VASCULAR ANATOMY OF FRACTURES OF THE SHAFT OF THE TIBIA AND FIBULA

The popliteal artery descends vertically between the condyles of the femur and passes between the medial and lateral heads of the gastrocnemius muscle. It ends at the distal border of the popliteus muscle, where it divides into the anterior and posterior tibial arteries. The anterior tibial artery passes between the tibia and the fibula over the proximal aspect of the intraosseous membrane, and enters the anterior compartment of the lower leg. The posterior tibial artery divides several centimeters distal to this point, giving rise to the peroneal artery (Fig. 31-1).⁵¹

Neural Anatomy of the Tibia and Fibula

The posterior tibial nerve runs adjacent and posterior to the popliteal artery in the popliteal fossa, and then enters the deep posterior compartment of the leg. This nerve provides innervation to the muscles of the deep posterior compartment and sensation to the plantar aspect of the foot. The common peroneal nerve passes laterally around the proximal neck of the fibula. It divides into the deep and superficial branches, and then passes into the anterior and the lateral compartments of the lower leg, respectively. Each branch innervates the muscles within its compartment. The deep peroneal nerve provides sensation to the first web space. The superficial branch is responsible for sensation across the dorsal and lateral aspects of the foot.

Fascial Compartments

The lower leg has four fascial compartments (Fig. 31-2). The anterior compartment contains the extensor digitorum longus, the extensor hallucis longus, and the tibialis anterior muscles; the anterior tibial artery and deep peroneal nerve run in this compartment. The lateral compartment contains the peroneus longus and brevis muscles. The superficial peroneal nerve runs through this compartment. The superficial posterior compartment contains the soleus and gastrocnemius muscles. The deep posterior compartment contains the flexor digitorum longus, the flexor hallucis longus, and the tibialis posterior muscles. The posterior tibial artery, peroneal artery, and posterior tibial nerve run in this compartment.⁵¹

FRACTURES OF THE PROXIMAL TIBIAL METAPHYSIS

The peak incidence for proximal tibia metaphyseal fractures is between the ages of 3 and 6 years. The most common mechanism of injury is a low energy force applied to the lateral aspect of the extended knee generating a valgus moment. The cortex of the medial tibial metaphysis fails in tension, often resulting in an incomplete greenstick fracture. Compression (torus) and complete fractures can occur in this area, but are less common. The fibula generally escapes injury, although plastic deformation may occur.^{4,6,23,24,53,75,79,84,116,134,142,148,153,158,163,164}

Children with proximal tibia metaphyseal fractures present with pain, swelling, and tenderness in the region of the fracture. Motion of the knee causes moderate pain, and in most cases the child will not walk. Crepitance is seldom identified on physical examination, especially if the fracture is incomplete.^{4,6,23,24,53,75,79,84,116,134,142,148,153,158,164} Radiographs usually show a complete or incomplete fracture of the proximal tibial metaphysis. The medial aspect of the fracture often is widened, producing a valgus deformity.

A possible sequela of a proximal tibial metaphyseal fracture is development of a progressive valgus deformity (Fig. 31-3). In 1953, Cozen²⁴ was the first to report valgus deformity following a proximal tibial metaphyseal fracture. He described four patients with valgus deformities after fractures in this area. In two cases, the valgus was present at the time of cast removal, suggesting loss of reduction as a potential cause of the deformity. In the other two patients the tibia valga developed gradually during subsequent growth of the patient. Since that time, many other investigators^{6,23,52,53,75,79,94,116,149,153,158} have reported development of tibia valga, even in fractures without any significant malalignment at the time of initial treatment. Nenopoulos reported a 90% incidence of progressive tibial valgus deformity in patients with minimally or nondisplaced proximal tibia metaphyseal fractures.¹¹³

Many theories have been proposed to explain the development of a valgus deformity after a proximal tibial metaphyseal fracture (Table 31-3). In some cases, proximal tibia valga can be the result of an inadequate reduction or the loss of satisfactory reduction in the weeks following the manipulation.^142,163 Lehner and Dubas⁹⁴ suggested that an expanding medial callus produced a valgus deformity, whereas Goff⁴⁷ and Keret et al.⁸⁴ believed that the lateral aspect of the proximal tibial physis was injured at the time of the initial fracture (Salter–Harris type V injury), resulting in asymmetric growth. Taylor¹⁵³ believed that the valgus deformity was secondary to postfracture stimulation of the tibial physis without a corresponding stimulation of the fibular physis. Pollen¹²² suggested that premature weight bearing produced an angular deformity of the fracture before union. Rooker and Salter¹³⁰ believed that the periosteum was trapped in the medial aspect of the fracture, producing an increase in medial physeal growth and a developmental valgus deformity.

Another theory postulates that the progressive valgus deformity occurs secondary to an increase in vascular flow to the medial proximal tibial physis after fracture, producing an asymmetric physeal response that causes increased medial growth.⁷⁹ Support for this theory includes quantitative bone scans performed months after proximal tibia metaphyseal fractures that have shown increased tracer uptake in the medial aspect of the physis compared with the lateral aspect.¹⁶³ Ogden¹¹⁶ identified an increase in the collateral geniculate vascularity to the medial proximal tibia in a cadaver angiography study of a 5-year-old child with a previous fracture. This further supports the theory that medial overgrowth occurs secondary to an increase in the blood flow supplying the medial aspect of the proximal tibia following injury.

Recent studies suggest that the postfracture tibia valga is the result of an injury to the pes anserinus tendon plate. It is suggested that the pes anserinus tethers the medial aspect of the physis, just as the fibula appears to tether the lateral aspect of the proximal tibial physis. Multiple authors believe that the proximal tibial fracture disrupts the tendon plate, producing a loss of the tethering effect. This, then, may lead to medial physeal overgrowth and a functional hemichondrodiastasis (physeal lengthening).^{6,27,29,158,164} Exploration of the fracture, followed by removal and repair of the infolded periosteum that forms the foundation of the pes anserinus tendon plate, has been suggested as an approach that may decrease the risk of a developmental valgus deformity. This theory is supported by the work of Houghton and Rooker, who demonstrated that division of the periosteum around the medial half of the proximal tibia in rabbits induced a valgus deformity. They hypothesized that the increasing valgus angulation was because of a mechanical release of the restraints that the periosteum imposes on activity of the physis.⁷¹

Developmental tibia valga has been reported to occur after simple excision of a bone graft from the proximal tibial metaphysis,¹⁵³ proximal tibial osteotomy,^4,75 and osteomyelitis of the proximal tibial metaphysis.^4,153 Tibia valga deformity can occur after healing of a nondisplaced fracture, and can recur after corrective tibial osteotomy, further supporting the premise that asymmetric physeal growth is the cause of most posttraumatic tibia valga deformities.¹⁶³

The natural history of postfracture proximal tibia valga is one of slow progression of the deformity, followed by gradual restoration of normal alignment over time. The deformity usually is apparent by 5 months post injury, and may progress for up to 18 to 24 months. Zionts and MacEwen¹⁶⁴ followed seven children with progressive valgus deformities of the tibia for an average of 39 months after metaphyseal fractures (Fig. 31-4). Most of the deformity developed during the first year after injury. The tibia continued to angulate at a slower rate for up to 17 months after injury. Six of their seven patients had spontaneous clinical corrections. At follow-up, all children had less than a 10-degree deformity.

Robert et al.¹²⁷ analyzed 25 patients with proximal tibial fractures. Twelve children with a greenstick or a complete fracture developed valgus deformities, whereas no child with a torus fracture developed a deformity. Altered growth at the distal tibial physis appeared to compensate for the proximal tibia valga in three children. Corrective osteotomies were performed in four children. The valgus deformity recurred in two of these four children, and two had iatrogenic compartment syndromes. If surgical correction is deemed necessary, it is important to remember that tibial osteotomy is not a benign procedure, and has a risk of significant complications. Gradual correction of the deformity with a proximal medial tibial hemiepiphysiodesis may be more appropriate, and certainly safer, treatment for recalcitrant postfracture tibia valga in a child with significant growth remaining.^{12,117,127,133,148,153}

AUTHOR’S PREFERRED TREATMENT

DIAPHYSEAL FRACTURES OF THE TIBIA AND FIBULA

Seventy percent of pediatric tibial fractures are isolated injuries.^140,159 The fractures can be incomplete (torus, greenstick) or complete. Most tibial fractures in children under 11 years of age are caused by a torsional force and occur in the distal third of the tibial diaphysis. These oblique and spiral fractures occur when the body rotates with the foot in a fixed position on the ground. The fracture line generally starts in the distal anteromedial aspect of the bone and propagates proximally in a posterolateral direction. If there is not an associated fibula fracture, the intact fibula prevents significant shortening of the tibia; however, varus angulation develops in approximately 60% of isolated tibial fractures within the first 2 weeks after injury (Fig. 31-9).¹⁶¹ In these cases, forces generated by contraction of the long flexor muscles of the lower leg are converted into an angular moment by the intact fibula producing varus malalignment (Fig. 31-10A). Isolated transverse and comminuted fractures of the tibia most commonly are caused by direct trauma. Transverse fractures of the tibia with an intact fibula generally are stable, and seldom displace significantly.^14,80 Comminuted or segmental tibial fractures with an intact fibula tend to drift into varus alignment similar to oblique and spiral fractures.^14,80,161

Approximately 30% of pediatric tibial diaphyseal fractures have an associated fibular fracture.^142,159,161 The fibular fracture may be either complete or incomplete with some element of plastic deformation. A tibial diaphyseal fracture with an associated displaced fracture of the fibula often results in valgus malalignment because of the action of the muscles in the anterolateral aspect of the leg (see Figs. 31-10B and 31-11). Any fibular injury must be identified and corrected to minimize the risk of recurrence of angulation after reduction (Fig. 31-12A–C).

An isolated fracture of the fibular shaft is rare in children, and results most commonly from a direct blow to the lateral aspect of the leg (Fig. 31-13). Most isolated fractures of the fibular shaft are nondisplaced and heal quickly with symptomatic care and immobilization (Fig. 31-14).

Signs and Symptoms of Fractures of the Tibia and Fibula

The signs and symptoms associated with tibial and fibular diaphyseal fractures vary with the severity of the injury and the mechanism by which it was produced. Pain is the most common symptom. Children with fractures of the tibia or fibula have swelling at the fracture site, and the area is tender to palpation. Almost all children with any type of tibia fracture will refuse to ambulate on the injured limb. If there is significant injury to the periosteum and fracture displacement, a bony defect or prominence may be palpable. Immediate neurologic impairment is rare except with fibular neck fractures causing injury to the common peroneal nerve.

Although arterial disruption is uncommon in pediatric tibial and fibular diaphyseal fractures, both the dorsalis pedis and the posterior tibial pulses should be assessed, and a Doppler examination should be performed if they are not palpable. Capillary refill, sensation, and pain response patterns, particularly pain with passive motion, should be monitored. Concomitant soft tissue injuries must be evaluated carefully. Open fractures must be treated aggressively to reduce the risk of late complications.

Radiographic Evaluation of Fractures of the Tibia and Fibula

Anteroposterior and lateral radiographs that include the knee and ankle joints (Fig. 31-15) should be obtained whenever a tibial and/or fibular shaft fracture is/are suspected. Though uncommon, tibial shaft fractures may occur in combination with transitional fractures involving the distal tibial metaphysis, and as such, close evaluation of the ankle radiographs is essential (Fig. 31-16A–D). Comparison views of the uninvolved leg normally are not indicated. Children with suspected fractures not apparent on the initial radiographs may need to be treated with supportive splinting or casting to control symptoms associated with the injuries. Technetium radionuclide scans obtained at least 3 days after injury are useful to identify fractures that are unapparent on radiographs; however, in most cases, patients with clinical findings consistent with a fracture are treated as though a fracture is present. Periosteal new bone formation evident on plain radiographs obtained 10 to 14 days after injury confirms the diagnosis in most cases.

Treatment for Fractures of the Tibia and Fibula

Cast Immobilization

The vast majority of uncomplicated pediatric diaphyseal tibial shaft factures, with/or without associated fibular shaft fractures, can be treated by closed manipulation and casting.⁶⁷ Fractures of the tibial shaft without concomitant fibular fracture may develop varus malalignment. Valgus angulation and shortening can present a significant problem in children who have complete fractures of both the tibia and the fibula.

Displaced fractures should be managed with reduction under appropriate sedation, using fluoroscopic assistance when available. This can be done in the emergency room or in the operating room depending on the availability of sedation and fluoroscopy. A reduction plan should be made before manipulation based on review of the deforming forces associated with the specific fracture pattern. A short-leg cast is applied with the foot in the appropriate position with either a varus or valgus mold, depending on the fracture pattern and alignment. The cast material is taken to the inferior aspect of the patella anteriorly and to a point 2 cm distal to the popliteal flexion crease posteriorly. It may be best to use plaster for the initial cast because of its ability to mold to the contour of the leg and the ease with which it can be manipulated while setting. The alignment of the fracture is reassessed after the short-leg cast has been applied. The cast is then extended to the proximal thigh with the knee flexed. Most children with complete, unstable diaphyseal tibial fractures are placed into a bent-knee (45 degree) long-leg cast to control rotation at the fracture site and to assist in maintaining non–weight-bearing status during the initial healing phase. The child’s ankle initially may be left in some plantar flexion (20 degrees for fractures of the middle and distal thirds, 10 degrees for fractures of the proximal third) to prevent generation of apex posterior angulation (recurvatum) at the fracture site. In a child, there is little risk of developing a permanent equinus contracture, as any initial plantar flexion can be corrected at a cast change once the fracture becomes more stable.

The alignment of the fracture should be checked weekly during the first 3 weeks after the cast has been applied. Muscle atrophy and a reduction in tissue edema may cause the fracture to drift into unacceptable alignment. Cast wedging may be performed in an attempt to improve alignment, and in some cases a second cast application with remanipulation of the fracture under general anesthesia may be necessary to obtain acceptable alignment. Acceptable position is somewhat controversial and varies based on patient age as well as location and direction of the deformity.³⁷ Remodeling of angular deformity is limited in the tibia. (Table 31-4) No absolute numbers can be given, but the following general guidelines may be beneficial in decision making:

• Varus and valgus deformity in the upper and midshaft tibia remodel slowly, if at all. Up to 10 degrees of deformity can be accepted in patients less than 8 years old, and a little more than 5 degrees of angulation in those older than 8 years of age.

• Moderate translation of the shaft of the tibia in a young child is acceptable, whereas in an adolescent, at least 50% apposition is recommended.

• Up to 10 degrees of apex anterior angulation may be tolerated, although remodeling is slow.

• Minimal apex posterior angulation (recurvatum) can be accepted, as this forces the knee into extension at heel strike during gait.

• Up to 1 cm of shortening is acceptable.

Cast Wedging

Patients with a loss of fracture reduction and unacceptable angulation may benefit from remanipulation of the fracture. This can be attempted in the clinic setting through the use of cast “wedging.” Fracture alignment in the cast can be altered by creation of a closing wedge, an opening wedge, or a combination of wedges. Unfortunately, this technique is labor intensive and has become something of a lost art. The location for wedge placement is determined by evaluating the child’s leg radiographically, and marking the midpoint of the tibial fracture on the outside of the cast. If fluoroscopy is not available, a series of paper clips are placed at 2-cm intervals on the cast and anteroposterior and lateral radiographs are then taken. The paper clips define the location of the fracture and the location most suitable for cast manipulation.

Closing Wedge Technique. A wedge of cast material is removed which encompasses 90% of the circumference of the leg with its base over the apex of the fracture. The exact width of the wedge is proportional to the amount of correction desired and therefore varies in each patient, and can be determined geometrically utilizing the amount of desired angular correction and the width of the cast in the location of the wedge. The cast is left intact opposite the apex of the fracture in the plane of proposed correction. The edges of the cast are brought together to correct the angulation at the fracture. This wedging technique may produce mild fracture shortening, and care must be taken to avoid pinching the skin at the site of cast reapproximation. Theoretically, the closing wedge technique may increase exterior constrictive pressure, as the total volume of the cast is reduced. In light of these concerns, it may be preferable to use the opening wedge technique whenever possible.

Opening Wedge Technique. The side of the cast opposite the apex of the fracture is cut perpendicular to the long axis of the bone. A small segment of the cast is left intact directly over the apex of the malaligned fracture (∼25%). A cast spreader is used to “jack” or spread the cast open. Plastic shims (Fig. 31-17) or a stack of tongue depressors of the appropriate size are placed into the open segment to maintain the distraction of the site, and the cast is wrapped with new casting material after the alignment has been assessed radiographically (Fig. 31-18). When using any wedging material, it is imperative that the edges do not protrude into the cast padding or cause pressure on the underlying skin. This wedging technique effectively lengthens the tibia while correcting the malalignment (Figs. 31-19A–D).

After any cast wedging, especially early after injury when there may be residual leg swelling, it is recommended to observe the patient for a short period of time to be certain that signs and symptoms of compartment syndrome do not develop. Cast wedging may be somewhat painful for a brief period of time, but that discomfort should subside. The family should be alerted that if increasing pain develops after cast wedging, the patient should return urgently for evaluation.

Operative Treatment

Historically, operative treatment has been recommended infrequently for tibial shaft fractures in children. Weber et al.¹⁵⁹ reported that only 29 (4.5%) of 638 pediatric tibial fractures in their study required surgical intervention. However, in the last decade there has been an increasing interest in surgical stabilization, particularly for unstable closed tibial shaft fractures as well as open fractures or those with associated soft tissue injuries. The current indications for operative treatment include open fractures, most fractures with an associated compartment syndrome, some fractures in children with spasticity (head injury or cerebral palsy), fractures in which open treatment facilitates nursing care (floating knee, multiple long bone fractures, multiple system injuries), and unstable fractures in which adequate alignment cannot be either attained or maintained (Table 31-5).^{5,11,26,38,41,44,54,72,83} Common methods of fixation for tibial fractures requiring operative treatment include percutaneous metallic pins, bioabsorbable pins,⁸ external fixation,^30,110,138 and plates with screws; the use of flexible intramedullary titanium or stainless steel nails or, in some cases, intramedullary Steinmann pins, is becoming increasingly common.^{45,48,50,91,110,115,124,132,155} Kubiak et al.⁹¹ compared the use of titanium flexible nails with external fixation in a mixed group of patients with open and closed tibial fractures. Although the groups were not matched and were reviewed retrospectively, the authors reported a clinically significant decrease in time to union with titanium nails compared to external fixation. Gordon et al.⁴⁹ retrospectively reviewed 60 pediatric patients with open or closed tibial shaft fractures managed with flexible nails. They found an 18% complication rate; the most common complication was delayed union. In this study, those patients with delayed time to union tended to be older (mean age 14.1 years) versus the mean age of the study population (11.7 years). Srivastava et al.¹⁴⁶ reviewed a mixed group of 24 patients with open or closed tibial shaft fractures managed with titanium nails. All patients went on to union at an average of 20.4 weeks. The total complication rate was 20%, including two patients with mild sagittal plane malunions at final follow-up.

OPEN TIBIAL FRACTURES

Most open tibial fractures in children involve the diaphyseal region, and are treated similarly to comparable injuries in adults. In addition, these fractures and associated soft tissue injuries are classified utilizing the Gustilo and Anderson System (Fig. 31-20).⁵⁷ Most open fractures of the tibia result from high-velocity/high-energy injuries.^19,129

Treatment Principles for Open Tibial Fractures

Management principles for open tibial fractures include:

• Timely debridement, irrigation, and initiation of appropriate antibiotic therapy¹²¹

• Fracture reduction followed by stabilization with either internal or external devices

• Intraoperative angiography (after rapid fracture stabilization) and management of possible elevation of compartment pressures when sufficiency of the vascular perfusion is unclear

• Open wound treatment with loose gauze packing or other methods^30,108

• Staged debridement of necrotic soft tissue and bone in the operating room as needed until the wounds are ready for closure or coverage.

• Delayed closure or application of a split thickness skin graft when possible; use of delayed local or free vascularized flaps as needed

• Cancellous bone grafting (autologous or allograft) for bone defects or delayed union after maturation of soft tissue coverage

These principles are similar to those utilized in adult patients. However, there is evidence that differences exist between pediatric and adult fracture patients. As such, the principles of treatment for open tibial fractures in adults are altered somewhat by the unique characteristics of the pediatric skeleton. These differences include the following.^{5,22,26,48,56,145}

• Comparable soft tissue and bony injuries heal more reliably in children than in adults, particularly in patients less than 11 years of age.⁷⁸

• Devitalized uncontaminated bone that can be covered with soft tissue can incorporate into the fracture callus, and in some cases may be left within the wound.

• External fixation can be maintained, when necessary, until fracture consolidation with fewer concerns about delayed or nonunions than in adults.

• Retained periosteum can regenerate bone, even after segmental bone loss in younger children.

• After thorough irrigation and debridement, many uncontaminated grade I open wounds may be closed primarily without an increased risk of infection.

Buckley et al.¹⁶ reported 41 children with 42 open fractures of the tibia (18 grade II, 6 grade IIIA, 4 grade IIIB, and 2 grade IIIC). Twenty-two (52%) of the fractures were comminuted. All wounds were irrigated and debrided, and antibiotics were administered for at least 48 hours. Twenty-two fractures were treated with reduction and cast application, and 20 with external fixation. Three children had early infections, and one of these patients developed late osteomyelitis. All infections had resolved at final reported follow-up. The average time to union was 5 months (range, 2 to 21 months). The time to union was directly proportional to the severity of the soft tissue injury. Fracture pattern also had an effect on time to union. Segmental bone loss, infection, and the use of an external fixation device were associated with delayed union. Four angular malunions of more than 10 degrees occurred, three of which spontaneously corrected. Four children had more than 1 cm of overgrowth.

In a series of 40 open lower extremity diaphyseal fractures in 35 children, Cramer et al.²⁵ reported 22 tibial fractures (1 grade I, 10 grade II, and 11 grade III). External fixation was used for 15 fractures, casting for five, and internal fixation for two. Two children required early amputation, four required soft tissue flap coverage, and 13 children had skin grafts. Two additional children with initially closed injuries required fasciotomy for compartment syndrome and were included in the group of open tibial fractures. Ten of the 24 injuries healed within 24 weeks. Five children required bone grafting before healing.

Hope and Cole⁶⁹ reported the results of open tibial fractures in 92 children (22 grade I, 51 grade II, and 19 grade III). Irrigation and debridement were performed on admission, intravenous (IV) antibiotics were given for 48 hours, and tetanus prophylaxis was administered when necessary. Primary closure was performed in 51 children, and 41 traumatic wounds were left open. Eighteen soft tissue injuries healed secondarily, and 23 required either a split thickness skin graft or a tissue flap. Sixty-five (71%) of the 92 fractures were reduced and immobilized in an above-the-knee plaster cast. External fixation was used for unstable fractures, injuries with significant soft tissue loss, and fractures in patients with multiple system injuries. Early complications of open tibial fractures in these children were comparable with those in adults. Primary closure did not increase the risk of infection if the wound was small and uncontaminated. At reevaluation 1.5 to 9.8 years after injury, the authors found that 50% of the patients complained of pain at the fracture site; 23% reported decreased abilities to participate in sports, joint stiffness, and cosmetic defects; and 64% had leg length inequalities. Levy et al.⁹⁶ found comparable late sequelae after open tibial fractures in children, including a 25% prevalence of nightmares surrounding the events of the accident. Blasier and Barnes¹⁰ and Song et al.¹⁴⁵ found that most late complications associated with pediatric open tibial fractures occurred in children over the age 12 and 11 years, respectively.

Skaggs et al.¹⁴¹ reviewed their experience with open tibial fractures and found no increased incidence of infection in patients initially debrided more than 6 hours after injury when compared to children treated similarly less than 6 hours after fracture. However, it appears that fractures with more severe soft tissue injuries were more likely to receive more expedient treatment, thereby complicating the analysis. This apparent selection bias in some ways limits the overall usefulness of the study.

There is some published data that provides concerns about the use of external fixators in tibia fractures in pediatric patients. Myers et al.¹¹⁰ reviewed 31 consecutive high-energy tibia fractures in children treated with external fixation. Nineteen of the fractures were open, with mean follow-up of 15 months. The authors found a high rate of complications in this patient population, including delayed union (particularly in patients of at least 12 years of age), malunion, leg-length discrepancy, and pin tract infections. However, Monsell et al. reported no nonunions and no complications in a group of 10 pediatric patients with open diaphyseal tibia fractures managed with a programmable circular external fixator. In addition, they had no patients with deep infection, nor were there any cases of refracture after fixator removal.¹⁰⁷ To date, there are no published studies which directly and prospectively compare the use of flexible intramedullary nails with external fixation for open pediatric tibial shaft fractures.

Overall, a recent systematic review of the literature demonstrates that the philosophy of treatment on pediatric open tibia fracture has remained essentially unchanged over the last 30 years.³ The authors found a strong correlation between Gustilo–Anderson classification and the incidence of infection, and that the fracture union rate was influenced negatively by the extent of the associated soft tissue injury.³

Open Tibia Fractures—Associated Issues

Soft Tissue Closure

Expedient coverage of an open tibial fracture that cannot be closed primarily reduces the morbidity associated with this injury.^46,86,109 Delayed primary closure can be performed if the wound is clean and does not involve significant skin and muscle loss. In such cases, it is imperative that closure under tension is avoided. Other options include a wide variety of local rotational or pedicled myocutaneous flaps. Vascularized free flaps are viable options in cases for which no other method of closure is appropriate.

Most of the literature addressing the subject of soft tissue coverage for open tibia fractures involves adult patients, and as such, must be extrapolated to pediatric fracture management.⁵⁸ In a series of 168 open tibial fractures with late secondary wound closure, Small and Mollan¹⁴³ found increased complications with early pedicled or rotational fasciocutaneous flaps and late free flaps, but no complications with fasciocutaneous flaps created more than 1 month after injury. Complications associated with free flaps were decreased if the procedure was performed within 7 days of injury. Hallock et al.⁶⁰ reviewed 11 free flaps for coverage in pediatric patients. They reported a 91% success rate, which was similar to their rate in adults. However, they reported a significant rate of complications at both the donor and the recipient sites.⁶⁰ Rinker et al.¹²⁶ reported their experience with free vascularized muscle transfers for traumatic lower extremity trauma in pediatric patients performed between 1992 and 2002. At their institution, 26 patients received 28 flaps during that period. The latissimus dorsi was used most commonly as the origin of the transfer. Twelve of the flaps were performed for coverage of open tibia fractures. There was a 62% overall complication rate, with infection and partial skin-graft loss being the most common problems. The authors concluded that patients receiving free flap coverage within 7 days of injury had a statistically significant lower complication rate than those covered later.¹²⁶

Ostermann et al. reported 115 grade II and 239 grade III tibial fractures in a series of 1,085 open fractures. All patients were treated with early broad-spectrum antibiotics, serial debridements, and the application of an external fixation device. Tobramycin-impregnated polymethylmethacrylate was placed into the wounds, and dressings were changed every 48 to 72 hours until the wounds spontaneously closed, underwent delayed primary closure, or received flap coverage. No infections occurred in grade I fractures; approximately 3% of grade II fractures and 8% of grade III fractures developed infections. No infections occurred in patients who had the wound closed within 8 days of injury. On the basis of these and other analyses, it is now recommended that wounds associated with open tibial fractures be covered within 7 days of injury whenever possible.^{18,19,21,82,118,156}

Multiple authors have reported on the use of subatmospheric pressure dressings in the management of soft tissue injuries in pediatric patients. Dedmond et al.³⁰ reviewed the Wake Forest experience with negative pressure dressings in pediatric patients with type III open tibia fractures. They found that use of this device decreased the need for free tissue transfer to obtain coverage in this patient population. When focusing on the rate of infection, Halvorson et al.⁶² found that use of negative pressure dressings in the management of open fractures, including open tibia fractures, appeared to be safe and effective when compared to historical controls.

Vascular Injuries

Vascular injuries have been reported in approximately 5% of children with open tibial fractures. Arterial injuries associated with open tibial fractures include those to the popliteal artery, the posterior tibial artery, the anterior tibial artery, and the peroneal artery. Complications are common in patients with open tibial fractures and associated vascular injuries. Amputation rates as high as 79% have been reported with grade IIIC fractures. Isolated anterior tibial and peroneal artery injuries generally have a good prognosis, whereas injuries of the posterior tibial and popliteal arteries have much less satisfactory prognoses, and more commonly require vascular repairs or reconstructions.^1,59,68 Patients with open tibial fractures and vascular disruption may benefit from temporary arterial, and possibly venous, shunting before the bony reconstruction is performed. This approach allows meticulous debridement and repair of the fracture, while maintaining limb perfusion until the primary vascular repair is performed.⁴⁴ However, in most cases, rapid fracture stabilization, usually utilizing external fixation, can be performed before vascular reconstruction without the need for temporary shunts.

AUTHOR’S PREFERRED TREATMENT

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