p2.ch3.4
3. Treatment practice
Foot deformities are divided into three categories; equinus,
equinovalgus and equinovarus. Each deformity has its own history
and treatment approach.
1. Equinus Deformity
Foot and ankle deformities present us with a very difficult
and demanding problem. Bleck expressed this difficulty in his
latest book and it is as follows:
"What surgical procedure do you perform to correct an
equinus deformity? Many have been proposed: neurectomy of
branches of tibial nerve to the gastrocnemius and/or soleus muscles,
gastrocnemius lengthening, gastrocnemius origin recession,
Achilles tendon lengthening and Achilles tendon translocation. All
are designed to reduce the increased stretch reflex and to lengthen
the muscle. All weaken the muscle, which one strikes the best
compromise between relieving the contracture and preserving the
strength? Lengthening weakens the muscle. We have no solution
except to try to avoid too much lengthening of the tendon."67
Stable weight bearing on the feet is decisively important for
stability of the lower limb. We have challenged this serious
dilemma and are going to provide a revolutionized solution.
Historical Reviews
Historically, Achilles tendon lengthening, neurectomy of
branches of tibial nerve to the gastrocnemius and/or soleus
muscles, gastrocnemius recession, gastrocnemius origin recession
and heel cord advancement have been reported.
Achilles Tendon Lengthening:
Achilles tendon lengthening is an established procedure. In
1943, White reported subcutaneous sliding lengthening of the heel
cord.201 In 1958, Banks and Green presented heel cord
lengthening in 112 patients, which included 133 of the open sliding
type and 31 Z-plasty type, and reported satisfactory results.195
Recently, Renshaw described the details of the technique of
Achilles tendon lengthening and recommended it as an useful
procedure, stating that complications of heel cord lengthening are
rare.158
Gaines reported that 65 of 68 feet treated with Achilles
tendon lengthening were judged satisfactory in achieving
plantigrade position and that there was no calcaneal gait due to
overlengthening.203 Yngve and associates also presented a
comparative study between the Vulpius method and Z lengthening
and concluded that there were no significant differences in any of
the parameters between these two methods at follow-up.204 Thus,
tendoachilles lengthening has been considered an effective
procedure for equinus deformity correction.
However, critical views about Achilles tendon lengthening
have also been presented. Segal and associates expressed serious
concerns about the post operative calcaneal gait and reported that
calcaneal deformity could be a significant iatrogenic complication,
after single Achilles tendon lengthening.205 Risk of the
postoperative calcaneal deformity after the Achilles tendon
lengthening was also described by Lee and Bleck,206 and by Rang
et al.66 In 1956, Strayer also described his disappointment about
Achilles tendon lengthening.32 He regretted that there seems to be
no alternative solution except the use of triple arthrodesis.
In our clinical experiences, the results of Achilles tendon
lengthening are disappointing with unstable gait especially in
patients with diplegia. If Achilles tendon is overlengthened,
calcaneal deformity or calcaneal gait will inevitably be caused (Fig.
95AB). On the other hand, if the heel cord is lengthened
insufficiently, recurrences occur easily. In our patients, good
results where heel contact and stability of the gait have been
accomplished by Achilles tendon lengthening have been rare.
Surely, even if heel contact might have been achieved, increased
instability is observed in the feet, especially in most of the diplegic
patients. On the basis of these bitter experiences in the past, we
have reached the conclusion that though Achilles tendon
lengthening alone could be used for sufficient correction of the
equinus deformity, it is not reliable for achieving sufficient
antigravity stability.61,202 Rang and associates also have a similar
opinion.66
In humans, length of the muscle and tendon unit of the
soleus is shorter than that of the gastrocnemius.207 Delp mentioned
about the sensitivity of the soleus muscle after the procedure of
Achilles tendon lengthening by the use of computer simulation and
calculated that there was a 50 % decrease of soleus power by
lengthening of 1.2cm with the soleus having 3.0cm optimal fiber
length. However in his calculation, in the gastrocnemius having
5.1cm optimal fiber length, 1.2cms of lengthening did not reduce
ower of the gastrocnemius by 50%.207 This proved that activities
of the gastrocnemius could not be easily reduced whereas the
activity of the soleus could be markedly decreased, by Achilles
tendon lengthening alone. According to their study, the soleus can
be selectively damaged and easily weakened by Achilles tendon
lengthening.
As previously mentioned, the soleus is more important than
the gastrocnemius as an antigravity plantar flexor. In the study by
Delp, it is clearly demonstrated that damage of the antigravity
soleus is much greater than that of the gastrocnemius with less
antigravity activities, if Achilles tendon lengthening alone is done.
This could be the main reason, why deteriorating gait is induced
by Achilles tendon lengthening.
In general, the gastrocnemius is considered to be hyperactive
in cerebral palsy. So, if the triceps surae including the
gastrocnemius and the soleus is insufficiently lengthened,
recurrence will be inevitable. On the other hand, if the heel cord is
overlengthened, the soleus is considerably weakened, the foot will
lose much of its supporting power, and then collapse will occur
causing further crouched posture. There seems to be no appropriate
length for Achilles tendon lengthening alone. Recurrence or
weakening seems to be inevitable. Thus, in our institute,
orthopaedic surgeons, physical therapists, parents of patients and
patients have lost trust for Achilles tendon lengthening alone.
Experimentally, when too much Achilles tendon lengthening is
conducted, antigravity activity of the soleus does not recover, and
deterioration in gait usually becomes persistent (Fig. 106AB).
A. Before ATL
B. After ATL
Stability is worsened.
Fig. 106AB. Loss og body-sopporting stability
after Achilles tendon lengthening
This loss of power of the antigravity soleus is not easily
noticed in a moment, due to compensatory activities of the other
plantar flexors, such as the tibialis posterior, peroneus longus,
flexor hallucis longus and flexor digitorum longus. But, since this
compensatory plantar flexion is not totally antigravity, sufficient
stability is not achieved. In hemiplegic patients in whom
compensatory body-supporting mechanism of the unaffected limb
is functioning, the loss of antigravity activities in the affected limb
may not be disclosed. However, in the diplegic or quadriplegic
patients in whom the compensatory body-supporting mechanism is
not provided by the opposite limb, the loss of stability is usually
clearly revealed on the side where Achilles tendon lengthening has
been carried out. Difficulty in the supporting mechanism of the
ankle causes the leg to tilt forwards resulting in a crouched posture.
These are the reasons why we orthopaedic surgeons,
physiotherapists, parents and patients hesitate in recognizing the
Achilles tendon lengthening as a reliable operation.
We abandoned single Achilles tendon lengthening, on the
basis of these clinical observations and views. More reliable
procedures should be considered.
Heel Cord Advancement:
In 1974, Pierrot and Murphy reported the heel cord
advancement, as a new approach for correction of the spastic
equinus deformity. He stressed the theoretical advantage of this
procedure, against Achilles tendon lengthening, and also presented
good results with a statistical analysis.208 Throop and associates
used this procedure for correction of equinus and reported
significant improvements.209 In 1990, Strecker and associates
reported outcomes of this operation in 161 involved lower
extremities of 100 patients. He mentioned that most of the patients
have done well with significant improvements in their gait, with no
recurrence or calcaneal gait, although intramuscular lengthening of
the gastrocnemius was needed in selected cases to achieve full
correction of the deformity.210 So, this report can be considered a
result of combined approach of heel cord advancement and Vulpius
procedures. The question regarding mechanical advantage of this
procedure against Achilles tendon lengthening is quite interesting.
Bleck described that the results of heel cord advancement did not
seem to be appreciably different from those reported with sliding
tendoachilles lengthening.67
Neurectomy of the Tibial Nerve:
In 1913, Stoffel reported selective neurectomy of branches
of the tibial nerve to the gastrocnemius muscle, for correction of
equinus deformity.211
However, neurectomy has been abandoned in the field of
orthopaedic surgery, because of the difficulty in achieving a
quantitative control in spasticity of the triceps surae muscle.
Recently, in the field of neurosurgery, Sindon and associates
reported selective neurectomy of motor branches of the posterior
tibial nerve to the gastrocnemius and soleus for correction of
equinus deformity by the microsurgical technique.212 It is really
interesting to note that the abandoned technique is being readopted
for the same purpose in another scientific field. How to overcome
the difficulty in attaining a quantitative control of spasticity in the
triceps surae and other plantar flexors to achieve a well balanced
inversion-eversion position would be the task before this group.
Selective Lengthening of the Gastrocnemius:
In 1913, Vulpius proposed a new surgical procedure for
correction of equinus in which the two-joint gastrocnemius was
selectively sectioned. This is a new concept, where the
gastrocnemius is sectioned while the soleus is preserved selectively.
31 211
Strayer also presented a similar concept. In 1950, Strayer
reported the procedure in which the gastrocnemius tendon is
severed at the insertion to the common tendon with the soleus with
excellent results.32 Interestingly, he got this idea from "Mechanics
of Normal and Pathological Locomotion in Man" written by
Steindler in 1935,213 in which the history and details of the
classification of biarticular muscles are discussed. He also reported
striking effects of this procedure in which concomitant relaxation of
the adductor spasms is obtained.32,34
Baker in 1956 also reported a similar procedure and stressed
the importance of orthopaedic surgery in the treatment of cerebral
palsy.33 He used an inverted U incision on the aponeurosis,
keeping the lateral and medial portions intact with underlying s
oleus muscle. The middle portion of the tongue is completely
dissected from the soleus, then is displaced distally and sutured to
the proximal aponeurosis at the four corners of the overlapping
portions. With this technique, he could control most of the
spasticity of the gastrocnemius and a part of the soleus, as well as
attain appropriate correction and stability.
The most interesting and consistent idea of these three
authors is that they were relieving spasticity, by selectively
releasing the two-joint gastrocnemius muscle. This is an
epoch-making concept, in the history of orthopaedic treatment in
cerebral palsy. Stable and effective correction was accomplished in
the foot and ankle with this concept, by reducing spasticity of the
gastrocnemius.
These gastrocnemius recession approaches have, however,
fundamental limitations. Effective correction is limited to the cases
with mild deformity in which passive dorsiflexion of the ankle
could be obtained to the degrees more than neutral position with
the knee in flexion. Effect could not be achieved in the feet in
which dorsiflexion could not be gained beyond neutral with the
knee in flexion. Correction of severe deformity was difficult, since
continuity of the muscle fibers of the soleus remained
unlengthened. It is also true that, in spite of this excellent concept
and approaches, recurrence rate is unacceptably high.
Lee and Bleck reported 29% of recurrence rate, although
they used gastrocnemius recession in mild or moderate deformity,
in whom the Silverskiold test was positive. This means that a high
rate of recurrence is inevitable in gastrocnemius recession, even in
mild or moderate dynamic equinus deformity.214 Sharrard and
associates in 1972, presented a comparative study on the recurrence
rate between the heel cord lengthening and gastrocnemius
recession and reported that recurrence rate was high in the
hemiplegic feet, where the gastrocnemius recession was applied.215
Yngve and associates made a kinematic comparison between
Vulpius and Z lengthening and concluded that Z lengthening may
be more appropriate when large amount of corrections is needed
for patients with severe fixed equinus.204 Olney and associates also
reported that recurrence rate was high and 105 of 219 feet (44%)
required repeat surgical treatment. He also reported high recurrence
rate of 62% in hemiplegic patients.216 Bleck stated the
Strayer-Baker type of gastrocnemius recession has lost its
popularity with many orthopaedic surgeons because of this high
rate of recurrence. One exception is a paper by Basset and Baker,
in which only 4 percent of recurrence is reported.217 But, as Bleck
stated that the length of follow-up was not specified.
Thus, there are many opinions that the gastrocnemius
recession is unacceptable, because of high recurrence rate, while
some authors opine that the Achilles tendon lengthening is
preferable, because of low recurrence rate. However, the question
arises whether gastrocnemius recession is really unacceptable, only
because of high rate of recurrence.
Sharrard and associates noted that it is better to do another
operation to correct the recurrent equinus, than to risk a calcaneal
gait or deformity, and hence recommended gastrocnemius
recession, as the operation of choice in diplegic cerebral palsy and
possibly in quadriplegic cerebral palsy.215 Javors and associates
reported 79 Vulpius procedure performed on 47 patients with
equinus contracture with excellent results. They mentioned there
were 3 cases of recurrence and 3 cases of over-lengthening.218
Rosenthal and Simon also presented a low recurrence rate of 14%
in 87 patients and mentioned that this recurrence rate is acceptable.
219 Schwartz and associates also stated that quadriplegic paresis
with dynamic deformity had a more satisfactory result, when the
gastrocnemius recession was applied.220
Our conclusion is that recurrence rate is not the only factor
to be evaluated, but postoperative antigravity stability after
selective gastrocnemius recession should also be evaluated at the
same time. It is our opinion that if antigravity stability is preserved
after gastrocnemius recession, recurrence is not always an
unacceptable pitfall as it can be treated with additional use of
minimal Achilles tendon lengthening. It looks quite reliable and
reasonable for me to relieve the hypertonicity of the gastrocnemius
selectively by using gastrocnemius recession. In all the cerebral
palsy feet, the gastrocnemius recession should be the first choice
of operation (Fig. 3AB, 25AB, 107AB, 117AB, 120AB).
A. Before OSSCS
B. After OSSCS
Fig. 107AB. Effect of OSSCS,
9-year-old girl, spastic diplegia
However, after gastrocnemius recession, residual
hypertonicity of the triceps surae can become a problem, in most of
the moderate and severe deformities. To relieve this residual
hypertonicity, combined use of Achilles tendon lengthening and
gastrocnemius recession will become an revolutionary procedure in
the history of orthopaedic surgery, promising stable weight bearing,
from the point of view of preserving antigravity mechanism (Fig.
6AB, 23AB, 24AB, 108AB, 120AB).30 The decision about
appropriate level of gastrocnemius recession in each deformity
should be made, keeping in mind the importance of preserving
activities the soleus muscle.
Proximal Lengthening of the Gastrocnemius:
The attempt to correct equinus deformity by the use of
proximal lengthening of the gastrocnemius seems reasonable.
Silverskiold presented a procedure to correct equinus deformity, by
transferring both the proximal heads of the gastrocnemius, to the
posterior aspect of the tibia.160 Banks and Green also reported
proximal lengthening of the gastrocnemius for correction of
equinus deformity.195
Problem of proximal lengthening is that equinus correction
will not be so effective as when done at the distal tendon. Proximal
release is more effective for correction of the knee flexion, and
therefore, should be used for correction of the knee deformity. 61,
192
Another problem of proximal lengthening is occurrence of
the postoperative genu recurvatum and posterior knee instability.
The proximal muscular and tendinous origins of the gastrocnemius
act, as stabilizers preventing hyperextension of the knee and
should not be released only for foot correction. In our experiences,
hazardous stiff legged knee and posterior instability was caused
after proximal releases of the gastrocnemius in 3 knees of 2
patients. Motor ability was markedly decreased in these patients. In
treatment of equinus deformity, attention should be addressed to
the distal tendon of the gastrocnemius.
Surgical Approaches
Considerations:
Muscle Release
A. Before OSSCS
B. After OSSCS
Fig. 108AB. Effect of OSSCS for equinus deformity
Posterior capsulotomy
Arthrodesis
Surgical Techniques:
Fig. 109: Sliding lengthening of the flexor hallucis longus
Fig. 110: Intramuscular lengthening of the tibialis posterior
Fig.111: Intramuscular lengthening of the peroneus longus
Fig. 112: Sliding lengthening of the Achilles tendon
Fig. 113: Intramuscular lengthening of the calf (aponeurectomy)
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A. Before pantalar arthrodesis
B. After pantalar arthrodesis
C. X ray after pantalar arthrodesis
Fig. 114ABC. Effect of panarthrodesis for fixed foot deformity
Fig. 115ABC: Details of panarthrodesis
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