BONE GRAFTING, BONE GRAFT SUBSTITUTES, AND GROWTH FACTORS

Bone grafts may be cortical, cancellous, or
corticocancellous. If structural strength is required, cortical bone
grafts must be used. However, the process of replacement produces
resorption as early as 6 weeks after implantation; in dogs, it may take
up to 1 year before the graft begins to regain its original mechanical
strength (45). Drilling holes in the graft does
not appear to accelerate the process of repair, but it may lead to the
early formation of biologic pegs that enhance graft union to host bone (17).

Cancellous bone has poor mechanical strength except when
loaded in compression after being packed into an area of bone defect.
For example, in repairing fractures of the tibial plateaus in which
cancellous bone has been lost as a result of crushing, cancellous bone
graft can be packed to support the articular surface of the plateau,
and can bear significant loads during rehabilitation. When the strength
of cortical bone combined with the more rapid incorporation that is
characteristic of cancellous bone is desirable, combined
corticocancellous grafts may be used. When a bone graft has a cortical
and cancellous surface, incorporation is enhanced by exposing the
cancellous portion to the surrounding soft tissues to facilitate
vascular invasion.

Bone graft terminology has changed, leading to some
confusion. In this text, we use the new terminology. The correlation
between the two is shown in Table 9.1. For
most applications, autogenous bone graft is indicated. Other types of
bone grafts are indicated only if autogenous bone graft is unavailable
or if it is insufficient and must be augmented. Another exception is
when structural whole or partial bones, with or without joint articular
surfaces, are needed for reconstruction of massive whole or partial
bone defects (10,13,19,20,44,56,57 and 58,76,81,91,92,95,106,108,146,156,165). This occurs most commonly in tumor surgery, in which preserved or fresh allografts are used (49,66,72,78,88,89,100,101,111,112). This is discussed in more detail later in this chapter and in Chapter 20, Chapter 106, Chapter 126, and Chapter 128.
For practical reasons, isografts are almost never used in human
surgery. Although xenografts have been tried in various forms in the
past, they have never met with much success, because of the immunologic
response of the host.

At the present time, autogenous cancellous bone is the
most osteogenic bone graft available and, therefore, is the most widely
used. Cancellous bone can be taken in strips or morcellized into fine
pieces that pack readily into small cracks or holes, or it can be used
to fill large, irregular voids. When packed firmly and contained,
cancellous bone provides good support against compression.The

best
source of cancellous bone is the ilium, although the metaphyseal region
of most long bones can be a source of bone graft. It is the principle
type of graft used for fractures, nonunions, and for arthrodesis of the
spine. If cancellous bone is in limited supply, it can be taken as
corticocancellous strips.

The single-onlay cortical bone graft was used most
commonly before the development of good quality internal fixation and
was employed for both osteogenesis and fixation in the treatment of
nonunions (Fig. 9.1A). The tibia is the most
common source of this graft; the split fibula can also be used. The
most common indication for this graft today is bone grafting and
stabilizing the cervical spine, although with modern techniques it is
rarely used. In osteoporotic bone, screws commonly do not achieve
adequate fixation. Even metal washers and nuts are inadequate, because
the bone collapses when they are tightened. In this situation, a
nonunion or fracture site can be bridged with a cortical bone graft and
a plate applied to the opposite cortex. The screws can then be placed
through the bone into the bone graft, resulting in a reasonably solid
construct. For this purpose, it is preferable to use one half or three
quarters of the thickened portion of the superior border of the iliac
crest rather than the tibia. If a long, straight graft is needed, the
fibula is preferred. The tibia is used as a last resort, because a
donor site of this size creates a large stress riser in the tibia that,
unless protected for a prolonged period of time, can lead to pathologic
fracture.

Boyd developed the dual-onlay cortical bone graft
technique in 1941 for the treatment of congenital pseudarthrosis of the
tibia (12). This technique is interesting for its historical significance (Fig. 9.1B).We
have not found an indication for this graft since the early 1980s.
Ilizarov techniques are more useful for severe problems of this type. A
version of this technique using allograft is useful for revision total
joint arthroplasty to replace bone insufficiency.

Albee popularized the inlay bone graft for the treatment of nonunions (3,4).
Inlay grafts are created by a sliding technique, graft reversal
technique, or as a strut graft. Although originally designed for the
treatment of nonunion of the tibia, these techniques are also used for
arthrodesis and epiphyseal arrest (Fig. 9.2A, Fig. 9.2B and Fig. 9.2C).

This technique is rarely used today, because internal
fixation combined with onlay cancellous bone graft provides a better
result. This technique may be combined with internal fixation if there
is limited space to place a cancellous graft. The disadvantages of the
sliding or reversed bone graft are that, after the cuts are made, the
graft fits loosely in the bed, and it creates stress risers proximally
and distally to the nonunion site. It is most safely used in
metaphyseal rather than diaphyseal regions. Its use today

has
been supplanted by rigid internal fixation and cancellous onlay bone
grafting. Onlay bone grafting has the additional advantage of providing
a higher polar moment of inertia than does the inlay technique. A
common use of the strut graft is for anterior vertebral fusion at all
levels of the spine. Ribs, fibula, or sections of iliac crest are
useful for this application (Fig. 9.2C). The reverse inlay graft is useful for nonunions of the medial malleolus.

The H-graft is a corticocancellous graft that is usually
harvested from the ilium and is specifically designed to achieve
posterior fusion of the cervical spine.

Dowel grafts were developed for the grafting of
nonunions in anatomic areas, such as the scaphoid and femoral neck,
where onlay bone grafting was impractical. In the carpal scaphoid, the
dowel is fashioned from dense cancellous bone (see Chapter 42). The use of the dowel graft for the management of nonunion of the femoral neck is illustrated in Figure 9.3.
Free microvascularized fibula grafts are more commonly used today. A
corticocancellous graft of appropriate length and approximately 25 mm
wide is harvested from the ilium or the tibia. The curvature of the
ilium often makes it difficult to obtain a straight graft of sufficient
length.

In most instances, dowel grafts have been replaced by
microvascularized fibular grafts and, on occasion, the quadratus
muscle-pedicle graft popularized by Meyers (see Chapter 29) or valgus osteotomy (96,97,98 and 99,163). Peg grafts have also been used to bridge the tibia and fibula to produce proximal and distal tibiofibular synostosis (94). Occasionally, these grafts are used for spine fusions as well (84).

Medullary grafts are not indicated for the diaphysis of
major long bones. Grafts in this location interfere with restoration of
endosteal blood supply; because they are in the central axis of the
bone, they resorb rather than incorporate. The only possible use for a
medullary graft is in the metacarpals and the metatarsals, where the
small size of the bone enhances incorporation. Even in this location,
however, internal fixation with onlay or intercalary cancellous bone
grafting may be a superior method.

In osteoperiosteal grafts, the periosteum is harvested
with chips of cortical bone. These grafts have not been proven to be
superior to onlay cancellous bone grafting, are more difficult than
cancellous bone to harvest, and may involve greater morbidity; they are
rarely used today.

Pedicle grafts may be local (139) or moved from a remote site using microvascular surgical techniques (see Chapter 36).
In local muscle-pedicle bone grafts, an attempt is made to preserve the
viability of the graft by maintaining muscle and ligament attachments
carrying blood supply to the bone or, in the case of diaphyseal bone,
by maintaining the nutrient artery. Two examples are the transfer of
the anterior iliac crest on the muscle attachments of the sartorius and
rectus femoris for use in the Davis type of hip fusion (see Chapter 106)
and the transfer of the posterior portion of the greater trochanter on
a quadratus muscle pedicle for nonunions of the femoral neck (see Chapter 29) (96,97,98 and 99).
Although technically more difficult, pedicle grafts have the advantages
of a high percentage of cell survival, rapid incorporation, and
increased active participation of the grafted cells in the healing
process. Free, microvascularized fibular grafts are used to replace
major deficiencies in long bones (see Chapter 36) and have been effectively used to treat avascular necrosis of the femoral head (see Chapter 125) (163).

The iliac crest is an ideal source of bone graft because
it is relatively subcutaneous, has natural curvatures that are useful
in fashioning grafts, has ample cancellous bone, and has cortical bone
of varying thickness. Removal of the bone carries minimal risk and
usually there is no significant residual disability. Abbott (1) demonstrated that the posterior third of the ilium is thickest (Fig. 9.4). This is confirmed by computer tomography (CT) scans (Fig. 9.5).

In treating small bone defects secondary to trauma or
small tumors, it may be most convenient to harvest the graft from the
ipsilateral extremity undergoing operation. The graft can often be
taken through the same incision or through a small, separate incision.
Most of these sites can be harvested through a small, 2.5 to 5.0 cm
longitudinal incision placed over the subcutaneous surface of the end
of the bone.

If a long, straight, large section of a cortical or corticocancellous bone is needed, harvest it from the proximal tibia.

Remove the shaft of the fibula through Henry’s approach, as described in Chapter 3.

Guidelines for the procurement, processing, and clinical
use of bone have been established by the American Association of Tissue
Banks. The goals of bone banking are to preserve the physical integrity
of the implant and its inductive proteins, reduce immunogenicity, and
ensure sterility. In general, a minimal interval (less than 24 hours)
between the death of the donor and the time of procurement is
desirable. Following the proper procedure for consent is essential.

Harvested bone is fashioned into various sizes and
shapes, and soft tissues and cells are removed to reduce
immunogenicity. Freezing to -70°C in a sterile state effectively
decreases immunogenicity and maintains sterility; this is generally
recommended for osteoarticular allografts (86).
Because the osteoarticular allografts frequently need to be matched for
size, the height and sex of the donor should be recorded by the bone
bank to permit as close a match as possible with the recipient (68). This method of storage decreases the strength of the allograft by about 10% (7).
Ethylene oxide sterilization also is effective, although it may destroy
bone-inductive proteins. The bone is preserved by freeze drying after
removal of ethylene oxide (79,118).
Freezing to -70°C and freeze drying reduce the immunogenicity of the
implant but with some compromise to its mechanical strength. Freezing
bone decreases its tensile and compressive strength by about 10% each,
whereas freeze drying decreases torsional strength by about 50% and
compressive strength by about 10% (114). The
process of replacement by host bone entails a transient reduction of
approximately 50% of strength. Sterilization of bone by heating to more
than 62°C, by autoclaving, or by gamma irradiation disrupts the
physical and chemical nature of bone and alters its mechanical
properties (18,35).
Bone implants subjected to these physically damaging processing methods
perform poorly. Bone subjected to freeze drying, partial
demineralization, or freezing incorporates more slowly than fresh
autografts or syngeneic grafts (11,107,161).

Osteoarticular shell allografts must be stored in a
fresh state for 24 to 72 hours until the donor has been adequately
screened. The joint surfaces usually are stored in situ in the donor body at 4°C in a morgue environment. This ensures adequate viability of the cartilage for transplantation (133,146).

Quality control measures must be enforced to avoid the
transfer of bacterial, fungal, or viral pathogens to the recipient.
Such measures should include patients’ histories and screening tests
for hepatitis, acquired immunodeficiency syndrome (AIDS), and syphilis.

Table 9.2 shows storage
techniques commonly used for various types of musculoskeletal
allografts. Their applications have been well summarized by Czitrom (37).

A successful bone graft eventually will be incorporated
into the skeletal system of the host. In the process of incorporation,
new bone deposited by the recipient envelopes and replaces the donor
bone tissue. How rapidly the graft is incorporated depends on its size,
structure, position, fixation, and genetic composition. The role of the
graft in stimulating incorporation may encompass osteoconduction,
osteoinduction, and osteogenesis.

The criteria that characterize an ideal graft follow
from the goal of restoring structural stability to bones or joints with
mechanical properties equal to adjacent bone and with an acceptable
cosmetic result. Therefore, the graft should be strong, potentially
viable, nonreactive (nontoxic, noncarcinogenic), sterile, storable,
capable of being shaped during surgery, and affordable.

The eventual choice of a graft depends on the type of
structural and osteogenic functions desired, the size and shape of
various donor bones, and whether viable articular

cartilage
needs to be transplanted. The morbidity attendant on procuring an
autogeneic graft is often a limiting factor in bone graft surgery;
however, the use of some autogeneic corticocancellous bone is almost
essential in certain applications (such as posterolateral lumbar and
cervical spine fusions and to supplement allografts at the
osteosynthesis site). Alloimplants seldom result in fusion across
transverse processes or posterior arch structures; autolyzed,
antigen-extracted allogeneic (AAA) bone may be an exception (151).
Some autograft bone should almost always be used with allografts
because it helps to avoid nonunion and stimulates incorporation.

The choice of grafting material depends on the anatomic
and spatial constraints of the area to be stabilized and the osteogenic
capacity of the host bed in orthotopic bone grafting. In general,
vertebral bodies, which are rich in cancellous bone and marrow, provide
far greater numbers of osteoprogenitor cells for remodeling a graft
than spinous processes, facets, and transverse processes, which are
composed mostly of cortical bone. Hence, demands placed on a graft
destined for posterolateral areas of the spine are greater than those
imposed on bone grafted to an intervertebral body location. For
posterolateral grafting of the spine, fresh autogeneic bone, either
alone or in a composite graft, is considered essential because the
graft provides surviving osteogenic precursor cells and inductive
factors. Frozen or freeze-dried devitalized allogeneic cortical and
cancellous bone may be used for cervical and lumbar interbody fusions
when less is demanded of the graft and when the recipient bed is rich
in marrow. At these locations, the incidence of fusion is the same with
allogeneic

bone and fresh autografts, although the rate at which the allograft fuses is slower (6,26,91,142).

At times, vertebral bodies of the cervical, thoracic,
and lumbar spine are lost because of degenerative processes, infection,
or neoplasia. Struts of allogeneic fibular bone can be used effectively
to restore stability; these struts are eventually incorporated and
remodeled. Even in the presence of recent osteomyelitis, devitalized
allogeneic bone can fuse and provide structural support for the
weakened spine (16). For large, multilevel
defects of several vertebral bodies, a femoral allograft frequently
will fill the defect and provide the correct curvature. In these cases,
additional internal fixation to protect the graft throughout its length
is advocated.

Long fusions that are necessary in operations for
scoliosis frequently are performed in young children who do not have
enough bone present in the iliac crests to provide adequate amounts of
autograft. In these cases, allograft bone (frozen, freeze-dried, or AAA
bone) may be morcellized and mixed with the child’s own bone to provide
adequate amounts of graft material. More recently, titanium cages
filled with various grafting materials have been used for interbody
fusions. See Chapter 146 for more details.

Allografts for major tumor surgery have been used during
the past 50 years, and recent results have approached 85% good or
excellent (72,76,116,124).
The needs for grafting in tumor surgery vary considerably, depending on
whether the defect is diaphyseal, ligamentous, tendinous, or cavitary
(cysts).

Because abrasion chondroplasty and arthroplastic reconstruction for joint surface defects can yield poor results (47,56,81,87),
biologic resurfacing of joint defects is being tried. The concept of an
autogenous free periosteal graft coupled with continuous passive motion
(105) or autogenous cartilage cell implant
combined with perichondrium is in early clinical trials and has
demonstrated mixed success (see Chapter 86). The use of autogenous osteoarticular autografts is an acceptable means of reconstruction (134,140,141).
However, this technique has the disadvantage that the available graft
materials seldom have a suitable shape for reconstructing a given
defect.

Somewhat better known is the use of shell allografts,
involving the transplantation of a devascularized, osteoarticular
allograft with a small bony component. Studies of osteoarticular shell
allografts in humans have not been followed long enough or often enough
to determine their outcome, but several authors have reported promising
early results (56,57 and 58,97). Of the shell allografts that have failed, some appear to have had a significant pannus reaction (75), suggesting that an immune response was induced by the cells of the subchondral bone (36,136).

The specific techniques in performing shell allografts vary to a certain extent, because the defects vary considerably.

Allografts for revision arthroplasties have been used
primarily in the hip. Major segmental defects in the acetabulum as well
as the proximal femur may occur after multiple revision arthroplasties.
These defects can be reconstructed with allografts (see Chapter 106). Acetabular defects may be divided into rim defects, medial wall defects, and global defects.

The use of bone and joint allografts after severe
traumatic destruction of skeletal parts presents many more difficult
problems than replacement of tumor or arthritis defects. Severe
soft-tissue injuries usually accompany the bony trauma, and many of the
wounds have been previously infected (Fig. 9.16).
Therefore, the surgeon is frequently operating in an area of decreased
blood supply, poor skin coverage, and persisting organisms from
previous infections. Most of the experience with allograft use in the
treatment of traumatic defects has come from the wartime experience,
and the following important prerequisites should be followed (15):

Failure to adhere to these principles places the graft at significant risk of failure.

Osteoinduction is the process of inducing
pluripotential, primitive mesenchymal stem cells to differentiate into
osteoblasts. The process of induction has been intensely investigated
by Urist et al., and others (7,8,143,147,148,149,150,151,152,153 and 154).
Induction of bone formation occurs, in part, as a result of nonsoluble,
noncollagenous, bone morphogenetic proteins, as well as other inductive
proteins (21,22,48,50,51,53,103,127,147,148,149,150,151,152,153 and 154,159). The most intensely studied of these proteins is from those composing the BMP super family. These proteins are summarized in Table 9.5.

The most intensively studied of these BMPs thus far has
been recombinant BMP2 (rhBMP-2) and rhBMP-7, also known as osteogenic
protein-1 (OP-1).

In one of the earlier studies, Heckman et al. (63)
found that when species-specific BMP was placed in a canine radius
nonunion model using a polylactic acid carrier, that a higher incidence
of union occurred as compared with that of controls. Yasko et al. (162),
using human rhBMP2 in a critical defect model in the femora of rats,
were able to demonstrate successful union compared with controls. This
was dose related, requiring a large dose of 11.0 µg to achieve union.
Gerhart et al. (48), using the same protein but
in a segmental defect in the femur of sheep stabilized by a plate,
showed no bony union in their negative control groups but complete
union in their experimental group and autograph controls. Similar
results were demonstrated in a rabbit critical defect model (166).
A significant number of human clinical trials are now under way with
these very interesting proteins. Recently published studies have
demonstrated successful use of a human BMP to augment one-stage
lengthening of femoral nonunions (73). When the
appropriate carrier vehicles are combined with the appropriate protein
or proteins, there is a high likelihood that they may replace the use
of autologous bone graft and nonstructural allografts to a great
extent. Future research in tissue engineering may result in synthetic
structural grafts as well.

Autologous red bone marrow, usually obtained by
aspiration in adults from the axial skeleton, contains a small but
significant number of pluripotential mesenchymal stem cells and
inductive factors that have been used to treat nonunions (27,28). Connolly et al. (27,28) have demonstrated the efficacy of repeated injection of tibial nonunions as a substitute for open operative grafting.

As opposed to induction discussed above, conduction
consists of the growth of host bone into a bone graft or matrix by the
growth into available channels in the graft of vascular buds, followed
by the laying down of osteoblasts along these channels with subsequent
bone formation. In some cases, osteoclastic resorption along the
channels may be a part of this process, but this is not necessary with
many materials. From the standpoint of a material introduced into a
bone defect site, this represents a passive rather than an active
phenomenon as in bone induction. Bone conduction can occur through an
open matrix, such as one would find in granules packed loosely
together, or through structural channels, such as found in some types
of coral, in which the ideal size appears to be somewhere between 250
and 600 µ in diameter. A number of synthetic or naturally derived
bone-filling materials, some of which promote bone formation through
conduction, are now on the market or under investigation. If these
materials are used as a carrier vehicle for inductive proteins, then
induction would of course also play a role. In their review of the role
of bone substitutes, Hollenger et al. (69) provide a list of those available in the United States as of 1996. This list is summarized in Table 9.6.

For orthopaedic applications, the most commonly used
materials at this time are Collagraft, Grafton, and ProOsteon 500. The
Norian SRS material has received considerable attention recently, but
it is still in clinical trials and is not available for general use.

Grafton is a form of demineralized bone matrix. It is
nonstructural and supplied as a particulate. It may retain some bone
induction capability. Most surgeons use it to graft fracture repairs
where some assistance is desired but the surgeon either does not wish
to incur the morbidity of harvesting a bone graft or is not prepared to
harvest a bone graft. Otherwise, most surgeons seem to be using it as
an adjunct to autologous bone grafting to expand the bone graft,
particularly in spine fusions.

Collagraft is a nonstructural graft supplied in strips
that, after rehydration, becomes soft and can be packed into bone
defects or laid on the surface of bone. In laboratory and clinical
studies, it has proven to be equally efficacious as autologous bone
graft in the experimental models and clinical applications chosen (24,32,59,90,93,102).
Collagraft has not experienced much popularity, however, because the
most common application of this type of material is to fill metaphyseal
defects where some structural integrity is necessary that the
Collagraft material does not offer.

This hydroxyapatite is provided in two differing
porosities with cross-connected channels and is manufactured by the
chemical transformation of the calcium carbonate skeleton of a marine
coral. It has been shown in canine critical defect models to
incorporate well with excellent bone growth into the open channels of
the graft (90,93).
Currently this material is approved by the Food and Drug Administration
(FDA) for the filling of metaphyseal defects. It is used at our
institution for filling the defects in juxtaarticular fractures such as
those in the distal radius, in tibial plateau fractures, and in pilon
ankle fractures. We also use it to fill defects created by the removal
of small benign bone tumors (104). This
material is available both in block and granular form. Because it is a
very brittle material it is difficult to work with. It is quite weak in
shear and tension. When contained in a bone cavity totally surrounded
by bone, where the cavity is firmly packed with the material, it offers
reasonable resistance to compression, sufficient enough that it is
practical for reconstruction of tibial plateau fractures. Additional
support with internal fixation is required. Excessive packing can crush
the blocks and granules and reduce their porosity, potentially
interfering with bone ingrowth, but this problem has not been
documented in practice.

Complications from the use of these materials are few.
Because it is essentially pure hydroxyapatite, it illicits no immune
response. Occasionally, joint surfaces will settle because of
structural weakness in the material, but this can usually be avoided by
appropriate internal fixation. Because it is a foreign body, it could
potentially be a problem if infection were to occur. However, the
studies noted earlier actually show a slightly lower infection rate
with ProOsteon when compared with autologous bone. If significant
infection were to occur, then resolution of the infection would most
likely require removal of the ProOsteon. Lastly, the granules can
occasionally get into anatomic sites that are not desirable. In packing
the granules into bony defects, they often become adherent to the
surrounding soft tissues. Although in our experience this results in no
untoward effects, it does produce a less pleasing radiograph. It is a
somewhat laborious task to pick each of the particles off the soft
tissue. In addition, we have seen one case of a ProOsteon 500
arthrogram of a knee in which a surgeon packed the granules into the
defect of

a
severe tibial plateau fracture, apparently unaware that there was an
opening in the joint surface that allowed passage of the granules into
the joint space. One year after this occurrence, we arthroscoped the
knee and found the knee joint cartilage and menisci to be in perfect
condition, with no evidence of untoward effects from the granules. The
granules were all adherent to the synovium and were visible through the
arthroscope but appeared to be covered by a thin membrane as they were
apparently incorporated into the synovium. Therefore, removal of the
granules was impractical and seemingly unnecessary. Whether there will
be any long-term untoward effects of this complication remains to be
seen.

The Norian material is in a new unique class of
injectable calcium phosphates. To a mixture of three different calcium
phosphates and calcium carbonate, a sodium phosphate solution is added,
resulting in a paste that is formable and injectable for approximately
5 minutes. It is biocompatible as it sets at physiologic temperatures
and Ph. The dahllite in the paste hardens after about 10 minutes,
obtaining an initial compressive strength of approximately 10 mPa.
Within 12 hours, full strength is achieved, with a maximum compressive
strength of approximately 55 mPa and tensile strength of 2.1 mPa (29). Orthopaedic surgeons have been seeking some type of bone glue and

injectable synthetic bone replacement for years, and this is the first
commercially available implant of its type to be shown to be clinically
useful. It is not truly a bone glue but can immobilize and fix
cancellous bone fragments into place by mechanical interlocking.
Cortical bone fragments pressed into the material can likewise be
immobilized by mechanical interlocking. When the material has set, it
is a relatively solid material that does not offer any porosity for
bone conduction. Animal studies show that the material is replaced by
host bone in a manner similar to bone remodeling on the surface of the
implant. The rate of remodeling and whether or not the Norian material
will eventually be entirely replaced by host bone in humans has not yet
been established. Preliminary clinical studies suggest that the Norian
SRS material may be useful in weak osteoporotic bone, Colles’ fractures
of the distal radius, tibial plateau fractures, other juxtaarticular
fractures involving cancellous bone, and possibly in spinal
reconstruction and revision acetabular arthroplasty (29,54).
At the time of this writing, this material was not yet approved by the
FDA for general use. Within the lifetime of this edition of Chapman’s Orthopaedic Surgery,
no doubt this material will be widely employed. Two potential
complications exist: Material may penetrate into the intraarticular
space when it is injected percutaneously; and when a large amount of
material is used relative to the size of the bone, particularly if it
covers the vast majority of the fracture interfaces, delayed or
nonunion could occur. To the best of our knowledge, neither of these
problems have been reported in the literature.

In 1989, Younger and Chapman (164)
reported a major complication rate of 8.5% and minor complication rate
of 20.6% at 243 bone graft donor sites harvested by all types of
surgeons at their institution. Potential early complications include
wound dehiscence, infection, seromas and hematomas, pain, inadvertent
injury of adjacent joints, muscle or bowel herniation, and injury to
important structures such as nerves, vessels, and the ureter.
Intermediate and long-term complications include an ugly or painful
scar; bony deformity; fracture, with or without nonunion; chronic pain;
persistence of neurologic injury; and reflex sympathetic dystropy, as
well as others. Younger and Chapman reported a higher incidence of
complications in patients undergoing posterior spine fusion in which
the bone graft was harvested through the same incision as used for the
spine surgery. Hugh and Bohlman (70), however,
focused on the incidence of fractures at the iliac bone graft harvest
site, finding 14 patients with fractures out of approximately 400
fusions divided equally between the cervical and lumbar spine. These
were either avulsion fractures of the anterosuperior iliac spine or
fractures of the iliac wing. All patients were treated nonoperatively
with excellent long-term outcomes. They identified older women with
osteopenic bone as being particularly prone to this complication. In
1997, Goulet et al. (55) reviewed 170 patients
from whom bone grafts were harvested. Major complications occurred in
four (2.4%) in whom deep infection developed. Thirty-seven patients
(21.8%) had minor complications. Several of their patients (18.7%)
continued to report pain more than 2 years postoperatively. In spite of
this incidence, the vast majority of patients were functioning well at
2 years postoperatively. Simple rules to minimize the risks of
complications in bone graft donor sites are detailed in the Hints and
Tricks sidebars throughout this chapter.

Large seromas or hematomas usually manifest themselves within the first few days by a large swelling at the incision

site with clear or serosanguineous drainage. These lesioms are usually
not a problem if they are contained by a tightly closed fascia.
However, a large seroma or hematoma presenting in the subcutaneous area
may require aspiration and compression dressing or exploration of the
wound for drainage, control of bleeding points, and repeat closure over
suction drainage. This is important because these lesions can be very
slow to resolve, and persistent drainage can lead to retrograde
infection of the donor site.

Postoperative wound infection nearly always occurs
early, within the first 1 to 3 weeks. Early surgical intervention to
drain and debride the operative site is nearly always indicated. Gram’s
stain and deep cultures are important, along with early institution of
appropriate intravenous bacteriocidal antibiotics. If surgical and
medical treatment is performed early, most patients respond quickly to
treatment, and chronic osteomyelitis is rare. Chronic osteomyelitis in
a donor site requires thorough debridement of all nonviable bone and
treatment, as outlined in Chapter 133.

Although most patients tolerate an area of loss of
sensation, some develop painful neuromas that can be disabling and even
lead to reflex sympathetic dystropy. Simple loss of sensation due to a
neuropraxia of the nerve secondary to retraction is usually managed
well by appropriate counseling of the patient and watchful waiting.
Persistent complaints with a definite trigger point, Tennel’s sign, or
palpable neuroma usually merit surgical exploration of the nerve.
Magnification should be used for careful inspection of the nerve. If an
intact nerve is found with minimal intraneural scarring, then simple
decompression with neurolysis may suffice. If a neuroma or dense
intraneural scarring is found, then resection of the injured segment
with repair of the nerve, or in some cases resection with burying of
the proximal stump, may be indicated depending on the nerve involved
and the patient.

Acute vascular injuries that do not threaten the
viability of important structures or the extremity are usually dealt
with at the time of initial injury with ligation of the vessel. Injury
of larger vessels that are important to function or limb survival
require acute repair and intervention of a vascular surgeon when the
orthopaedic surgeon is not qualified to perform vascular repairs. The
most vexing late complication of a vascular injury is a pseudoaneurysm
in which the initial vascular injury was not appreciated by the
surgeon. Most typically, these lesions present as a mass or swelling
that may or may not be painful. On physical examination, they may be
pulsatile or have a bruit on oscultation or palpation. Ultrasound or
arteriogram, or both, is usually necessary to make a diagnosis, and
vascular surgery consultation for surgical correction is nearly always
indicated.

The most common fracture is avulsion of the
anterosuperior iliac spine or a split in the anterior column resulting
in inferior and anterior displacement of the anterior fragment to which
the sartorius and occasionally the rectus femuris are attached. The
vast majority of these fractures can be treated nonoperatively with
limited weight bearing with crutches. Union usually occurs within 6 to
10 weeks. The patient may be left with some deformity of the pelvis,
but usually this is asymptomatic and not of cosmetic concern. For the
most part, these fractures occur in elderly osteoporotic women.
Occasionally, they occur in young active athletes. In these cases, open
reduction and internal fixation may be indicated.

Fractures of long bones due to bone graft harvest in
metaphyseal areas with minimal displacement can usually be treated
nonoperatively. Displaced unstable mid-diaphyseal fractures,
particularly in the tibia and femur, are usually best treated with
closed reamed intramedullary nailing. Reaming of the medullary canal
grafts the defect site, and if necessary, additional cancellous bone
can be added by the intramedullary or subperiosteal route (23).
Intramedullary nailing usually allows early weight bearing and return
to function. Because these fractures can be very slow to heal, the
intramedullary nail provides prolonged protection of the fracture site.

All surgeons fear the day when an important autologous
bone graft just harvested from the patient is accidentally dropped to
the floor of the operating room. Little has been written about what to
do in this circumstance other than to abandon the graft and harvest
another one, if available. Presnal and Kimbrough (117)
found that 50 surplus bone grafts dropped in the operating room in
their institution and submitted for culture were sterile. Therefore,
they recommended that, if a bone graft that had been dropped on the
operating room floor was to be implanted in the patient, extensive
sterilization was not essential. Our approach to the dropped graft is
as follows:

Careful monitoring of the patient postoperatively and
appropriate postoperative intravenous bacteriocidal antibiotics are
appropriate. Counseling of the patient is wise.