Tibia shaft fracture

Tibia shaft fracture is a fracture of the proximal third of the tibia. Due to the location of the tibia on the shin, it is the most commonly fractured long bone in the body.

Epidemiology

Tibial shaft fractures are some of the most common long bone fractures in humans. They account for approximately 17% of lower extremity fractures. They also account for approximately 4% of fractures among Medicare patients. Tibial shaft fractures occur more often in males than females. The age distribution of these fractures is bimodal, with peaks in younger and older adults. Younger patients often sustain tibial shaft fractures from high energy trauma mechanisms such as motor vehicle accidents and sports injuries. In older adults, low-energy mechanisms like falls are most common. Tibial shaft fractures can be anatomically categorized by diaphysial location. Fractures of the midshaft are most frequent. Proximal and distal third fractures are less common.

Mechanism of injury

Low energy tibial shaft fractures usually result from indirect torsional forces such as falls from standing heights, twisting injuries, or rotational forces applied to the leg. These mechanisms create rotational stress along the diaphysis. This typically results in a spiral fracture pattern. Spiral tibial fractures from these mechanisms are often associated with a fibular fracture at a different level. They also involve less severe soft tissue injury compared with high-energy mechanisms.
High energy fractures result from direct trauma such as motor vehicle accidents, falls from significant heights, or severe sports injuries. These mechanisms usually produce wedge or short oblique fractures with comminution. They are often associated with a fibular fracture at the same level. High energy fractures have a higher likelihood of severe soft tissue injuries, having associated compartment syndrome, and of being open fractures.

Anatomic location

Proximal third fractures necessitate thorough assessment of the knee to exclude extension into the tibial plateau. Articular involvement may be difficult to detect on x-ray and in such instances may require a CT scan. Due to deforming muscular forces, proximal third fractures are prone to valgus and procurvatum malalignment during intramedullary nailing. In particular, the procurvatum results from the gastrocnemius pulling the distal fragment in to flexion while the patellar tendon pulls the proximal fragment in to extension. Valgus malalignment results from the per anserinus pulling the proximal fracture fragment in to varus.
Spiral distal third tibial shaft are more commonly associated with posterior malleolar fractures. Extension to the posterior malleolus can affect syndesmotic stability. Careful evaluation of the ankle is thus required when such fracture patterns are present. CT scan may be warranted if X-ray findings are equivocal.
Around 5% of all tibial fractures are bifocal, meaning there are 2 separate fractures of the tibia.

Clinical evaluation

Clinical evaluation of tibial shaft fractures should begin with a thorough neurovascular assessment. This is essential in all cases and especially important in open injuries. Distal perfusion should be assessed by palpating the dorsalis pedis and posterior tibial pulses. Neurologic examination should include careful assessment of the common peroneal and tibial nerves. The soft tissue envelope should be evaluated. Fracture blisters may delay or contraindicate early operative reduction, particularly for periarticular fractures.
Patients should be closely monitored for compartment syndrome with these fractures. Pain out of proportion to the injury serves as the most reliable clinical indicator. But compartment pressure measurements may assist in diagnosis. A differential between diastolic blood pressure and compartment pressure less than 30 mm Hg is indicative of compartment syndrome. Deep posterior compartment pressures can be elevated even when superficial compartments appear soft. There is an 8.1% risk of compartment syndrome in diaphyseal fractures, compared to proximal and distal fractures.

Classification

Gustilo and Anderson Classification of open fractures
Source:

Type	Description
Type I	Clean skin opening of <1 cm, usually a “poke hole” from inside to outside; minimal muscle contusion; simple spiral or short oblique fractures
Type II	Laceration >1 cm long, with extensive soft tissue damage; minimal-to-moderate crushing component; simple transverse or short oblique fractures with minimal comminution
Type III	Extensive soft tissue damage greater than 10 cm in length, including muscles, skin, and neurovascular structures; often a high-energy injury with a severe crushing component
IIIA	Extensive soft tissue laceration, adequate soft tissue coverage; segmental fractures, gunshot injuries, minimal periosteal stripping
IIIB	Extensive soft tissue injury with periosteal stripping and bone exposure requiring soft tissue flap closure; usually associated with massive contamination
IIIC	Vascular injury requiring repair

Tscherne classfication of closed fractures

source

classifies soft tissue injury in closed fractures

Grade	Description
Grade 0	Injury from indirect forces with negligible soft tissue damage
Grade I	Closed fracture caused by low-moderate energy mechanisms, with superficial abrasions or contusions of soft tissues overlying the fracture
Grade II	Closed fracture with significant muscle contusion, with possible deep, contaminated skin abrasions associated with moderate to severe energy mechanisms and skeletal injury; high risk for compartment syndrome
Grade III	Extensive crushing of soft tissues, with subcutaneous degloving or avulsion, with arterial disruption or established compartment syndrome

Treatment

'''Nonoperative treatment'''

This may be appropriate for isolated, closed, low-energy injuries with minimal displacement and comminution, or for patients not able to undergo surgery. Treatment typically consists of fracture reduction followed by application of a long leg cast with progressive weight bearing. When casting, the knee should be positioned in approximately 0 to 15 degrees of flexion to facilitate early mobilization. Patients may begin weight bearing with crutches as tolerated. Progressing to full weight bearing should be considered by the second to fourth week. After three to six weeks, the long leg cast can often be transitioned to a patella-bearing cast or functional fracture brace. Union rates with nonoperative treatment are high, reaching up to 97%. But delayed weight bearing may occur in cases of delayed union or nonunion. Hindfoot stiffness is a notable limitation.
Acceptable alignment following reduction includes less than 5 degrees of varus or valgus angulation, less than 10 degrees of anterior or posterior angulation, and less than 10 degrees of rotational deformity, with external rotation generally better tolerated than internal rotation. Shortening should be limited to less than 1 cm, as even 5 mm of distraction can significantly delay healing. At least 50% cortical contact is recommended. These are essentially the non-operative tolerances. Surgery is recommended for any fracture reduction that exceeds these parameters. Clinically, overall alignment can be assessed by ensuring collinearity of the anterior superior iliac spine, the center of the patella, and the base of the second proximal phalanx.
Time to fracture union is approximately 16 ± 4 weeks but varies widely depending on fracture pattern and the degree of soft-tissue injury. Delayed union is typically defined as healing beyond 20 weeks. Nonunion is characterized by loss of healing potential, evidenced by persistent fracture gaps, sclerotic fracture ends, and lack of radiographic progression on serial imaging rather than time alone.

Operative treatment

Operative management of tibial shaft fractures most commonly involves intramedullary nailing. This offers several biological and biomechanical advantages. This technique preserves the periosteal blood supply, minimizes additional soft-tissue disruption, and provides reliable control of fracture alignment, translation, and rotation. This makes it suitable for the majority of fracture patterns.
Intramedullary nails may be locked or unlocked. Locked nails provide rotational stability and effectively prevent shortening in comminuted fractures or those with bone loss. Interlocking screws may be removed later to dynamize the fracture site if healing is delayed. In contrast, nonlocked nails allow axial impaction with weight bearing but offer poor rotational control and are therefore used infrequently.
Nails may also be reamed or unreamed. Reamed intramedullary nailing is indicated for most closed and many open fractures. It allows placement of a larger, stronger nail with improved resistance to bending forces. It also affords enhanced intramedullary stability and increases periosteal blood flow. Unreamed nailing has traditionally been favored in some open fractures to preserve remaining endosteal blood supply and reduce operative time. But more recent evidence suggests it is also acceptable in closed fractures. Hardware failure is more closely related to implant size than reaming technique.
Nail insertion can be performed through either an infrapatellar or suprapatellar approach. Suprapatellar nailing performed in a semiextended position has been associated with reduced postoperative knee pain, improved sagittal alignment, decreased fluoroscopy time, and may facilitate reduction of proximal tibial fractures.