Managing open fractures (Proceedings)

The goal in management of open fractures is to prevent further contamination, prevent additional damage to the bone and surrounding soft tissues especially nerve and vascular supplies and facilitate timely stabilization.

Initial assessment

Patients presenting with open fractures have undergone a certain level of trauma sometimes markedly so. Thorough evaluation and stabilization of the patient should be the primary focus initially. Remember you're A, B, C, D's. Airway, breathing, circulation, drugs (pain management) take precedence. Do not get distracted by the obvious ie: the bone sticking out. Stabilization of the fracture is not the primary focus unless significant arterial and possibly venous hemorrhage is occurring. Even in that situation the focus is directed at controlling bleeding to allow patient stabilization rather than primary fracture repair. Once the patient is stabilized assessment and management of the open fracture begins. Exam gloves should be worn to prevent further contamination of the wound from human handling. The limb should be assessed for fracture location, degree of tissue loss, vascular and nerve supply. Degree of tissue loss influences the type of wound management and type of fracture repair selected. Perfusion is determined through palpation of pulses, warmth, return of color after blanching of light colored skin or nail beds under pressure and bleeding of wounds distal to the fracture or from a quicked toenail. A Doppler applied to the distal extremity is another way to assess perfusion. A thorough neurologic exam is performed paying particular attention to reflexes, pain response to superficial or deep pain stimuli and response to stimulation of specific dermatomes especially if there is concern about a particular nerve supply.

Classification of open fractures

Classification of open fractures can aid in determining the type of fracture repair and soft tissue management required. Classification also aids in assessing risk of complications and functional outcome. Classification incorporates not only how the fracture occurred but also the energy required to create the fracture, the degree of tissue loss and what is required to repair the fracture and surrounding soft tissues. One important point to remember is bone may not currently be protruding through the skin at the time of presentation. Any wound over an extremity containing a fracture is considered open and treated as such.

Type 1 (First-degree)

The bone itself penetrating the skin typically causes type 1 or first-degree fractures. The wound is usually 1cm or less and there is minimal muscle/soft tissue damage. The energy required to create the fracture is generally low. In a large number of these cases the bone is no longer protruding through the skin at the time of presentation.

Type 2 (Second-degree)

The energy required to create a type 2 fracture is greater (high-energy) and the resulting wound is typically >1cm with moderate soft tissue and muscle injury. The bone itself may have caused the trauma but more likely external forces created the opening.

Type 3 (Third-degree)

These fractures are high-energy fractures resulting in significant soft tissue trauma and loss along with bone loss. These are typically the result of high-energy external forces such as gunshot wounds and vehicular trauma. They are subdivided into 3 groups. Type 3a requires no significant skin reconstruction in order to cover the bone or close the wound. Type 3b does require skin reconstruction in order to cover the bone or close the wound. Type 3c results in arterial damage that requires repair.

Type 4 (Fourth-degree)

This classification probably applies more to human medicine than the veterinary side. Type 4 open fractures result in amputation or near amputation. In humans, where limb salvage is critical this classification is necessary. In the veterinary field it would most likely indicate the need to complete the already started amputation or tidy up the savagely performed amputation.

Wound management

All open fractures are considered contaminated. Open fractures or wounds greater than 8 hours old are presumed infected. Appropriate aseptic technique is required any time you are dealing with an open fracture. Care is taken not to further damage soft tissues, vascular or nerve supply during manipulation. Depending on the fracture classification and whether the bone is still penetrating the skin will influence whether the initial preparation, irrigation, decontamination and reduction of the bone back into to the soft tissues is done with sedation or under general anesthesia. The stability of the patient will also factor into this decision. On initial presentation a sterile bandage or cover can be applied solely to prevent further contamination from hospital pathogens. Once the patient is stabilized focused wound care can begin. The wound should be covered with sterile lube and sterile gauze placed over the wound prior to clipping the surrounding hair. The hair should be clipped from the wound margins out to prevent pushing more hair into the wound and wide margins should be created. After clipping, copious flushing is performed with warmed saline or lactated Ringer's solution to prevent patient hypothermia especially in debilitated patients or ones with extensive wounds. Chlorhexidine in a 0.05% dilution can be added to the flush but remember 'dilution is the solution to pollution' so the key is copious flushing. Next the initial gross debridement is performed. This consists of removing foreign material and obviously nonviable tissue. The viability of tissue is determined by the 3 P's – pink, perfusion and palpation. If in doubt, leave it for the next debridement session. Bone fragments with soft tissue attachment are left alone. Small fragments without soft tissue attachment may be removed but large fragments should be left. Again, if in doubt leave it in. First and second-degree fractures where the bone is still protruding from the wound should be reduced once the initial preparation, irrigation and decontamination is performed. This will aid in keeping the bone hydrated and preventing further damage to the bone. This typically requires the patient be anesthetized although sometimes heavy sedation is sufficient. If the patient is not stable for anesthesia, you are unable to reduce the bone under the skin or surgical stabilization is forthcoming, the protruding bone should be covered with sterile moist gauze, the surrounding wound appropriately dressed and the proper splint applied to prevent further trauma to surrounding structures and provide some degree of patient comfort. If the patient is being transported to another facility for surgical stabilization or continued wound management the above steps still apply. The patient should not be transported until stabilized, the wound addressed and an appropriate splint is applied. For fractures involving the digits, metacarpals, carpus or metatarsals either a lateral or caudal (Mason Metasplint or spoon) splint is applied. For fractures below the elbow or stifle a lateral splint is applied. A caudally placed splint is unable to stabilize the tibitarsal joint or the elbow appropriately. A humeral fracture should be stabilized with a Spica splint. This is important since a large number of humeral fractures occur at the level of the radial nerve. Increased motion of the fracture during transporation may result in laceration or further trauma to the radial nerve. A lateral splint alone without including the shoulder joint and scapula will result in a fulcrum at the level of the fracture increasing the risk of further trauma to the nerve, vasculature and surrounding soft tissues. For the femur, either a Spica splint should be placed or no splint. The argument for not placing a splint is the large volume of muscle surrounding femur fractures allows most patients to protect the limb coupled with the difficulty of appropriately placing a Spica splint especially on the rear limb. Either way the wound must still be managed over the femur. For first-degree and minor second-degree open fractures an island dressing (nonadhesive dressing with adhesive margins) can be applied to protect the wound once the area is clipped, lavaged, cleaned and dried. Second and third degree open fractures may require a tie-over bandage if you elect not to place a Spica splint. Wound closure may or may not be coordinated with surgical fracture stabilization. The wound may be able to be completely excised and closed primarily or allowed to heal by second intention, as is the case in some first and possible second-degree open fractures. Other wounds may require multiple debridements and repeated wound dressings before closure, grafting or flaps are placed.

Radiographs

True lateral and craniocaudal orthogonal view radiographs including the joint above and the joint below should be performed once the patient is stabilized and the wound managed appropriately. Magnification markers should be placed at the level of the bone when performing radiographs especially digital radiographs. This will allow the ability to compensate for magnification when planning fracture repair. Additional views such as oblique, stress or skyline views may also be needed to provide additional information prior to repair. Radiographs of the opposite limb may also be needed to assess for appropriate length or template for implants such as an interlocking nail. Air adjacent to the fracture site is consistent with an open fracture but not all open fractures have subcutaneous air on radiographs. In trauma cases, radiographs of the chest are indicated. In addition, radiographs of the abdomen or other injured areas may be indicated.

Antibiotics

All open fractures are considered contaminated. Open fractures or wounds greater than 8 hours old are presumed infected. Broad-spectrum, bactericidal, intravenous antibiotics should be started once an IV catheter has been placed. Cultures are taken at the time of fracture repair or primary wound closure to ensure no residual infection is present. If there is significant soft tissue damage or loss that will result in delayed wound closure, cultures are taken at the time of debridement, after copious lavage. If the culture result is negative and there is no sign of infection the antibiotics may be discontinued.

Surgery

Surgical stabilization of the open fracture is indicated as soon as the patient is stable. Due to the increased soft tissue trauma, damage to the vascular supply, increased risk of infection and delayed healing along with the need to provide appropriate wound care, rigid fixation, either internal or external, is selected over external coaptation alone. This may coincide with primary wound closure or not. If possible, the wound should be avoided when making the approach to the fracture. First-degree open fractures can be treated as closed fractures once the wound is appropriately managed. Typically with grade 1 fractures the wound can be excised or appropriately debrided and closed primarily at the time of fracture stabilization. Minimally invasive or open-but-don't-touch (OBDT) approaches should be selected for second and third degree open fractures to further minimize the already compromised blood supply. External skeletal fixation is a good choice for second and third degree open fractures although plates and interlocking nails can also be used. Due to the expected delay in healing secondary to damage to the vascular supply the stability of the repair should be increased 20-30% above what would be used for a closed fracture.

Additional reading

Textbook of Small Animal Surgery, Ed: Douglas Slatter, 3rd edition. Pub. Saunders of Elsevier Science, Philadelphia, 2003

Handbook of Small Animal Orthopedics and Fracture Repair, Ed: D Piermattei, G. Flo, C. DeCamp, 4th edition. Pub. Saunders of Elsevier Science, Philadelphia, 2006

Small Animal Surgery, Ed. T. Fossum, 3rd edition. Pub. Mosby of Elsevier Science, St. Louis, 2007