Diaphyseal Tibial Fractures 

Fractures of the tibia and the fibula are the subject of ongoing controversy and discussion. Despite newer innovations in implants and external fixation devices, tibial fractures essentially remain unresolved; they are among the most challenging fractures to be treated by an orthopedic surgeon. These injuries are different and variable in presentation, and their outcomes are unpredictable.

The literature has traditionally included 2 schools of thought regarding management of these injuries: operative and nonoperative therapy. Although gray zones have been resolved, no consensus has been reached on the optimal management of diaphyseal fractures of the tibia. This problem is predominantly attributed to the high prevalence of concomitant closed and open soft-tissue injuries. Therefore, diaphyseal tibial injuries are prone not only to infection and nonunion in the long term but also to significantly increased morbidity caused by polytrauma and associated injuries in the acute setting.

An image depicting a tibial fracture can be seen below.

The delayed unions and nonunions that occur in these fractures are themselves a separate problem covered extensively in the literature and in academic forums. As Marvin Tile wrote:^[1]

"We should reject the theories of the dogmatists who say that all tibial fractures should be treated operatively or that all tibial fractures should be treated nonoperatively. It is time to remove this kind of dogma from one's thinking and to individualize the treatment of these fractures.

"The optimal treatment of a tibia fracture stems from an analysis of the natural history of the fracture. A thorough assessment of the fracture type and pattern and then correlating it with the natural history of a similar fracture type permits achievement of the best functional outcomes for each individual patient."^[1]

The Edwin Smith papyrus (an ancient Egyptian treatise on trauma surgery from the 17th century BC) contained references to the management of long-bone fractures with splints and bandages. Hippocrates recommended the use of bandages and splints in his treatise on fractures; he stressed the need to change these bandages frequently to accommodate changes in limb swelling.

The advent of plaster and the design of functional casts revolutionized the management of tibial fractures.^{[1, 2, 3, 4]} Anthonius Mathijsen, Fedor Victor Krause, Pierre Delbet, and, more recently, Augusto Sarmiento have considerably refined the indications and methods of conservative management of tibial fractures. Understanding wound debridement and knowing Sir Joseph Lister's work on antisepsis enabled surgeons to treat open diaphyseal tibial fractures with some prospect of avoiding amputation.

Albin Lambotte first pioneered external fixation in the tibia, and Ernest William Hey Groves introduced internal fixation with nails, which Gerhard Küntscher and J Otto Lottes later popularized. The AO (Arbeitsgemeinschaft für Osteosynthesefragen) school further refined the practice of intramedullary nailing and interlocked nailing.

The tibial shaft is the bone most commonly fractured in road traffic accidents. The ability to treat this fracture by conservative or operative means depends on what is often termed the natural history of the fracture. John Charnley hypothesized that the periosteal hinge was the important factor in the management of fractures. Conservative management was more likely to fail in fractures that had a residual fracture gap or an intact fibula than in others.

Some factors that influence the natural history of tibial fractures include the location and extent of displacement, comminution, soft-tissue injury, and contamination. Another factor is antecedent sepsis.

Frequency

Overall rates

Tibial fractures are among the most common lower limb injuries to be treated by an orthopedic surgeon. In the early 1990s, tibial fractures accounted for 77,000 hospitalizations per year. The incidence has increased to approximately 500,000 cases in the United States per year. On average, almost 26 tibia fractures occur per 100,000 population per year.

Age and sex

The average age of those with a tibial fracture is approximately 37 years, with an average of 31 years for men and 54 years for women. Data indicate a bimodal distribution, with a preponderance in young men. In fact, the highest incidence of adult diaphyseal tibial fractures is seen in male adolescents aged 15-19 years, in whom the incidence is approximately 109 cases per 100,000. The second peak, which appears after age 80 years, especially affects the female population and is attributed to osteoporosis. However, a change in demographic patterns can be expected with the institution of stringent gun control laws and better road safety measures.

Epidemiology

An epidemiologic analysis of open long-bone fractures at the Edinburgh Orthopaedic Trauma unit was performed over 6 years.^[4] The authors also analyzed 2450 consecutive fractures of the tibia and the fibula over 3 years.^[5] Of these fractures, 21.3% were diaphyseal.

The average age of affected patients rises almost linearly as the injuries progress from AO type A to AO type C (see Workup, Staging). The most common causes are road traffic accidents and sporting injuries. Open fractures account for 23.5% of these fractures, with Gustilo grade 3 being the most frequent of the 3 types. Only 8% were grade 3C, requiring vascular reconstruction.

Results of a later study of open fractures showed that the severity of injury represented by the fracture index was correlated with the injury severity score for each fracture type and location.^[6]

Approximately 21% of patients who present with open fractures have considerable musculoskeletal injuries. Those with open femoral fractures tend to be most severely injured. Patients with distal tibial fractures tend to have an injury severity score and a fracture index that are lower than those of patients with diaphyseal tibial fractures. Most vascular injuries occur in persons with diaphyseal fractures, and most of these persons eventually undergo amputation.

The mechanism of a diaphyseal tibial injury can be direct or indirect. Direct mechanisms of injury are high-energy fractures (road traffic accidents), penetrating injuries, and 3-point bending injuries. High-energy mechanisms produce transverse or comminuted displaced diaphyseal injuries, with a higher incidence of compounding and soft-tissue injury.^{[7, 8]}

Penetrating injuries (eg, gunshot wounds) may produce a variable pattern, depending on the missile involved in the injury. Bending forces (eg, ski-boot injuries) produce short, oblique, spiral fractures and sometimes a small butterfly fragment. On occasion, a highly comminuted segmental pattern of injury may be observed. The prevalence of open and closed soft-tissue injuries is high.

Indirect mechanisms are primarily torsional, low-energy injuries, which produce spiral, nondisplaced, minimally comminuted fractures with minimal soft-tissue damage.

The pathoanatomy of the fracture includes the location, morphology, and soft-tissue status of the limb. Because of its subcutaneous location, the tibia is extremely prone to soft-tissue injury and compounding, as shown below. This damage can occur at the time of injury or at the time of surgery. Closed soft-tissue trauma can be significant and may go unrecognized.

Diaphyseal fractures are slow to heal and are often unpredictable in terms of their course to union. Trauma is greater with long, spiral fractures than with transverse and short oblique fractures. The degree of trauma is further manifested in the extent of the comminution and displacement, both of which are also indicative of extensive soft-tissue disruption. Soft-tissue damage may be overt or may be a frank open injury.

Ipsilateral limb fractures, polytrauma, visceral injuries, and comorbid factors, such as the patient's general condition and age, as well as coexistent arterial or nerve injuries, also markedly influence outcomes.

Good nonoperative management is preferred to bad operative management.

Upon admission, a detailed patient history must be obtained to determine the nature of the injury and to determine whether any other injuries are present. Clinical examination starts with excluding life-threatening injuries and stabilizing all vital parameters. A comprehensive screening to rule out pelvic, abdominal, chest, and head injuries is necessary. Thereafter, attention should be given to the limb to immediately assess for limb-threatening vascular and neurologic injuries. The patient should be assessed for compartment syndromes, closed soft-tissue injury, and open wounds. The extent of injury is roughly classified, with the final assessment coming when the patient enters the operating suite. A bulky dressing and an above-the-knee splint are applied, and radiographs are ordered.

Definitive indications for surgery

Definitive indications for surgery include associated intra-articular and shaft fractures, open fractures, major bone loss, neurovascular injury, limb reimplantation, compartment syndrome, and a floating knee.

Relative indications for surgery

Relative indications for surgery include associated intra-articular and shaft fractures, unstable fractures, an inability to maintain reduction, relative shortening of segmental fractures, a tibial fracture with an intact fibula, a transition zone fracture, and polytrauma.

Delayed indications for surgery

Delayed indications for surgery include failure to maintain the reduction, unacceptable reduction, and complications (see images below).

Knowledge of the relevant anatomy is essential for recognizing and planning management of the soft-tissue injuries that are associated with diaphyseal tibial fractures.

The tibia is triangular in cross-section, with proximal and distal flares. It has 3 surfaces: medial, lateral, and posterior. This bone is thinnest in cross-section at the junction of the middle and lower thirds. The anteromedial border is subcutaneous throughout its length and is called the shin. The broad and smooth medial surface is also subcutaneous throughout its length.

The nutrient artery to the tibia arises from the posterior tibial artery, which enters the tibia at the posterolateral cortex distal to the origin of the soleus at the oblique line of the tibia. Inside the medullary canal, it gives off 3 ascending and 1 descending branch, which form the endosteal vascular tree. This, in turn, anastomoses with the periosteal vessels originating from the anterior tibial artery.

As it passes through a hiatus in the interosseous membrane, the anterior tibial artery is particularly prone to injury in diaphyseal fractures of the tibia. The peroneal artery has an anterior communicating branch to the anterior tibial artery. Hence, an occlusion of the peroneal artery may exist, even in the presence of a dorsalis pedis pulse. The distal third of the tibial shaft is supplied by the periosteal anastomoses around the ankle, with branches entering the tibia through ligamentous attachments. A watershed zone may exist at the junction of the middle and lower thirds of the tibial shaft.

When the nutrient artery is obstructed, reverse flow is established through the cortex. In such a situation, the periosteal blood supply becomes more important. This situation emphasizes the importance of preserving the periosteal attachments during fixation procedures.

Tight osteofascial compartments surround the tibia. The crural fascia divides the leg into 4 compartments. One of these is for the weaker muscle group of extensors, whereas 3 serve the stronger flexor musculature.

The septa include (1) the anterior septum, which is between the anterior and lateral compartments; (2) the posterior septum, which is between the lateral and posterior compartments; (3) the transverse septum, which is between the medial and posterior compartments; and (4) the interosseous membrane, which is between the anterior and middle compartments.

The compartments of the leg are the (1) anterior (extensors and dorsiflexors of the foot), (2) lateral (strong everters and plantarflexors of the foot), (3) superficial posterior (plantarflexors of the foot), and (4) deep posterior or medial (plantarflexors of the foot).

Contraindications and relative contraindications are discussed in Surgical therapy.