Introduction
Most common long bone fractures. Most commonly seen open fracture. The incidence of these fractures is approximately 26 per 100,000 people. Men are more commonly affected than women. Compared with other fractures these have a high incidence of infection, delayed union, nonunion, and malunion due to the relatively poor blood supply.
Anatomy
The tibia is triangular is cross section. Four tight fascial compartments - the anterior, lateral, superficial posterior and deep posterior compartments, bound this bone. The tibia articulates with the femur and patella superiorly, the fibula laterally and the talus inferiorly to make part of the ankle joint. The two main arteries that supply the tibia with blood are the nutrient artery (main supply) and the anterior tibial artery. Coursing through the anterior compartment is the deep peroneal nerve. The lateral compartment contains the superficial peroneal nerve. The tibial nerve runs through the deep posterior compartment.
Classification
Tibia shaft fractures are classified using a descriptive scheme (proximal/middle/distal 1/3, transverse/oblique/spiral/butterfly, comminuted, displacement, cortical contact, etc...)
The Gustilo and Anderson Classification System is used to describe open fractures:
Grade I - clean skin opening of <1 cm, usually from inside to outside; minimal muscle contusion; simple transverse or short oblique fractures.
Grade II - Laceration >1 cm long, with extensive soft tissue damage; minimal to moderate crushing component ' simple transverse or short oblique fractures with minimal comminution.
Grade III - Extensive soft tissue damage, including muscles, skin, and neurovascular structures; often a high-energy injury with severe crushing component.
IIIA - Extensive soft tissue laceration, adequate bone coverage; segmental fractures, gunshot injuries, minimal periosteal stripping.
IIIB - Extensive soft tissue injuries with periosteal stripping and bone exposure requiring soft tissue flap closure; usually associated with massive contamination.
IIIC - Vascular injury requiring repair.
The Tscherne Classification System describes closed fractures:
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 sever 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
Physical Examination
Physical exam must include a detailed motor and sensory exam as well as an evaluation of the skin and soft tissue envelope. Compartment syndrome should be ruled out; Clinical findings include pain with passive motion and pain out of proportion to injury. Intracompartmental pressures indicative of compartment syndrome include those higher than 30mm Hg and pressure within 30mm Hg of diastolic pressure. The exam should also include a ligamentous assessment of the knee. Approximately 5% of all tibia fractures are bifocal.
Radiographic studies
Radiographs of the entire tibia with visualization of the knee and ankle joint should be obtained in the anteroposterior and lateral possition. Oblique views may also be helpful. Computed tomography (CT) and magnetic resonance imaging (MRI) are usually not necessary, but MRI, along with technetium bone scans may be useful in diagnosing occult stress fractures. Angiography is indicated if arterial injury is suspected.
Associated injuries
Diagnosis is usually made based on clinical examination and radiographic findings. During the initial evaluation the patient should be assessed for open wounds at the fracture site, neurovascular sufficiency, and elevated compartment pressures. The fibula, along with the ligamentous structures of the knee and ankle should also be evaluated for disruption. Any condition that can lead to demineralization of bone should be ruled out in any elderly patient who presents with minimal trauma to the lower leg, leading to a diagnosis of a tibial shaft fracture.
Treatment
Acceptable reduction parameters include <5o of varus/valgus angulation, <10 o of anterior/posterior angulation, and <10 o of rotational deformity. <1 cm of shortening and <5 mm of distraction are acceptable. >50% of cortical contact is recommended.
Nonoperative treatment may be initiated in isolated, closed, low-energy fractures with minimal displacement and comminution. Greater than 50% displacement and 50% cortical comminution are risk factors for developing nonunion. Fracture reduction is followed by application of a long leg cast with the knee in 0-5 degrees of flexion. Weight bearing as tolerated is initiated with advancement to full weight bearing by the second to fourth week. Following 4-6 weeks the cast may be exchanged for a patella-bearing cast or a fracture brace.
Tibial stress fractures can usually be treated with activity modification (e.g. avoiding the activity which caused the injury). A short leg cast may be applied in some situations, with partial-weight-bearing ambulation.
Operative fixation is needed for unstable tibial fractures. Intramedullary (IM) nailing offers preservation of periosteal blood supply and limited soft tissue damage along with the ability to control alignment, translation, and rotation and is therefore recommended in most fractures. Nail type may be locked/nonlocked, reamed/unreamed, or flexible/rigid. Other operative choices are external fixation or plates and screws.
Intramedullary Nail
Plate fixation
External Fixation
Four compartment fasciotomy is need in compartment syndrome.
Complications
Malunion, nonunion, infection, soft tissue loss, stiffness at knee/ankle joint, knee pain, hardware breakage, thermal necrosis, reflex sympathetic dystrophy, compartment syndrome, neurovascular injury, fat embolism, and claw toe deformity are among the most common and serious complications.
Red Flags and controversies
The general consensus is that IM nail is the standard of care for most tibial shaft fractures. However, some controversy exists on weather the tibia should be reamed before the IM nail is placed and the type of nail used.
Outcomes
The average time to union is 16 ±4 weeks, with variability owing to fracture pattern and soft tissue injury. Tibial shaft fractures almost always heal with some rotation, angulation or shortening, which alters load transmission across the extremity.
