Bone Grafting and Reconstruction

August 10, 2011 | By | Reply More
Bone Grafting and Reconstruction
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Bone Grafting and Reconstruction


o    Historical background:

n     Surgeons have gained their experience in reconstruction from the numerous wars

n     Civilian injuries produces the largest number and the most extensive tissue loss almost indistinguishable from ware injuries

o    It started in WW I and concentrated around reconstruction of the mandible but without antibiotic support

o    In WW II distant bone blocks were transplanted from the ilium, rib and tibia with routine use of antibiotic

n     No cancellous cellular marrow

o    Mowlem in 1944, introduced the concept of “Iliac cancellous bone chips” beginning the evolution of predictable bony reconstruction of the jaw bone

o    Boyne brought about the “use of particulate bone and cancellous marrow” with metallic trays splinted to large acellular cortical bone

Biology of bone grafting

o       Three biological mechanism are involved:

n      Osteogenesis:

o     Is the production of new bone by proliferation, osteoid production and mineralization

n      Osteoconduction:

o     Is the production of new bone and migration of local osteocompetent cells along a conduit e.g. fibrin, blood vessel or even certain alloplast material like hydroxyapatite

o     Originate from the endostium or residual periostium of the host bone

n      Osteoinduction:

o     Is the formation of bone by stem cells transforming into osteocompetent cells by BMP

o     It induct the recipient tissue cells to form periostium and endostium


Surgical anatomy           The Rib

o       The first, eleventh and twelfth ribs are atypical

o       A typical rib has a head, a neck and a shaft.

n       The shaft slopes down and laterally to an angle and then curve forward

n       The upper border is blunt and lateral to the angle the lower border form a sharp ridge sheltering a costal groove

o      This feature identify right from left ribs

o        Typical rib:

n        The head:

o      Bevelled by two articular facets that slope away from a dividing ridge.

o      The lower one is vertical and articulate with the upper border of its own vertebra

o      The upper facets faces up and articulate with the lower border of the vertebra above

o      Each form a synovial joint separated by a ligament attached to the ridge

n        The neck:

o      Is flattened with its upper border curving into a thin, prominent ridge, the crest

n        The tubercle:

o      Shows two small facets lying medial and lateral

o      The medial one is covered with hyaline cartilage and form synovial joint with the transverse process of its vertebra

o      The lateral facet is smooth surfaced and receive the costotransverse ligament

o       Costal cartilages:

n       They form a primary cartilaginous joints at the extremities of all twelve ribs

n       The first is short and articulate with the manubrium and the clavicle

n       They increase in length below and the seventh has the longest.

n       They are bend from a downward slope with the rib to upward slope toward the sternum

o    Rib harvesting:

n     Indicated for costochondral graft to restore pseudoarticulation of the TMJ, or to replace a missing part of the anterior mandible to reconstruct a functional articulation

n     The rib is usually 5th or 6th typical one

n     Incision is placed in the infra-mammary crease, to hide the scar

n      Right rib is always preferred because:

o     It could be contoured to fit either side of the mandible or facial bones

o    Postoperative pain is less likely to be confused with cardiogenic pain

n      The 6th rib is where the distal origin of the pectoralis major muscle, dissection transect the muscle minimally

n      Sharp dissection is carried through full thickness of skin, subcutaneous tissues and the muscle, to expose the rib periostium, the chest wall cortex

n     The periostium is incised from 1 cm onto the rib cartilage to the full desired length, the anterior border of the latissimus dorsi muscle, about 12 cm.

n     Reflected carefully from the chest wall cortex around the inferior and superior rib edges to the pleural cortex periostium, using a maxillofacial surgery periosteal elevator rather than Doyen rib stripper

n     This is to avoid creating pleural tear, because of the irregularities and bony projection to which periostium and lung pleura are firmly attached, leading to pneumothorax

n     A releasing incision made at right angle to the rib incision carried to the rib edges help in reflecting the perichondrium and gaining access to the cartilage

n     The cartilage is separated first by scalpel blade and the proximal part is cut with a saw or rib cutter after lifting the rib and carefully separating any adherent periosteal membrane from the pleural cortex

n     The closure is layered, periostium, subcutaneous tissue, dermis and lastly skin

n     Drain is not necessary

o       The length of the cartilage is related to the growth of the graft not to the prevention of bony ankylosis

n       Disadvantages:

o     Longer length create a longer lever arm, promoting separation (2-3 mm)

o     Associated with overgrowth

o       Incorporation of the perichondrium or periostium sleeve, in the graft does not enhance survival or stability of the graft

n       In children the cartilage is easily separated from bone, sleeve reduce the chance of separation

n       In adult the cartilage is firmly incorporated to bone

n       Increases the probability of pneumothorax

o    It is recommended, a 2 – 3 mm of cartilage length without adherent periostium of perichondrium for both costochondral growth grafts in children and articulation graft in adult

Surgical Anatomy:      Iliac crest

o       Hip Bone:

n       Made of three bones fused in a Y-shaped epiphysis involving the acetabulum, (hip joint socket), a concave hemisphere,

n       Pubis and ischium form incomplete bony wall for pelvic cavity, their outer surface gives attachment to the thigh muscles

n       The ilium forms a brim between the hip joint and the joint with the sacrum

o      The anterior 2/3 is thin bone forming the iliac fossa, posterior abdominal wall

o      The posterior 1/3 is thick bone and carries the articular surface for the sacrum

o      The ilium is nearly at right angle to the other two bones

o       The outer surface rises wedge-shaped along an anterior border to the anterior superior iliac spine

o       Behind the acetabulum, it passes up as a thick bar of weight-bearing bone and curve back to the posterior superior iliac spine

o       It is the attachment of the muscles of the buttock, Gluteus minimus, medius and maximus

o       The upper border between the anterior and posterior superior iliac spines , the iliac crest, has a bold upward convexity and curve from front backward in a sinuous bend

o       The anterior part is curved outwards and it’s external rim has a more prominent convexity behind the anterior superior iliac crest spine, the iliac tubercle

o       The gluteal surface:

n       Convex in front, concave behind, conforming to the curvature of the iliac crest

o       The anterior border:

n       Shows a gentle S-shaped bend

n       Sartorius muscle is attached a finger breadth below the anterior spine

o       The posterior part of the crest is thicker than the rest

o      The inner surface:

n       The iliac fossa, shows a gentle concavity and is paper thin in it’s deepest part

n       The lower 2/3 is bare bone

n       The iliacus muscle and fascia are attached to the inner lip of the crest over the whole area

o    Bone harvesting:

n     The lateral approach to the anterior ilium affect the gait the most

n     The medial anterior approach involve the large iliacus muscle which is not necessary for normal gait but large medial haematoma might produce gait disturbances

o     Surgical access:

n      Incision should be placed 1 cm posterior to the anterior superior spine and extend to the iliac tubercle

n      It should be placed lateral to the bony prominence to prevent irritation by tight cloths or belt

n      Proceed down to bone medial to the muscles, tensor fascia lata and gluteus medius and lateral to the iliacus and the external abdominal muscles

n      Cancellous bone is available in the anterior ilium within the upper 2 – 3 cm and between the tubercle and the anterior superior spine, Iliac crest graft.

n      “Trap door” is one of the most common osteotomy used for anterior ilium harvest

n      During closure, strict attention should be followed in order to reorient and reposition the muscles in their original positions

n      A drain is required to because of the dead space and should be placed within the bony cavity

Surgical Anatomy:      The tibia

o      Is the largest and medial bone of the lower leg, has a large upper end and a smaller lower one

o      The shaft is vertical and triangular in cross-section

o      Its anterior and posterior borders with the medial surface between them are subcutaneous

o      The anterior border is sharp above and blunt below where it continue with medial malleolus

o      The posterior border is blunt and run down into the posterior border of the medial malleolus

o      On the fibular side it has a sharp interosseous border

o     The upper end:

n      Expand widely with prominent tuberosity projecting anteriorly from its lower part

n      The surface bone is a very thin compact-type which is fragile around the margins

n       The superior articular surface or plateau shows a pair of condylar concavity to articulate with meniscus and the condyle of the femur

n       Between the condylar surfaces, the plateau is elevated into intercondylar eminence and grooved by the medial and lateral tubercles

o      The lower end:

n       Is rectangular in section

n       Medially, it is subcutaneous, anteriorly, it is bare bone

n       Laterally, the surface is triangular and articulate with the fibula

o       The extensive subcutaneous surface of the tibia makes it an accessible donor site for bone grafts

o     Bone harvesting:

n      The tibial plateau is an excellent reservoir for cancellous bone

n      It can provide up to 40 cc of bone without affecting the structural support of the tibia

n      Indication:

o    Small bony defects

n      Non-union,

n      Osteotomy defects

n      Dentoalveolar defects

n      Sinus lift procedure

o     Surgical access:

n      Could be done under local anaesthesia and conscious sedation

n      Incision over the lateral tubercle best accomplished by flexing the leg at the knee joint

n      It is 6 – 10 mm from the skin and dissection is made through the thin subcutaneous tissue

Sharp dissection to reflect the tensor fascia lata band and make 1 cm opening into the cortex and the cancellous bone could be harvested lateral and inferior to the midline to avoid damage to the knee

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