Reconstruction

Question 1

What nerve is most commonly injured during anterior iliac crest bone graft harvest?
A. L1
B. L2
C. L3
D. T12

Answer 1

A. L1
The most commonly injured nerve during harvest is the lateral cutaneous branch of the iliohypogastric nerve (L1). This occurs if the incision extends past the anterior tubercle of the ilium. The lateral cutaneous branch of the subcostal nerve (T12) is also at high risk for injury.
The lateral femoral cutaneous nerve can be injured if the incision is too close to the anterior superior iliac spine. In 2% of patients, this nerve runs over the ASIS (it runs deep to the inguinal ligament in everyone else). Damage to lateral femoral cutaneous nerve is the most worrisome because it is associated with meralgia paresthetica. This involves numbness, burning, and tingling

Question 2

Stripping of what muscle in an AICBG leads to gait disturbance?
A. Psoas
B. Iliacus
C. Tensor Fascia Lata
D. Gluteus Maximus

Answer 2

C. Tensor Fascia Lata

Up to 50 cc of bone can be harvested from an anterior iliac crest bone graft. The nerve most often injured when harvesting from this site is the lateral cutaneous branch of the iliohypogastric nerve (L1).

Question 3

What are the muscular attachments for the posterior iliac crest bone graft?

Answer 3

Attachments: gluteus maximus, gluteus minimus, thoracodorsal fascia of the latissimus dorsi

Question 4

What is the blood supply to the posterior iliac crest?

Answer 4

Deep circumflex artery

Question 5

What nerves run adjacent to the posterior iliac crest?

Answer 5

The superior cuneal nerves (dorsal rami of L1, L2, and L3) innervate the skin over the posteromedial buttocks. The medial cuneal nerves arise from S1, S2, and S3 innervate the medial buttocks. The insertion of the gluteus maximus is between the superior and medial cuneal nerves.

Question 6

How much bone can be harvested from a tibial bone graft?
A. 10 cc
B. 30 cc
C. 50 cc
D. 100 cc

Answer 6

B. 30 cc

About 20-40 cc of bone can be harvested from a tibial bone graft. 50 cc can be harvested from an AICBG and 100 cc can be harvested from a PICBG. 10-15 cc of bone can be harvested from a ramus graft.

Question 7

What is the significance of palpating Gerdy’s Tubercle during a tibial bone graft?
A. To avoid intra-articular hematoma formation
B. To avoid the deep peroneal nerve
C. To avoid injury to the patellar tendon
D. To avoid the sciatic nerve

Answer 7

C. To avoid injury to the patellar tendon

The incision is made over Gerdy’s tubercle, which is a bony protuberance located between the patellar tendon and head of the fibula. There are no major vessels or nerves in this area. It’s a very safe dissection

Question 8

Is a ramus graft
A. osteoinductive
B. osteoconductive
C. osteogenic
D. All of the above

Answer 8

D. All of the above

Osteoinduction: growth factors stimulate mesenchymal cells to differentiate into osteoblasts climate lineages (ex: BMP).
Osteoconduction: graft material acts as a matrix for bone growth (ex: allografts and xenografts).
Osteogenesis: transplanted osteoblasts and periosteum produce bone (ex: autogenous grafts).
Autogenous bone grafts have all 3 properties (i.e they are osteogenic, osteoconductive, and osteoinductive).

Question 9

Which of the following conditions is a contraindication for placement of BMP?
A. Cancer
B. HIV
C. Cleft palate
D. Arthritis

Answer 9

A. Cancer

Question 10

What is the thickness of a split thickness skin graft?
A. 0.012 to 0.018 cm thick
B. 0.012 to 0.018 in thick
C. 0.12 to 0.18 cm thick
D. 0.12 to 0.18 in thick

Answer 10

B. 0.012 to 0.018 inches thick

Split-thickness skin grafts (STSG) are usually 0.012 to 0.018 inches thick. They contain the entire epidermis and a portion of the dermis. A portion of the dermis remains at the donor site, protecting the underlying subcutaneous tissues. The donor site heals by secondary re-epithelialization, which takes 7-21 days. The STSG has to be immobilized during healing to ensure optimal contact between the graft and the recipient site while minimizing shear forces.

Question 11

Where does nutritional support for a skin graft come from? Differentiate between early and later support.

Answer 11

Plasmatic imbibition: nutritional support for a free skin graft is initially provided by plasma that exudes from the dilated capillaries of the host bed. Fibrinogen is also being released, which assists with anchorage of the graft to the recipient site. This occurs during the first 24-48 hours.
Inosculation: direct anastomoses between the graft and host vasculature. This starts by POD #3 or 4.

Question 12

What is the vascular supply to the trapezius flap?
A. Superficial Cervical Artery only
B. Dorsal Scapular Artery only
C. Superficial branch of the transverse cervical artery
D. Both the superficial cervical and dorsal scapular arteries

Answer 12

D. Both the superficial cervical and dorsal scapular arteries

Vascular supply to trapezius flap is two-fold, because the trapezius is divided into 3 parts, the descending (superior) part, the transverse (middle) part, and the ascending (inferior) part. Only the middle and inferior parts of the trapezius muscle are used as reconstructive flaps. The arterial supply to the middle (transverse) part is the superficial cervical artery (superficial branch of the transverse cervical artery). The inferior part is supplied by the dorsal scapular artery (deep branch of the transverse cervical artery). Both of these arteries arise from a common trunk that may be a branch of the thyrocervical trunk or of the subclavian artery

Question 13

What is the vascular supply to superior based platysma flap?

A. Submental
B. Superior thyroid
C. Occipital
D. Sublingual artery?

Answer 13

A. Submental Artery

Superior platysmal flap is supplied by the submental artery.
Posterior platysmal flap is supplied by the occipital artery.
Inferior platysmal flap is supplied by the superior thyroid artery.

Question 14

What is the vascular supply to the pec major flap?

Answer 14

Pectoral branch of the thoracoacromial artery (branch of axillary artery, which is branch of the subclavian artery).
The internal mammary artery perforators supply pectoralis major and the overlying skin along the inferior and medial aspects of the flap.
The lateral thoracic and superior thoracic arteries also provide some vascular supply to pectoralis major, however they are usually sacrificed during harvest to allow for a greater arc of rotation.

Question 15

What is the vascular supply to the fibula flap?
A. Popliteal
B. Anterior tibial
C. Posterior tibial
D. Peroneal

Answer 15

D. Peroneal artery

The popliteal artery branches into the anterior and posterior tibial arteries. The posterior tibial artery gives rise to the peroneal artery.
The peroneal vessels are found between the tibialis posterior and flexor hallucis muscles.
The peroneal artery gives off a nutrient medullary artery that provides endosteal vascular supply to the fibula, as long as multiple periosteal feeding vessels. The vascular supply to the skin comes from numerous fasciocutaneous perforators.

Question 16

How much bone from the proximal and distal fibula should be maintained during a FFF?
A. 5-6 cm
B. 6-7 cm
C. 7-8 cm
D. 8-9 cm

Answer 16

B. 6-7 cm

22-25 cm can be harvested. 6-7cm should be preserved both proximally and distally to maintain integrity and functional stability of both the knee and the ankle joints.

Question 17

What are the advantages of an anterolateral thigh (ALT) flap vs. a radial forearm free flap (FFF)?

Answer 17

ALT pros: versatility in design, variable thickness, pretty atherosclerotic free pedicle, long vascular pedicle (12cm), can create a chimeric flap.
ALT cons: color mismatch with skin, hair, donor-site paresthesia, can be too thick in some patients.
RFFF pros: consistent vascular anatomy, long pedicle and large diameter vessels, thin pliable skin flap.
RFFF cons: aplastic radial artery, poor blood flow to hand, persistent paresthesia, poor donor site cosmesis.

Question 18

What is the cause of poor cosmesis at the donor site of a temporal flap?
A. scar formation
B. temporal hollowing
C. fat perforation through fascia
D. hair loss

Answer 18

B. temporal hollowing

One of the downfalls of a temporalis flap is temporal hollowing, usually from fat wasting. This can be improved with a Medpor implant or repositioning of the flap posteriorly.

Question 19

What is the significance of the Allen’s test? How is it performed?

Answer 19

The Allen’s test looks for dual vascular supply to the hand. It prevents loss of blood supply to the thumb, 2nd, and 3rd digits. It tests the patency of the radial and ulnar arteries.
Have patient elevate their hand and clench their fists. Apply pressure to both the ulnar and radial arteries. While the hand is still elevated, the hand is opened. It should appear pale. The ulnar pressure is released, but the radial pressure is still held. If the color returns within 5-15 seconds, the Allen’s test is normal and the hand can still be supplied by the ulnar artery alone (it’s safe to proceed with RFFF). If the color does not return, the ulnar supply to the hand is insufficient and the radial artery cannot be sacrificed or accessed.
The radial artery sits between brachioradialis and flexor carpi radialis muscles.
Radial and Ulnar arteries: These two arteries converge to form the palmar arches, with the ulnar artery contributing more to the superficial palmar arch, and the radial artery contributing more to the deep palmar arch.
The arches ensure that even if one artery (radial or ulnar) is compromised, the blood supply to the hand can still be maintained through the collateral circulation provided by the other artery.

Question 20

What side of alloderm is graft is placed towards the vascular bed?
A. smooth
B. rough
C. medial
D. lateral

Answer 20

A. smooth side

The smooth, shiny side is the dermal side, while the rough, dull side is the basement membrane side. To test which side is which, apply a drop of blood to both sides. The blood will be absorbed on the dermal side, so naturally this is the side that is applied to the vascularized bed. The basement membrane side repels blood.

Question 21

What is the normal prevertebral soft tissue thickness at C2?
A. 3 mm
B. 6 mm
C. 9 mm
D. 12 mm

Answer 21

B. 6 mm

The normal prevertebral soft tissue thickness at C2 (the second cervical vertebra) should be no more than 7 mm in adults.
At C2 (Cervical vertebra 2): The normal prevertebral soft tissue thickness is usually less than 7 mm in adults.
At C6 (Cervical vertebra 6): The normal thickness is generally less than 22 mm.

Question 22

Are the muscles of facial expression innervated from the superficial or deep aspects?

Answer 22

To innervate facial muscles, the nerve pierces on the superficial side and penetrates deep to innervate the muscle (except for the marginal mandibular nerve)

Question 23

What is the time frame for the proliferation phase of wound healing?
A. 0-6 days
B. 4-14 days
C. 14-28 days
B. 1-3 months

Answer 23

B. 4-14 days

Inflammation occurs during the first 4-6 days. Platelets come first to help establish a fibrin clot. This provides a scaffold and producing cytokines and growth factors. Tons of cytokines are produced, including PDGF, VEGF, and TGF-β. Neutrophils come next, releasing pro-inflammatory cytokines. Finally, macrophages come, producing more cytokines, including TGF-α, TGF-β1, PDGF, IGF-I, IGF-II, TNF-α, and IL-1.
Proliferation begins 4-14 days after injury and lasts up to 6 weeks. During this time, epithelialization, angiogenesis, and collagen production occur. Type III collagen is being produced during this stage, as are GAGs. Fibroblasts produce granulation tissue.
Remodeling/maturation is the final stage of healing, which can last for years. The type III collagen produced during the proliferative phase is now replaced by type I collagen. At this stage, the collagen becomes organized and cross-linked.
The healed wound will only have 80% of its original strength.

Question 24

What produces TGF in healing tissues?
A. Neutrophils
B. Macrophages
C. Endothelial cells
D. Platelets

Answer 24

B. Macrophages

Activated macrophages
– Mediate fibroblast growth factor (FGF), platelet-derived
growth factor (PDGF), transforming growth factor (TGF)
– Essential for progression to proliferative phase

Question 25

How long do the vasoconstrictor effects of smoking last?
A. 15 min
B. 30 min
C. 60 min
D. 90 min

Answer 25

B. 30 minutes

Question 26

Which nerve is implicated in altered gait after an anterior iliac crest bone graft?

A. Iliohypogastric nerve
B. Lateral femoral cutaneous nerve
C. Medial femoral cutaneous nerve
D. Saphenous nerve

Answer 26

Lateral Femoral Cutaneous Nerve

The nerve most commonly implicated in altered gait after an anterior iliac crest bone graft is the lateral femoral cutaneous nerve (LFCN). This nerve is susceptible to injury during the harvesting procedure due to its anatomical course near the anterior superior iliac spine (ASIS). Injury to the LFCN can result in meralgia paresthetica, characterized by numbness, burning, tingling, or pain in the anterolateral thigh, which can affect gait

Question 27

Name the blood supply to the following flaps:

Pec Major
Fibula
Temporalis
Platysma
Trapezius
Supraclavicular
Latissimus Dorsi
Paramedian

Answer 27

Pec flap - thoracoacromial
Fibula - peroneal artery
Temporalis - anterior/posterior deep
Platysma - submental
Trapezius - Dorsal scapular
Supraclavicular flap - Transverse cervical
Latismus dorsi - Thoracodorsal
Paramedian - Axial, musculo, random or combo

Question 28

What is the base width of a paramedian forehead flap?

A. 1-1.4 cm
B. 1.5-1.9 cm
C. 2-2.4 cm
D. 2.5-2.9 cm

Answer 28

A. 1-1.4 cm

The base size of a paramedian forehead flap (PMFF) is typically designed to include the supratrochlear artery, which is located approximately 1.2 cm lateral to the midline of the glabella. This design ensures adequate vascular supply to the flap, which is crucial for its survival and successful integration in nasal reconstruction.

Question 29

What is the upper limit of how much bone can be harvested from a posterior iliac crest bone graft?

A. 50 cc
B. 100 cc
C. 25 cc
D. 75 cc

Answer 29

B. 100 cc

PICBG can supply a 5x5 cm cortical block and 100 cc of bone

AICBG can supply a 4x5 cm cortical block and 50 cc of bone

Tibia graft can supply a 1x2 cm cortical block and 25 cc of bone

Ramus can supply a 3x3 cm cortical block and 2.3 cc of bone

Symphysis of the mandible can supply a 2x1 cm cortical block and 4.7 cc of bone

Question 30

What does the cluneal group of nerves innervate?

A. Gluteal musculature and skin
B. Anterior hip musculature and skin
C. Posterior hip musculature and skin
D. Anterior thigh musculature and skin

Answer 30

A. Gluteal musculature and skin

The cluneal nerves are a group of nerves that innervate the skin of the gluteal region. They are divided into three main groups: superior, middle, and inferior cluneal nerves.