AICB Graft

Question 1

brief description of AICB graft
type?
yield?

Answer 1

corticocancellous and cancellous marrow for grafting

provides on average 15-20 cc of non compressed bone

MAX of 50 cc

up to 2x6 cm cortico-cancellous block graft

cn reconstruct up to 5 cm defect (~10 cc = 1 cm)

Question 2

basic difference between corticocancellous block graft and cancellous / cortical only

Answer 2

cortical = Composition: Dense, outer layer of bone
Source: Often harvested from mandibular ramus, chin, or iliac crest

Advantages:
High mechanical strength and space maintenance
Resists resorption over time

Disadvantages:
Poor vascularity (slow revascularization and incorporation)
Higher risk of sequestration or delayed integration
Requires more healing time before implant placement

Best used for:
Structural support or onlay grafts where volume stability is critical

cortico-cancellous =
Composition: Combination of cortical bone and inner cancellous (spongy) bone

Source: Iliac crest, tibia, or intraoral sites (e.g., mandibular symphysis)

Advantages:
Balance of strength (from cortical component) and vascularity (from cancellous component)
Faster integration and revascularization than pure cortical grafts
Improved osteoconductive and osteoinductive potential

Disadvantages:
Less structural stability than pure cortical grafts
Some degree of resorption expected

Best used for:
Larger volume defects or when quicker incorporation is needed
Ridge augmentation prior to implant placement

Question 3

main blood supply and main sensory supply to AICB graft

Answer 3

blood supply = deep circumflex iliac artery
- medial surface of the ilium is covered by the iliacus muscle

the deep circumflex artery courses superficial to the iliacus muscle medially

main sensory supply = lateral femoral cutaneous branch

Question 4

Meralgia paresthetica

Answer 4

A condition caused by compression or entrapment of the LFCN, often at the level of the inguinal ligament.

Symptoms: Burning, numbness, tingling, or pain over the anterolateral thigh

Causes: Tight clothing, obesity, pregnancy, pelvic surgeries, or prolonged hip flexion (e.g., in certain surgical positions)

Diagnosis: Clinical exam, sensory testing, sometimes nerve conduction studies or ultrasound

Treatment: Conservative measures (weight loss, avoiding compression), nerve blocks, or surgical decompression if refractory

Question 5

Mechanism of Injury in Iliac Crest Bone Harvest

Answer 5

The LFCN runs medial to the ASIS and under or through the inguinal ligament, crossing the iliacus muscle.

During anterior iliac crest graft harvest, especially with larger exposures or more medial dissection, the LFCN can be:

Directly transected

Stretched or compressed

Entrapped in scar tissue or sutures

Injury is more likely when the incision extends too medially or deep dissection is done near the ASIS.

Question 6

Layers of Dissection – Anterior Iliac Crest Bone Graft

Answer 6

1. Skin
   Incision made parallel to and slightly posterior to the ASIS

***Avoid overly medial extension to reduce risk of LFCN injury

2. Subcutaneous Tissue (Superficial Fascia)
   ** CAMPER fascia
   Fat and connective tissue
   ** SCARPA fascia
   Careful blunt dissection is used to minimize trauma to underlying neurovascular structures
3. Fascia Overlying External Oblique Muscle

Sharp dissection exposes the external oblique aponeurosis

Incise fascia in line with muscle fibers to minimize injury and ease closure

4. Muscle Layers

External Oblique Muscle: Separated or split along its fibers

Internal Oblique and Transversus Abdominis (if graft harvest is more medial): May be encountered and split or retracted if deeper exposure is needed

These muscle layers may contribute to abdominal wall herniation risk if not properly closed

5. Periosteum of Iliac Crest

Incised and elevated to expose the cortical bone

Elevate subperiosteally to preserve vascular supply and minimize postoperative pain

6. Iliac Crest Bone

Harvest cortical or corticocancellous bone using osteotomes, chisels, or a saw

The inner table should be preserved if possible to maintain iliac integrity and avoid hernia risk

Question 7

attachments to ASIS

Answer 7

inguinal ligament
sartorius muscle
tensor fascia lata (lateral)
liacus muscle (medial)

Question 8

attachments to iliac crst

Answer 8

internal oblique muscle
external oblique muscle
transverse abdominus
gluteus medius and minimus
latissimus dorsi

Question 10

retract medial to ensure?

Answer 10

incision is approx. 2 cm lateral to the iliac crest

Question 11

Stay ___ posterior to?

Answer 11

stay 2 cm posterior to ASIS from the harvest site

• so most anterior cut should be at least 2 cm posterior to ASIS