. The purpose of the present study was to investigate
whether a functional deficit is present during level and uphill walking
after such a procedure.
Methods: Five subjects who had completely recovered
from the initial injury were studied with use of comprehensive gait
analysis during free level, fast level, and uphill walking on a
ramp at a 10° inclination.
Results: Gait analysis revealed no relevant donor-site
morbidity affecting level gait at a free walking speed (mean, 1.27
m/sec; range, 1.18 to 1.40 m/sec). When the subjects walked at a
higher velocity (mean, 1.89 m/sec; range, 1.58 to 2.43 m/sec), an asymmetry
of the ground-reaction forces was seen. The second vertical peak
force during push-off was reduced by a mean of 7.3% (range, 0.94%
to 12.24%), and the impulse in the direction of progression was
reduced by a mean of 8.7% (range, 0.13% to 17.87%) on the affected
side (p = 0.04). During uphill walking, a compensatory strategy
to reduce the demand on the posterior calf muscles was seen in all
subjects-that is, they shortened the length of the step on the contralateral
side by a mean of 3.9 cm (range, 2.2 to 6.2 cm), which corresponded
to a mean side-to-side difference of 5.6% (range, 2.18% to 6.18%)
(p = 0.04). A calcaneal motion pattern, denoted as increased ankle
dorsiflexion, was seen in three of the five subjects during uphill
walking as a sign of decreased function of the posterior calf muscles.
Two of them (both with a soleus flap) also had a calcaneal pattern
during fast gait.
Conclusions: We concluded from this study that the
functional donor-site morbidity after harvest of one head of the
triceps surae muscles is mild in subjects who have had a complete
recovery from their initial injury. Normal level gait is possible.
However, deficits are seen in more demanding tasks such as fast walking
or uphill walking.
Muscle-flap techniques are standard procedures in the treatment
of severe soft-tissue injuries associated with open fractures1,2 or chronic bone or joint infections3-6. For injuries around the knee and
the leg, one of the gastrocnemius muscle heads or the soleus muscle
is commonly used as a donor muscle. Le Nen et al.7,
in their report on forty-two flap procedures, advocated the use
of the gastrocnemius and the proximal pedicle of the medial soleus
as a reliable and excellent choice for reconstruction of the proximal
and middle thirds of the leg. Pico et al.8 analyzed
forty-one muscle and musculocutaneous gastrocnemius flaps. They
found that the superiorly based, denervated gastrocnemius muscle
flap can be used to create an aesthetically excellent and functionally
good cover for defects of the proximal one-third of the calf, the
knee, and the distal one-third of the thigh. Several authors have
reported on the successful use of muscle-flap techniques in the treatment
of exposed or infected sites of total knee arthroplasty4-6. While prophylactic and salvage
muscle flaps can provide the soft-tissue coverage necessary to allow successful
reconstruction in the appropriate circumstances4-8,
not much attention has been paid to the functional deficit that
may result from depriving the donor muscle of its function. In our
review of the literature, we found only very limited data on the
functional implications of these procedures. The goal of the present
study was to determine whether functional donor-site morbidity is
present during locomotor activities after harvest of the medial
head of the gastrocnemius or soleus muscle for a flap procedure.
A methodological problem in functional outcome studies is created
by the many variables among subjects, particularly when several
joints or segments of the locomotor chain are affected. The subjects
in the present study, therefore, were selected carefully, with particular
attention paid to both evidence of a complete functional recovery from
the original injuries and the absence of additional locomotor pathology.
The major role of the ankle plantar flexors during gait is to
provide ankle and knee stability by restraining the forward rotation
of the tibia on the talus during stance phase and thus allowing
the body to lean farther forward beyond its base of support than
would be the case without that muscle activity. The components of
the "calcaneal limp" associated with insufficient function of the
ankle plantar flexors was described by Sutherland et al.9, who studied five normal adults before
and after a tibial nerve block. They observed that ankle dorsiflexion
progressively increased during single-limb stance until contralateral
foot-strike occurred and that the ipsilateral heel did not leave
the floor until weight was transferred to the contralateral foot. Simon
et al.10 found that the compensatory
mechanisms in the absence of a functioning calf muscle were primarily directed
toward controlling the existing forward progression of the body's
center of mass by a fine-tuned adaptation of the trunk lean with
cessation of single-limb support and shortening of the contralateral
step length. In the present study, we used similar methods of instrumented
gait analysis to address the question of a functional deficit during
gait after harvest of part of the calf muscles for the flap procedure.
Subjects
Thirty-nine patients were treated with a muscle-flap procedure
at the University Hospital of Zurich between 1983 and 1991. The
subjects were screened carefully and were included in our study only
if they did not have a gait impairment or another functional deficit
unrelated to the muscle-flap procedure itself. Fourteen subjects
who underwent the muscle-flap procedure as a secondary treatment
for osteomyelitis or wound-healing problems were excluded. Of the
remaining twenty-five subjects, thirteen were excluded because of involvement
of the knee joint, substantial pain in the region of the initial
injuries, involvement of the ankle joint, or regional weakness due
to poliomyelitis. Five subjects had had inadequate follow-up. Only
seven subjects met the inclusion criteria, and five consented to
participate in the gait study. All five had sustained a unilateral
open fracture of the leg or ankle with a substantial soft-tissue
wound (type II or type IIIb as classified according to the system
of Gustilo et al.2) (Table ITable I). One
subject had had a skiing accident, and the other four subjects had
been involved in a motor-vehicle accident. The medial head of the
gastrocnemius muscle had been used as a flap to cover the soft-tissue
injury in two subjects, and the soleus muscle had been used in three
subjects. All subjects were enrolled in the present study after
they had completely recovered, more than two years (range, thirty-three
months to seven years) after the injury and the surgical procedures.
Standard physical examination with use of a goniometer revealed symmetrical
passive and active range of motion and joint stability in all lower-extremity
joints in all subjects. One subject (Case 4) had a limb-length discrepancy
of 2.5 cm, with the shorter limb on the side with the flap.
Muscle Test
The maximum isometric torque for plantar flexion was measured
with use of a Cybex machine (Lumex, Ronkonkoma, New York) as a reference for
the dynamic electromyographic study. All of the other muscle groups
of the lower extremity were tested against manual resistance.
Gait Analysis
The gait performance of each subject was assessed at the Laboratory
for Biomechanics, ETH Zürich. Kinematic, kinetic, and electromyographic
data were collected simultaneously during level walking on a 25-m
walkway. Each subject was asked to walk at his or her most comfortable
speed (self-selected free gait velocity) and at a self-selected fast
gait velocity. Uphill walking was tested on a ramp with 10° of inclination.
The ramp was not connected to the force-plates; therefore, only
kinematic and electromyographic data were sampled for uphill walking.
Five trials were recorded for each condition, and each consisted
of two gait cycles for level gait and one gait cycle for uphill
gait.
Kinematic Analysis
Data capture: Three-dimensional motion analysis was performed
with use of a five-camera VICON System (Oxford Metrics, Oxford,
England) for data capture. Twenty-one spherical retroreflective
markers (25 mm in diameter) were placed over anatomical landmarks
on the trunk and the upper and lower extremities bilaterally. The
five phase-locked and strategically placed VICON cameras recorded
the marker position coordinates bilaterally at a sampling rate of
60 Hz. This recording technique allowed a simultaneous assessment
of motion of both lower extremities as well as the trunk and arm positions.
With a calibrated measuring volume of 3.0 by 1.5 by 2.0 m, it was
possible to record two sequential gait cycles (four steps) during
each trial.
Data processing: Additional data processing was performed by
the biomechanical analysis package ANALYZE, written by D.A. Meglan11 and adapted by our laboratory. The
kinematic analysis was based upon the principles of three-dimensional
rigid-body mechanics. Segment position and orientation were calculated
relative to a global coordinate system with use of the recorded
marker-based information and anthropometric data. Individual joint
angles then were calculated relative to a joint-centered coordinate
system, referenced to the proximal segment.
Data analysis: A parametric analysis of ankle dorsiflexion during
stance was used to compare the two sides statistically. Peak dorsiflexion
on the side with the flap was compared with the dorsiflexion at the
corresponding percentage of the gait cycle on the contralateral
side.
Dynamic Electromyography
Data capture: A dynamic twelve-channel electromyographic telemetry
system with surface electrodes (Laboratory for Biomechanics, ETH
Zürich) was used for dynamic electromyography. Surface electrodes
were placed bilaterally over the rectus femoris, medial hamstrings,
tibialis anterior, peroneus longus, lateral head of the gastrocnemius,
and medial head of the gastrocnemius or soleus (whichever was not
used as a flap). The sampling rate for the electromyographic signal
was 480 Hz. Isometric muscle tests were performed for each muscle with
sampling of the electromyographic signal during maximum effort.
For the plantar flexors, torque was measured with use of a Cybex
machine.
Data processing: The digitally sampled, raw electromyographic
data were filtered by a high-pass filter with a cutoff frequency
of 30 Hz. To allow quantification, the signal was additionally processed
by full-wave rectification and by moving-window averaging. Normalization
of the signal amplitude was performed by expressing the sampled
signal as a ratio of the mean electromyographic amplitude registered
during a maximum effort test (Cybex). The signal duration was normalized
to the gait cycle.
Data analysis: The onset and duration of the individual activity
phases as well as modulation of the relative activity amplitude
were interpreted in relation to the simultaneously recorded motion
data and by means of comparison between the two sides.
Kinetic Analysis
Data capture: The ground-reaction forces were recorded by two
3D Kistler force-plates (Kistler Instrumente AG, Winterthur, Switzerland),
which were embedded in the floor in the middle of the 25-m walkway.
The sampling rate was 240 Hz.
Data processing and analysis: The vertical, mediolateral, and
fore-aft forces were normalized to body weight and graphed. The
force-plate recordings were additionally analyzed by a parameter-analysis
program, developed at the Laboratory for Biomechanics, ETH Zürich,
by Stüssi et al.12. Specific parameters,
such as the peak values of the ground-reaction forces in all three
dimensions and the integral of the fore-aft shear forces (impulse), were
used for statistical analysis.
Time-Distance Parameters
The time-distance parameters calculated from the kinematic and
force-plate readings included velocity, cadence, stride length,
step length, and relative and absolute duration of the individual
gait phases (total stance time, single-limb stance time, and double-limb
stance time on each side).
Statistical Analysis
Five trials were analyzed for each subject and each testing condition
to calculate the mean and standard deviations of the time-distance
parameters, force-plate parameters, and chosen kinematic parameters. The
asymmetry index (ASI) described by Herzog et al.13 was used to quantify
the difference between the side with the flap and the contralateral
side:
where x "flap" is the variable recorded for the side with the
muscle flap and x "opposite" is the corresponding variable for the
contralateral side. A value of zero for the asymmetry index indicates
that there is perfect symmetry for that particular gait variable. A
negative value indicates that the value for the flap side is smaller.
Additional side-to-side comparison was performed with use of
a nonparametric test (Wilcoxon signed-ranked test). Values were
considered significant at a level of p < 0.05.
Subjective Results
At the time of the gait study, none of the five patients had
any restrictions in the activities of daily living. They felt only
slightly limited during strenuous tasks, such as dancing, carrying
weight, gymnastics, skiing, or jogging. Four of the five subjects
had slightly reduced strength on the side with the flap. All had
returned to their previous occupation.
Muscle Testing
On Cybex testing, all of the subjects demonstrated a reduced
effort of the plantar flexors on the flap side compared with that
on the contralateral side, with a mean reduction of 19.5% (standard
deviation, 17.6; range, 4.1% to 49.5%). This reduction was significant
(p = 0.04) (Table IITable
II). No qualitative difference between the sides was noted for the
manually tested ankle dorsiflexors, knee flexors, and knee extensors.
Gait Analysis Results
Time-Distance Parameters
Level gait: The mean free gait velocity was 1.27 m/sec (range,
1.18 to 1.40 m/sec) (Table IIITable III). Statistical analysis
of the whole group showed no significant asymmetry of the step parameters.
Step length was symmetrical, with a mean asymmetry index of 0.3%
(range, -5.19% to 4.58%). This indicates a normal side-to-side variability
of the step length comparable with that of healthy subjects13,14, with some subjects having a
shorter step on the flap side (a negative value) and others having
a shorter step on the contralateral side (a positive value). Single-limb-stance
duration displayed a clinically irrelevant mean asymmetry of -2.0% (shorter
on the flap side) for the whole group, with an inter-individual
variability (range of asymmetry index, -10.28% to 4.53%). Only one
subject (Case 2) had a relevant reduction of the single-limb-stance
duration on the flap side (asymmetry index, -10.28%).
Fast gait: All subjects were capable of increasing the gait velocity
when they were asked to walk fast (mean, 1.89 m/sec; range, 1.58
to 2.43 m/sec) (Table IVTable IV). The time-distance parameters
remained symmetrical for the whole group. Only two subjects (Case 2,
with an asymmetry index of 6.1%, and Case 4, with an asymmetry index
of -8.3%) had a reduced single-limb-stance duration on the flap
side.
Uphill gait: During uphill gait, all subjects shortened the contralateral
step length, with a mean side-to-side difference of 5.6% (range,
2.18% to 6.18%), which was significant (p = 0.04) (Table VTable V). This
corresponds to a shortening of the contralateral step length by
a mean of 3.9 cm (range, 2.2 to 6.2 cm).
Ground-Reaction Forces
Level gait: Statistical analysis of the whole group showed no
significant asymmetry of the force parameters (Table IIITable III).
The second vertical peak force was reduced by a mean of 2.8%, with
the asymmetry index ranging from -7.02% to 0%, and the impulse was
reduced by a mean of 5.8%, with the asymmetry index ranging from
-13.42% to 1.34%. Only one subject (Case 1) had a relevant reduction
(7.0%) of the second vertical peak force on the flap side. The impulse
on the flap side was reduced in three subjects (Cases 1, 2, and
4), by 5.8%, 13.4%, and 10.7%, respectively.
Fast gait: Increasing the gait velocity resulted in a significant
reduction of the ground-reaction forces on the flap side compared
with that on the contralateral side (p = 0.04) (Table IVTable IV).
The second vertical peak force during push-off and roll-off was
reduced by a mean of 7.3%, with the asymmetry index ranging from
-0.94 to -12.24%, and the impulse in the direction of progression
was reduced by a mean of 8.7%, with the asymmetry index ranging
from -0.13% to -17.87%). These reductions were seen in three subjects
(Cases 1, 2, and 4).
Motion Analysis
Ankle Motion During Stance Phase (Fig. 1Fig. 1)
"Normal pattern": Only two subjects (Cases 2 and 5) had a normal
and almost symmetrical ankle-motion pattern during stance phase,
with slightly reduced plantar flexion on the flap side at toe-off
in all three test conditions in one (Case 2) and during uphill gait
in the other (Case 5).
"Calcaneal pattern": Two subjects (Cases 1 and 3) had increased
ankle dorsiflexion at the end of single-limb stance, reflecting
a calcaneal gait pattern9. During
free level gait, the difference between sides measured only 5, with
the flap side in more dorsiflexion than the contralateral side at
the corresponding percentage of the gait cycle. This difference
became more pronounced during fast gait and during uphill gait (12.1
and 16.7°, respectively, for Case 1, and 5.9° and 14.7°, respectively,
for Case 3). The motion pattern of another subject (Case 4) was
influenced by a limb-length discrepancy of 2.5 cm, with the limb
shorter on the flap side. This subject walked with the ankle in
more dorsiflexion on the side of the longer, contralateral limb
during free level and fast level gait (a difference between sides
of 6.4° and 5.8°, respectively). During uphill gait, this subject
had a bilateral calcaneal pattern with increased dorsiflexion during
late single-limb stance on both sides. The difference of 2.5° between
sides at peak dorsiflexion was less marked compared with that during
previous test conditions.
Ankle Motion During Swing Phase (Fig. 1Fig. 1)
Decreased plantar flexion was seen at toe-off in two subjects
(Cases 1 and 2) in all test conditions and in two other subjects
(Cases 3 and 5) during uphill gait. During swing phase and initial
contact, all subjects had a normal ankle dorsiflexion pattern in all
test conditions, indicating normal function of the ankle dorsiflexors.
Knee Motion During Stance Phase
Motion at the knee displayed a normal pattern with regard to
flexion during weight acceptance and extension during single-limb
stance in all test conditions. The pattern was almost symmetrical
in all subjects except one (Case 1), who had the most marked calcaneal
pattern at the ankle. In that subject, knee flexion was reduced
during weight acceptance on the flap side, with premature extension early
in single-limb stance and increased flexion late in single-limb
stance.
Knee Motion During Swing Phase
Increased peak knee flexion on the flap side was seen in three
subjects (Cases 1, 2, and 5), particularly during uphill gait. The
difference between sides was 14.3° in Case 1, 5.3° in Case 2, and
8.1° in Case 5.
Dynamic Electromyographic Studies
Because of equipment failure, no electromyographic data were
available for one subject (Case 5), who had the most normal and
symmetrical motion pattern.
Triceps surae (lateral and medial heads of the gastrocnemius
or soleus depending on muscle flap): During the locomotor activities,
the electromyographic signal equaled or even exceeded the signal of
the isometric muscle test, indicating that the isometric test was
performed on a submaximum level (Fig. 1Fig. 1). In three subjects (Cases
1, 2, and 4), the dynamic electromyographic signal displayed a higher
relative amplitude (in relation to the signal of the isometric muscle
test) on the flap side during free and fast gait. During uphill
gait, the electromyographic amplitude was lower and less asymmetrical.
One subject (Case 3) had a symmetrical electromyographic pattern
in all three test conditions; it was, however, accompanied by a
calcaneal motion pattern.
Tibialis anterior: The activity pattern during swing phase and
weight acceptance was normal and symmetrical in all four subjects.
Peroneals: Three subjects (Cases 1, 3, and 4) had a smaller relative
signal amplitude on the flap side during late single-limb stance
in all three test conditions. Another subject (Case 2) had symmetrical activity
during the stance phase of level gait and slightly increased activity
on the flap side during fast and uphill gait associated with a normal
and symmetrical ankle motion pattern.
Medial hamstrings: Three subjects (Cases 1, 3, and 4) had a smaller
relative amplitude on the flap side during late swing phase and
weight acceptance. Another subject (Case 2) had a normal and symmetrical
activity pattern for level gait. During fast and uphill gait, the
relative amplitude was slightly higher on the flap side.
Quadriceps (rectus femoris and vastus intermedius): All subjects
had a normal and symmetrical activity pattern during level gait,
with the major activity during the end of swing phase and weight acceptance.
Prolonged and increased activity was seen on the flap side in one
subject (Case 1) during fast gait and in another subject (Case 2)
during uphill gait.
Only very limited data are available with regard to the functional
implications of muscle-flap procedures in the lower extremity. Lattermann
and Lobenhoffer15 described possible
biomechanical changes in the hip, femur, and knee after transfer
of a tensor fasciae latae flap. Bochdansky et al.16 evaluated
gait and muscle strength five years after a musculocutaneous tensor
fasciae latae and rectus femoris flap was used to cover the abdominal
wall in a patient with recurrent sigmoid carcinoma. They found a
slight deficit on the side of the harvest with regard to the parameters
of strength and endurance and changes in pelvic rotation and knee
extension during the stance and swing phases. All other parameters
(peak torque) were equal on the two sides. They considered it a
good functional result without major impairment of the ability to
perform everyday activities. Knopp et al.17 performed
isokinetic testing in twenty patients who had had a local muscle-flap
transfer procedure. At a mean of three years postoperatively, they
found a mean reduction (and standard deviation) in the muscle-strength
profile during flexion of the foot of 21% 16% after transfer of
the gastrocnemius muscle and of 31% 20% after transfer of the soleus
muscle. Miller et al.18 performed
functional evaluation at the site of harvest of the medial head
of the gastrocnemius in rats and found hypertrophy of the remaining
synergistic muscles, as a compensation for part of the deficit at the
donor site.
In order to investigate the functional donor-site morbidity after
a gastrocnemius or soleus muscle-flap procedure, we carefully selected
the subjects in the present study, paying particular attention to
evidence of a complete functional recovery from the original injuries.
Although Cybex muscle-testing demonstrated a weaker isometric peak
torque of as much as 40% (mean, 17%) on the flap side, there were
no clinically relevant deficits during free level gait. All subjects
walked at a gait velocity that was considered to be within normal
limits14,19,20. The mild asymmetries
of the step and force parameters, with an asymmetry index of less
than 5%, are considered to be functionally irrelevant and fall into
the range of variability among healthy subjects13.
There were only very mild signs of calf-muscle weakness during free
level gait. Only two subjects (Cases 1 and 3), with a soleus flap,
demonstrated a mild tendency toward a calcaneal gait pattern (as described
by Sutherland et al.9). All subjects
were capable of increasing the gait velocity when asked to walk
fast. During fast level gait, however, only one subject (Case 5),
who had a medial gastrocnemius flap, had a symmetrical gait pattern
without signs of calf-muscle weakness; the others had signs of a
functional deficit. During uphill walking, the deficit due to the
functionally missing portion of the calf muscle became more obvious
as all subjects had a shortened step length on the contralateral
side. We consider this to be a compensatory strategy to reduce the
demand on the posterior calf muscles during the stance phase on the
affected side. In addition to this compensation, three subjects
(two with a soleus flap and one with a gastrocnemius flap) displayed
a calcaneal motion pattern with increased ankle dorsiflexion.
The dynamic electromyographic studies revealed a compensatory
increase of the activity of the remaining heads of the triceps surae
during free and fast walking, with a higher relative amplitude (in relation
to the amplitude on the isometric muscle test) on the flap side
compared with that on the contralateral side in three subjects (Cases
1, 2, and 4). Since the isometric muscle test demonstrated a weakness
on the flap side, a higher proportion of the relative signal during
gait would be expected if a normal gait pattern was maintained.
An inability to increase the relative amplitude on the flap side would
be expected to be associated with a more asymmetrical motion pattern.
This was seen in one subject (Case 3), who had a symmetrical relative-muscle-activity
pattern but displayed a calcaneal motion pattern with increased
ankle dorsiflexion on the flap side in all three test conditions.
As a result of the compensatory strategy during uphill gait, the relative
amplitude of the muscle activity was less asymmetrical compared
with that in the fast walking condition. Thus, the need for a compensatory increase
in the remaining calf-muscle activity was reduced by the motion
strategy. All subjects with a calcaneal motion pattern had decreased
activity of the peroneals on the flap side. This indicates that the
peroneals, which act as secondary plantar flexors, did not sufficiently
compensate for the reduced function of the triceps surae in these
subjects. One subject (Case 2) used the peroneals successfully as a
compensation strategy. The increased peroneal activity during fast
and uphill gait helped to maintain a normal ankle-motion pattern.
The motion pattern at the knee on the flap side displayed a compensatory
strategy during the swing phase of uphill gait, with increased peak
knee flexion in the three subjects (Cases 1, 2, and 5) who had decreased
ankle plantar flexion after push-off. During stance phase, the knee
pattern was normal and almost symmetrical in all three test conditions
in all subjects except one (Case 1), who had the most severe calcaneal
motion pattern. This difference was seen particularly during fast
gait. As a result of the deficient plantar flexors in that patient,
the knee was kept in more extension during early stance phase with
prolonged quadriceps activity. Toward late stance phase, knee flexion
increased along with the increased ankle dorsiflexion. Prolonged
quadriceps activity during single-limb stance was also seen in one
subject (Case 2) during both fast and uphill gait as a compensation
for the plantar flexor weakness. In that subject, the compensation
was sufficient to result in a normal ankle-motion pattern.
We concluded from the present study that the functional donor-site
morbidity after harvest of one head of the triceps surae muscles
is mild in subjects who have had a complete clinical recovery from their
initial injuries. Normal level gait is possible. However, deficits
and compensatory strategies are seen during more demanding tasks
such as fast or uphill walking. Since all subjects had subjective complaints
of deficiencies during sports activities, an analysis of running
or jumping could provide more objective substantiation of those
symptoms. Additional research should be performed to address this
topic.
The subject with the most function had a medial gastrocnemius
flap. All subjects who had a soleus flap showed some deficits. Because
of the strict selection criteria, however, the number of subjects was
too small for us to draw conclusions about a certain type of flap.
Amgwerd MG; Trentz O; Schütz K; and Meyer V: Concept for the management of combined bone-soft tissue
defects of the lower extremity. Swiss Surg,1995.2: 90-5, German290
1995
[PubMed]
Gustilo RB; Merkow RL; and Templeman D: The management of open fractures. J Bone Joint Surg Am,1990.72: 299-304, 72299
1990
[PubMed]
Ger R, and Efron G: New operative approach in the treatment of chronic osteomyelitis
of the tibial diaphysis. A preliminary report. Clin Orthop,1970.70: 165-9, 70165
1970
[PubMed]
Gerwin M; Rothaus KO; Windsor RE; Brause BD; and Insall JN: Gastrocnemius muscle flap coverage of exposed or infected
knee prostheses. Clin Orthop,1993.286: 64-70, 28664
1993
[PubMed]
Greenberg B; LaRossa D; Lotke PA; Murphy JB; and Noone RB: Salvage of jeopardized total-knee prosthesis: the role
of the gastrocnemius muscle flap. Plast Reconstr Surg,1989.83: 85-9, 97-9, 8385
1989
[PubMed]
Markovich GD; Dorr LD; Klein NE; McPherson EJ; and Vince KG.: Muscle flaps in total knee arthroplasty. Clin Orthop.,1995.321: 122-30, 321122
1995
[PubMed]
Le Nen D; Fabre A; Yaacoub C; and Lefevre C: Flaps of the gastrocnemius muscles. Rev Chir Orthop Reparatrice Appar Mot,1995.81: 66-73, French8166
1995
[PubMed]
Pico R; Lüscher NJ; Rometsch M; and de Roche R : Why the denervated gastrocnemius muscle flap should be
encouraged. Ann Plast Surg,1991.26: 312-24, 26312
1991
[PubMed]
Sutherland DH; Cooper L; and Daniel D: The role of the ankle plantar flexors in normal walking. J Bone Joint Surg Am,1980.62: 354-63, 62354
1980
[PubMed]
Simon SR; Mann RA; Hagy JL; and Larsen LJ: Role of the posterior calf muscles in normal gait. J Bone Joint Surg Am,1978.60: 465-72, 60465
1978
[PubMed]
Meglan DA. Enhanced analysis
of human locomotion [dissertation]. Columbus (OH): Ohio State University;
1991
Stüssi E; Stacoff A; and Segesser B: Biomechanical considerations of the load on the ankle
joint. Orthopade,1992.21: 88-95, German2188
1992
[PubMed]
Herzog W; Nigg BM; Read LJ; and Olsson E: Asymmetries in ground reaction force patterns in normal
human gait. Med Sci Sports Exerc,1989.21: 110-4, 21110
1989
[PubMed]
Kadaba MP; Ramakrishnan HK; Wootten ME; Gainey J; Gorton G; and Cochran GV: Repeatability of kinematic, kinetic, and electromyographic
data in normal adult gait. J Orthop Res,1989.7: 849-60, 7849
1989
[PubMed]
Lattermann C, Lobenhoffer P.: Biomechanical changes in the hip, femur and knee joint
after removal of a tensor fasciae latae flap. Handchir Mikrochir Plast Chir.,1996.28: 76-82, German2876
1996
[PubMed]
Bochdansky TL; Zauner-Dungl A; Kollmitzer J; and Piza-Katzer H: Functional follow-up of combined musculocutaneous tensor
fasciae latae and rectus femoris flap repair. Supplementary information
on the Handchir. Mikrochir. Plast. Chir. 21(1989)315-17 contribution. Handchir Mikrochir Plast Chir,1994.26: 84-90, German2684
1994
[PubMed]
Knopp W; Buchholz J; Muhr G; and Steinau HU: Negative effects of local tibial muscle flap repair on foot
function. Unfallchirurg,1993.96: 229-34, German96229
1993
[PubMed]
Miller SW; Opiteck JA; White TP; and Faulkner JA: Functional evaluation at
the medial gastrocnemius donor site in rats. J Reconstr Microsurg,1996.12: 143-7, 12143
1996
[PubMed]
Murray MP; Mollinger LA; Gardner GM; and Sepic SB.: Kinematic and EMG patterns during slow, free, and fast
walking. J Orthop Res,1984.2: 272-80, 2272
1984
[PubMed]
Perry J. Gait analysis.
Normal and pathological function. Thorofare (NJ): Slack;
1992.
Baker SP; O'Neill B; Haddon W Jr; and 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
[PubMed]
Müller ME, Allgöwer M, Schneider R,
Willenegger H. Manual der osteosynthese. AO-technik. 2nd
ed. Berlin: Springer; 1977. p 152-7.