Tibial shaft fractures — Musculoskeletal Medicine for Medical Students — OrthopaedicsOne

Tibial shaft fractures.
Description.
Tibial shaft fractures are the most common long bone fracture. They can be the result of high energy traum, such as a motor vehicle accident, or low energy mechanisms, such as a slide tackle in a soccer game. The significance of these fractures include not only the impairment on mobility, but their propensity for causing compartment syndrome.
Structure and function.
The tibia is the primary weight-bearing bone of the leg. Much of the tibia is subcutaneous, leaving it susceptible to direct injury and to open fractures. The tibia is surrounded by 3 of the 4 fascial compartments of the leg and injury to the tibia that results in bleeding or edema in these spaces can result in a limb threatening Compartment syndrome . The proximal and distal regions of the tibia form the knee and ankle joint respectively; injuries to those areas (plateau and pilon fractures) are considered separately.
Epidemiology.
There are about half a million tibial shaft fractures annually in the US resulting in greater than 70,000 hospitalizations (3). Nearly a quarter of tibial fractures are open, and of those that are open, greater than 50% are related to motor vehicular injury. Among sports related tibial-shaft-fractures, soccer accounts for 80%. These injuries are particularly present in the 15-19 year old male population, and in the elderly (2).
Clinical presentation.
Tibial shaft fractures are almost never a diagnostic dilemma: they are the result of known trauma and they are very painful. (Those who present with a tibial shaft fracture without a history of trauma, or an insufficient mechanism should be worked up for other causes of pathologically weakened bone, such as cancer.) Some common signs and symptoms include inability to bear weight, limb deformity, tenderness to palpation, and skin changes or breaks.
A low force injury, such as a sports tackle in a younger patient may present as pain at the site of fracture or injury to adjacent joint structures.
Elderly patients may present with a history describing a fall or positioning involving compressive or rotational forces that preceded the injury.
A high force trauma (eg, motor vehicular collision) is more likely to result in an open fracture and have an obvious deformity. They may also have concomitant injuries that command a provider’s primary care.
The essential steps in evaluation include: Restoring repiratory and hemodynamic stability, excluding other injuries from the trauma; verifying the integrity of the skin and soft tissue; and examining the distal neurovascular function. Tense compartments or pain on passive motion must have a high index of suspicion for compartment sydrome.
Initial fracture management includes: cleaning and covering any wounds, fracture reduction splinting, and initiation of appropriate antibiotics.
Compartment syndrome : Increased pressures lead to decreased limb viability.
Neurovascular injury: Check for pulses and motor/sensory function distal to the injury.
Infection: Broken skin requires antibiotics.
Pathologic Fracture: The “Why” it happened is just as important as the “How”. Fractures from low energy mechanism deserve particular scrutiny.
Fat emboli: The tibia is a long bone. Even a minor fracture has the potential to dislodge some fat from the marrow space and create a fat embolism (1).
Differential diagnosis.
Objective evidence.
The physical exam may find areas of obvious bone discontinuity, deformity or soft tissue wounds. A thorough neurovascular exam, including capillary refill, pulses, and motor and sensory function can help identify the extent of the injury as well as determine baseline functionality.
Standard non-weight bearing AP and Lateral radiographs should be obtained to determine the location, type, displacement and angulation of the fracture. The radiographs should also show the knee joint and ankle mortise. In addition to the primary break be sure to identify any 2 nd fracture or signs of ligamentous injury. Remember, open fractures are 4 times as likely to involve other bones (2). Additioanl x-ray films or a CT scan may be obtained as needed.
Risk factors and prevention.
Those who work at heights, play contact sports, or travel in or around motor vehicles are at increased risk for tibial shaft fractures. Additional risk factors include age, osteoporosis, and other pathologies that weaken bone integrity.
The wearing of proper work and sport related equipment, such as shin guards and safety harnesses, as well as management of medical risk factors are the best prevention.
Treatment options.
Closed, Non-displaced fracture: A long leg cast maintains alignment without surgical complications. Stability is increased by immobilizing the knee and ankle joints. The amount of displacement and deformity that can be tolerated is minimal. The long leg cast crosses the knee and the ankle and has the potential to create stiffness in these joints. Once the fracture begins to heal, it may be reasonable to convert to short leg cast.
Open, or displaced fracture: A surgically placed intramedullary nail provides structural stability and proper alignment. Displaced fractures are likely to cause nuerovascular damage and require surgical evaluation in addition to fixation. Surgical plating is generally not used as a primary treatment due to the lack of soft tissue around the tibia, but may be a valid option for non-union.
Poly trauma, comminuted fracture, or extensive soft tissue damage: External fixation approximates the fracture ends when intramedullary nailing is not an option. These may later be converted to an intramedullary nail.
Weight-bearing is graduated in proportion to fracture stability and callus formation in order to encourage healing, maintain function, and avoid re-injury. This may include immediate weight-baring after reduction of a simple fracture by intramedullary nail, or in a non-displaced transverse fracture.
A good algorithm for open tibial fractures can be found at http://www.jaaos.org/content/18/1/10/F1.expansion.
The prognosis following tibial shaft fractures is dependent on the severity of the injury. Simple closed fractures generally heal in 4-5 months. More traumatic injuries may take longer.
Possible, but less common, outcomes and complications may include:
Fat embolism Delayed/ Non-union Malunion Bony callus Infection Limb length discrepancy.
Holistic medicine.
Smoking delays fracture healing (6).
The patient’s nutritional status may affect healing times.
Healing may be augmented by use of pulsed electromagnetic field stimulation or a bone stimulator.
Miscellany.
The hardest fracture to find is the second fracture. Never assume any lesion works alone.
Low force fractures tend to be more angulated or torus due to bending and twisting.
High force injuries tend to cause more shearing.
Question: A soccer player is kicked in the shin during a game and is unable to bare weight on that leg. He is taken to the Emergency Department. His leg is slightly deformed and swollen on arrival. He reports extreme pain and paresthesias. On physical exam he is alert and oriented, his lungs are clear, he is mildly tachycardic, and lacks distal pulses in that extremity. What is the most appropriate step in management?
Answer: Tibial shaft fractures can lead to a limb threatening compartment syndrome. Any clinical suspicion should be treated with emergent surgical decompression.
Tibia, Leg fracture Compartment Syndrome ORIF Intramedullary Nail External Fixation Casting Long Bone.
The student should gain an opportunity to observe and participate in X-ray interpretation, Nuerovascular examination, Splinting, Casting, Fixation, and Compartment pressure measurement.

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