Tibia Fractures

The tibia fracture is the most common long bone fracture with an approximate incidence of 26 diaphyseal fractures per 100 000 population per year. There is a high incidence of open fractures as one-third of the tibial surface is subcutaneous.

The tibia is a long tubular bone with a triangular cross-section and is responsible for 85% of weight-bearing load, whereas the fibula transmits the remaining.

The endosteal blood supply is from the nutrient artery that arises from the posterior tibial artery, and the bulk of the periosteal blood supply arises from the anterior tibial artery. The distal third is supplied by periosteal anastomoses around the ankle with branches entering the tibia through ligamentous attachments. There is a watershed area at the junction of the middle and distal thirds where the blood supply is reduced. If the nutrient artery is disrupted, there is reversal of flow through the cortex, and the periosteal blood supply becomes more important. It is important to preserve the periosteal attachments during fracture fixation.

Mechanism of Injury

Tibia Fractures may occur as a result of direct or indirect trauma:

• Direct injuries are usually high-energy injuries and result in transverse or comminuted fractures with displacement and a high incidence of associated soft-tissue injury.
• Indirect injuries on the other hand occur as a result of torsion and result in spiral, minimally displaced fractures and little soft tissue damage.
• Bending forces give rise to short oblique fractures.
• Crush injuries result in highly comminuted or segmental fracture patterns and are associated with extensive soft-tissue injury.
• Isolated fibular shaft fractures result from direct trauma to the lateral aspect of the leg.
• Tibial fractures associated with segmental fibular fractures usually indicate severe energy or violence.

See Also: Tibial Plateau Fracture

Symptoms & Signs

The diagnosis of tibia fractures is usually obvious and evaluation of the neurovascular status in every patient is imperative. The extent of soft-tissue injury dictates the line of management. The presence of fracture blisters may contraindicate early open reduction.

Compartment syndrome is a devastating complication of tibia fractures. The limb must be monitored for compartment syndrome as it may present late. The classical clinical features are pain out of proportion to the injury, a tense limb and pain on gentle passive dorsiflexion of the foot. Any patient with persistent and severe pain even after splinting and paraesthesia in the foot must be suspected to have compartment syndrome.

See Also: Lateral Compartment of Leg

It is important to remember that the pulse can be normally felt in the early stages, and a pale, pulseless paralytic limb are late signs of established compartment syndrome. If compartment syndrome is suspected, compartment pressures should be monitored at regular intervals. Compartment pressures higher than 30 mmHg and/or pressure within 30 mmHg of diastolic pressure are considered indications for four-compartment (anterior, lateral, superficial posterior and deep posterior) fasciotomy.

Deep posterior compartment syndrome may be missed because of uninvolved overlying superficial compartment and can result in claw toes.

Tibia fractures can also be associated with a high incidence of knee ligament injuries. Following stabilization of the fracture, the presence of ligamentous instability must be checked intra-operatively.

See Also: Anterior Compartment of Leg

Radiology

Radiographic evaluation must include anteroposterior and lateral views that include the entire tibia with visualization of the ankle and knee joints. The radiographs must also be assessed for the presence of secondary fracture lines that may cause displacement during operative treatment, osseous defects and for gas in the soft tissues.

Gas in the soft tissues is usually secondary to open injuries but may also signify the presence of gas gangrene, necrotizing fasciitis or other anaerobic infections.

CT or magnetic resonance angiography is indicated if an arterial injury is suspected.

Tibia Fractures Classification

Tibial shaft fractures may be classified descriptively based on the:

1. Location: proximal, middle or distal one third.
2. Pattern: spiral, oblique or transverse.
3. Extent of displacement: shortening, translation, angulation or rotational deformity and percentage of cortical contact.
4. Extent of comminution: comminuted, segmental or butterfly fragment.
5. Status of soft-tissue envelope: open or closed.

The tibia fracture AO classification advocates a higher level of classification for an increasing severity of injury:

1. Type A fractures are simple fractures that are spiral, oblique or transverse.
2. Type B fractures result from higher energy dissipation at the level of the injury and are classified as spiral, bending or fragmented wedges.
3. Type C fractures are complex fractures with multiple spiral fractures, segmental fractures or highly comminuted fractures.

Tibia Fractures Treatment

The treatment of a fractured tibia depends on the:

1. Morphology of the fracture,
2. Status of the soft-tissue envelope,
3. The neurovascular status,
4. Associated skeletal and other major organ injuries
5. The general medical status of the patient.

Most of the tibial fractures may be treated operatively or non-operatively. Tibia fractures surgical treatment is generally the preferred method of treatment as it allows early mobilization and avoids complications of prolonged immobilization.

Non-Operative Treatment

This is generally reserved for isolated, closed, low-energy fractures with minimal displacement and comminution. Union rates as high as 97% have been reported.

Non-operative treatment involves achieving an acceptable reduction and immobilization in a long leg cast with partial weight bearing with crutches as soon as tolerated by the patient. Advancement to full weight bearing can begin by the second to fourth week. After 4–6 weeks, the long leg cast may be exchanged for a patella-bearing cast or fracture brace.

The tibia fracture healing time in adults depends on the pattern of fracture and soft tissue injury and is generally about 16 weeks.

Recommendations for acceptable tibia fracture reduction are:

1. Less than 5° of varus–valgus angulation,
2. Less than 10° of anteroposterior angulation,
3. Less than 10° of rotation (with external rotation better tolerated than internal rotation),
4. Less than 15 mm of shortening.
5. More than 50% cortical contact is recommended.

A rough guide to alignment of the limb is that the anterior superior iliac spine, centre of the patella and base of the second proximal phalanx should be in the same linear axis.

Operative Treatment

Depending on the personality of the tibia fracture, intramedullary nails, plates or an external fixator may be used to stabilize these fractures.

Intramedullary (IM) nailing – interlocking nails or flexible IM nails (Enders, rush rods) have numerous advantages over plates:

1. They preserve the periosteal blood supply and limit the soft-tissue damage.
2. Interlocking nails also have the advantages of being able to control alignment, translation and rotation and are therefore recommended for most fracture patterns.
3. Locking provides rotational control, prevents shortening in the presence of comminution and bone loss and hence it is the preferred method of internal fixation.

The debate over the use of reamed vs unreamed nails is now resolved in favour of reaming. Reaming allows for the use of a larger diameter, stronger nail and gives better results in both closed and open fractures. Unreamed nails preserve the intramedullary blood supply in open fractures where the periosteal supply has been destroyed and are currently reserved mainly for higher grade open fractures. It is however significantly weaker than the larger reamed nails and is associated with a higher incidence of nonunions, loss of reduction and implant failures.

With the success of interlocking nails, flexible nails are rarely used. They are recommended only in children and adolescents with open physes.

The significant advantage of ‘biological fixation’ with IM nails and the attendant complications of infection and wound breakdown associated with the use of plates have decreased their use as the primary mode of stabilization. These are generally reserved for fractures extending into the metaphysis or epiphysis. Union rates of up to 97% are reported.

Plating usually requires open surgery, and the location of the incision and careful handling of the soft tissues are vital in order to minimize complications. However, a certain amount of soft-tissue damage and periosteal stripping is inevitable, and this is a particular problem in comminuted or open fractures. In recent years, plates have been developed that have less periosteal contact (low-contact dynamic compression plates).

Biological plating refers to a subcutaneous plating technique in which the plate is placed in position using image guidance after fracture reduction and screws are inserted percutaneously. The recent development of locking plates has potentially increased the scope of biological plating. These plates will mainly be used for extraarticular proximal tibial plateau and distal tibial plafond fractures rather than for diaphyseal fractures. They undoubtedly provide superior fixation in osteopenic bone, as all the screws have to loosen for the plate to fail. They are therefore particularly useful in treating proximal tibial fractures in older patients. The plates can be used with unicortical or bicortical screws.

Currently, tibial plating is not advocated for the routine management of diaphyseal fractures. Not only does it cause unnecessary soft-tissue damage, but it is also inappropriate in comminuted fractures, as long plates are required. The only circumstances in which it might be used are when there is a proximal tibial diaphyseal fracture and when there is a combination of a proximal diaphyseal fracture and a tibial plateau fracture. Under these circumstances, the use of locking plates is preferred.

External fixation is primarily used as a temporary stabilization to treat severe open tibia fractures. It is also indicated in closed fractures complicated by compartment syndrome and in polytrauma situations where rapid stabilization of fractures is required. Conversion to IM nails is preferably carried out within 2–3 weeks as otherwise the pin tracts may get colonized, increasing the rate of infection. Although high union rates of up to 90% have been reported, external fixators are rarely used as a definitive method of treatment owing to the high incidence of pin tract infections and poor patient tolerance.

References & More

1. Mercer’s Textbook of Orthopaedics and Trauma, Tenth edition.
2. McQueen MM, Gaston P, Court-Brown CM. Acute compartment syndrome: who is at risk? Journal of Bone and Joint Surgery (British) 2000;82:200–3. Pubmed
3. Bhandari M, Tornetta P III, Sprague S, et al. Predictors of reoperation following operative management of fractures of the tibial shaft. Journal of Orthopedic Trauma 2003;17:353–61. Pubmed
4. Keating JF, O’Brien PI, Blachut PA, et al. Reamed interlocking intramedullary nailing of open fractures of the tibia. Clinical Orthopaedics and Related Research 1997;338:182–91. Pubmed
5. Collinge CA, Sanders RW. Percutaneous plating in the lower extremity. Journal of the American Academy of Orthopaedic Surgeons 2000;8:211–16. Pubmed
6. Ricci WM, O’Boyle M, Borrelli J, et al. Fractures of the proximal third of the tibial shaft treated with intramedullary nails and blocking screws. Journal of Orthopedic Trauma 2001;15:264–70. Pubmed
7. Henley MB, Chapman JR, Agel J, et al. Treatment of type II, IIIA, and IIIB open fractures of the tibial shaft: A prospective comparison of unreamed interlocking intramedullary nails and half-pin external fixators. Journal of Orthopedic Trauma 1998;12:1–7. Pubmed
8. Bhandari M, Guyatt GH, Tong D, et al. Reamed versus nonreamed intramedullary nailing of lower extremity long bone fractures: a systematic overview and meta-analysis. Journal of Orthopedic Trauma 2000;14:2–9. Pubmed