A 26-year-old male sustained a shrapnel injury to his left lower extremity . He was treated initially with an external fixator, which was removed 6 months later. Patient presented with nonunion, shortening, and varus deformity (a). A 6-cm avascular segment of the nonunion was resected, and acute shortening with application of an Ilizarov fixator was performed. An intramedullary rush pin contributes to initial alignment of the fracture site (b, c). Osteotomy was performed proximally for bone lengthening at a rate of 1 mm per day. Seven centimeters of bone were regenerated and consolidated with no complications. The fixator was removed after 1 year (d)
A 35-year-old male sustained an injury to his left lower extremity from an explosive device . He was managed initially with debridement and application of a monolateral frame (a). He presented 2 weeks later for further management. An arteriogram revealed an anterior tibial artery injury. The deep peroneal nerve and the posterior neurovascular bundle were intact. A radical debridement was performed, a cement spacer was inserted, and the wound was left open. We proceeded with bifocal treatment using an Ilizarov fixator; lengthening through a proximal osteotomy and shortening at the fracture site (b). After 2 months, debridement of fracture site with removal of cement was performed with bone graft substitute grafting of the docking site and secondary closure of the wound (c). Lengthening was then continued for a total of 12 cm of regenerate that healed as well as the fracture site (d). The total time in fixator was 12 months. The patient has equal leg length with a well-aligned axis
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Patients with an infected nonunion have a superimposed infection to their fracture. Often these infections are polymicrobial with multidrug-resistant bacteria. In our experience, imipenem has been the most commonly used antibiotic to treat these infections due to the prevalence of gram-negative organisms cultured from these wounds, particularly Acinetobacter, Enterococcus, and Klebsiella. Similar findings have been reported in the literature from war-injured soldiers in Iraq . In addition, we have had a very low threshold to resect the affected bone and treat the infection locally, with the use of antibiotic-impregnated calcium sulfate pellets . These two steps have significantly decreased the duration of systemic antibiotics and increased the rate of infection eradication and bone healing . This was an important advancement for our patient population due to their limited financial resources and inability to continue prolonged intravenous antibiotic administration. This has also decreased the duration of hospitalization as well as the side effects associated with prolonged antibiotic use.
These patients can be divided into two categories:
The infection is mainly in the bone without signs of systemic infection
There is purulent drainage usually associated with systemic signs of infection
In the first category , resection of the infected dead bone edges may result in sterilization of the field. Often, we applied the one step or global approach. This includes radical debridement and cleansing of the soft tissue, resecting dead bone until paprika sign is noted. The gap is then filled with calcium sulfate pellets (Stimulan, BiocompositesR) impregnated with 1 g of vancomycin powder and 240 mg of gentamycin liquid for each 10 cc (which replaced the mixing liquid provided by the manufacturer) . Then the external fixator is applied, a remote osteotomy is performed, and the wound is closed primarily or with local flaps, if need be. These patients typically receive a very short course of systemic antibiotics (3–14 days) (Fig. 11.3).
A 36-year-old male sustained a right proximal tibia shrapnel injury. He had a type 2 Gustillo-Anderson open fracture of the right proximal tibia that was treated with internal fixation (a). He developed a deep wound infection treated with intravenous antibiotics for 3 months. He developed an atrophic nonunion with a draining sinus but no systemic signs of infection. Six months later, he underwent removal of the internal hardware, radical debridement of dead bone (a segment of 10 cm of bone was resected), and application of a circular frame. The wound was closed over calcium sulfate pellets impregnated with vancomycin and gentamycin. Distal osteotomy for bone transport was performed at the same setting (b). Three months after the end of bone transport, CT scan revealed persistent nonunion. The docking site was grafted (c). The fixator was removed 3 months later (11 months in fixator) (d)
In the second category, we prefer the two-stage approach. The first stage includes resection of necrotic bone and soft tissue , filling the defect with a cement spacer impregnated with high doses of vancomycin and gentamycin (2 G Vancomycin and 240 mg Gentamycin for each 40 mg methylmetacrylate), and applying the external fixator. The second stage takes place after 3–6 weeks of systemic antibiotic administration . It consists of removing the cement spacer and application of the calcium sulfate pellets impregnated with vancomycin and gentamycin, as above. The remote osteotomy for bone regeneration can be done at either stage. The duration of systemic antibiotics depends on the host, bacteria, and condition of the wound (Fig. 11.4).
A 30-year-old male presented with a gunshot injury to the left thigh resulting in a Gustillo-Anderson type 2 femur fracture . Plating of the fracture was performed after debridement of the soft tissue (a). Postoperatively, the patient developed fever as well as erythema and swelling of his thigh wound. The wound was opened, the pus was drained, and patient was initiated on IV antibiotics. However the infection persisted. The patient was transferred to us. The plate was removed, 7 cm of dead bone were resected, and a monolateral fixator applied with a cement spacer (b). After 6 weeks of systemic antibiotics, the cement was removed, calcium sulfate impregnated with vancomycin, and gentamicin laid down in the gap that was partially compressed. A remote osteotomy was then performed for bone transport and later lengthening (c). Patient healed with no need for additional grafting (d)
Another appealing approach is the membrane-induced technique described by Masquelet . The main indication for this technique is a patient with a proximal femur fracture that was initially fixed with an intramedullary rod, or after wound healing. In this scenario an external fixator may be difficult to apply and the pins may have to be intracapsular. In this two-stage technique, we debride the fracture site in the first stage without exchanging the nail. Cultures are taken and intravenous antibiotics are started. Typically, a cement mantle is applied as described previously. After 6 weeks, the cement is removed and bone grafting is performed using a combination of autogenous bone graft and calcium sulfate pellets (Fig. 11.5).
A 42-year-old male who sustained a gunshot injury of the proximal femur treated with a temporary external fixator exchanged to a nail after 6 weeks. The patient had a deep infection with a persistent draining sinus, elevated ESR and CRP with no evidence of callus formation (a). Masquelet technique was performed with debridement of the infected bone segment. Cement spacer was inserted in the defect (b). After 3 months of systemic antibiotics, the membrane was opened, the spacer was removed, and the defect was filled with mixed autogenous and artificial bone graft. The fracture healed in 4 months (c)
Alternatively, a vascularized or non-vascularized free fibula graft may be used in a single-stage procedure to fill the bone defect and create a structural graft. This procedure has the benefit of having a relatively straightforward dissection, high union rate, and excellent functional outcomes [9–12]. Additionally, in an adult there is up to 26 cm of length available for harvesting, provided the fibular head and distal one-quarter of the fibula are retained for knee and ankle stability, respectively. In children, a syndesmotic screw is placed through the distal fibular stump to prevent a valgus ankle deformity. The ipsilateral fibula may be transposed or the contralateral fibula can be harvested. When harvesting a vascularized graft, the peroneal or anterior tibial vessels may be used, with or without a cutaneous flap . The anterior tibial vessel is preferred for epiphyseal transfers due to better blood supply . The fibula graft should be imbedded into the canal of each end of the long bone with a large segmental defect, whether the tibia or femur . Fixation may be achieved with cannulated screws, small diameter elastic stable intramedullary nails, external fixators, or bridge plating [9, 12, 14] (Fig. 11.6).
A 23-year-old male soldier who was hit by an explosive device and sustained a severely comminuted distal tibia shaft fracture treated with an external fixator for 6 months. There was no sign of bone healing and the soft tissue envelope was unstable (a). He had resection of the comminution and the gap was filled with a microvascular tissue transfer of the contralateral fibula with a skin paddle (b). The soft tissues healed nicely and the junctions of the graft healed by 6 months (c)
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