Operative Technique in Plastic Surgery – Kevin C.Chung

SURGICAL MANAGEMENT
Preoperative Planning
■ Evaluation by the primary care physician or pediatrician and requisite
specialists (such as pulmonologists, neurosurgeons) should be completed prior
to the procedure.
■ Anesthesia should evaluate the patient preoperatively; airway concerns should
be discussed with the surgeon, given that the airway might be challenging
postoperatively.
■ Type and cross +/− familial blood donation should all be done prior to the day
of surgery.
■ Several units of blood should be available at the time of incision.
Positioning
■ Position the patient supine on the operating room table with the arms tucked in
a padded, anatomically favorable position.
■ The head should be placed on a hydraulic donut.
■ A Foley catheter should be inserted.
■ A warming blanket should be placed either under or over the patient’s body.
■ All wires and monitoring devices should be padded to ensure there are no
pressure points on the body during a prolonged case.
■ Secure the endotracheal tube with wire fixation to the dentition for easy
maneuvering of the head without concern of extubation.
Approach
■ Coronal and intraoral upper buccal sulcus incisions are used to access the
osteotomy sites.

FIG 3 • These results show Dr. Tessier’s ability to treat a
2-year-old child with a traditional monobloc facial
advancement and wire-only fixation for the
osteosynthesis. A, C. Preoperatively, the patient has
forehead retrusion, proptosis, and midface deficiency.
B,D. Postoperatively, the degree of advancement of the
alveolus and forehead is harmonious. (From Wolfe SA.
A Man from Héríc: The Life and Work of Paul Tessier,
MD, Father of Craniofacial Surgery. Miami, FL: Lulu
Press; 2011, with permission.)

FIG 4 • This patient underwent a monobloc facial
advancement by Dr. Tessier around age 6.
Postoperative pictures demonstrate normal facial
features with a normal nasofrontal relationship. (From
Wolfe SA. A Man from Héríc: The Life and Work of Paul
Tessier, MD, Father of Craniofacial Surgery. Miami, FL:
Lulu Press; 2011, with permission.)
T E C H N I Q U E S
■ Monobloc Using an Expansile Bandeau

Preparation and Exposure
■ A metal-reinforced endotracheal tube is placed orally and fixated using
circum-mandibular wires.
■ If a tracheostomy is present, the tube is sutured to the chest wall to prevent
dislodgement.
■ The nose is packed with Neo-Synephrine-soaked pledgets.
■ The coronal incision is marked; several mm both above and below the
incision is shaved free of hair.
■ Hair surrounding the incisions is braided and secured with ties.
■ A sterile head wrap is placed and towels are stapled just below the incision
to prevent occipital hair from entering the surgical field.
■ The scalp is infiltrated with a dilute adrenaline solution (1:250 000).
■ With the patient asleep, the eyelids are retracted with cotton tip applicators
well beyond the equator of the globe—referred to as the “Tessier sign”
(TECH FIG 1).
■ The coronal incision is made with a knife; dissection continues to the plane
between galea and pericranium anteriorly to the supraorbital ridges where the
dissection becomes subperiosteal.
■ Subperiosteal dissection of the upper orbital cavities, the lateral orbital wall
and the anterior zygoma is performed through the coronal incision. Orbital
floor dissection is extended to the infraorbital nerve.
■ While dissecting through the fat layer to the superficial temporal
aponeurosis, one should avoid injuring the frontal branch of the facial nerve.
■ The temporalis muscle is dissected from the temporal fossa, including
posteriorly.
■ A limited oral dissection is performed with incisions over the maxillary
molar teeth.
Osteotomies and Advancement
■ Markings are then made for the osteotomies:
■ A methylene blue–impregnated 0 silk is used to provide a straight line
about 12 mm above the supraorbital rim.
■ Bur holes are marked above this transverse line and then on either side of
the midline posteriorly.
■ The neurosurgery team performs a frontal craniotomy with a dissection of
the anterior cranial base inferiorly to the crista galli with visualization and

preservation of the most anterior olfactory fibers. The dissection is extended
beneath the sphenoid ridge into the temporal fossa (TECH FIG 2A).
TECH FIG 1 • Normal eyelids cannot be retracted
behind the globe. This retraction is referred to as the
Tessier sign.
■ The osteotomy through the zygomatic arch is made with a reciprocating saw:
through the arch from the temporal fossa to the orbit, flush with the cranial
base, and then inferiorly to the inferior orbital fissure and superiorly across
the orbital roof with the neurosurgery team directly observing the osteotomy
through the intracranial route (TECH FIG 2B,C).
■ Provide adequate irrigation to prevent burning the bone from the thermal
energy of the saw.
■ Pterygomaxillary disjunction is then performed with a curved Tessier
osteotome.
■ An osteotomy is made through the crista galli and then a double-guarded
osteotome is placed through the cranial approach into this cut and aimed at
the operator’s finger placed at the posterior nasal spine.
■ The Rowe forceps are then inserted and the midface down fractured and
mobilized extensively (TECH FIG 2D).
■ The distraction forceps are placed behind the maxillary tuberosity through
the coronal approach and then through the oral approach to provide further
mobilization of the midface.

■ The midface is freed to the point that it can be advanced into a class 2
occlusion.
■ Nasopharyngeal tubes are passed under direct vision and palpated in the
pharynx.
Grafting and Fixation
■ With the midface separated from the anterior cranial base, a 6 × 6 cm
pericranial patch is taken from the posterior parietal area and sutured over the
anterior cranial base in a watertight fashion (TECH FIG 3B).
■ Bone grafts from the skull can be placed over the cranial base defect to fill in
the area of advancement (TECH FIG 3C).
■ A 2.0-mm miniplate is fixed to the lateral orbital rim; a second plate is fixed
to the cranium posteriorly and to the lateral rim medially (see videos).
■ A gap is present at the zygomatic arch, which is roughly similar to the orbital
distance. Another plate is placed across this zygomatic arch defect.
■ Bone grafts are harvested from the inner table of the cranial flap and placed
at the lateral orbital rim defects and within the zygomatic arch (TECH FIG
3D).
■ The temporalis muscle is replaced and fixed with appropriate tension to the
lateral orbital wall and posteriorly.
■ Bilateral passive temporal no. 10 round catheters are placed but without
suction.
■ A lateral canthopexy is performed through the coronal approach grasping the
tendon 6 or 7 mm lateral to the commissure and fixing it to the stabilized
temporal fascia.
■ The remaining portion of the temporal aponeurosis that was previously
divided is now resuspended.
■ The coronal incision is closed with bilateral passive drains, and the short oral
incision is closed with a single chromic or Vicryl suture.
■ The nasopharyngeal tubes are left in place and remain postoperatively for 5
to 6 days.

TECH FIG 2 • A. The method of monobloc frontofacial
advancement without distraction that we have used
over the years is modified from Henry Kawamoto’s
simplification of the Tessier/Ortiz Monasterio

procedure. The osteotomy is passed through the
cranial base to the posterior nasal spine and is
important in completely dividing the septum and
ethmoid. Dr. Tessier’s technique for monobloc used an
expansile bandeau showing osteotomies (B and C)
and monobloc advancement (D). (B, illustration by
Evy Dyer; C from Wolfe SA. A Man from Héríc: The
Life and Work of Paul Tessier, MD, Father of
Craniofacial Surgery. Miami, FL: Lulu Press; 2011,
with permission.)
TECH FIG 3 • A. Intraoperative photo demonstrates
the precision of the bone work in a monobloc
advancement. B. The pericranial patch (not flap) is

key in preventing CSF leaks. C,D. Note the use of
bone grafts after advancement as needed. (A, from
Wolfe SA. A Man from Héríc: The Life and Work of
Paul Tessier, MD, Father of Craniofacial Surgery.
Miami, FL: Lulu Press, 2011; B, C, and D, illustrations
by Evy Dyer, with permission.)
■ Modifications for Monobloc Frontofacial
Advancement With a Facial Bipartition
■ The frontal bandeau is maintained during the mobilization of the midface.
■ A dissection of the palate is performed through two lateral palatal incisions
dissecting across the midline to prevent an iatrogenic cleft palate.
■ A careful intradental osteotomy is performed with a fine saw between the
central maxillary incisors.
■ Removal of a V-shaped segment of the interorbital naso-orbital-ethmoid
maxillary bone is performed with overcorrection of the hypertelorbitism.
■ Before removing the flat original frontal orbital bandeau, a new
appropriately curved bandeau is harvested from the posterior parietal and
occipital area (TECH FIG 4).
■ This new bandeau is fixed in an appropriate position above the native flat
frontal bandeau with 3.0 mm titanium screws.
■ After fixation, the underlying original bandeau is removed.
■ The previously mobilized orbital segments with the inner orbital bone
appropriately removed are moved medially and fixed to the new fronto-
orbital bandeau after trimming the supralateral portion of the orbital facial
segment for appropriate fit.
■ Wire is used for fixation to allow the vector to appropriately mobilize the
facial segment into the desired position.
■ Expansion of the dental arch may be noted, creating an appropriate diastema.
If this is not desired, a wire loop is placed around the cuspids to prevent
maxillary expansion during the correction of the hypertelorbitism.
■ A lateral canthopexy is performed as described previously, and wound
closure with passive drains is completed as in the monobloc advancement.

TECH FIG 4 • Monobloc frontofacial advancement (A)
with facial bipartition (B) and fabrication of properly
curved bandeau (C) from the posterior cranial vault.
This procedure allows concomitant advancement of
the face and forehead with hypertelorism correction.
(Illustrations by Erin Wolfe and reproduced with
permission.)
PEARLS AND PITFALLS

Physical
findings
■ A close relationship with neurosurgical colleagues is helpful when
performing these procedures.
■ Monobloc advancement for relatively mild to moderate Crouzon
with no other complicating factors can safely be done without
distraction and with a better result.
Technique
■ Following separation of the face from the cranial base, cover the
cranial base with periosteum, and fill the space with bone grafts.
■ Always use bone grafts to stabilize the advanced monobloc
segments.
■ Monobloc advancement should be limited to 10 mm.
■ Provide adequate irrigation to prevent burning the bone from the
thermal energy of the saw.
Postoperative
■ Extubation should not be rushed.
■ Steroids may be used to diminish facial swelling.
POSTOPERATIVE CARE
■ If the patient does not have a tracheostomy, the anesthetic team should be
made aware that access to the airway may be limited.
■ Extubation should not be rushed; the plan is to keep the patient intubated
overnight and even a 2nd or 3rd day if there is persistent nasal bleeding.
■ Nasopharyngeal tubes are removed on postoperative day 4 or 5 when airway
swelling has decreased.
■ Postoperative steroids may be used to diminish facial swelling.
■ Monitoring for 3 to 4 days in the intensive care unit is required.
■ We recommend cefazolin and clindamycin for 1 week following monobloc
advancement.
OUTCOMES
■ Monobloc advancement can be stable postoperatively (FIGS 5 and 6).
■ Stability is maintained with appropriate bone grafting to all advanced
segments.
■ Respect the upper limit of advancement of 1 cm.
■ Monobloc distraction is utilized for movements of greater than 1 cm.
■ Concerns persist for infection following advancement.1–4
■ Separating the cranial base from the sinus spaces with periosteum decreases
infection.

■ Monobloc distraction has also decreased rates of infection.4
COMPLICATIONS
■ Tessier operated on 6 adult patients with Crouzon disease using the “BO-Fort”
procedure. Two patients developed retrofrontal fluid collections, epidural
abscesses, and loss of the frontal bone, which led to abandoning the procedure.
■ In 7 monobloc patients, Monasterio et al. reported one frontal bone loss; all 7
patients experienced transient CSF leakage, but no persistent CSF fistulas.1
■ Kawamoto et al. reported the first monobloc advancement in the United States
and acknowledged a high percentage of CSF leaks, frontal bone loss, and
meningitis.3
■ Our monobloc experience with 93 patients demonstrated a similar spectrum of
complications.2
■ Kawamoto et al. presented monobloc distraction, introducing a 5-day latency
with no CSF leaks.3
■ Arnaud et al. presented 36 cases of monobloc distraction with significantly
decreased complication rates.4
■ Development of lateral canthal downward tilt, which may require correction
(FIG 7)

FIG 5 • A1-A3. Frontal view of one of Dr. Tessier’s
patients operated on in the mid-1960s is shown with
early and 20-year postoperative results, demonstrating
the long-term stability of the procedure. B1-B3. Profile
views of the patient. A4 demonstrates a preoperative
lateral cephalogram; B4 demonstrates a 20-year follow-
up cephalogram. (From Wolfe SA. A Man from Héríc:
The Life and Work of Paul Tessier, MD, Father of
Craniofacial Surgery. Miami, FL: Lulu Press; 2011, with
permission.)
FIG 6 • This patient has Crouzon syndrome as well as a
cleft lip repaired by Ralph Millard. He is shown

preoperatively (A) and after monobloc advancement at
ages 6 (B) and 10 (C). By age 15 (D), he had evident
maxillary retrusion, which was treated with a Le Fort 1
advancement (E). The lateral canthi have maintained
their proper position. F. The patient’s final occlusion
after Le Fort 1 maxillary advancement. (Photographs by
Jorge Insua.)
FIG 7 • A. Preoperative view of a patient with Apert’s
syndrome. B. In this postoperative result after monobloc
advancement and facial bipartition, note the downward
displacement of the lateral canthi. (Photographs by
Jorge Insua.)
ACKNOWLEDGMENTS
We would like to acknowledge Erin M. Wolfe, BS, in preparing this chapter.
REFERENCES
1. Monasterio FO, Del Campo AF, Carrillo A. Advancement of the orbits and the
midface in one piece, combined with frontal repositioning, for the correction of
Crouzon’s deformities. Plast Reconstr Surg. 1978;61(4 suppl):507-516.
2. Wolfe SA, Morrison G, Page LK, Berkowitz SL. The monobloc frontofacial
advancement: do the pluses outweigh the minuses? Plast Reconstr Surg.
1993;91(6 suppl):977-987.
3. Bradley JP, Gabbav JS, Taub PJ, et al. Monobloc advancement by distraction
osteogenesis decreases morbidity and relapse. Plast Reconstr Surg. 2006;118(7
suppl):1585-1597.

4. Arnaud E, Marchac D, Renier D. Reduction of morbidity of the frontofacial
monobloc advancement in children by the use of internal distraction. Plast
Reconstr Surg. 2007;120:1009-1026.

9
CHAPTERMonobloc Distraction
Peter J. Taub and Vincent Chavanon
DEFINITION
■ Craniofacial dysostosis syndromes result in disproportions of the skull and
facial bones leading to reduced intracranial volume, midface retrusion,
exorbitism, airway obstruction, and malocclusion.1,2
■ The midface hypoplasia associated with these syndromes may lead to corneal
exposure that threatens vision, sleep apnea, and malocclusion, as well as
deformities.
ANATOMY
■ A combination of cranial vault and facial growth disturbances exists among
multiple craniofacial syndromes.
■ Monobloc advancement separates the anterior portions of the skull base,
orbits, maxilla, and dental arch, which remain in continuity and are moved
anteriorly.
■ The scalp is composed of five layers: the skin, subcutaneous tissue, galea
aponeurotica, loose areolar subgaleal tissue, and pericranium.
■ Dissection may proceed at different levels in different approaches.
■ The temporal branch of the facial nerve (cranial nerve VII) lies immediately
above the superficial layer of the deep temporal fascia and must be preserved
when elevating the soft tissues of the forehead to avoid injury.
■ The anterior ethmoidal artery exits the medial orbital wall approximately 24
mm deep to the orbital rim, and the medial wall osteotomy should be planned
anterior to this landmark.
■ The bones of the cranium and the facial skeleton articulate at the frontal
bandeau, the floor of the anterior cranial fossa anterior to the cribriform plate,

the lateral orbital wall (greater wing of the sphenoid), the zygomatic arch, the
medial orbital wall (ethmoid complex), the nasal septum, the orbital floor, and
the pterygomaxillary fissure.1
■ The palpebral complex is anchored by the medial and lateral canthal tendons,
which insert onto the posterior lacrimal crest and Whitnall tubercle, deep to the
orbital septum.
PATHOGENESIS
■ A number of genetic, molecular, cellular signaling pathways, as well as
mechanical forces, interact to produce the craniofacial dysostosis syndromes.
■ Patients with the same genotypes may have a broad variety of penetrance,
influencing the level and severity of expression of the syndrome in individual
patients.
■ Different mutations in the fibroblast growth factor receptor-2 (FGFR-2) gene
may lead to either Crouzon or Apert syndrome, which both display autosomal
dominant inheritance.
■ The restricted skull base growth in these syndromes leads to
brachyturricephaly and elevated intracranial pressure (ICP). Facial hypoplasia
results in orbital retrusion and narrowing of the nasopharynx and Angle class
III malocclusion.3
NATURAL HISTORY
■ Cranial vault restriction may lead to elevated ICP, which has negative
consequences on long-term cognitive, psychological, and functional outcomes.
■ Chronic sleep apnea has an additional deleterious effect on psychosocial
outcomes.3
■ Reduced orbital volume may cause exorbitism, which may lead to corneal
exposure and loss of vision.1
PATIENT HISTORY AND PHYSICAL FINDINGS
■ A thorough evaluation of the patient’s cognitive, psychological, functional,
and aesthetic status is required.
■ Evaluation by a multidisciplinary team permits a 360-degree assessment of the
patient and improves preoperative planning. The team comprises plastic
surgeons, neurosurgeons, ophthalmologists, otolaryngologists, oral surgeons,
pediatricians, geneticists, psychologists, speech-language pathologists,
orthodontists, and pediatric dentists.

■ The neurosurgical member of the team helps to identify Chiari malformations
and is needed for exposure of the anterior cranial vault.
■ An ophthalmologic exam identifies papilledema secondary to elevated ICP,
increasing the urgency for surgery.
■ A neuropsychological exam identifies baseline functional deficits that may
improve with early surgical intervention.
■ Genetics evaluation confirms the diagnosis, uncovers other potential medical
problems in the child, and identifies risks for future family planning.
IMAGING
■ True or reformatted lateral cephalograms may assist with advancement
planning.
■ Computed tomography (CT) with three-dimensional reformatting may show
evidence of suture fusion, hydrocephalus, and signs of ICP elevation (copper-
beaten skull).
■ Magnetic resonance imaging is not usually necessary unless a brain
abnormality requires evaluation.
DIFFERENTIAL DIAGNOSIS
■ Apert syndrome or acrocephalosyndactyly (1:65 000)4
■ Crouzon syndrome (1:25 000)4
■ Pfeiffer syndrome (1:65 000)
■ Carpenter syndrome
■ Saethre-Chotzen syndrome1
■ Antley-Bixler syndrome2
NONOPERATIVE MANAGEMENT
■ Continuous positive airway pressure (CPAP) or supplemental oxygen can be
used for mild obstruction or tracheostomy for severe airway obstruction.
■ Patching, moisturizing eye drops, and tarsorrhaphy are useful to protect the
cornea against orbital exposure.1
■ The benefit from tarsorrhaphy may be self-limited and ultimately ineffective
due to tissue stretch and dehiscence.
■ Herniation of the globe after tarsorrhaphy may impede reduction of the globe
resulting in loss of vision.1
SURGICAL MANAGEMENT

■ Indications for monobloc distraction:
■ Exorbitism with corneal exposure or visual loss
■ Upper airway obstruction
■ Malocclusion
■ Midface retrusion
■ Patients with facial retrusion and a brow or infraorbital rim to cornea
relationship of 5 mm (FIG 1) or 5 mm of negative overjet in occlusal
relationship are optimal candidates for advancement.2
FIG 1 • Significant exorbitism due to maxillary
hypoplasia.
■ Timing for surgery has traditionally followed the sequence of craniofacial
growth, starting with the cranial vault (0–5 years), orbit and midface (5–12
years), and lower face (greater than 12 years).
■ Marchac and Arnaud3 have suggested benefits to a single-stage frontofacial
monobloc distraction (at 18 months) after posterior vault expansion at 6
months. Their findings suggest improved ICP and long-term psychological
results.

Preoperative Planning
■ A cephalometric analysis should be performed prior to surgery to plan for the
total distraction distance required.
■ CT scans (both 2D and 3D) should be carefully reviewed prior to the
operation.
■ The surgeon must choose either internal or external distractors and be
comfortable with the chosen technique.
■ Adequate intravenous access and intra-arterial monitoring should be used.
Packed red blood cells should be cross-matched and available in the room
throughout the procedure.
Positioning
■ The patient is positioned supine on the operating room table.
■ The head is placed on a padded ring support and the arms are tucked by the
patient’s side.
■ All bony prominences are padded.
■ A Foley catheter is placed to monitor urine output as a measure of volume
replacement.
■ The table is rotated 180 degrees after intubation to permit unrestricted access
by the surgeon and one or two assistants.
■ The head of the table is rotated back toward the anesthesiologist after the
procedure to allow better airway management.
Approach
■ A coronal (or bitemporal) zigzag incision for improved camouflage is used to
create osteotomies of the orbital roofs, medial and lateral orbital walls, orbital
floors, septum, and anterior zygomatic arches.
■ A transoral (Keen) incision is used to access the pterygomaxillary osteotomy.
■ A craniotomy of the frontal bone with retraction of the frontal lobes is used to
expose the anterior cranial fossa and orbital roofs and allow for osteotomies of
the roofs and septum.
T E C H N I Q U E S

■ Exposure
■ The coronal incision is marked and injected along its length with 0.5%
lidocaine and 1:200 000 epinephrine to assist with hemostasis.
■ The incision proceeds to the pericranium.
■ Raney clips on the scalp may be used for hemostasis.
■ The scalp flaps are elevated in a subgaleal plane 2 to 4 cm and all bleeding
vessels are cauterized.
■ Excessive use of cautery at the skin edges may lead to peri-incisional
alopecia.
■ Scalp elevation is continued anteriorly to the orbital rim.
■ The pericranium is incised transversely 2 to 3 cm above the level of the
orbit.
■ Further anterior dissection into the orbit is continued in a subperiosteal
plane into the orbit (TECH FIG 1A).
■ Laterally, the temporalis is left in place to prevent temporal hollowing
(TECH FIG 1B).
■ The lateral orbit may be approached using a limited dissection of the
temporalis from the posterolateral aspect of the orbit.
Video p2-c009_01
■ Continuing this dissection inferiorly, the anterior zygomatic arch is
exposed.
00:00 / 00:00

Video p2-c009_02
■ If the supraorbital and supratrochlear neurovascular bundles exit the frontal
bone via foramina, they need to be released.
■ A 2-mm osteotome is directed inferiorly from the opening on either side of
the bundle to release the inferior bridge of bone and free the bundle from
the foramen.
Video p2-c009_03
■ Once this is done, or if no foramen exists, the coronal flap may be reflected
further inferiorly to continue subperiosteal dissection within the superior
portion of the orbit.
■ Subperiosteal dissection is continued along the superior, medial, and lateral
orbital walls and over the zygomatic body for access to the orbital floor.
00:00 / 00:00
00:00 / 00:00

Video p2-c009_04
■ The medial canthi should be preserved. If the lateral canthi are released,
they should be reconstructed after the skeletal surgery.
■ The anterior ethmoidal artery will be visualized in the medial orbital wall
and should be preserved.
■ Bilateral intraoral incisions are marked and injected with 1% lidocaine and
1:200 000 epinephrine above the mucogingival junction.
■ The incision is made through the mucosa using electrocautery and down to
bone.
■ The maxilla is exposed and the periosteum is elevated from the bone
posteriorly with sharp periosteal elevators to allow access to the
pterygomaxillary fissure.
TECH FIG 1 • A. Subperiosteal dissection of the orbit.
00:00 / 00:00

B. Limited dissection of the anterior temporalis muscle
attachments to the lateral orbital wall to minimize
temporal hollowing.
■ Osteotomies and Distractor Placement
■ The forehead bone flap is removed by the neurosurgeon, who then retracts
the dura to facilitate exposure of the orbital roofs.
■ Osteotomies are made using reciprocating saw and small hand osteotomes.
■ The anterior portion of the zygomatic arch is cut with the reciprocating
saw.
Video p2-c009_05
■ Lateral tenons are created in the lateral portion of the orbital bandeau with
the reciprocating saw.
■ With a malleable retractor within the orbit to protect the globe, the tip of
the reciprocating saw enters the infraobital fissure from behind the orbit
and is advanced superiorly to create an osteotomy along the lateral orbital
wall.
00:00 / 00:00

Video p2-c009_06
■ Using two malleable retractors, one within the orbit and another anterior to
the frontal lobe, an osteotomy is made across the orbital roof anterior to the
cribriform plate.
Video p2-c009_07
■ The malleable retractor is then moved to the lateral aspect of the globe to
protect and retract it, and the bilateral lateral orbital walls are similarly
osteotomized.
00:00 / 00:00
00:00 / 00:00

Video p2-c009_08
Video p2-c009_10
■ The osteotomy is made posterior to Whitnall tubercle where the lateral
canthal tendon inserts.
■ The osteotomy is continued through the lateral orbital floor to join the
osteotomy made in the floor medially, thus completing the circumferential
orbital osteotomies.
00:00 / 00:00
00:00 / 00:00

Video p2-c009_09
■ While using a malleable retractor to protect the globe, bilateral medial
orbital wall osteotomies are made using an osteotome. This osteotomy is
made posterior to the insertion of the medial canthal tendon and is directed
inferiorly to the medial aspect of the orbital floor.
Video p2-c009_11
■ A curved osteotome is placed through the transoral incision along the
maxillary bone into the pterygomaxillary fissure. With one finger on the
maxillary process medially, the osteotomy is made between the maxilla and
pterygoid plates. Orient the osteotome properly to avoid injury to the
terminal branches of the maxillary artery.
00:00 / 00:00
00:00 / 00:00

Video p2-c009_12
■ Rowe disimpaction forceps are placed in the nasal cavities and over the
palate to grasp the monobloc segment and downfracture it (TECH FIG 2A).
■ As the bone separates, a guarded septal osteotome is directed inferiorly
from the anterior cranial fossa to make a septal osteotomy (TECH FIG
2B).
■ With the monobloc segment fully downfractured, it may be mobilized side to
side to loosen its soft tissue attachments and confirm completeness of the
separation.
■ The segment is returned to its original position for attachment of the
distractor device.
■ An internal distraction device is secured anteriorly to the zygomatic body
near the osteotomy (TECH FIG 2C).
■ Posteriorly, the distractor is secured to the temporal bone, immediately
behind the zygoma and anteriorly to the external auditory canal.
■ If an external device is used, the frame is secured with percutaneous pins to
the temporal bones, and percutaneous wires are attached to the monobloc
segment (TECH FIG 2D,E).
■ The distractors are then tested and returned to their initial position.
■ The turning arms of the distractors exit posteriorly through stab incisions in
the scalp.
■ The forehead bone flap is secured to the frontal bandeau with miniplates to
provide rigid fixation.
■ A silicone drain is placed through a stab incision posterior to the ear.
00:00 / 00:00

■ The galea is reapproximated using interrupted, buried 2-0 PDS sutures.
■ A running, locking plain gut suture is used to close the skin. The intraoral
incisions are closed with a running, locking 3-0 chromic suture.
■ The skin incision is dressed with bacitracin, Xeroform, and sterile gauze
dressings.
TECH FIG 2 • A. Placement of Rowe disimpaction
forceps. B. Use of osteotome to create septal
osteotomy. C. Fixation of internal distraction devices.
D,E. External distraction device in place.
■ Removal of Distractors
■ Distractors are removed after at least 8 weeks of a consolidation phase
following completion of distraction.
■ The same coronal incision from the initial surgery is used to access the
distractors.
■ Dissection is performed in a subgaleal plane to expose the zygomatic body
and temporal bone.

■ The distractors are removed and the incision is closed with resorbable
sutures similar to the initial surgery.
PEARLS AND PITFALLS
Indications
■ Airway obstruction, exorbitism, occlusion, midface retrusion.
Exposure
■ Avoid electrocautery on the scalp to prevent peri-incisional alopecia.
■ Lidocaine with epinephrine should be injected 20–30 minutes prior to
incision to assist with hemostasis.
■ In older patients with the presence of frontal sinuses, the central
portion of the superior orbit osteotomy may be performed via a trans-
sinus approach to avoid intracranial exposure to the nasal passage and
avoid the midline structures.5
■ Free the supraorbital neurovascular bundle to improve exposure of the
orbit.
Osteotomy
■ The anterior zygomatic arch may be osteotomized via the coronal or
the transoral approach.
■ Use caution during the pterygomaxillary disjunction to avoid injuring
the terminal branches of the maxillary artery.
Distraction
■ 5–7 day latency period.
■ Distract 1 mm/d (0.5 mm twice a day).
■ Consolidation at least 8 weeks; some surgeons recommend longer.
POSTOPERATIVE CARE
■ A 5- to 7-day latency period is used after the operation.
■ This delay allows healing of the nasal mucosa, which helps prevent infection.
■ After the latency period, the pins are each distracted 1 mm/d at a rhythm of
two turns per day (0.5 mm twice daily).
■ The pin sites are monitored closely for infection.
■ Following completion of distraction, the turning arms are removed.
■ A consolidation period of 8 weeks to 6 months has been used, after which the
distractors are removed.
OUTCOMES

■ In comparing the traditional technique of monobloc and immediate
advancement to monobloc by distraction, Bradley et al.6 noted the distraction
group had less morbidity and achieved greater advancement with less relapse
compared with conventional methods of acute monobloc advancement
accompanied by bone grafting.
■ Monobloc distraction is an alternative to staged fronto-orbital advancement
followed by Le Fort III advancement.
■ Gwanmesia et al.7 reviewed 20 patients with a mean follow-up of 10 years.
■ The authors reported no significant relapse in these patients.
■ Fourteen of the 20 patients had moderate to severe sleep apnea and 7 required
tracheostomies; 5 were decannulated.
■ Of the younger patients receiving this treatment, 9 of 11 were in mainstream
education. Of the older patients, 7 of 9 sought higher education or had jobs.
■ Arnaud and Di Rocco8 analyzed 104 patients undergoing monobloc distraction
with a mean follow-up of nearly 5 years and noted significant improvement in
exorbitism, respiratory function, and occlusion.
COMPLICATIONS
■ Death
■ Bleeding
■ Frontal bone loss
■ Meningitis
■ CSF leak
■ Wound infection
■ Pin site migration
REFERENCES
1. Britto JA, Greig A, Abela C, et al. Frontofacial surgery in children and
adolescents: techniques, indications, outcomes. Semin Plast Surg.
2014;28:121-129.
2. Kumar AR, Steinbacher D. Advances in the treatment of syndromic midface
hypoplasia using monobloc and facial bipartition distraction osteogenesis.
Semin Plast Surg. 2014;28:179-183.
3. Marchac A, Arnaud E. Cranium and midface distraction osteogenesis: current
practices, controversies, and future applications. J Craniofac Surg.
2012;23:235-238.
4. Hopper RA. New trends in cranio-orbital and midface distraction for

craniofacial dysostosis. Curr Opin Otolaryngol Head Neck Surg. 2012;20:298-
303.
5. Nikkhah D, Farhadieh R, Jeelani O, Dunaway D. An intrasinus approach to
the monobloc osteotomy. Plast Reconstr Surg. 2013;131:455e-456e.
6. Bradley JP, Gabbay JS, Taub PJ, et al. Monobloc advancement by distraction
osteogenesis decreases morbidity and relapse. Plast Reconstr Surg.
2006;118:1585-1597.
7. Gwanmesia I, Jeelani O, Hayward R, Dunaway D. Frontofacial advancement
by distraction osteogenesis: a long-term review. Plast Reconstr Surg.
2015;135:553-560.
8. Arnaud E, Di Rocco F. Faciocraniosynostosis: monobloc frontofacial
osteotomy replacing the two-stage strategy? Childs Nerv Syst. 2012;28:1557-
1564.

10
CHAPTER
Split Calvarial Bone Graft
Harvest
Peter J. Taub
DEFINITION
■ Calvarial bone grafts are used for replacement of deficient bone.
■ These grafts are ideal for calvarial, orbital, nasal, and midfacial reconstruction.
■ Paul Tessier previously described, and extensively used, autologous bone
grafts from the calvarium for facial and cranial reconstruction.1
ANATOMY
■ Because many primary craniofacial procedures are performed via a coronal
incision, there is no additional access for the donor site.
■ Calvarial bone has a diploic structure including an inner and outer “table” of
rigid cortical bone surrounding a center of softer cancellous bone.
■ A rich vascular system allows for rapid revascularization, and its
intramembranous lineage is thought to undergo less resorption compared to
endochondral bone grafts.
■ The natural curvature of the calvarium can be useful in reconstructing
similarly curved structures, and additional bending is possible by incorporating
kerfs on the concave surface (FIG 1).
PATHOGENESIS
■ Bone graft healing is affected by numerous variables.
■ Adequate blood supply is arguably the most important. Devascularized bone is
unable to activate the process of remodeling and over a period of 6 to 12
months becomes necrotic and predisposed to infection and repeat fracture.

FIG 1 • Kerfs created on the concave surface of a
calvarial bone graft to facilitate curvature of the bone.
■ Revascularization occurs through a process known as haversian remodeling.
The process begins with osteoclasts traversing the fracture line. Vascular
endothelial growth factor (VEGF) regulates the process of angiogenesis by
increasing vascular sprouting, endothelial cell migration, and proliferation
adhesion. Capillaries and osteoblasts follow to form vascularized lamellar
bone.2
■ External radiation impairs secondary reconstruction by inhibiting bone healing
and growth, limiting microvascular supply, and decreasing the integrity of
surrounding soft tissue.3
■ Stability (elimination of motion) of the bone graft is critical to primary bone
healing, whereas micromotion has been shown to facilitate bone healing
through osteogenesis.4 Insufficient fixation leads to the deposition of fibrous
tissue within the gap between bony segments, resulting in nonunion.
■ Patient age plays an important role in bone graft healing.
■ Younger patients demonstrate faster rates of healing than do adults, likely
secondary to the increased angiogenic potential of younger bone.
■ Advancing age decreases angiogenesis, stem cell function, signaling
cascades, and periosteal structure, all of which are essential to bone graft
healing.
NATURAL HISTORY
■ Bone grafts heal via three mechanisms: osteointegration, osteoinduction, and
osteoconduction.

■ Osteointegration refers to the connection between the surface of the native,
living bone and that of the bone graft.
■ Osteoinduction refers to the process of stimulation of undifferentiated
pluripotent cells into bone-producing cells through the release of growth
factors.
■ For bone grafts, the architecture of the graft (cancellous vs cortical) dictates
the success of incorporation. Cancellous bone graft incorporation tends to be
more favorable compared to cortical bone, owing to its open architecture,
which allows for more rapid revascularization and differentiation of
osteoprogenitor cells into bone forming osteoblasts.5
■ Osteoconduction refers to bone formation from either adjacent bone or
periosteum via the ingrowth of capillaries and osteoprogenitor cells from the
recipient bed to, around, and through the graft. The graft acts as a scaffold for
new bone formation.
PATIENT HISTORY AND PHYSICAL FINDINGS
■ Among bone replacement materials, autogenous bone grafts remain the
standard. They are the only material that is truly osteogenic; cells from the
bone graft contribute to new bone formation.
■ Bone grafts can be used for replacing acquired bone defects, such as following
tumor extirpation or continuity defects following trauma; augmenting deficient
skeletal surfaces, such as placement of bone graft for zygomatic or chin
augmentation; or reconstructing congenital anomalies, such as alveolar cleft
defects or hypoplastic mandibular rami.
IMAGING AND OTHER DIAGNOSTIC STUDIES
■ Preoperative evaluation should include a CT scan to assess the thickness of the
parietal bones for harvesting grafts and of any potential midline abnormalities.
■ Younger patients may lack a true diploic architecture (FIG 2), whereas older
patients may have areas of thin calvarial bone.
SURGICAL MANAGEMENT
Preoperative Planning
■ Care must be taken when choosing the site of bone harvest. In general, the flat
parietal region is ideal for most applications.
■ The midline sagittal suture overlies the sagittal venous sinus and must be
avoided. Similarly, the anterior coronal and posterior lambdoid sutures are sites

of dural adherence and should be avoided.
FIG 2 • CT scan demonstrating diploic architecture of
calvarial bone.
FIG 3 • Preparation of the scalp for a coronal incision by
shaving a strip of hair and excluding the remaining hair
from the operative field.
Positioning

■ The patient is best positioned supine with the head stabilized. This may be as
simple as a foam “donut,” a horseshoe extension of the operating table, or a
Mayfield clamp.
■ The torso should be restrained with a belt in case the table is rotated during the
procedure.
■ A strip of hair can be shaved over the coronal incision and the hair on either
side combed away from the incision and gathered into elastics for control (FIG
3).
■ The surgical prep should include the hair (and face if needed) down to the
level of the bed.
■ Care should be taken to avoid exposure keratitis by applying ointment to the
eyes and using a more dilute prep solution in this area.
■ The face can be draped out of the operative field or incorporated into it as
desired.
Approach
■ Access to the parietal calvarium may be achieved in two ways depending on
the amount of bone required.6
■ A small zigzag incision directly over the parietal scalp may be used when a
smaller graft is needed and is easily hidden by a patient’s hair.
■ A coronal incision provides ideal exposure for larger grafts. The dissection
proceeds through the skin, underlying soft tissue and galea, to the pericranium.
The pericranium may be dissected from the calvarium or left in place to
maintain continuity of loose bony fragments of the outer table. Elevation of the
pericranium is performed with an Obwegeser-type periosteal elevator.
■ Hemostasis from underlying perforating vessels to the periosteum may be
achieved with direct electrocoagulation or with sterile bone wax.
T E C H N I Q U E S
■ Shave Graft
■ The thinnest type of calvarial graft is a “shave” graft performed with a wide,
sharp chisel.
■ The graft is taken midway through the outer table of cortical bone, and

although harvested as numerous shavings, they are held together by the
overlying pericranium.
■ When removed, the graft actually curves to simulate the natural floor of the
orbit.
■ A shave graft is useful for reconstruction of the orbital floor and is harvested
through a small zigzag incision in the parietal region.
■ Dissection in this instance should not violate the pericranium, which can be
dissected laterally with a blunt instrument.
■ An outline of the graft is made though the pericranium with the Bovie
electrocautery. This should be slightly larger than the actual bone graft size
because the pericranium will contract after being incised.
■ A wide osteotome is then angled at roughly 30 degrees and directed down
the length of the graft. The graft may be wider than the osteotome, and thus,
the instrument may need to move side to side to capture the full width of the
graft required for harvest.
■ The graft often comes off in small pieces held together by the pericranium.
The osteotome should not be advanced too superficially so as not to violate
or tear the pericranium. It should also not be advanced too deeply to avoid
entering the diploic space or cranial cavity.
■ The intervening diploic space often provides a “warning track” to indicate
excessive depth and when to redirect the osteotome more superficially.
■ Gentle finger pressure over the graft is recommended, so the graft is not
inadvertently lost from the operative field.
■ The graft is removed and the donor site inspected. Bleeding can be managed
with Gelfoam, Surgicel, bone wax, cautery, or any combination of the above.
The base should be palpated to rule out inadvertent violation of the cranial
vault.
■ Outer Table In Situ Split Calvarial Graft
■ A thicker split calvarial graft may be harvested in situ through a direct
incision over the harvest area or through a coronal incision.
■ This thicker graft may be used in areas that require greater stability, such as
the orbital rim, forehead, or remaining calvarium.
■ The graft will retain its natural shape but may be gently bent if thinned.
Alternatively, kerfs can be added to facilitate manipulation (see FIG 1).

■ With this type of graft, preservation of the outer pericranium is not necessary
because the graft should be removed as a single piece.
■ The border of the graft is created with a small fissure bur. This should extend
down to the level of the diploic space, which is indicated by slight bleeding
easily controlled with bone wax. The surgeon should confirm that the channel
extends all the way around the border of the graft.
■ Common areas that are often incompletely burred are in the graft corners
where there is a change in direction of the bur.
■ In the proximal channel of the graft, the outer edge can be further burred
down to create a slope to allow the osteotome to be directed at a more acute
angle beneath the graft (TECH FIG 1A).

TECH FIG 1 • A. Using a cutting bur to create a
beveled edge to the diploic space. B. Direction of the
curved osteotome to avoid violation of the inner table.
C. Removal of a portion of the outer table to be used
as graft material.
■ Curved osteotomes of varying widths are then advanced within the diploic
space along the length of the graft (TECH FIG 1B).
■ An assistant surgeon should keep a finger on the graft to prevent it from
being lost off the operative field.
■ The graft is then removed for further contour (TECH FIG 1C).
■ As above, the donor site may be covered with Gelfoam, Surgicel, and bone
wax or cauterized.
■ The harvest site base should be visually inspected and palpated to rule out
violation of the intracranial space. The pericranium should be reapproximated
if possible, followed by the galea and subcutaneous tissue and skin.
■ A closed suction drain is left prior to final closure of the scalp with sutures
or staples.

■ Outer Table Ex Vivo Split Calvarial Graft
■ Removal of an entire segment of calvarial bone may also be used for harvest.
A team approach with a neurosurgeon is recommended in these instances.
■ An intracranial approach may be a better option, especially in the pediatric
patient for whom in situ splitting may not be feasible secondary to a thin or
irregular skull. If a formal craniotomy has already been performed, the
segment can be retrieved from the free edge of the bone.
■ Alternatively, a segment of bone can be removed separately.
■ Usually, four small craniotomies are made in the corners of the proposed
graft for access (TECH FIG 2A). Care must be exercised to avoid injury to
the underlying dura.
■ Modern craniotomes have been designed to cut only bone and preserve the
dura. The diameter of each corner opening is often large, however, and a
standard craniotome may be preferable.
■ The dura should be visualized through each of the openings. A no. 4 Penfield
or Freer elevator is inserted into the opening and gently used to free the dura
from the undersurface of the calvarium. Ideally, the elevator should be able to
pass from one opening to the other.
■ With an extradural path created between all the openings, an osteotome with
a footplate is advanced from opening to opening until the graft is free for
removal.
■ The dura should be inspected to ensure that it has not been violated. A moist
laparotomy pad is placed on the exposed dura.
■ On a sterile, back table, the outer table of bone is separated from the inner
table at the level of the diploic space. This may be done with a reciprocating
saw or a hand osteotome. Often, the saw blade is too short to traverse the
width of the graft, and an osteotome is required.
■ Once separated, half of the bone—either the outer or inner table—can be
used to repair the donor defect. The other half is used for the reconstruction.
■ In either instance, the bone is rigidly fixed with titanium plates and screws
(TECH FIG 2B).
■ The wound is irrigated and the scalp closed in layers over a subcutaneous
drain.

TECH FIG 2 • A. Full-thickness cortical bone graft
harvested via four corner osteotomies. B.
Replacement and fixation of bone segments.
PEARLS AND PITFALLS
Graft
harvest
■ Safety first. Calvarial bone overlies the dura and brain. Dural injury can
result in persistent and worrisome CSF leak. Brain injury can result in
permanent neurologic deficit.
■ Review the preoperative imaging (preferably CT scan) to determine the
best location for graft harvest.
■ Before harvesting the bone graft, decide if the overlying periosteum is to
be preserved or reflected.
■ “Visualize” the path of the osteotome to minimize inadvertent graft
fracture or intracranial violation.
Fixation
■ Adequate fixation of bone graft is important for healing.
POSTOPERATIVE CARE
■ A simple dressing of bacitracin and nonstick gauze is applied to the incision.
■ A gauze head wrap is applied.
■ If a drain is placed, it should be monitored and emptied daily (or twice daily,
as needed). The drain can be removed early if the output is low and there is no
suspicion of a cerebrospinal fluid (CSF) leak. The space between the scalp and
bone is small and heals quickly.

OUTCOMES
■ In the absence of inner table violation and associated dural injury, the outcome
following harvest of calvarial bone is relatively good.
■ The healing of calvarial bone grafts parallels that of fracture repair. Although
osteocytes from the donor site seldom survive following grafting, bone
viability is usually maintained following transfer.
■ The duration of exposure to air should be minimized.
■ On the back table, the graft should be wrapped in a blood-soaked sponge with
a moist, saline sponge on top and labeled to avoid inadvertent disposal.
■ The recipient site should be healthy and well vascularized. If not, debridement
to healthy tissue is required.
■ Poor harvest technique may lead to decreased viability with impaired healing
and bone strength. Osteocyte activity takes place primarily at the recipient
site.5
■ Viability is affected by the size and thickness of the graft, as well as the
suitability of the recipient site. Onlay bone grafts tend to resorb, whereas inlay
bone grafts have more favorable survival.7
COMPLICATIONS
■ The complication rate of calvarial harvest is reported to be as low as 0.25%.6
■ Similar to other donor sites, pain, paresthesia, and hemorrhage are the most
frequent complications.
■ Palpable irregularities may also occur, whereas visible deformities are rare and
usually covered by hair.
■ Alopecia along the incision line occurs with spreading of a tight closure and/or
injury to the hair follicles and may be minimized by avoiding thermal injury to
this area.
■ Any violation of the dura should be repaired to avoid leakage of CSF. This
may be performed with either interrupted or running 4-0 Nurolon suture. Bone
outside the repair may need to be removed for access and to facilitate
placement of one or more sutures. Pericranial or galeal grafts with fibrin
sealant may be used to augment the repair.
REFERENCES
1. Tessier P. Autogenous bone grafts taken from the calvarium for facial and
cranial applications. Clin Plast Surg. 1982;9:531-538.

2. Taub PJ, Silver L, Weinberg H. Plastic surgical perspectives on vascular
endothelial growth factor as gene therapy for angiogenesis. Plast Reconstr
Surg. 2000;105(3):1034-1042.
3. Maeda M, Bryant MH, Yamagata M. Effects of irradiation on cortical bone
and their time-related changes. A biomechanical and histomorphological study.
J Bone Joint Surg Am. 1998;70:392-399.
4. Salisbury Palomares KT, Gleason RE, et al. Mechanical stimulation alters
tissue differentiation and molecular expression during bone healing. J Orthop
Res. 2009;27:1123-1132.
5. Oppenheimer AJ, Tong L, Buchman SR. Craniofacial bone grafting: Wolff’s
law revisited. Craniomaxillofac Trauma Reconstr. 2008;1:
49-61.
6. Tessier P, Kawamoto H, Matthews D, et al. Taking calvarial grafts, either split
in situ or splitting of the parietal bone flap ex vivo-tools and techniques: V. A
9650-case experience in craniofacial and maxillofacial surgery. Plast Reconstr
Surg. 2005;116(5):54S-71S.
7. Rogers GF, Greene AK. Autogenous bone graft: basic science and clinical
implications. J Craniofac Surg. 2012;23:323-327.

11
CHAPTER
Cranioplasty Reconstruction
with Autogenous Rib Graft
Scott J. Rapp
DEFINITION
■ Cranial defects resulting from trauma, oncologic resection, decompressive
craniotomies, osteomyelitis, congenital defects, and cranial vault
expansion/remodeling for craniosynostosis may require reconstruction when
the defect is large. In the young patient, defects greater than 4 cm2 will not
close spontaneously, leading to gross contour irregularities and risk of
intracranial herniation or injury if left unrepaired.1
■ Other factors that influence healing of bone include age of patient, nutritional
status, previous scarring, and surgeries.
■ Autogenous rib inlay grafting represents a useful cranioplasty technique to
provide structural rigidity to the cranial vault, maximizing bony integration
while minimizing infection and resorption.
ANATOMY
■ The neurocranium arises from paraxial mesoderm and neural crest cells (FIG
1).
■ The calvaria develops through intramembranous ossification.
■ The cranial base develops through endochondral ossification.
■ A definitive diploic space forms by around age two to three and thickness
varies on anatomic location.
• Craniosynostosis leads to both thin calvarial wall and diploic thickness.2

FIG 1 • The neurocranium develops from both
endochondral and intramembranous ossification.
■ Rib development occurs from paraxial mesoderm and arises from sclerotome
cells within the costal process of thoracic vertebrae.
■ True ribs (1–7) attach to the sternum directly by their own cartilage.
■ False ribs (8–10) attach to the sternum by synchondrosis.
■ Floating ribs (11,12) do not attach to the sternum (plain film; FIG 2).
PATHOGENESIS
■ A critical-sized defect is one that will not heal spontaneously and leads to a
fibrous nonunion.
■ 4-cm2 gaps are considered “small” with defects greater than 5 cm in diameter
or 25 cm2 considered “large.”
■ Healing of bone gaps in the cranial vault occur through multiple pathways:
■ The dura mater is an important contributor providing a primary source of
osteogenic cells and the source of osteoinductive growth factors.
• Bone growth occurs both centrally and peripherally within the defect.3
■ The periosteum, when present, provides an important source of growth
factors and mesenchymal cells including osteoblasts, pericytes, fibroblasts,

and periosteum-derived stem cells.
• Growth factors released include BMP-2, IGF-1, and TGF-β.
■ Partial bone growth from the margins of the wound occurs from local
osteoblasts through osteogenesis.
NATURAL HISTORY
■ Surgical intervention to reintroduce structural integrity within the defect may
be accomplished through alloplastic, allograft, and autograft sources.
■ Alloplastic materials are biocompatible and hold the advantage of ease of use,
ample supply, and no donor-site morbidity.
■ The bone substitute acts as a structural lattice, and new bone formation
occurs through osteoconduction.
• May provide greater mechanical strength to the repair
■ Useful for small defects utilizing a “spackle” technique
■ Larger-sized defects under 5 cm require an absorbable or titanium mesh
underlay to provide support against the pulsing dura beneath.
■ Titanium mesh may provide intracranial protection rapidly when the defect is
large.
FIG 2 • Plain film of floating ribs 11 and 12.
■ Alloplastic materials are not recommended in the rapidly growing pediatric
skeleton and are associated with higher rates of extrusion and infection.

• Infection rates have been reported to be 5 times higher than other bone
grafting materials.4
■ Avoid using these materials in a postradiated wound bed with diminished
blood supply.
■ Allograft materials are derived from cadaveric bone.
■ May be fresh or frozen bone
■ Most available source is demineralized bone matrix.5
■ Bony regeneration occurs predominately through osteoconduction but may
also confer osteoinduction properties as some osteoclasts may survive the
free transfer.6
■ Autogenous bone grafting is the current “gold standard” to correct vault
defects long term.
■ Bony healing occurs through osteoinduction, osteoconduction, and
osteogenesis—whereby the transplanted osteoblasts survive and contribute to
the creation of de novo bone formation.
• Indications for use include complex or large-sized defects, need for staged
procedures, defects near sinuses, previous reconstruction failures, radiated
tissue beds, and colonized or infected sites.
■ Autogenous bone grafts can become revascularized.
■ Most frequent autogenous sources of bone grafting to the skull include
• Iliac crest
• Split calvarial bone
• Split rib
• Parascapular osteocutaneous flap
• Vascularized bone grafting based on superficial temporal vessels
■ The use of rib grafts as a surgical intervention was first described in 1917 by
Brourt.7
• Multiple ribs may be used.
• Once healed, the bone is smooth and radiographically indistinct by CT
imaging.8
PATIENT HISTORY AND PHYSICAL FINDINGS
■ Cranial defects can first be identified by physical exam and palpation.
■ In the young pediatric population, even large-sized defects can be observed for
closure spontaneously until patients are more physically active.

■ Intervention is usually performed when the patient with a large skull defect
becomes more mobile, exposing intracranial contents to risk for harm or
herniation.
■ Congenital bony abnormalities requiring intervention can result from:
■ Cutis aplasia
■ Cleidocranial dysplasia
■ Craniofrontonasal dysplasia
■ Encephaloceles, gliomas
■ Hypophosphatasia
■ Hypothyroidism
■ Fibrous dysplasia
■ Elevated intracranial pressure from multisuture craniosynostosis
IMAGING
■ Noncontrast CT with 3D reconstructions identifies defects adequately.
■ Coronal cuts are useful to evaluate diploic space thickness to assess split
calvarial bone grafting as an alternate option for treatment.
■ In complex or the multiply operated cranial vault, virtual surgical modeling
may be helpful in determining calvarial thickness and location of multiple
defects within an area of concern.
NONOPERATIVE MANAGEMENT
■ If the patient is unable to undergo surgical reconstruction for any reason and
the cranial defect is such that the intracranial contents are at risk, a protective
orthotic helmet may be used until comorbidities are corrected.
SURGICAL MANAGEMENT
■ Calvarial defects with surface areas large enough to put the intracranial
contents at risk necessitate reconstruction.
■ Small defects less than 5 cm in size may be repaired with bone substitutes or
allograft.
■ Bone substitutes are composed of various polymers:
• Methyl methacrylate
• Bioactive glass
• Hydroxyapatite cement
• Hydroxyapatite/polylactide
• Polylactide-co-glycolide