1 General considerations topenlarge
Open fractures of the tibia are the commonest of open long-bone fractures, perhaps because of its thin anteromedial soft-tissue coverage.
They are caused by various mechanisms, ranging from low-energy twisting forces to high-energy motor vehicle crashes or penetrating injuries (gun shots, blasts). Although the principles of management for open tibial fractures are constant, the path to the final result may vary.
Open tibial fractures can present as isolated injuries or in the context of a multiply injured patient. The patient’s clinical status must dictate the primary and ongoing treatment of the open tibial fracture. Thorough evaluation of the entire patient is essential before focusing on the injured leg.
Classification of open tibial fractures
The classification of such soft-tissue wounding is commonly according to two systems, namely that of Gustilo, Mendoza & Williams (See: Gustilo RB, Mendoza RM, Williams DN (1984) Problems in the management of type III (severe) open fractures. A new classification of type III open fractures. J.Traum Aug;24(8):742-6); and also that of the AO.
An additional influence is the ability of the host to combat infection, based on both systemic and local factors. For details see Cierny classification.
Gustilo and Anderson. (JBJS 1976)
This work largely addressed lower leg injuries, but has some value in other anatomical sites.
The Gustilo – Anderson classification divides soft-tissue wounding of open fractures into three grades – I, II & III.
This illustration summarizes the three basic grades – I, II & III.
Gustilo, Mendoza and Williams. (J.Trauma 1984).
The III grade was later further subdivided into types IIIA, IIIB & IIIC.
These examples illustrate the three types IIIA, IIIB & IIIC.
AO classification (adapted from Tscherne)
The AO classification of fracture wound severity provides a grading system for injuries of each of the skin (I), muscles and tendons (MT), and neurovascular (NV), each of which is divided into five degrees of severity.
It is designed to provide a unique, unequivocal definition of any injury and thereby, allows accurate comparison of cases.
A full understanding of the severity of an open fracture requires consideration of each of these elements.
This very detailed classification is designed to be used in conjunction with the AO/OTA Fracture and Dislocation Classification.
This comprehensive classification is better suited for research than routine clinical use, but it should remind the clinician that a thorough evaluation of each of the included tissues is essential for an adequate understanding of a fracture wound.
Management of open tibial fractures can be challenging. In some situations, primary amputation may be necessary.
While most open tibial fractures can be managed satisfactorily , those which are more severe, pose serious challenges and may have poor results.
The grade of open fracture, condition of the soft tissues, degree of contamination and the thoroughness of surgical debridement will have influence on the risk of infection. In the worst injuries (type III b or c), open tibial fractures carry an infection risk of up to 25-50 %. (1)
Loss or irreparable damage to the soft-tissue envelope is a frequent feature of severe open tibial fractures. This may result directly from the injury or from delayed wound necrosis. Soft-tissue defects require early closure with healthy tissue to reduce the risk of infection. Local or free-tissue transfers may be required, if tension-free closure is not possible.
Impaired bone healing
Delay or failure of bone healing is common with open tibial fractures. Average time to union is about a year (2). Failure to unite may require additional surgery, such as bone grafting and/or revised fixation. Stimulation of bone healing remains a developing field.
Elevated compartment tissue pressure is not prevented by an open fracture wound. Perhaps because of their more severe soft-tissue injury, open fractures may have a higher incidence of compartment syndrome than that of comparable closed injuries. The surgeon must anticipate this possibility, monitoring the patient carefully and considering fasciotomy during open fracture debridement.
For more details on compartment syndrome read here.
Factors affecting tibial fracture management
Each aspect of an open tibial fracture must be considered in planning initial and definitive management.
The entire patient, the injured extremity and the specific details of the open fracture itself must each be considered. Associated arterial injury must be identified and treated urgently to salvage the limb. Wound debridement will be necessary. Its thoroughness appears to be more important than how quickly it is done. The severity of the injuries to soft tissues, bone and neurovascular structures must be identified and used for treatment planning.
2 Assessment top
The entire soft-tissue envelope must be inspected. This includes the posterior aspect of the leg. If an open wound is identified, it should immediately be covered with a sterile dressing. It should not be again inspected until the patient is in the OR for debridement.
The dorsalis pedis and posterior tibial pulses should be palpated in the foot. Reduced pulses require urgent further assessment.
Motor function in each of the four leg compartments should be evaluated (toe flexion, toe extension, ankle eversion and plantarflexion).
Test sensation of the following nerves:
- tibial (plantar surface of foot)
- deep peroneal (dorsal webspace between 1st and 2nd toe)
- superficial peroneal (dorsal lateral foot)
- saphenous (medial foot)
This may not be possible in all patients (ie intubated, multiple injured, comatose), but should be always be attempted and documented.
Evaluation for compartment syndrome is critical.
Severe pain and tense swelling are strong suggestions of this problem.
Pain with passive toe range of motion is a sensitive indicator of early compartment syndrome.
Loss of sensation and motor strength are typically seen late in the development of compartment syndrome, and pulses are usually preserved.
Imaging to assess location and severity of fracture
Full-length AP and lateral radiographs of the tibia and fibula on a single cassette are necessary.
In addition, obtain biplanar x-rays centered on the knee and ankle to exclude intra-articular injuries. Ipsilateral fractures of the tibial plateau and/or ankle are not rare. (3)
3 Emergency management topenlarge
As in all open fracture injuries, the patient must receive anti-tetanus prophylaxis and appropriate antibiotic coverage. Antibiotics should be given intravenously as soon as possible.
Generally, all open fractures are treated with coverage for typical skin bacteria, often a 1st generation cephalosporin. Higher grade open fracture wounds will require additional coverage for gram-negative organisms. With soil or barnyard injuries, high-dose penicillin should be added to cover possible clostridial infection (gas gangrene).
After initial inspection the wound should be covered with a sterile dressing which should not be removed until it is taken down in the OR. A digital photograph of the wound, before dressing, will remove the temptation for successive attendant to expose the wound for inspection.
A temporary splint may be applied to protect the soft tissues while awaiting the availability of an operating room.
Definitive classification of the open fracture is best done in the OR.
4 Débridement and irrigation top
The patient is positioned supine in the OR or in a position that allows best access to the open fracture wounds. Skin preparation and draping should include access to the major proximal vessels in case their exposure becomes necessary. Tourniquets should be avoided when possible to prevent additional ischemic injury to the soft tissues.
General principles of debridement
It is important to perform a thorough surgical débridement in an organized manner. Starting with the skin, each layer is debrided systematically. One can imagine a clock face; wound débridement starts at the 12 o’clock position and continues in a clockwise manner around the circumference of the wound. This is repeated for each layer down to the level of the bone. Necrotic tissue is removed and only viable tissue is left behind. The exception is skin, where none is removed unless obviously
The quality of the muscle tissue is assessed using the classic 4 C’s:
- Color (red or brown)
- Consistency (how does the muscle feel)
- Capillary Circulation (does it bleed?)
- Contractility (responds to pinch or electro-cautery)
The bone ends must be inspected. When debriding bone, the fracture edges are curetted and all dirt and non-viable bone are removed. This includes any bone without soft-tissue attachments.
Note: Adequate débridement should include the entire zone of injury.
Healthy tissue should be identified in all zones of the débridement. This often requires a longer skin incision, and further dissection.
Débridement does not necessarily need to be through the open fracture wound. In fact, in certain situations it may be advisable to incorporate the débridement through the planned surgical approach for fracture fixation so as to avoid additional trauma to the injured soft tissues.
The initial débridement thus requires consideration of, and planning for, the definitive surgery.
After removing visible dirt and necrotic tissue, irrigation with several liters of fluid is a key component of the decontamination of the injury zone. If available, a balanced salt solution is routinely used. In more austere environments, any water that is “clean enough to drink” is acceptable. Controversies exist regarding the optimal volume and delivery methods. We recommend large volumes, with low pressure to avoid additional tissue injury. Gravity flow, with large-bore cystoscopy tubing, is a well accepted
5 Fracture stabilization topenlarge
Temporary stabilization of the tibia is chosen in situations where future débridements are felt to be necessary. This is most common in the high-grade open fractures.
Temporary stabilization, usually achieved with an external fixator, minimizes additional soft-tissue injury. This fixation facilitates access to the wound for inspection between débridements.
It also allows simple, rapid disassembly for repeated wound débridements when necessary.
External fixation can be applied using either modular or uniplanar techniques. The modular frames have the advantage of being more versatile, avoiding the complex wounds that are often seen.
The disadvantage of a modular frame is, that it is less rigid than the uniplanar fixator because of its multiple connections.
Pin placement outside of the anticipated zone of the definitive implant is a consideration, although not always possible. Reduce the fracture as well as possible, to avoid soft-tissue tension.
6 Wound management topenlarge
Systemic antibiotics are a critical part of open fracture wound management. Their choice and duration will depend upon several factors including severity of the wound, patient comorbidities, contamination etc.
Antibiotics may also be applied locally to deliver high concentrations directly to the wound site itself.
Methylmethacrylate impregnated with heat-stable antibiotics is shaped into small beads to increase their surface area and to optimize antibiotic elution. After placement onto a suture, the beads are placed within the wound to fill the dead space. The wound is then closed primarily or covered with an adhesive drape. Generally, beads are left in for at least 2-5 days.
Vacuum assisted closure (VAC)
Negative pressure wound dressings (“VACs”) can provide helpful temporary coverage of an open wound. They reduce external wound contamination, remove edema fluid, help to shrink wounds, and promote growth of granulation tissue, even over exposed bone. Such dressings may allow definitive closure by the subsequent use of split thickness skin grafts, instead of more complex flaps. In this manner, a VAC can be used as a bridge to definitive soft-tissue coverage for type IIIA and IIIB wounds. They should be changed every 48-72 hours.
Repeated débridement may be necessary in the higher grade open fracture wounds when there is a concern for additional necrotic tissue or when initial wounds were so badly contaminated that a second look is necessary. This procedure should be repeated, generally every 2-3 days, until only healthy, viable tissue remains and no further necrotic tissue is found on follow-up débridements.
The wound is closed, when the surgeon believes no further débridements are necessary. This may be done primarily, but is often done after a secondary procedure.
When skin grafting or soft-tissue flaps are necessary, they should be done as soon as possible. For this reason, an expert with in these techniques should be consulted early.
Optimally, coverage should occur within the first two weeks after injury (4).