Below-Knee Amputation Surgery
Henry E. Loon, M.D. *
Throughout the history of lower-extremity
amputation surgery, the relative emphasis placed on various parts of the
procedure has undergone many changes as new techniques have become available and
as new goals have been appreciated. At present, the amount and direction of
available knowledge demand the surgeon's concern with fundamental principles.
Since some of these problems must be considered whatever level is chosen for
amputation, they will be discussed before those that are peculiar to below-knee
amputation.
As seen in the earliest reports on
amputation, from the times of Hippocrates and Galen, this drastic measure was
taken for the sole purpose of saving life but, as it usually turned out, it was
instead a lethal procedure owing to shock and to loss of blood. Therefore, all
emphasis was placed on the speed with which the operation could be completed.
Patients who survived the operation frequently died of septicemia. After
hemostasis, antisepsis and asepsis, and anesthesia all came into use in the
mid-nineteenth century, however, speed became less important, less painful and
extreme surgical procedures could be developed, and surgeons began to give more
attention to conservation of tissues. Another change in emphasis was prompted by
technical advances in articulated prostheses (first invented in the sixteenth
century). Functional aspects of the stump then became the main consideration,
and together with the prosthesis they came more and more to dictate the level
and type of amputation.
This development is most fully
illustrated by the popularity-which persists even now
 -of the zur Verth scheme, or "site-of-election" concept. A "functional" means
of determining the optimum amputation level, this arbitrary plan was obviously
never intended for use in any and all situations, such as trauma, and certainly
not under conditions of mass casualties, where conservation of tissue and open
drainage are essential. But it has been used in such situations and has led to
unnecessary loss of valuable segments of limbs. Dederich points out
that a military order of the German Army Medical Corps during the last part of
World War II was necessary to prohibit use of zur Verth's scheme for primary and
usually septic amputations, the order directing that tissue-sparing open
amputations be used.
Since that time it has become
increasingly clear that distinctions must be made in regard to the conditions
under which the amputation is done and that the technique must be related to
these distinctions. Under emergency conditions, the primary consideration of the
surgeon is to treat for shock to save the life of the patient. His thought and
his actions are directed toward preservation of the limb rather than toward
amputation. Conservation of blood supply, restoration of nerve connections, and
debridement of crushed tissue are his main concern. Large operative procedures
should not be undertaken, because surgical shock cannot be added to the already
existing shock. If amputation becomes a matter of life or death, the level is
then not the choice of the surgeon. It is forced on him. He will try to preserve
as much useful tissue as possible, but the general condition of the patient
dictates the measures. It is because of these factors that even revised stumps
are often not of a length that the limbfitter might consider ideal.
In a recent publication of the
Committee on Trauma of the American College of Sur geons, it was stated:
For the lower extremity, the desideratum
is weight-bearing, and for this reason adequate soft tissue coverage over the
end of the stump is more important than extra length. If it appears likely,
however, that revision of the stump will be necessary, it is best to leave as
much length as possible at the primary amputation.
Also emphasized was the point that the
preferences of the limbmaker should not be considered in emergency amputations,
but approval was given for reamputations "in accordance with accepted concepts
concerning elective levels for a prosthesis."
The implications of this persistent
concept need to be examined, particularly since the surgeon, in fashioning a
stump, is often faced with difficulties that are not related to principles of
prosthetics at all. His decision as to the level of amputation has to be based
on the reaction of individual tissues. Thus present-day practice should not have
as much influence as present knowledge of anatomic and physiological changes
that occur as the result of amputation of an extremity or of any part of
it.
Unfortunately, few publications evaluate
these changes completely and relate them to the functional losses. The
techniques they recommend often seem inadequate and, in many instances,
contradictory. Even techniques valuable in themselves are given limited
application, and advances in amputation procedures have come about very slowly.
Over the past 75 years a number of surgeons have published new techniques,
successful in their hands, which were not widely accepted because definite and
fundamental biological principles were lacking. Also implicated in this
situation is the frequently found-and understandable- attitude of the physician
who has attempted to save an extremity with all the skill at his command and
makes the decision to amputate only as a last resort and reluctantly, then
performing the operation as expediently as possible.
For the patient, however, amputation
initiates a new life with a whole set of new problems. In addition to the
functional loss, psychological trauma is inevitable. Preamputation psychological
preparation is, if time permits, always advised, but while it can do much to
alleviate some of the problems it is not enough if persistent physiological
disorders prevent the patient from using a prosthesis
adequately. The goal of rehabilitation, which may in this way begin before
amputation, is return of the amputee to as near a normal life as possible, and
this calls for coordinated efforts by various workers-efforts that should begin
with the surgeon's understanding of the many biological and biomechanical
principles involved. It was postulated at the Biomechanics Laboratory,
University of California, that these principles could be derived from a
cooperative, interdisciplinary approach to the various aspects of
lower-extremity amputation and then applied back to specific procedures and
treatments. It is from this point of view that the following
sections review the known principles and how they have been and can be brought
to bear in surgical practice in regard to pain, bone, muscles and fascia, and
skin. First to be described are the special problems of below-knee amputation
and how other workers have sought to solve them.
Special Problems in Below-Knee
Amputation
It has long been accepted, but for
varying reasons over the years, that the middle third of the leg is the best
site for a below-knee amputation. This gives a stump of 5 1/2 to 7 in.
below the knee joint. Current opinion is based mainly on
reasons of circulation, which is often reported to cause problems when
amputation is done in the lower third where the circulation is relatively poor,
and on prosthetics practice, which is conventionally most able to make use of a
bone lever at least 2 in. long. It must be remembered, however, that
satisfactory results can be achieved with both longer and shorter stumps. As
Watermann has indicated, very short below-knee stumps are preferable
to reamputation at an above-knee level, providing that the insertion of the
patellar ligament is retained or re-established, and long below-knee stumps may
be kept if soft-tissue and circulatory conditions are adequate.
Peculiar to below-knee amputation is the
presence of two bones. The tibial crest, lying close to the surface of the skin,
is always beveled slightly. But the fibula, normally a non-weight-bearing bone,
has received various treatments. Its complete excision is frequently recommended, at least
in very short stumps, first because of its tendency to lateral deviation and
rotation caused by pull of the tendon of the biceps and, secondly, because of
the protuberance of the head, which is subjected to pressure by the prosthetic
socket. For stumps of average length, the advice usually is to section the
fibula 1 to l 1/2 in. above the end of the tibia in order to facilitate fit in
the socket. This treatment does not, however, take account of
certain surgical provisions, which are discussed more fully in the next
section.
Treatment of Tissues
The whole problem of pain in the amputee,
both in the stump and in the phantom, is known to be extremely complex. It is
clear that removal of so large a mass of tissue must cause a gross disturbance
in the balanced input of peripheral sensory nerve impulses. For one thing, a
neuroma forms at the cut end of nerves. Its regenerating nerve fibers
intertwine, and it may be considered a grossly abnormal "receptor organ" which is painful on mechanical stimulation. The mobilization of skin in
forming flaps is inevitably accompanied by partial denervation and often by
regeneration that is faulty and incomplete. Transection of muscles naturally
deprives them of their insertions so that they then lack normal antagonistic
action, and impulses from the muscle spindles and Golgi organs in the tendons
are altered or absent. Other scars and inflammatory lesions of the soft tissues
and bone may contribute to the generation of impulses that are interpreted as
pain. Furthermore, it is known that painful stimuli elsewhere in the body tend
to produce pain in the stump or phantom.
In the knowledge of these unavoidable,
devastating changes, the surgeon has the obligation to try to prevent any tissue
destruction that is unnecessary or that can be circumvented in any way. He must
try to fashion a stump that will function in as nearly "normal" a way as
possible. This will eliminate at least some kinds of pain and help to normalize
sensory return.
Bone
Bone is a living tissue composed of
ossein (a protein) intimately combined with inorganic substances, chief among
which is calcium phosphate. The inorganic substances give hardness and rigidity
to the bone, while the ossein determines its toughness. Bone function is
affected by alterations in nutrition and in the metabolism of both organic and
inorganic substances, as well as in conditions of loading.
Of the various functions of normal bone,
the principal one with which we are here concerned is to transmit load. The long
bones of the thigh and leg transmit loads that, at moments, amount to many
hundreds of kilograms. These forces, together with muscle forces, determine the
final detailed form and internal structure of the bone. When the
bone is severed and no longer bears weight in its long axis, changes in the
mineral metabolism occur rapidly, and osteoporosis, which can be a cause of
exquisite tenderness and spontaneous pain, sets in. Severing the diaphysis of a
long bone leaves an open-end medullary cavity, thus altering normal conditions
of pressure and circulation within the bone. In addition, joints proximal to the
amputation show such degenerative changes as sclerosis and narrowing of the
joint spaces. These changes are the usual lot of most lower-extremity amputees
today. If, however, direct loading along the long axis of the bones can be
provided after amputation, many of these undesirable changes can be prevented.
In this case, the socket of the prosthesis transfers the floor reaction to the
skeletal system via the distal end of the stump. This theoretically desirable
goal is, however, not easy to attain, which explains why it is not even
attempted by most surgeons or planned for by most prosthetists. The great
majority of amputees cannot stand pressure on the distal end of the stump for
any length of time, even when the tissues are confined in a cuplike socket end
to provide hydrostatic cushioning by the soft tissues. Deep palpation of the
tissues over the transected end of the bone usually causes pain in the
hypersensitive bone.
Many methods have been proposed for
making the distal end of the stump less sensitive and more capable of bearing
weight. In 1893 Bier described the pain felt over the cut end of the bone and ascribed it to the
"Knochennarbe," or bone scar. He recommended an osteoplastic procedure in which
the cut end of the bone was covered with a flap of cortical bone attached by a
periosteal hinge. This method was later largely abandoned, perhaps because of
difficulties similar to those we often encountered when we attempted to use it:
sometimes bony union did not take place; some plates became sclerotic, others
required an excessively long healing time.
The next attempt to desensitize the end
of the bone was that of Bunge, who attempted to achieve an "ebonized" end by
stripping the periosteum to a few millimeters from the distal end of the bone
and scraping out the endos-teum to the same level. This technique became much
more popular and is still recommended by some textbooks. Since, however, this procedure destroys the periosteal and endosteal blood
supply to the end of the bone, it usually results in a ring sequestrum that may
cause foreign-body reactions and that may even be eliminated by the body. Even
without this drastic procedure, avascular necrosis develops at the end of the
transected bone, and this greatly inferior bone tissue is a constant source of
irritation and pain.
How might this zone of avascular necrosis
be eliminated? Even if Bier's osteoplastic procedure was not entirely
satisfactory, it still seemed logical to cover the cut end of the bone with
osteogenic material. Ertl developed a special adaptation-the pliable
osteoperiosteal flap for below-knee amputees. As he described this procedure,
three periosteal flaps, with small flakes of cortical bone attached to them, are
cut, two from the tibia and one from the fibula. The three flaps are fashioned
into a tube, which is attached to the two bones in such a way as to bridge them
and cover both distal surfaces (Fig. 1). The method has several advantages:
(a) elimination of the exposed cut surfaces of the bones and thus of the
possibility of avascular necrosis; (b) provision of an insensitive
surface capable of partial end-bearing; (c) prevention of lateral
deviation and rotation of the residual fibula; (d) occlusion of the
medullary cavities of both tibia and fibula, thus restoring normal
intramedullary pressure and normal deep venous return; and (e) provision of a protective wall for the cut ends of nerves and vessels in the interosseous
space. For this procedure, the fibula should be sectioned at the same level as
the tibia, and the anterior tibial crest should be beveled in the usual
manner.
Muscle
The principal function of normal skeletal
muscle is to provide motion, stabilization, or restriction of bony structures.
In the conventional amputation, the muscles are severed, usually through the
muscle bellies, and are thus deprived of their distal attachments and
consequently of the length-tension relationships under which they normally act
to best advantage. In the typical conventionally amputated stump, the muscle
tissue atrophies rapidly; circulation becomes poorer, especially since venous
return is no longer aided by the muscle pump, so that stasis and edema may
result. Mondry developed a satisfactory method of dealing with this
problem. The flexors, tapered if necessary, and the extensors, including the
musculature of the fibula, are sutured together over the osteoperiosteal bridge
and to the periosteum of the tibia (Fig. 2). Thus the muscles have new
attachments and are able to become more functional. The stump is stronger and,
with improved circulation, much healthier. When a total-contact prosthesis is
used, the well-developed muscles are able to hold the prosthesis on by their
contraction alone.
Blood Vessels and Nerves
Blood vessels should be dissected out
carefully, with the veins separated from the arteries, ligated, and cut at
different levels. The main nerve trunks are cut high under moderate traction.
Trunks of both nerves and blood vessels are buried in the interosseous space
proximal to the osteoperiosteal bridge.
Such techniques for the treatment of
nerves as alcohol injection, cauterization of the cut end of the nerve, and
suturing of the sheath over the cut end have not seemed to influence the
formation of neuromas or the presence of phantom sensation or pain, as has been
claimed for them, but not enough evidence has been obtained to allow anv
conclusions. Further study must also be undertaken before statements can be made about Lenggenhager's
technique in which three progressively weaker compression points
are applied at successive distances of about 1 cm. from the transected area of
the nerve for elimination of phantom pain. In another method of altering
conditions with which pain occurs, as studied by Boldrey the nerve
end is removed from mechanical irritation by being implanted and thus
protectively enclosed in the medullary cavity of the residual bone. The neuroma
that might then develop is also said to be reduced in size, but, again, results
have not been conclusive.
Fascia
The fascia should be kept in place as
much as possible during the amputation procedure, and any part that has been
separated from the underlying muscle should be entirely removed since otherwise
this mobilized fascia reattaches itself to the musculature in the form of
a hard fibrous cover that forms a barrier to the penetration of the blood
vessels serving the skin. It may even become necrotic and be extruded shortly
after operation.
Skin
One reason for skin breakdown is poor
circulation in the stump, with resulting stasis, edema, and anoxia. Attempting
to provide, at the time of surgery, for as good circulatory conditions as
possible is, therefore, requisite to the subsequent health of the skin. Impairment of the blood vessels and nerves serving the skin cannot be
avoided in amputation, but it can be minimized by the following procedures:
(a) placement of the skin flaps directly over well-functioning muscles;
(b) moderate reduction of subcutaneous fat; and (c) careful
suturing of the skin, with avoidance of excessive tension on the flaps and
placement of the scar so that it does not lie
directly over the end of the bone and is not subject to irritation by the
prosthesis. Other than this consideration, the position of the scar is
immaterial if healing is per primam. A good choice is an
anterolateral-to-posteromedial suture line, the resulting scar lying at right
angles to the suture line of the muscles (Fig. 2B). The skin flaps should
then be of equal length. This approach is in agreement with Marquardt.
Preoperative and Postoperative Treatment
Prolonged and intensive preoperative care
is essential for the success of an osteoplastic-myoplastic amputation or
revision. The patient should be hospitalized preoperatively for a minimum of
three weeks, preferably for six. During this time everything possible should be
done to improve the condition of the limb.
If localized infections are present, they
should be treated topically. The skin should be given the best of care.
Hydrotherapy for stimulation of circulation and drugs (intra-arterial procaine
to the femoral artery of the affected side) to increase peripheral circulation
may be administered. The limb should be exercised within the limits of tolerance
of the patient.
Equally important is proper postoperative
treatment. Postoperative hematoma should be prevented by use of suction-drainage
(negative-pressure bottle), which will help avoid tissue destruction because of
pressure, painful distention, and the presence of a medium for growth of
bacteria.
A splint should be used for two to three
weeks with the knee in slight flexion; no exercises are prescribed for this
period. Then an Ace bandage should be applied and exercises gradually increased
over a period of time, the aim being especially to strengthen the
anterior tibial and calf muscle groups. A shrinker
should be used only if distention is present. The distal surface of the slump
should be toughened by pounding and by vibration treatments.
After eight to ten weeks, well before
solidification of the bone bridge, the prosthesis can be fitted. A pad should be
put in the bottom of the socket and the pressure on the distal end gradually
increased. This procedure will accelerate the solidification of the bone bridge
and further decrease postoperative edema and the sensitivity of the distal end
of the stump.
Brief Reports of Cases
Of the cases illustrated here, 2 through
6 are of amputees seen in Herborn, Marburg, and Bonn, Germany, in 1958, and 1,
7, and 8 are taken from recent experience with osteoplastic-myoplastic
procedures at the Biomechanics Laboratory.
Case 1
Fig. 3 shows evidence of partial
synostosis between the tibia and fibula of a man whose primary amputation was done 32 years ago,
when he was 9 years of age. This roentgenogram substantiates the statement made
by Ertl that Nature itself tries to connect the transected surfaces
of the fibula and tibia, thus showing the way for surgical action.
Case 2
Reamputation of both legs of a
52-year-old man was done by Mondry in 1950. The left stump, which is 7 in. long,
is shown in Fig. 4. Excellent results were obtained in this case by the
osteoplastic-myoplastic procedures used at reamputation. At the time of
examination, 8 years postoperatively, the patient reported that he could walk
well, with good control of his prostheses, and that he had proprioception in
both stumps and no phantom pain. Examination showed good temperature and no
discoloration of the skin or hypersensitivity at the distal end of the stumps;
the bone bridge was palpable through the soft-tissue pad; and there was full
range of motion of the knee joint. Some atrophy of the gastrocnemius-soleus
muscle group had occurred. It is unfortunate that the prostheses did not provide
for at least some end-bearing, since the patient could support weight on both stump ends.
The roentgenogram shows a well-rounded bone bridge, with good bone tissue
extending to the distal ends of both bones except for slight osteoporosis
resulting from use of a prosthesis that did not provide for any axial
loading.
Case 3
A 58-vear-old man, also a bilateral
amputee, had revision of his right stump only. The operation was performed by
Ertl in 1947 with use of the osteoplastic technique because of pain, increased
sensitivity of the bone, inability to wear a prosthesis, and, finally,
penetration of the bone through its inadequate skin cover. The two sides may be
compared in Fig. 5 and from the following observations. With respect to the
right stump, no complaints of the sort heard before revision were heard
afterward. Shortened to 7 1/4 in., the bone was soon insensitive and capable of
bearing weight, although no postoperative physical therapy for toughening of the
stump had been given. At the time of examination the left stump (8 in. long)
was, however, reported by the amputee to be subject at times to
inflammation, neuritis, and radiation of pain
into the adductor region of the thigh. Both stumps had only skin over the bone
at the distal end, and the bone bridge of the right stump was palpable. Myoplasty had not been done at the
time of revision of the right stump, and resulting atrophy of the anterior
tibial group was noticeable. On the left (unrevised) side, an exostosis was
present on the medial aspect of the distal end of the fibula. While the left
stump was sensitive to palpation, the right stump was completely insensitive,
even to heavy punishment. Skin changes resulting from use of open-end prostheses
with thigh corsets were present but less severe on the right side (Fig. 6).
Case 4
Fig. 7 shows a bone bridge in formation
soon after revision was done for the purpose of anchoring the fibula in a very
short stump. The resulting short but well-shaped and functional stump is shown
in Fig. 8.
Case 5
A variation of the osteoplastic technique
was successfully done in another case. In order not to reduce length, a
homogeneous graft from the anterior tibial crest was applied in bridging the two
bones (Fig. 9). The operation, including a myoplastic procedure, was performed
by Ertl in 1947. When the amputee, a 34-year-old man, was examined in 1958, he
stated that since revision he had never had any discomfort in his stump and
could walk considerable distances. His socket provided for weight-bearing over
the medial tibial flare none over the stump end. The stump (Fig. 10) was pointed and its musculature somewhat atrophied; there was hyperkeratosis
anteriorly over the distal end of the tibia, as well as abrasions and signs of
constriction in the area of weight-bearing. These conditions, along with
discoloration from the supporting thigh corset, were evidence that the patient's
prosthesis did not exploit the potentialities of his stump. He had full range of
motion at the knee joint, and the muscle power was good.
Case 6
Fig. 11 shows a fracture that occurred
in the bone bridge of an unusually athletic amputee. The shortness of the fibula
in relation to the tibia, with resulting curved and slanting bone bridge, should
be noted. At the time of examination the stump was, however, completely
insensitive over the distal end, and the patient had no complaints.
Case 7
Primary amputation of the left leg of a
31-year-old man was done in 1951 because of a war injury. After recurrent
breakdown of the redundant soft tissue along the surgical scar, persistent
severe stump and phantom pain which had led to drug addiction and prevented
rehabilitation, and prevailing coldness of the stump skin, osteoplastic-myoplastic
revision was carried out on March 24, 1961. The roentgenogram shown in Fig. 12
was taken on July 31, 1961. At the time of writing, the shape and condition of
the stump are most satisfactory-warm and insensitive to pressure, with normal
skin color. The patient is wearing a well-fitting prosthesis with a
total-contact socket that provides for patellar-tendon-bearing and partial
end-bearing. He has no localized or phantom pain and has resumed a normal life
with steady employment.
Case 8
In 1955, when the patient was 48 years
old, his left foot was crushed in a railway accident. After a variety of efforts
to save the foot had failed on account of prolonged osteomyelitic suppuration, a below-knee amputation was
done in December 1956. Because the patient had continuous, severe stump and
phantom pain, which was established to be of peripheral origin, an
osteoplastic-myoplastic procedure according to Ertl and Mondry was done in
January 1961. At this time the bone tissue was found to be of a deep yellow
color, with rarefication of the trabeculae and almost no points of bleeding from
the bone. Although healing was slow (see Fig. 13, photo taken 7 months after
revision), the patient's condition appears to be considerably improved. He no
longer has the acute phantom pain that used to torture him; phantom pain now
occurs only during occasional stump pain. The latter, considerably less than
before, is probably due to the poor bone material with its protracted healing
time. The patient's stump is being toughened by percussion and by use of a
total-contact prosthesis which provides
vertical loading of the bone.
Conclusions
The osteoplastic-myoplastic procedure,
occasionally used as a primary procedure under special conditions, is indicated
for revision of below-knee stumps (a) when there is intractable stump
pain with clearly established peripheral cause; (b) when the stump is
severely hypersensitive, either superficially or in the deeper tissues; (c) when
the stump has gross circulatory deficiencies, is easily distended and edematous,
or is subject to skin breakdown, ulceration, or types of hyperplastic growths
that may become malignant; (d) when the stump has redundant tissue and
excessive scar tissue, adherent or nonadherent to deeper tissues, preventing
tolerance of the prosthesis; (e) when the stump is long and has atrophic
retracted musculature; and (f) when there is at the distal end of the
stump a localized, deep infection which after nonoperative treatment has proved
inadequate, must be resected in toto with reamputation at a slightly
higher level. For unequivocal success, however, it is important to amputate
through viable, well-vascularized bone. In the presence of advanced atrophy and
osteoporosis, the solidification of the bone bridge takes much longer, and
complete elimination of spontaneous, deep-seated pain becomes questionable (Case
8).
Much has been written about the optimum
level of amputation below the knee, and usually from the point of view of how
well the conventional prosthesis could be applied. Thus, the main reason for the
2-in. minimum given by various authors has been the problem of maintaining the
stump in the socket. With certain prosthetic advances that are now coming into
use, however, a shorter stump can be fitted successfully, provided some
weight-bearing potential exists at the distal end. Most very short stumps are
completely insensitive over the cut surface of the tibia because the cancellous
bone at this high level heals well with formation of a solid bony cover. The
main problem, then, is the presence of the head of the fibula, which, when it is
deprived of much of its interosseous membrane, is subjected to the full force of
the pull of the biceps tendon, with resulting abduction of the
distal end of the residual fibula and rotation of the head. The solution many
surgeons recommend is resection of the head of the fibula, but doing so gives a
conical stump even more difficult to fit because of excessive stump rotation
inside the socket.
What might be done in these cases is
demonstrated in Case 4, in which a modification of Ertl's technique was done.
Not only was anchorage of the head of the fibula achieved in this case, but
allowance was made for full use of the knee joint in an adequate prosthesis.
Because of the high level of amputation in this type of case, the anterior
tibial group is dissected at or close to its tendinous origin, so that a muscle
plasty is not only technically difficult to perform but also not
essential.
A shortening of the stump occurs as a
result of fashioning the osteoperiosteal flaps from the surfaces of the tibia
and fibula, but the surgeon should not hesitate to make this sacrifice in length
when an increase in function can thereby be obtained. Because of sensitivity of
bone or excoriated skin, most conventional stumps can be fitted snugly in the
proximal half only. The distal half is subjected to excursion and resulting
mechanical irritation in a loose socket because it has to be relieved of
pressure. When the hypersensitivity of the tissues is eliminated by the
osteoplastic and myoplastic procedures herein described, the stump can be fitted
closely over its full length, thereby reducing excursions in the socket and
actually increasing functional length. If, however, the surgeon is reluctant to
shorten the bones in the presence of adequate viable soft tissue at the distal
end, an equally satisfactory bridge can be formed with use of a homogeneous bone
graft, as is illustrated by Case 5.
Contrary to the recommendations, given
with other surgical techniques, to shorten the fibula in relation to the tibia,
with the osteoplastic technique best results are obtained when the two bones are
transected at the same level. The bridge is then approximately horizontal to the
ground. When the fibula is shorter, the bone bridge must be formed on a
sagittally directed slant. While the presence of the bridge is, in any case,
desirable to prevent biological difficulties, any slant will
subject it during weight-bearing to vertical shearing forces it may not be able
to withstand. The fracture reported in Case 6 is one of two seen in 1958-both
being diagnosed only through roentgenograms since they were asymptomatic and did
not prevent the patients from participating in competitive sports.
Of relatively less importance is the
placement of the scar. Even if it falls across the distal surface of the bone,
the well-vascular-ized, relatively insensitive skin is able to withstand socket
rub and shear effectively.
Good circulation to the deep as well as
to the superficial tissues is one of the most advantageous results of the
osteoplastic-myo-plastic operation. The muscles, able to contract by
virtue of distal attachments, are used continuously. The bones, protected by the
bone bridge and used for weight-bearing throughout their length, are preserved
from the avascular necrosis to which the distal ends of conventionally amputated
bones are ordinarily subject. Participation of the fibula in weight-bearing
leads to hypertrophy of the cortex and increase of the over-all diameter.
Finally, support of weight on the distal end leads to much greater
proprioception, with resulting greater security in walking and improved ability
to use the prosthesis easily even in poor light.
In 1923, Burrows had conceived
of stumps that were functional in much the same way and for the same reasons as
have been described in this paper, but he felt forced to abandon his idea of an
osteoplastic operation to create conditions for end-bearing because, as he said,
"it seems to be impossible to get a limb-maker to get out of his groove and make
a suitable limb for such a stump," and he had to conclude that, until more
imaginative prosthetists were found, "osteoplastic flaps must be classed as
surgical mistakes." Now we are no longer faced with this dilemma. The
patellar-tendon-bearing cuff-suspension prosthesis is easily adapted for total
contact and partial end-bearing, so that now there is no excuse for inadequate
amputation surgery. Results of clinical experience in Germany and at the
Biomechanics Laboratory of the University of California have shown
definitely the advantages to be had from the osteoplastic-myoplastic
procedure.
Acknowledgments
Fig. 1 and Fig. 2 were drawn by Mr. Thomas
Harris. I wish also to express my thanks to the director of Gehschule Hessen,
Oberre-gierungs-Medizinalrat Dr. Rost, Marburg an der Lahn; the director of the
Orthopedic Clinic in Herborn, Dr. Hanns Lerch; and Oberarzt Dr. R. Dederich, St.
Petrus Kran-kenhaus, Bonn, Germany, for their assistance in obtaining some of
the case material.
References:
- Alldredge, R. H., and E. F. Murphy, The influence of new developments on amputation surgery, Chap. 2 in Human limbs and their substitutes, P. E. Klopsteg, P. D. Wilson, et al., McGraw-Hill Book Company, Inc., New York, 1954.
- Bechtol, C. O., Amputations and artificial limbs, in Christopher's Textbook of surgery, L. Davis, ed., W. B. Saunders Co., Philadelphia, 1960.
- Bier, A., Uber Amputationen und Exartikulalionen, Sammlung klin. Vortrage, n.s., No. 264 (Chirur-gie, No. 78), January 1900. Pp. 1439-1474.
- Boldrey, E., Amputation neuroma in nerves implanted in bone, Ann. Surg., 118:1052 (1943).
- Bunge, R., Zur Technik der Erzielung tragfahiger Diaphysensti'mpfe ohne Osteoplastik, Bruns. Beitr. klin. Chir., 47:808-827 (1905).
- Burrows, H., Mistakes and accidents of surgery, Balliere, Tindall, and Cox, London, 1923. Pp. 298-299.
- Committee on Trauma, American College of Surgeons, The management of fractures and soft tissue injuries, W. B. Saunders Company, Philadelphia, 1960. Chap. 21.
- Dederich, R., Amputationsstumpfkrankheiten und ihre chirurgische Behandlung, Mschr. Unfall-heilk., 63:101 (1960).
- Derra, E., Allgemeines Uber Absetzung von Gliedmassen und uber Operationen an den Gelenken, in Chirurgische Operationslehre, Bier, Braun, and Kummell, ed., 7th ed., Barth Verlag, Leipzig, 1958. Vol. 6, Chap. 32.
- Ertl, J., Uber Amputationsstumpfe, Chirurg., 20:218 (1949).
- Kirk, N. T., and L. T. Peterson, Amputations, in Lewis' Practice of surgery, W. Walters, et al., eds., W. F. Prior Company, Inc., Hagerstown, Md., 1955.
- Lenggenhager, K., Zur Verhinderung der postoperativen Phantomschmerzen nach Amputationem, Helv. chir. Acta, 26:559 (1959).
- Loon, H. E., Biological and biomechanical principles in amputation surgery, in Prosthetics international, Proceedings of the Second International Prosthetics Course, Committee on Prostheses, Braces, and Technical Aids, International Society for the Welfare of Cripples, Copenhagen, 1960.
- McKeever, F. M., Amputations, in Operative technic in general surgery, W. H. Cole, ed., Appleton-Century-Crofts, Inc., New York, 1955.
- Marquardt, W., Gliedmassenamputationen unci Gliederersatz, Wissesckaftliche Verlagsgesellschaft, Stuttgart, 1950.
- Mondry, F., Der muskelkraftige Ober- und Unter schenkelstumpf, Chirurg., 23:517 (1952).
- Noordenbos, W., Pain. Problems pertaining to the transmission of nerve impulses which give rise to pain, Elsevier Publishing Company, Amsterdam, 1959.
- Pauwels, F., Der Schenkelhalsbruch. Ein mechanisches Problem. Grundlagen des Heilungsvor-ganges Prognose und kausale Therapie, Z. Orthop., 1935. Vol. 63, supplement.
- Slocum, Donald B., An atlas of amputations, The C. V. Mosby Company, St. Louis, 1949.
- Vasconcelos, E., Modern Methods of amputation, Philosophical Library, New York, 1945.
- Watermann, H., Amputationsprobleme, Z. Orthop., 79:93 (1949).
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