Anterior Iliac Crest
Jameel kifayatullah

Indications
• When autogenous grafting is desired that
requires a high ratio of cancellous to cortical
bone (a high volume of osteocompetent cells)
• Hard tissue maxillofacial defects requiring 50
mL or less of cancellous bone

Contraindications
• Reconstruction of maxillofacial defects
requiring more than 50 mL of cancellous bone
• Patients with previous head and neck
radiation involving the graft recipient site

Anatomy
• Anterior ilium: Located
between the anterior
iliac spine and the ilium
tubercle. The ilium
serves as a site for
numerous muscular
attachments
responsible for normal
gait and core stability.

Anatomy
• Anterior superior iliac
spine: Serves as the
attachment of the
external abdominal
oblique muscle medially
and the tensor fascia
lata laterally

Anatomy
• Tensor fascia lata: Originates
at the anterior superior iliac
spine and the antero‐lateral
portion of the anterior iliac
crest, and inserts into the
iliotibial tract of the lateral
thigh. The iliotibial tract (band)
continues inferiorly and inserts
along the lateral condyle of
the tibia. Damage or excessive
retraction of this muscle is the
most common cause of
postoperative gait
disturbances.

Anatomy
• Iliacus muscle:
Originates along the
superior half of the iliac
fossa (medial iliac
crest). The iliacus
muscle joins the psoas
major muscle and
inserts along the lesser
tro-chanter of the
femur

Anatomy
• Sensory cutaneous nerves (3):
• Iliohypogastric nerve (L1, L2):
The lateral cutaneous branch
of the iliohypogastric nerve is
located overlying the ilium
tubercle and is the most
commonly injured nerve
during an anterior iliac crest
bone graft (AICBG). The
iliohypogastric nerve provides
sensory innervation to the skin
of the pubis and lateral aspect
of the buttock.

Anatomy
• Lateral branch of the
subcostal nerve (T12,
L1): Located overlying
the anterior superior
iliac spine. The
subcostal nerve is
located medial to the
iliohypogastric nerve
and provides sensory
innervation to the
lateral buttock.

Anatomy
• Lateral femoral cutaneous
nerve: Located between the
psoas major and the iliacus
muscle, medial to the
subcostal nerve. In 2.5% of the
population, the lateral femoral
cutaneous nerve can be found
within 1 cm of the anterior
superior iliac spine. The lateral
femoral cutaneous nerve
provides sensory innervation
to the skin of the anterior and
lateral thigh. Damage to this
nerve may result in a meralgia
paresthetica.

Anterior Iliac Crest Bone Graft (AICBG)
Harvesting Technique (Medial Approach
• Preoperative intravenous
antibiotics are admin-
istered. The patient is
intubated and positioned
supine on the operating
room table. A hip roll is
placed under the pelvis to
accentuate the anterior iliac
crest anatomy. Surgical
markings are made to
include the locations of the
anterior superior iliac spine,
the ilium tubercle, and the
anterior iliac crest

Anterior Iliac Crest Bone Graft (AICBG)
Harvesting Technique (Medial Approach
• After palpation of the
anterior superior iliac
spine and the ileum
tubercle, the anterior iliac
crest is palpated and
drawn. The inferior-
lateral marking
represents the location of
the proposed skin incision
(inferior and lateral to the
anterior iliac crest) to
minimize postoperative
pain along the beltline

Anterior Iliac Crest Bone Graft (AICBG)
Harvesting Technique (Medial Approach
• A hand is used to place medial
(toward the abdomen)
pressure, and the anticipated
incision line is marked 2–4 cm
lateral to the height of the
anterior iliac crest . Incisions
placed directly overlying the
anterior ilium will cause
postoperative pain along the
beltline. Local anesthetic
containing a vasoconstrictor is
injected within the area of the
proposed skin incision within
the subcutaneous tissue.

Anterior Iliac Crest Bone Graft (AICBG)
Harvesting Technique (Medial Approach)
• The patient is prepped and draped in a sterile
fashion

Anterior Iliac Crest Bone Graft (AICBG)
Harvesting Technique (Medial Approach
• A 4–6 cm skin incision is
made with a #10 blade
1 cm posterior to the
anterior superior iliac
spine and terminating
1–2 cm anterior to the
ilium tubercle

Anterior Iliac Crest Bone Graft (AICBG)
Harvesting Technique (Medial Approach
• The dissection proceeds
through the
subcutaneous tissue
until Scarpa’s fascia is
reached. A 4 × 4 sterile
gauze is used to bluntly
dissect Scarpa’s fascia
Scarpa’s fascia is identified.

Scarpas fascia
• The fascia of Scarpa is the deep membranous
layer (stratum membranosum), of
the superficial fascia of the abdomen. It is
a layer of the anterior abdominal wall. It is
found deep to the Fascia of
Camper and superficial to the external oblique
muscle.

Anterior Iliac Crest Bone Graft (AICBG)
Harvesting Technique (Medial Approach
• A #15 blade is used to transect Scarpa’s fascia. A
hypovascular tissue plane is identified overlying the
anterior iliac crest between the insertions of the ten-
sor fascia lata laterally and the external and trans-
verse abdominal muscles medially. Elevating within this
hypovascular tissue plane will minimize bleeding and
postoperative pain or gait disturbances. The
periosteum is released, and dissection proceeds within
a subperiosteal tissue plane over the medial (inner)
iliac cortical plate. The iliacus muscle is identified and
reflected to expose the medial iliac crest (iliac fossa).

Anterior Iliac Crest Bone Graft (AICBG)
Harvesting Technique (Medial Approach)
• A blunt retractor (i.e., a Bennett retractor) is
placed to retract the musculoperiosteal layer
and to protect the intra‐abdominal contents
during the medial approach to the anterior
ileum.

Anterior Iliac Crest Bone Graft (AICBG)
Harvesting Technique (Medial Approach)
• Osteotomies are made utilizing combinations
of saws, burs, and chisels based on the type of
graft required (corticocancellous block or
cancellous graft) and the size of the defect
requiring reconstruction. Regard- less of the
osteotomy design, it is imperative to pre-
serve the attachments to the anterior superior
iliac spine and to maintain a minimum safe
distance of 1 cm from the anterior superior
iliac spine and 1–2 cm from the ilium tubercle.

Anterior Iliac Crest Bone Graft (AICBG)
Harvesting Technique (Medial Approach)
• For standard medial
(inner) AICBG harvest,
the author marks the
proposed osteotomy
site with either a sterile
marking pen or
electrocautery

Anterior Iliac Crest Bone Graft (AICBG)
Harvesting Technique (Medial Approach)
• A subperiosteal dissection
is performed to expose
the medial (inner) cortical
plate of the anterior
ilium. Electrocautery is
used to outline the
osteotomy design and to
maintain a minimum safe
distance of 1 cm from the
anterior superior iliac
spine and 1–2 cm from
the ilium tubercle.

Anterior Iliac Crest Bone Graft (AICBG)
Harvesting Technique (Medial Approach)
• A reciprocating saw
with copious irrigation
is used to outline the
osteotomy along the
medial aspect of the
anterior iliac crest

Anterior Iliac Crest Bone Graft (AICBG)
Harvesting Technique (Medial Approach)
• If only cancellous bone is required, the medial
cortical plate is outfractured with a chisel,
marrow is removed with curettes and bone
gouges, and the medial plate is repositioned
(clamshell technique)

Anterior Iliac Crest Bone Graft (AICBG)
Harvesting Technique (Medial Approach
• If a corticocancellous
block graft is required,
the inferior aspect of the
medial cortical plate (just
superior to the fusion of
the inner and outer iliac
plates) is scored with
either a reciprocating or a
sagittal saw, and a sharp
chisel is used to
outfracture the medial
plate
A sharp, broad osteotome is used
to carefully initiate the osteotomy
.

Anterior Iliac Crest Bone Graft (AICBG)
Harvesting Technique (Medial Approach)
• The chisel is directed
against the outer (lateral)
cortical plate to maximize
the amount of cancellous
bone attached to the
inner (medial) cortical
bone
• Additional marrow is
removed with curettes
and bone gouges to
increase the amount of
graft material and to
minimize marrow oozing. The osteotome is used to separate
the corticocancellous block graft from
the outer (lateral) cortical plate.

Anterior Iliac Crest Bone Graft (AICBG)
Harvesting Technique (Medial Approach)
• The corticancellous
block graft is removed,
and the remaining
marrow is curetted.

Anterior Iliac Crest Bone Graft (AICBG)
Harvesting Technique (Medial Approach)
• After the harvest is completed, the wound site is
irri- gated copiously and inspected for
hemostasis. Marrow bleeding is minimized with
the removal of all bone marrow from the harvest
site and with the placement of hemostatic agents
(i.e., microfibrillar collagen, gel- foam, bone wax,
and topical thrombin). If minor to moderate
marrow oozing is present that is refractory to
marrow removal and hemostatic agents, a drain
may be placed within the bony defect, placed to
low suction, and monitored closely
postoperatively.

Anterior Iliac Crest Bone Graft (AICBG)
Harvesting Technique (Medial Approach)
• Meticulous layered
closure is required to
minimize postoperative
hematoma and seroma
formation

Harvested 4 cm corticocancellous block graft.

Postoperative Management
• Nonsteroidal anti‐inflammatory drugs and narcotics are utilized
postoperatively. A pain‐controlled anal- gesia pump (PCA) may be
required in the immediate postoperative period.
• Drains are typically removed when they become non- productive
for a 24‐hour period.
• Antibiotics are recommended for 5–7 days.
• Ambulation is initiated within 24 hours postoperatively. Ambulation
should be closely monitored with the assistance of a physical
therapist and nursing sup- port prior to discharge from the hospital.
Ambulation aids (cane and walker) may be required for short peri-
ods of time postoperatively.
• Moderate- to high‐impact physical activity is restricted for a period
of 6 weeks.

Complications
Early Complications
• Pain and gait disturbances: Minimized with preservation of the muscular
attachments to the anterior superior iliac spine (tensor fascia lata and
external abdominal oblique) and the lateral iliac crest (tensor fascia lata
and gluteus medius).
• Nerve injury: Involved areas are dependent on the specific nerve(s)
injured (i.e., iliohypogastric, subcostal, and lateral femoral cutaneous).
• Hematoma formation: Minimized with meticulous dissection, hemostasis
prior to wound closure, and the use of local hemostatic agents and drains
when applicable.
• Infection: Infections rates from AICBG harvests coincide with infection
rates from similar orthopedic procedures (1–3%). Appropriate
preoperative anti- biotic administration, proper site preparation, main-
tenance of a sterile field, and meticulous wound closure will minimize
infection occurrences. Infection management is aimed toward incision and
drainage procedures, with antibiotic coverage based on culture and
sensitivity results.

Complications
• Cosmetic deformity: Avoided by taking split‐thick- ness grafts (avoiding
harvesting of both the medial and lateral cortical plates) and maintaining
an intact supero‐lateral rim of the anterior iliac crest.
• Peritoneal perforation: Minimized by maintain- ing an intact
musculoperiosteal layer during medial reflection, using blunt abdominal
retractors (i.e., a Bennett retractor), avoiding excessive retraction, and
judiciously using periosteal elevators and electrocau- tery during initial
dissection of the medial crest (iliac fossa).
• Fracture: Minimized by maintaining a minimum safe distance of 1 cm from
the anterior superior iliac spine and 1–2 cm from the ilium tubercle, and
by avoidance of moderate- to high‐impact activity for 6 weeks
postoperatively. Treatment typically consists of bed rest followed by
activity restriction and assisted ambulation.
• Meralgia paresthetica: Numbness and/or pain to the outer thigh caused
by injury to the lateral femoral cutaneous nerve.

AICBG
• When evaluating a maxillofacial defect prior to definitive
reconstruction, typically 10 mL of uncompressed bone is required
to reconstruct a 1 cm bony defect. For mandibular continuity
defects where a reconstruction plate will be placed or has already
been placed, each screw hole span is roughly 1 cm. A mandibular
continuity defect with a four–screw hole span would require a
minimum of 40 mL of uncompressed marrow to appropriately
reconstruct the defect.
• AICBGs are ideal for segmental and marginal defects in which less
than 50 mL of bone are required.
• For continuity defects spanning greater than 5 cm and for patients
who have undergone previous head and neck radiation therapy,
microvascular reconstruction is recommended.

AICBG
• The size of the graft harvested or the
osteotomy design is based on the defect size.
The maximum size of the graft is limited
anteriorly‐posteriorly by maintaining a
minimum safe distance of 1 cm from the
anterior superior iliac spine and 1–2 cm from
the ilium tubercle. The maximum vertical
height is traditionally 4–5 cm and coincides
with the fusion of the medial and lateral cor-
tical plates.