General Principles of Fracture Treatment

Open Fractures Caused by Firearms

Evaluation of a patient with an open fracture caused by a firearm should include plain anteroposterior and lateral radiographs of the area of injury, as well as the joints above and below the injury. Arthrography may be necessary to identify joint penetration by a projectile. CT should be used to determine the precise location of the missile if the spine or pelvis is involved and is helpful in evaluating articular injuries. If vascular injury is suspected, angiography or arteriography may be necessary to confirm the diagnosis.

As encountered in civilian practice, firearm wounds are of three distinct types: (1) low-velocity pistol or rifle wounds, (2) high-velocity rifle wounds, and (3) close-range shotgun wounds. In low-velocity pistol or rifle wounds, soft-tissue damage usually is minimal and extensive debridement is unnecessary ( Fig. 53.4 ). The wounds of entry and exit are small. They usually do not require closure, and only their skin edges require debridement. In low-velocity gunshot wounds, irrigation and local debridement, tetanus prophylaxis, and a single dose of a long-acting intramuscular cephalosporin have been found to be as effective as 48 hours of intravenous antibiotics, and oral and intravenous administrations of antibiotics were shown to be equally effective for prophylaxis against infection. Infection in this type of wound is rare. A proposed treatment protocol for intraarticular fractures includes 1 to 2 days of antibiotic prophylaxis for injuries in which the bullet passed through “clean” skin or clothing and 1 to 2 weeks of broad-spectrum antibiotic treatment for wounds in which the bullet penetrated lung, bowel, or grossly contaminated skin or clothing. Civilian gunshot wounds have been classified according to energy, vital structures involved, wound characteristics, fracture, and degree of contamination. This classification, however, is complex, has not been validated, and offers no guidelines for treatment.

Some gunshot wounds can be treated with outpatient oral antibiotics following a single dose of intravenous cephalosporin. Dickson et al. reported that a superficial infection occurred in only one of 41 patients (44 fractures) with Gustilo type I or II open fractures caused by low-velocity gunshot wounds who were treated with their outpatient protocol: tetanus toxoid, 0.5 mL, irrigation and local wound debridement, closed reduction (if necessary), placement of a dressing or splint, 1 g of intravenous cefazolin, and 500 mg of oral cephalexin four times daily for 7 days.

In high-velocity rifle and shotgun wounds, the damage to soft tissue and bone is massive and tissue necrosis is extensive ( Fig. 53.5 ). These wounds should be treated in much the same manner as battle wounds. They require wide exposure and debridement of all devitalized soft tissues. These wounds should be left open for delayed primary or secondary closure depending on the nature of the wound. In close-range shotgun wounds, damage to soft tissue and bone is extensive. Unless the wound is through and through, the wadding of the shell usually is retained within it and can cause severe foreign body reactions. All wadding must be found and removed and devitalized soft tissue excised. Removing all of the lead shot is unnecessary; it seems to cause little reaction, and attempting to remove it can cause further damage to the soft tissues. However, bullets and bullet fragments should be removed from intraarticular or intrabursal locations because they can produce complications of mechanical wear, lead synovitis, and systemic lead toxicity. Systemic lead toxicity has been reported to occur as early as 2 days and as late as 40 years after intraarticular gunshot injury. These wounds also should be left open and are closed later.

Although both delayed and immediate reamed interlocked nailing have been successful in the treatment of femoral fractures, immediate nailing of femoral fractures caused by gunshots has been reported to result in shorter hospital stays, with significant decreases in hospital expenses, and no detrimental effect on clinical results compared with delayed nailing. Statically locked intramedullary nailing is currently our preferred treatment for most low-velocity and mid-velocity femoral shaft fractures, including most subtrochanteric and supracondylar fractures. Femoral fractures caused by high-velocity weapons or shotguns can be temporarily stabilized with external fixation. When wound healing is satisfactory, intramedullary nailing can be performed (approximately 2 weeks after injury). Some high-velocity fractures can be treated with immediate unreamed intramedullary nailing. Primary amputation may be required for severe soft-tissue injury that includes vascular and neurologic injury. In a series of 52 femoral fractures with arterial injuries treated at our local level 1 trauma center, limb salvage was successful in 32 (61.5%). All 22 limbs in which the femoral fractures were stabilized with intramedullary nails either initially (16 limbs) or after traction or external fixation were salvaged. Primary amputation was required in eight limbs with high-velocity injuries, secondary amputations were required in nine limbs, and three patients died of other injuries. No disruption of the anastomoses occurred in patients in whom vascular repair preceded fracture fixation ( Fig. 53.6 ).

External fixation may be appropriate for severe (Gustilo type III) injuries. Ilizarov fixation and delayed primary closure have been reported to yield a low overall complication rate and a low infection rate in these complex fractures.

In a report of gunshot injuries to the hip, the best diagnostic test to detect joint penetration was hip aspiration followed by an arthrogram. Although selected patients were treated successfully with antibiotic therapy without arthrotomy, all transabdominal injuries required immediate arthrotomy. Bullets left in contact with joint fluid resulted in joint destruction or infection. Because all displaced femoral neck fractures treated with internal fixation had poor results, hip arthroplasty or arthrodesis was recommended for definitive management of these injuries.

Amputation Versus Limb Salvage

The development of sophisticated protocols for open fracture management has permitted the development of techniques that result in salvaged but nonfunctional extremities. There is concern, however, about “technique over reason” and not only the end result of a useless limb but also the physical, psychologic, financial, and social effects on the individual. Inevitable amputation often is delayed too long, with increased financial, personal, and social expenses and, more important, the attendant morbidity and possible mortality. In a study of open tibial fractures, patients who had limb salvage had more complications, more operative procedures, longer hospital stays, and higher hospital charges than patients who had early below-knee amputations. More patients with limb salvage considered themselves disabled than did those with early amputation.

Several attempts have been made to better evaluate injuries and identify injury patterns that would best be treated by early amputation. The Mangled Extremity Severity Score (MESS) is based on a four-group system: skeletal and soft-tissue injuries, shock, ischemia, and age ( Table 53.3 ). Some studies have found that limbs with scores of 7 to 12 ultimately required amputation, whereas scores of 3 to 6 resulted in viable limbs; others have found no predictive utility of the MESS, Limb Salvage Index (LSI), or Predictive Salvage Index (PSI). A high specificity of the scores confirmed that low scores could be used to predict limb-salvage potential, but the low sensitivity failed to support the validity of the scores as predictors of amputation. These scoring systems appear to have limited usefulness and cannot be used as the sole criterion to determine whether amputation is indicated, and lower extremity injury-severity scores at or above the amputation threshold should be used with caution in determining the potential for salvaging a lower extremity with a high-energy injury.

Rajasekaran et al. proposed a scoring system for Gustilo types IIIA and IIIB open fractures of the tibia that evaluated skin coverage, skeletal structures, tendon and nerve injury, and comorbid conditions ( Box 53.3 ). Using this system, they divided 109 type III open tibial fractures into four groups to assess the possibilities of limb salvage. Group 1 had scores of 5 or less, group 2 had scores of 6 to 10, group 3 had scores of 11 to 15, and group 4 had scores of 16 or greater. A score of 14 or greater as an indicator for amputation had a sensitivity of 98%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 70%. These were similar to the MESS scores of 99% sensitivity and 97% positive predictive value, but better than the 17% specificity and 50% negative predictive value. The high specificity of this new scoring system may make it a much better predictor of amputation. Currently, however, the predictive power of all extremity injury scores remains low.

Antibiotic Treatment

The treatment of an open fracture wound actually is an exercise in applied microbiology. Once the skin barrier is disrupted, bacteria enter from the local environment and attempt to attach and grow ( Fig. 53.7 ). The greater the zone of injury and the more necrotic the tissue, the greater the potential for nutritional support of the bacteria. With impairment of circulation in the injured area, the body’s immune system is compromised in its ability to use cellular and humoral defenses. A race then ensues between the bacteria to establish an infection and the body to mobilize sufficient immune mechanisms to combat the infection.

The virulence of the infecting organism depends on its ability to adhere to the host substrate (e.g., necrotic skin, fascia, muscle, and bone), its pathogenicity, and its offensive efforts to neutralize the host defenses by the bacteria’s own humoral and mechanical factors. The foreign body reaction is now recognized as a complex interaction of bacterial glycoprotein that protects the bacteria from the phagocytic white blood cells ( Fig. 53.8 ). After the bacteria have invaded the body, adhered to the host cellular substrate, and secreted the humoral and glycoprotein protective shield, they can then proceed with cell replication, establishing a clinical infection. Growth of the bacteria then proceeds in a logarithmic fashion until the available nutrients are exhausted, the host dies, or the host defenses successfully neutralize the infection. If the latter occurs and the host survives, the bacteria either will be eradicated or suppressed and isolated, creating chronic osteomyelitis ( Fig. 53.9 ).

The care of open wounds generally includes postoperative systemic antibiotics. A 2004 Cochrane systematic review confirmed the benefit of antibiotics in patients with open fractures. This review showed that the administration of antibiotics after open fracture reduces the risk of infection by 59%. The data reviewed supported the conclusion that a short course of first-generation cephalosporins, begun as soon as possible after injury, significantly lowers the risk of infection when used in combination with prompt, modern orthopaedic fracture wound management. Evidence was insufficient to support other common management practices, such as prolonged courses or repeated short courses of antibiotics, the use of antibiotic coverage extending to gram-negative bacilli or clostridial species, or the use of local antibiotic therapies such as beads.

Most protocols recommend the use of a broad-spectrum antibiotic, usually a first-generation cephalosporin, with the addition of an aminoglycoside, such as tobramycin or gentamicin, for highly contaminated wounds in which there is a risk of gram-negative contamination (Gustilo type III). If there is the possibility of anaerobic organisms, such as Clostridium, high-dose penicillin is recommended. The duration of antibiotic treatment should be limited because in most series the infecting organisms are hospital acquired. Gustilo recommended administration of 2 g of cefamandole on admission and 1 g every 8 hours for 3 days only in types I and II open fractures. In type III open fractures he recommended an aminoglycoside in dosages of 3 to 5 mg/kg daily, adding penicillin, 10 to 12 million U daily, for farm injuries. Gustilo continued double antibiotic therapy for 3 days only and repeated the antibiotic regimen during wound closure, internal fixation, and bone grafting. Okike and Bhattacharyya recommended the administration of cefazolin, 1 g intravenously, every 8 hours until 24 hours after the wound is closed, with intravenous gentamicin (with weight-adjusted dosing) or levofloxacin (500 mg every 24 hours) added for type III fractures. Because of their adverse effect on healing, fluoroquinolones should not be used for antibiotic prophylaxis in patients with open fractures.

Although there is general agreement regarding the effectiveness of antibiotic treatment in open fractures, debate is ongoing about the duration, mode of administration, and type of antibiotics. A prospective, double-blind study showed a 13.9% infection rate without antibiotics compared with a 2.3% infection rate with cephalosporin treatment, but these results have been questioned, and the number of reliable studies in this area is very limited. Another study found that a once-daily, high-dose regimen of antibiotic therapy was as effective as a divided, low-dose regimen. Our current antibiotic protocol for open fractures is intravenous cefazolin 2 g every 8 hours for 24 hours after operative debridement in types I and II open fractures. In patients with cephalosporin or penicillin allergies, clindamycin 900 mg is substituted. For type III open fractures, patients receive intravenous piperacillin/tazobactam 3.375 g every 6 hours for 24 hours after operative debridement; intravenous clindamycin 900 mg every 8 hours with intravenous aztreonam 2 g every 8 hours is substituted for patients with penicillin or cephalosporin allergy. In patients with open pelvic fractures associated with bowel injury, antibiotics are continued for 48 hours. Nonoperatively treated gunshot fractures receive one dose of cefazolin 2 g or clindamycin 900 mg intravenously.

The appropriate time to obtain cultures from open wounds also is controversial. A very small number of bacteria present before debridement are believed to eventually cause infection, suggesting that bacterial cultures taken before or after debridement are essentially of no value. The most common infecting organisms appear to be gram-negative and methicillin-resistant Staphylococcus aureus (MRSA), which may be hospital or community acquired. We do recommend obtaining cultures when obvious clinical findings of infection are present at the second debridement. More recently, a marked improvement was noted in infection rates using cultures obtained after debridement and irrigation to determine the need for repeat formal irrigation and debridement, although there was an increased rate of return to surgery with this rationale. Early and rapid empirical administration of antibiotics as determined by wound protocols has been shown to be the most effective means of preventing infection in open fractures.

Debridement

Individual patient characteristics should be considered in determining the exact extent of debridement necessary, but generally the skin should be debrided until there is a bleeding edge. This should not be done under tourniquet control because the viability of the skin may not be known.

Muscle debridement should remove all nonviable muscle that is noncontractile or grossly contaminated. Completely severed tendon ends that are highly contaminated also may require excision, although this becomes a much more questionable practice if the musculotendinous unit is intact. Removal of contamination with preservation of the tendon itself may be possible. Care must be taken to maintain moisture around such structures because once the tendon becomes dried it is dead and excision will be necessary. Early flap placement or a sealed dressing may prevent desiccation of these delicate tissues. When dealing with muscles, the four “ C ”s must be observed: consistency, color, contractility, and circulation. Normal muscle contraction should be seen when the muscle is pinched or electrically stimulated. The muscle should be of normal consistency, not waxy , fibrotic, or friable. The muscle should be a normal color of red, not brown. Good circulation should be visible within bleeding edges.

The empirical standard for timely debridement has been the “6-hour rule,” although only a few studies have shown decreased infection rates when debridement was done within 6 hours, and many studies have questioned the validity of this standard. A few authors have suggested that operative debridement might be unnecessary for low-grade open fractures. We consider thorough operative debridement done as soon as possible after injury the standard of care for all open fractures, however. One recent study questioned whether surgeons were removing normal muscle at times. The surgeons’ impression of muscle viability based on the four “ C ”s was compared with histologic analysis. In 60% of specimens, histologic analysis revealed normal muscle or mild interstitial inflammation of tissue deemed dead or borderline by the surgeon. It is unclear what would have happened to this muscle if left in situ. Until better methods of intraoperative assessment of muscle viability are available, it seems prudent to debride any questionable tissue (or return to the operating room for a second-look debridement).

After the dead, contaminated, and necrotic tissues have been removed, the next step is copious irrigation. Some experimental but few clinical studies have evaluated the efficacy of irrigation ( Table 53.4 ). The most commonly used irrigant is normal saline, and it can be applied by bulb syringe, pouring, or low- or high-pressure lavage. Each method has its benefits. High-pressure irrigation removes more bacteria and necrotic tissue than a bulb syringe and may be more effective when there has been massive contamination or delay in treatment. However, a decrease in new bone formation has been noted in the first week after high-pressure irrigation when compared with control sites, and contamination has been found 1 to 4 cm away from the wound after pulsatile lavage, as well as some propagation of the contamination down the bone canal. In addition, the position of the irrigation tip close to the tissue may affect the degree of cleaning. More recently, Draeger and Dhaners noted more soft-tissue damage in an in vitro experimental model in which high-pressure pulsatile lavage was used than when bulb-syringe suction was used. They also noted that the high-pressure lavage removed less contaminant than other debridement methods and postulated that the lavage may drive contaminants deeper into the tissue. Other authors also have shown increased soft-tissue damage with high-pressure lavage compared with low-pressure lavage. The current consensus seems to lean toward high-volume, low-pressure lavage repeated an adequate number of times to effect the best healing and prevention of infection.

The amount of fluid used varies with the method of application. There also is a question of whether additives to the irrigation solution are beneficial. Additives are generally of three types: antiseptics, which include among others povidone-iodine, chlorhexidine gluconate, hexachlorophene, and hydrogen peroxide; antibiotics, such as bacitracin, polymyxin, and neomycin; and surfactants, such as castile soap or benzalkonium chloride ( Table 53.5 ). Bhandari et al. noted that the combination of low-pressure lavage and 1% liquid soap was the most effective irrigating solution for in vivo removal of bacteria. In a more recent prospective, randomized, controlled trial, Anglen compared nonsterile castile soap with bacitracin solution for the irrigation of 398 lower extremity open fractures. Anglen found no significant differences with respect to infection and bone healing, but wound healing problems were more common in the bacitracin group.

All these additives have advantages and disadvantages, but none has been shown to be clinically efficacious at this time. The FLOW study (Fluid Lavage of  Open Wound) was undertaken to help clarify the conflicting recommendations regarding irrigation pressure and irrigation solutions. In an international, multicenter, blinded, randomized, controlled trial, patients with open extremity fractures were divided into six groups: high-pressure irrigation (>20 psi), low-pressure irrigation (5 to 10 psi), or very low-pressure irrigation (1 to 2 psi), with either normal saline or a 0.45% solution of normal saline and castile soap. Fractures of the hands, toes, and pelvis were excluded. Reoperation within 12 months for bone or wound healing problems or wound infection was chosen as the primary end point of the study. In 2447 eligible patients, there was no significant difference in reoperation among the pressure groups (13.2% high pressure, 12.7% low pressure, and 13.7% very low pressure). Reoperation was significantly higher in the soap group (14.8%) than the saline group (11.6%). The authors concluded that very low-pressure irrigation is an acceptable, low cost alternative to pressure-irrigation devices and that soap solution is not superior to saline alone.

Our protocol has been to use 9 L of gravity-flow irrigation in most cases. Additional fluid may be needed in highly contaminated fractures, whereas lesser amounts (5 to 6 L) are usually sufficient in minimally contaminated upper extremity injuries. Our previous protocol called for genitourinary irrigant as an additive; however, we are currently not placing additives in our irrigation fluid. Regardless of the type of irrigation, the most important part of wound cleansing is the surgical debridement of dead and contaminated tissue.

Controversy also surrounds the closure of wounds after irrigation. Historically, leaving the wound open has been recommended, but, with the development of powerful antibiotics and early aggressive debridement, more institutions are reporting success with loose closure of wounds, with or without drainage. If debridement does not result in a surgically clean wound, closure should not be done. In addition, the skin should not be closed under tension because this may result in further skin necrosis and ischemia. The proper tension has been described as a wound that can be closed with 2-0 nylon without breaking. Structures should be kept moist with occlusive dressings. The use of a “bead pouch” in which methyl methacrylate impregnated with powdered antibiotics, such as vancomycin or tobramycin, is rolled into small beads that are placed on a wire and laid in the wound has been shown to be very cost effective in control of deep infection.

Early closure of the wound has been shown to decrease the incidences of infection, malunion, and nonunion. A variety of methods can be used for wound closure, including direct suturing, split-thickness skin grafting, and free or local muscle flaps. The method chosen depends on several factors, including the size and location of the defect and associated injuries. In a multicenter study of 195 tibial fractures that required flap coverage, ASIF/OTA class C injuries that were treated with a rotational flap were 4.3 times more likely to have a wound complication requiring operative intervention than were injuries treated with a free flap.

A relatively recent innovation, vacuum-assisted closure (KCI, San Antonio, TX), has been reported to be useful in accelerating wound healing by reducing chronic edema, increasing local blood flow, and enhancing granulation tissue formation. The few reports of the use of vacuum-assisted closure in the management of orthopaedic injuries have been generally favorable, but its efficacy has not been clearly proven. The vacuum-assisted closure device usually is applied at the end of each irrigation and debridement until the wound is considered clean.

Fracture Stabilization

An open fracture generally should be stabilized with the method that provides adequate stability with a minimum of further damage to the vascularity of the zone of injury and its associated soft tissues. For type I wounds, essentially any technique that is suitable for closed fracture management is satisfactory. Treatment of types II and III wounds is more controversial, with proponents of traction, external fixation, nonreamed intramedullary nailing, and occasionally plate and screw fixation. Generally, external fixation is preferred for metaphyseal-diaphyseal fractures with occasional limited internal fixation with screws. In the upper extremity, casting, external fixation, and plate and screw fixation are popular methods of stabilization. In the lower extremity, open diaphyseal femoral and tibial fractures have been treated successfully with intramedullary nailing, and results are encouraging for the use of nonreamed intramedullary nails in types I, II, and IIIA fractures.

Our experience with open femoral and tibial fractures treated at the Elvis Presley Regional Trauma Center confirms the effectiveness of unreamed intramedullary fixation of these fractures. Of 125 open femoral fractures treated with unreamed and reamed nailing, all united, and infection developed in only five (4%). Of 50 open tibial fractures (three Gustilo type I, 13 type II, 22 type IIIB, and 12 type IIIB), union was obtained in 48 (96%), infection occurred in four (8%), and malunion occurred in two (4%). Eighteen fractures (36%) required dynamization, bone grafting, or both to obtain union. For types IIIB and IIIC injuries that are salvageable, external fixation is still the primary method of treatment. As important as any other factor is the surgeon’s familiarity with the surgical stabilization technique chosen, as long as further devascularization is minimized.

The method used to reduce and immobilize the fracture depends on the bone involved, the type of fracture, the efficacy of the debridement, and the patient’s general condition. When it is desirable to limit further trauma from surgery, and when the fracture is stable, it can be reduced and a cast applied as for a closed fracture. The cast must be bivalved or windowed to allow inspection of the wound. External fixation allows easy evaluation of the skin and soft tissues and may be preferable even for stable fractures with unstable soft tissues, such as tibial pilon fractures. Open fractures involving the shaft of the humerus, the tibia, the fibula, or the small bones can be reduced and immobilized in this fashion. If sophisticated techniques are unavailable, skeletal traction provides enough stability and allows adequate exposure of most wounds. The more unstable a fracture, the more justified is some type of surgical stabilization or a staged stabilization.

Fractures involving joints or physes may require internal fixation to maintain alignment of the articular surfaces and physes. Usually, Kirschner wires or limited internal fixation with or without external fixation is sufficient to accomplish this purpose without introducing much foreign material. If possible, we treat the soft tissues and the wound, allow the soft tissues to heal, and then proceed with open reduction and internal fixation of intraarticular fractures through a clean surgical wound. Specific methods of fracture fixation are discussed later in this chapter.

Bone Grafting

Autologous Bone Grafts

Autologous bone grafts contain the three required components for the formation of bone: osteoconduction, osteoinduction, and cellular osteogenesis. Osteoconduction refers to the scaffolding that allows bone ingrowth. Osteoinduction is the ability to induce the production of osteoblasts. Primitive osteocytes are necessary to form osteoblasts.

Autologous grafts are obtained from multiple areas. Local bone removed at the time of arthrodesis can be reused after removing all soft tissue and then morselizing this bone into much smaller pieces. A bone mill also can be used to finely morselize this bone. This increases the number of live cells and proteins for osteoinduction.

The iliac crest is the second most common area for autograft harvest. The posterior iliac crest offers more bone for grafting than the anterior surface and can be used for morcelized bone or structural bone such as a tricortical graft. Unfortunately, bone harvest from the iliac crest is prone to complications such as donor site pain, neuromas, fracture, and heterotopic bone formation. Techniques for harvest of iliac bone grafts are described in Chapter 1 .

The fibula can be used for a structural graft, and the ribs can be used for a structural or morcelized graft. The tibia also has been used for long corticocancellous structural grafts, but the use of these structural grafts has declined with the advent of rigid internal fixation and reliable allografts.

The harvest of femoral bone marrow using the techniques of femoral nailing and a specialized reamer/irrigator/aspirator (RIA) (Synthes) is a more recent method for obtaining significant amounts of marrow from the femur ( Fig. 53.14 ). The RIA was developed to decrease intramedullary pressure and fat embolism during reaming, and significant decreases in intramedullary pressure and femoral vein fat have been documented with its use. In the process of doing this, the reamings and effluent are captured, and a sizable amount of marrow may be aspirated for bone grafting. Depending on the patient and the source bone, from 25 to 90 mL of bone may be captured. These bony fragments are rich in mesenchymal stem cells. Additionally, the supernatant is rich in fibroblast growth factor (FGF)-2, insulin-like growth factor (IGF)-beta1, and latent TGF-beta1 but not bone morphogenetic protein-2 (BMP2). As a result, the RIA is a potential source for autologous bone, mesenchymal stem cells, and bone growth factors. When used as a spinal graft, however, this technique may require obtaining the graft before the spinal procedure with a different position and draping.

This technique is not without complications. Fractures of the donor bone have been reported, some requiring additional fixation. Perforation of the cortex of the reamed bone that required insertion of prophylactic intramedullary fixation also has been described. Significant blood loss from aspiration has been reported. To avoid or minimize these problems, several actions have been suggested.

• ▪

  Preoperative radiographs of the donor bone should be evaluated for deformity, and the isthmus should be measured to determine the limits of reaming.

• ▪

  Blood should be available to replace aspirated blood and marrow.

• ▪

  The aspirator should be turned off when reaming is not being performed to avoid unnecessary blood loss.

• ▪

  The donor bone should be carefully evaluated after reaming to check for perforations. A prophylactic intramedullary device should be available if a perforation is detected.

• ▪

  Postoperative ambulation should be protected to prevent donor bone fracture.

• ▪

  The patient’s hematocrit level should be checked at the end of the procedure and over the next 24 hours to detect significant blood loss.

• ▪

  Finally, patients with known metabolic bone disease such as osteoporosis or even simple osteopenia of the involved bone may not be the best candidates for this procedure.

Bone Graft Substitutes

Although autogenous material, such as iliac crest bone, remains the gold standard for filling bone defects caused by trauma, infection, tumor, or surgery, its use increases the morbidity of the surgical procedure, increases anesthesia time and blood loss, and often causes significant postoperative donor-site complications (e.g., pain, cosmetic defect, fatigue fracture, heterotopic bone formation). The amount of autogenous bone available for grafting also is limited. Because of these limitations, a number of bone graft substitutes have been developed.

A bone graft substitute classification system proposed by Laurencin et al. divides these into five major categories: allograft-based, factor-based, cell-based, ceramic-based, and polymer-based ( Table 53.6 ). Allograft substitutes use allograft bone with or without other elements and can be used as structural or filler grafts. Factor-based substances include both natural and recombinant growth factors and can be used alone or in combination with other products. Cell-based substitutes use cells to produce new bone. Ceramic-based substitutes use various ceramics as a scaffold for bone growth, and polymer-based substitutes use biodegradable polymers alone or with other materials. A miscellaneous group includes tissue from marine sources such as coral and sponge skeleton.