Pelvis and Acetabulum

Place the patient supine on the operating table. Because
the graft usually is taken in conjunction with other procedures, the
iliac crest should be draped as a separate unit. There is much to be
said for preparing this area routinely in all cases of open reduction
and internal fixation of long-bone fractures. Place a small sandbag
under the gluteal (cluneal) area of the side from which the graft will
be taken to elevate the crest and rotate it internally, making it more
accessible.

Muscles either take origin from or insert onto the iliac
crest, but do not cross it. Therefore, the crest offers a truly
internervous plane.

The tensor fasciae latae, gluteus minimus, and gluteus
medius are the muscles affected most directly by grafts taken from the
anterior portion of the crest, because they originate from the outer
portion of the ilium and are supplied by the superior gluteal nerve.
The abdominal muscles take their origin directly from the iliac crest
and are supplied segmentally.

Retract the skin and identify the iliac crest. Cut down onto the iliac crest with a scalpel (Fig. 7-3). In children,

the crest still may be an avascular apophysis. If so, incise it and
remove the muscle through the crest in either direction with a Cobb
elevator. No apophysis will be present in adults.

Take care not to carry the incision from the apophysis
or iliac crest onto the anterior superior iliac spine itself; if this
occurs, the origin of the inguinal ligament may be detached and an
inguinal hernia may result.

The muscles may be stripped off either the inner or the
outer wall of the ilium. Initially, cut down onto the bone using a
scalpel. Follow the contour of the bone, sticking to it rigidly (Fig. 7-4).
Below the crest itself, the ilium narrows considerably, so the sharp
dissection will need to follow the contour of the bone carefully to
avoid straying out of plane and into trouble. After coming around the
corner of the crest onto the ilium, continue the dissection using blunt
instruments such as a Cobb elevator. The muscles will come away from
the bone easily. Alternatively, push a swab into the plane between the
iliac wing and the overlying muscles. Using a blunt instrument,
introduce more and more of the swab into the plane. The swab will act
as a tissue expander, pushing the muscle away from the bone, while at
the same time protecting the soft tissues. Corticocancellous strips may
be taken from either side of the bone, or a complete block of the ilium
can be removed. Pure cancellous bone can be taken by elevating a small
piece of the cortex of the crest. Be aware that the largest supply of
cancellous bone is directly underneath the subcutaneous surface of the
crest.

Both the crest of the ilium and the anterior superior
iliac spine should be left intact to preserve the normal appearance of
the pelvis. If the anterior superior iliac

spine is taken as graft material, the inguinal ligament might retract, causing an inguinal hernia.

Place the patient prone on the operating table, with
bolsters running longitudinally to support the chest wall and pelvis,
allowing the chest wall and abdomen to expand without touching the
table. Place drapes distally enough so that the beginning of the
gluteal cleft and the posterior superior iliac spine can be seen (see Fig. 6-83).

Muscles insert into or take origin from the iliac crest,
but do not cross it. Therefore, the outer border of the iliac crest is
truly an internervous plane. The gluteus medius, minimus, and maximus
muscles take their origins from the outer surface of the ilium (the
gluteus medius and minimus are supplied by the superior gluteal nerve
and the gluteus maximus is supplied by the inferior gluteal nerve). The
segmentally supplied paraspinal muscles take their origin from the
iliac crest itself, as does the latissimus dorsi, which is supplied
proximally by the long thoracic nerve. Thus, an incision into the iliac
crest does not denervate muscles, even if it is not placed exactly on
the outer lip of the crest.

The subcutaneous tissues should be dissected until the
iliac crest is reached. In children, the iliac apophysis is white and
quite visible; it may be incised or split in line with the iliac crest,
using it as an avascular plane. In adults, the apophysis is ossified
and fused to the crest; the incision lands directly on the crest itself.

The Cobb elevator should be used to remove the apophysis
or muscles from the iliac crest both medially and laterally, to bare
the surface of the posterior portion of the crest.

Strip the musculature completely off the posterior
portion of the lateral surface of the ilium so that a large enough
graft can be obtained. Take care to stay in a subperiosteal plane while
passing from the iliac crest to the outer cortex of the ilium.
Proceeding 1.5 cm down the ilium in the area of the posterior superior
spine, the elevated posterior gluteal line can be seen and felt; pass
subperiosteally up over the line and then down its other side. Do not
err by letting the line direct the incision outward from bone into
muscle. A Taylor retractor will help the exposure by holding the
muscles laterally. Note that the posterior gluteal line separates the
origins of the gluteus maximus (posterior) from the gluteus medius
(anterior; Fig. 7-6).

Place the patient supine on the operating table.

An internervous plane is not available for use in this
approach. Because the rectus abdominis muscles receive a segmental
nerve supply, they are not denervated, even though they are divided by
this approach.

Incise the subcutaneous fat in the line of the skin
incision, deepening the incision down to the anterior portion of the
rectus sheath (Fig. 7-8). Identify, ligate, and
divide the superficial epigastric artery and vein that run up from
below across the operative field. Then, divide the rectus sheath
transversely,

about 1 cm above the symphysis pubis. The two rectus abdominal muscles now are visible (Fig 7-9).
In most cases of rupture of the symphysis pubis, one of these muscles
will have been detached from its insertion into the pubic symphysis.
Divide the remaining muscle a few millimeters above its insertion into
the bone.

Retract the cut edges of the rectus abdominal muscles superiorly to reveal the symphysis and pubic crest (Fig. 7-10).
If access to the back of the symphysis is required, use the fingers or
a swab to push the bladder gently off the back of the bone. Palpation
of the posterior surface of the body of the pubis is useful to identify
the correct direction for the insertion of screws. This dissection is
very easy to perform unless adhesions have formed due to damage to the
bladder. Such adhesions make it difficult to open up this potential
space (the preperitoneal space of Retzius) (Fig. 7-11). The pubic symphysis and superior pubic rami now are exposed adequately for internal fixation.

Place the patient in a supine position on the operating
table and put a large sandbag under the buttock. The iliac crest should
be pushed up toward the surgeon. Support the opposite iliac wing with a
support attached to the operating table and then tilt the table 20°
away, allowing the mobile contents of the pelvis to fall away.

No true internervous plane is available for use. The
approach consists simply of stripping muscles off the pelvis; because
the bone is being approached via its subcutaneous surface, no muscle is
denervated.

Deepen the skin incision through the subcutaneous fat.
Expose the deep fascia overlying the glutei and tensor fasciae latae
muscles at the point where it attaches to the outer lip of the iliac
crest. Next, incise the periosteum of the entire anterior third of the
iliac crest and gently strip the muscles off the outer wall of the
pelvis to expose about 1 cm of the outer surface below the crest of the
ilium. Predrill the iliac crest for easy reattachment. Using an
oscillating saw, transect the wing of the ilium at this level, cutting
only the outer cortex and the cancellous bone underneath (Fig. 7-13).
Next, crack the inner cortex with an osteotome. This allows the
anterior superior iliac spine to be detached along with the transected
portion of the iliac wing (Fig. 7-14).

The iliacus muscle arises from the inner wall of the
ilium; detach it by blunt dissection. As the dissection is deepened,
the detached anterior superior iliac spine, which still is attached to
the lateral end of the inguinal

ligament,
must be mobilized. This block of bone and muscle must be moved
medially; to accomplish this, divide some fibers of both the tensor
fasciae latae and sartorius muscles (Fig. 7-15).
Note that the lateral cutaneous nerve of the thigh is very close to the
anterior superior iliac spine and may have to be divided to permit this
mobilization.

Remaining strictly in a subperiosteal plane, strip the
iliacus muscle off the inner wall of the pelvis to expose the
underlying sacroiliac joint (see Fig. 7-15).
The distance is surprisingly short. As the muscle is stripped off, some
nutrient vessels will have to be detached from the inner wall of the
pelvis. Bleeding usually can be controlled by bone wax. Mobilizing the
iliacus muscle off the inside of the pelvis with a large bone block
allows the muscles to be reattached securely with screws during
closure. The muscle then resumes its anatomic position, and the dead
space beneath it is obliterated. Failure to securely reattach the iliac
crest will produce impaired function, a poor cosmetic result, possible
chronic pain, and a high risk of hematoma formation.

Place the patient prone on the operating table. Position
bolsters longitudinally to support the chest wall and pelvis; the
bolsters should allow the chest wall and abdomen to expand without
touching the table. Take great care during preparation and draping to
exclude the contaminated anal region from the operative field.

Palpate the subcutaneous posterior iliac crest, which terminates in the posterior superior iliac spine.

No internervous plane is available for use. Both the
gluteus maximus and gluteus medius muscles must be detached partially
from their origins, but their individual neurovascular pedicles are
preserved easily.

Divide the subcutaneous tissues in line with the skin
incision. Anteriorly, small cutaneous nerves (the superior cluneal
nerves) may have to be cut, but they are of little clinical
significance. Cut down into the outer border of the subcutaneous
surface of the iliac crest to reveal the layer of fascia that covers
the gluteus maximus muscle. Detach the origin of the gluteus maximus
from the crest and carefully reflect the muscle downward and laterally (Fig. 7-17).
Two vital structures penetrate this muscle from its deep surface.
First, branches from the inferior gluteal artery, which emerge from the
pelvis, with the piriformis muscle through the greater sciatic notch,
penetrate the muscle. In addition, the inferior gluteal nerve emerges
from the notch beneath the piriformis to supply the muscle. Because it
is imperative that these two structures be preserved, they limit the
inferior mobilization of the muscle. As the gluteus maximus muscle is
reflected, the gluteus medius and piriformis muscles will be uncovered
as they emerge through the greater sciatic notch.

Gently elevate the gluteus medius muscle from the outer
wing of the ilium. The muscle cannot be elevated much anteriorly
because its deep surface is tethered by its neurovascular bundle—the
superior gluteal nerves and vessels (Fig. 7-18). In cases of trauma, the ruptured sacroiliac joint or fracture is easily visible, but reduction is extremely difficult. To

evaluate any reduction, detach part of the origin of the piriformis
muscle from around the greater sciatic notch and insert a finger
through the notch to palpate the joint from its anterior surface. The
surface of the joint will feel smooth if it has been reduced (Fig. 7-19).

The approaches described in this chapter all obtain
access via a subcutaneous portion of the bony pelvis. Thereafter,
access is afforded by stripping the muscular coverings off the bone
while remaining in a strictly subperiosteal plane. Using this
technique, the approaches avoid vital structures and, therefore, are
extremely safe. More muscles must be stripped and the view becomes
poorer, however, the further one proceeds from a subcutaneous part of
the bone. For this reason, these approaches are limited in the exposure
they provide. They cannot be extended and afford only limited access to
certain portions of the bony skeleton.

Two superficial parts of the innominate bones are used
for access. The iliac crest has the external oblique and transversus
abdominis muscle arising from its surface. The wing of the ilium itself
is sandwiched between

two
masses of muscles, the glutei and tensor fasciae latae muscles on the
outer side, and the iliacus muscle on the inner side. The pubic
tubercles and upper parts of the superior pubic rami have the rectus
abdominis muscle attached to them, and these must be detached for
access to the superior surface of the structures.

In all approaches, superficial surgical dissection
consists of incising down onto the superficial portion of the bone. In
the iliac crest, this merely involves dividing the

overlying
fat. In the symphysis pubis, the rectus sheath must be opened. The
rectus sheath is a tough fibrous structure derived from all three
muscles of the anterior abdominal wall. It forms a tough anterior
covering to the underlying rectus muscle, which is easy to repair (see Fig 7-9).

Muscles can be stripped safely off both aspects of the
anterior third of the iliac crest, but only from the outer aspect of
the posterior third of the crest.

Dissection of the outer side of the ilium involves
detaching the origin of the tensor fasciae latae. Covering this muscle
is a thick layer of fascia that is continuous with the fascia covering
the gluteus maximus muscle. The tensor fascia latae, gluteus maximus
and the fascia can therefore be thought of as the outer layer of the
buttock anatomy (Fig. 7-20). This is analogous
to the position of the deltoid muscle in the shoulder. Deep to the
structures are the origins of the gluteus medius and gluteus minimus
muscles from the outer wing of the ilium. These can be lifted off the
bone entirely to provide a view of the wing of the ilium. It is
important to realize, however, that the rectus femoris muscle still
remains between the surgeon and the hip joint, thus limiting the
approach.

The inner surface of the ilium serves as origin for the
iliacus muscle. This can be lifted off the bone safely, providing
access down to the brim of the true pelvis.

The sacroiliac joint is a paradox. It is a true synovial
joint, yet any movement is very difficult to demonstrate. The joint is
reinforced heavily by anterior and posterior supporting ligaments.
Approached from the front, the sacroiliac joint is perpendicular to the
plane of dissection. Approached from the rear, the joint is overhung by
the posterior iliac crest, making it oblique to the plane of
dissection. It is critically important to appreciate this obliquity
when planning the insertion of any screws that may be used to cross the
joint.

In contrast, the pubic symphysis is not a synovial
joint, but a secondary cartilaginous joint. Its superior surface is
readily accessible once the insertion of the rectus abdominis muscle
has been detached. Behind the symphysis pubis is a potential space
filled with loose areola tissue; this is known as the cave of Retzius.
This potential space lies between the symphysis pubis and the bladder,
and allows access to the inner surface of the pubis down to the muscles
of the pelvic floor.

Place the patient supine on the operating table with the
greater trochanter at the edge of the table. This allows the buttock
muscles and gluteal fat to fall posteriorly away from the operative
plane. Insert a urinary catheter. A full bladder will obscure vision.

There is no true internervous plane. The dissection
consists essentially of lifting off muscular, nervous, and vascular
structures from the inner wall of the pelvis.

Dissect down through the subcutaneous fat to expose the aponeuroses of the external oblique muscle (Fig. 7-23).
The lateral cutaneous nerve of the thigh will appear in the lateral
edge of the dissection. In most cases, the nerve will need to be
divided. Divide the aponeurosis of the external oblique muscle in the
line of its fibers from the superficial inguinal ring to the anterior
superior iliac spine (Fig. 7-24). This will
expose the spermatic cord in the male and the round ligament in the
female. Carefully isolate these structures in a sling (Fig. 7-25).
Continue the dissection medially, dividing the anterior part of the
rectus sheath to expose the underlying rectus abdominis muscle. Strip
the iliacus muscle from the inside of the wing of the ilium. Initially,
you will need to use sharp dissection, but once inside the pelvis, use
blunt dissection.

Divide the rectus abdominal muscle transversely 1 cm
proximal to its insertion into the symphysis pubis. Using blunt
dissection, develop a plane between the back of the symphysis pubis and
the bladder. This space (the Cave of Retzius) is easily developed with
a finger.

Cut through those fibers of the internal oblique and
transversus abdominus muscles that form the posterior wall of the
inguinal canal (Fig. 7-26). Take care when approaching the deep inguinal ring; the inferior epigastric artery and vein cross the posterior

wall of the canal at the medial edge of the deep inguinal ring and must
be ligated at that point. Inadvertent division of these structures
results in profuse hemorrhage that is difficult to control. Now divide
those fibers of the transversus abdominus and internal oblique muscles
that arise from the lateral half of the inguinal ligament (Fig. 7-27).

The peritoneum covered with extraperitoneal fat is now
exposed. Using a swab, push the peritoneum upward to reveal the femoral
vessels, the femoral nerve, and the tendon of iliopsoas (Fig 7-28).
Isolate the femoral vessels together in the femoral sheath and protect
them with a sling. Pass a second sling around the tendon of iliopsoas
with the femoral nerve lying on top of it (Fig. 7-29).
Retract these structures either medially or laterally to gain access to
the underlying medial surface of the acetabulum and superior pubic
ramus (Fig. 7-30).

Three windows are created. The lateral window, lateral
to the iliopsoas gives access to the inner surface of the ilium. The
middle window, medial to the iliopsoas but lateral to the femoral
artery and vein gives access to the quadrilateral plate. The medial
window, medial to the femoral artery and vein gives assess to the
superior pubic ramus and symphysis. For best visualization of the
medial window, the surgeon should move to stand on the opposite side of
the patient. Tilting the operating table also improves visualization of
the medial window.

The spermatic cord contains
the vas deferens and testicular artery. Although it is easily
mobilized, it must be treated gently during the approach and the
closure to avoid ischemic damage to the testicle.

The bladder is easily
mobilized off the back of the symphysis pubis. Be aware that fractures
of the lower half of the anterior column, especially displaced fracture
of the superior pubic rami, may have caused bladder damage and
adhesions.

The applied anatomy of this approach is conveniently divided into two parts.

The dissection consists of the division of the fascia of the external oblique muscle and anterior rectus sheath. The external oblique,
which is the outer layer of the abdominal muscles, arises from the
lower eight ribs. It inserts as fleshy fibers into the anterior half of
the iliac crest. However, from the anterior superior iliac spine, it
becomes aponeurotic. The aponeurosis attaches to the pubic tubercle and
medially becomes fused with the aponeurosis of the opposite external
oblique muscle to form the anterior part of the rectus sheath.
Therefore, the splitting of the fibers of the external oblique muscle
and the incision of the anterior rectus sheath are both in the same
plane. There is a free lower border of this muscle between the anterior
superior iliac spine and the pubic tubercle. This free edge is called
the inguinal ligament. The aponeurosis curls back on itself to form a
gutter, and the free edge of this gutter is the origin of part of the
internal oblique and transversus abdominis muscles.

Just above the pubic tubercle, there is a gap in this aponeurosis to allow the passage of the spermatic cord in the male and the round ligament in the female. This gap is known as the superficial inguinal ring (Fig. 7-31).
Dividing the fascia of the external oblique opens up the inguinal
canal, which is an oblique intramuscular slit running from the deep to
the superficial inguinal rings. These contain the spermatic cord in the
male and the round ligament in the female (Fig. 7-32).

The rectus abdominis muscle is enclosed in a sheath of
fascia. In the region of this approach, however, the posterior layer of
fascia is inferiorly deficient. The anterior rectus sheath also
receives some tissue from both the internal oblique and transversus
abdominis muscles.

The spermatic cord consists of the vas deferens
accompanied by its artery and the testicular artery and vein. As these
structures emerge through the abdominal wall, they get coverings from
each layer they pass through (Fig. 7-33). The
transversalis fascia covers the cord with a thin layer of tissue known
as the internal spermatic fascia. Passing through the transversus
abdominis and internal oblique, the cord gets covered with a layer of
muscle known as the cremasteric muscle. As it passes through the
external oblique at the superficial inguinal ring, it is covered by a
thin layer known as the external spermatic fascia. The round ligament
in the female is also covered by these three fascial layers. Both the
spermatic cord and round ligament can be mobilized easily in the
inguinal canal during the superficial surgical dissection.

Once the spermatic cord has been mobilized, the
posterior wall of the inguinal canal is seen. In the lateral half of
the inguinal canal, the rolled free edge of the external oblique
aponeurosis gives origin to muscle fibers from both the internal
oblique and the transversus abdominis. These muscle fibers arch up over
the spermatic cord and fuse to form a conjoint tendon that is attached
posterior to the spermatic cord into the pubic crest. Therefore, in the
medial half of the inguinal canal, its posterior wall consists of this
conjoint tendon, which needs to be divided for access to the underlying
structures. The spermatic cord exits from the abdominal cavity through
the deep inguinal ring to enter the inguinal canal. Lateral to the deep
inguinal ring, fibers of the internal oblique and transversus abdominis
arise from the inguinal ligament and also have to be divided (see Fig. 7-33). Medial to the deep inguinal ring lies the inferior epigastric artery,
which usually requires ligation. Deep to these muscles lies the thin
transversalis fascia, extraperitoneal fat, and finally the peritoneum (Fig. 7-35).

The dissection completely disrupts the anatomy of the
inguinal canal. Careful repair of all these structures on a
layer-by-layer basis is important to prevent the development of an
inguinal hernia.

Passing under the inguinal ligament from the abdomen into the thigh are the femoral nerve, the femoral artery, and the femoral vein, as well as the psoas and iliacus muscles (Fig. 7-34). The iliacus arises from the hollow of the iliac fossa, and runs into the thigh underneath the lateral part of the inguinal ligament. The psoas muscle
arises from the anterior aspect of the lumbar spine and passes into the
thigh below the middle of the inguinal ligament. Between these two
muscles, the femoral nerve runs down into the thigh. It is intimately
related to the iliopsoas and is mobilized with the muscle to avoid
excessive retraction. Medial to the nerve, the femoral artery and vein
enter the thigh. As these vessels leave the abdomen, they take with
them a fascial layer derived from the extraperitoneal fascia. This is
known as the femoral sheath. In addition to the artery and vein, the
femoral sheath has a space in it, medial to the vein, known as the
femoral canal. This is used for the passage of lymphatic vessels and
also allows the vein to expand at times when the blood return from the
leg becomes increased.

It is also, however, the site of a femoral hernia.
Because the femoral artery and vein are enclosed in a common fascial
sheath, they should be mobilized together. Separate mobilization of the
femoral vein will traumatize it, leading to possible thrombosis.

The bladder is separated
from the pubic bones by a space known as the Cave of Retzius. It is
occupied by very thin tissue, the bladder, and, in the case of the
male, the prostate. The prostate can be easily mobilized from the back
of the pubis. However, in cases of fracture, there may be pathologic
adhesions in this area, and great care should be taken not to
accidentally produce a bladder rupture. A full bladder will make safe
access to this area impossible, and a urinary catheter inserted
preoperatively is vital (Fig 7-36).

Two positions are possible. If the approach is to be
used for fractures of the posterior lip and/or posterior column, place
the patient in the lateral position.

Alternatively, if the approach is to be used for transverse fractures, place the patient in the prone position (Fig. 7-38).
If traction is to be used, place a skeletal pin transversely through
the lower end of the femur with the knee flexed to reduce the risk of a
traction injury to the sciatic nerve.

With the patient in the lateral position, there is a
natural tendency for the femoral head to move medially in cases of
transverse acetabular fracture. Operating in the lateral position,
therefore, makes reduction of these fractures more difficult. Reduction
of the fracture in this position can only be obtained by an assistant
lifting the femoral head out of the acetabulum. The use of the prone
position facilitates reduction of transverse fractures.

There is no true internervous plane in this approach.
However, the gluteus maximus that is split in the line of its fibers is
not significantly denervated because it receives its nerve supply well
proximal to the split.

Deepen the incision through subcutaneous fat. Incise the
fascia lata in the line of the skin incision in the lower half of the
wound, and extend this incision superiorly along the anterior border of
the gluteus maximus muscles (Fig. 7-40). Retract the split edges of the fascia to reveal the piriformis muscle and the short external rotators of the hip (Fig. 7-41). Partial detachment of the insertion of gluteus maximus from the femur will facilitate mobilization of this muscle.

Internally rotate the leg to put the short external
rotators and the piriformis on the stretch and detach these muscles as
they insert into the femur (Fig. 7-42). Using
the short external rotator muscles as a cushion, carefully insert a
retractor into the greater sciatic notch. Do not apply great pressure
on this retractor as this will create a sciatic nerve palsy. Insert a
second retractor into the lesser sciatic notch to expose the posterior
column in its whole extent.

The posterior capsule of the hip is revealed. This is
often torn or detached in cases of trauma. If the posterior capsule is
intact and a direct inspection of the joint is required, make a
T-shaped capsulotomy. Ensure that you avoid damage to the limbus when
incising the capsule.

The inner surface of the acetabulum can only be viewed
by distracting the femoral head. This can either be achieved by
skeletal traction or with the help of a Schanz screw placed in the
femoral head.

Posterior lip fractures of the acetabulum can be
adequately visualized and fixed at this stage. If you require more
extensive exposure of the posterior column, perform an osteotomy of the
greater trochanter. Divide the greater trochanter from posterior to
anterior, removing a piece of bone 5 mm in size. This bone will have
the gluteal muscles attached to it superiorly and the vastus lateralis
attached to it inferiorly. Progressively evert the trochanter with its
attached muscles over the anterior surface of the femur using a sharp
retractor. The small remaining attachment of

gluteus
medius to the intertrochanteric ridge will now need to be released. If
difficulty is encountered mobilizing the fragment, the insertion of
piriformis may sometimes need to be partially released.

If you require access to the anterior surface of the hip
joint capsule, flex and externally rotate the hip. Mobilize the
insertion of gluteus minimus from the retroacetabular surface along the
superior capsule to its femoral insertion along the anterior aspect of
the trochanter (Fig. 7-43). If further exposure
of the anterior capsule is required, mobilize the proximal portion of
the vastus intermedius from the femur to allow access to the anterior
hip joint capsule (Fig. 7-44). This
trochanteric fragment can be reattached easily with screws during
closure. Note that trochanteric osteotomies are associated with
heterotopic bone formation in acetabular surgery.