Timing of Operative Debridement in Open Fractures




The optimal treatment of open fractures continues to be an area of debate in the orthopedic literature. Recent research has challenged the dictum that open fractures should be debrided within 6 hours of injury. However, the expedient administration of intravenous antibiotics remains of paramount importance in infection prevention. Multiple factors, including fracture severity, thoroughness of debridement, time to initial treatment, and antibiotic administration, among other variables, contribute to the incidence of infection and complicate identifying an optimal time to debridement.


Key points








  • Patients with open fractures are at high risk of infection if not treated expediently.



  • The historic 6-hour time limit for debridement of open fractures has been challenged in contemporary publications.



  • In the context of early antibiotic administration, debridement within 6 hours has not been shown to be an independent risk factor for infection after open fracture.



  • Delayed versus primary wound closure is determined based on the clinical experience of the surgeon, but may not have an effect on infection rates.






Background


An open fracture is defined as a fracture that involves a violation of the soft tissue envelope with communication through to the fracture fragments, the associated fracture hematoma, or both. Although Gustilo and Anderson espoused universal agreement that open fractures require emergent treatment to include adequate irrigation and surgical debridement of the open wound, few issues in orthopedics today are debated more than the appropriate timing and management of open fractures. However, there is consensus that these low- or high-energy injuries result in wound contamination, devitalized tissue, local edema, and surrounding ischemia that interfere with the body’s natural immune defense mechanisms to resist infection. As a result of thorough surgical techniques, antibiotic options and administration, and advanced techniques for soft tissue coverage, the ability to manage open fractures has improved. The treating orthopedic surgeon must be able to address these injuries appropriately to limit the risk of infection and promote adequate healing.


This article addresses the evaluation of a patient with an open fracture and analyzes the evidentiary support regarding the historic “6-hour rule” in the timing of operative management.




Background


An open fracture is defined as a fracture that involves a violation of the soft tissue envelope with communication through to the fracture fragments, the associated fracture hematoma, or both. Although Gustilo and Anderson espoused universal agreement that open fractures require emergent treatment to include adequate irrigation and surgical debridement of the open wound, few issues in orthopedics today are debated more than the appropriate timing and management of open fractures. However, there is consensus that these low- or high-energy injuries result in wound contamination, devitalized tissue, local edema, and surrounding ischemia that interfere with the body’s natural immune defense mechanisms to resist infection. As a result of thorough surgical techniques, antibiotic options and administration, and advanced techniques for soft tissue coverage, the ability to manage open fractures has improved. The treating orthopedic surgeon must be able to address these injuries appropriately to limit the risk of infection and promote adequate healing.


This article addresses the evaluation of a patient with an open fracture and analyzes the evidentiary support regarding the historic “6-hour rule” in the timing of operative management.




Historical perspective


The use of excisional debridement to prevent wound infection dates back to the time of Hippocrates. In 1898, a German military surgeon and bacteriologist, Paul Leopold Friedrich, conducted an experiment using guinea pigs whereby he created open wounds in the triceps region and contaminated them with mud and house dust. Wounds were cleaned in intervals of 30 minutes. He found that when wounds were debrided within 6 hours of inoculation, the guinea pigs survived. All of the guinea pigs whose wounds were debrided after 8.5 hours died. Thus, Friedrich showed that the early phases of bacterial growth within contaminated wounds terminated within 6 to 8 hours after inoculation and that extensive debridement to viable tissue within this time period could decrease the risk of infection. Of note, Friedrich’s work did not involve administration of local or systemic antibiotics. Before World War II, open injuries were left to heal by secondary intention. Military surgeon Joseph Trueta aptly described treatment of an open wound (ie, soft tissue injury) as the principal part of the treatment of an open fracture. He believed that the greatest danger of infection lay not in the infection of the bone, but rather the muscle. By the end of the war, Friedrich’s study was adopted to reflect the time required to close open wounds. This “6-hour rule,” although based primarily on historical opinion and limited clinical evidence, has since been extrapolated to open fractures and was adopted as a treatment guideline in the orthopedic community for many years. Not until recently have many studies started to challenge the 6-hour rule, shifting away from the previous doctrine of emergently operating on open fractures.




Epidemiology


The tibia is the most common location for an open fracture. Its proximity to the skin and limited soft tissue envelope enable even low-energy fractures to violate the soft tissue envelope. Most open fractures occur in the fifth decade of life, commonly as a result traffic accidents, crush injuries, or falls. As with most fracture patterns, there is a bimodal distribution: lower energy injuries occur in the elderly most commonly from falls, whereas higher energy injuries occur in younger patients. In a recent review, Court-Brown and colleagues evaluated the epidemiology of open fractures over a 15-year period. They reported 30.7 open fractures per 100,000 person-years, a steady increase as compared with previous reports of 11.5 per 100,000 person-years. In their cohort, 69.1% occurred in males and 30.9% occurred in females.


As a result of the disruption of the protective skin barrier, injuries with exposed bone and soft tissue are more prone to infection. For open tibia fractures, an infection rate of 13% to 25% has been reported. Further studies have elucidated the differences in infection rate based on the Gustilo-Anderson classification system and the timing of operative debridement. In a retrospective review by Templeman and colleagues, none of 29 type I fractures, 1 of 36 (3%) type II fractures, and 14 of 68 (21%) type III fractures became infected. Early administration of antibiotics has been shown to be an extremely important factor in the prevention of infection following open fractures. Although antibiotic administration has been deemed “prophylactic,” work by several authors has shown that antibiotic use is actually therapeutic. Most current recommendations suggest that antibiotics should be administered for 24 to 48 hours after the last debridement.




Classification


The Gustilo-Anderson classification of open fractures is the most commonly used system in current practice. This system takes into consideration the energy of the fracture, soft tissue damage, and the degree of contamination. In their retrospective (n = 673) and prospective (n = 352) reviews of 1052 open fractures, a type I injury was defined as a low-energy injury with minimum soft tissue damage and a small (<1 cm) wound. These were typically inside-out puncture injuries with minimal comminution. A type II injury described a low- to moderate-energy injury with moderate soft tissue damage and an open wound up to 10 cm, but without periosteal stripping. Originally, a type III injury was an umbrella category for either an open, segmental fracture with extensive soft tissue damage, or a traumatic amputation. This description was found to be too inclusive, so Gustilo and colleagues modified their type III classification several years later. A type IIIA injury has adequate soft tissue coverage despite the high-energy comminution and segmental nature, irrespective of the wound size. However, an injury with a wound greater than 10 cm was also characterized as IIIA. A type IIIB open fracture necessitates local or distant flap coverage of areas of exposed bone (not including skin grafting). In addition, these fractures are commonly associated with extensive periosteal stripping ( Fig. 1 ). Finally, a type IIIC injury results in a vascular injury that requires repair to preserve limb survival. Isolated injuries to the anterior or posterior tibial artery are not included in this description ( Table 1 ). Importantly, the final classification of the injury is determined in the operating room. To test the reliability of this system, 245 surgeons were given clinical histories, physical examinations, radiographs, and video footage of the operative debridement of 12 open fractures. The overall interobserver agreement was a moderate 60% (range, 42%–94%).




Fig. 1


Anteroposterior radiograph ( A ) and clinical image ( B ) of the right tibia in a 27-year-old male who sustained a Gustilo-Anderson type IIIB fracture after a motor vehicle accident. ( C ) Soft tissue defect after operative debridement. ( D ) Delayed soft tissue coverage with a rotational soleus flap and split thickness skin grafting.

( Courtesy of [ D ] S. Kovach, MD, Philadelphia, PA.)


Table 1

Gustilo-Anderson classification of open fractures






















Subtype Description
I Wound <1 cm; clean; simple fracture pattern; minimal comminution; minimal soft tissue damage
II Wound 1–10 cm; simple fracture pattern; moderate soft tissue injury
IIIA Wound >10 cm; extensive soft tissue injury with maintained soft tissue coverage over bone; high energy, comminuted, or segmental injuries
IIIB Extensive soft tissue damage with periosteal stripping; inadequate soft tissue coverage of the area of injury
IIIC Vascular injury requiring repair

Adapted from Cross WW, Swiontkowski MF. Treatment principles in the management of open fractures. Indian J Orthop 2008;42(4):381; with permission.


More recently, the Orthopedic Trauma Association developed a more comprehensive classification of open fractures, because the Gustilo Anderson classification was designed only for tibial shaft fractures and was shown to have only moderate interobserver reliability. Therefore, based on an extensive review of the literature, the workgroup ranked 34 factors to classify open fractures independent of body site and age. The highest ranking factors included the presence of a skin defect, muscle injury, arterial injury, bone loss, and wound contamination. Contamination was included for its overall contribution to the risk of infection. These factors were each divided into 3 subcategories based on severity. The system was then applied to prospectively collected data of 99 open fractures to determine the clinical feasibility. To accurately assess the zone of injury and the tissue damage, the classification was implemented after the initial operative debridement ( Table 2 ). Although this system represents a comprehensive method to classify open fractures, further study is warranted to evaluate its reliability and validity on a larger scale.



Table 2

Orthopedic trauma association classification of open fractures






















Category Severity
Skin

  • 1.

    Able to approximate closure


  • 2.

    Not able to be approximate closure


  • 3.

    Extensive degloving injury

Muscle

  • 1.

    No muscle death, intact muscle function


  • 2.

    Muscle loss but function remains; some necrosis


  • 3.

    Loss of function, necrotic muscle, disruption of muscle–tendon unit; muscle defect not able to be approximated

Arterial

  • 1.

    No arterial injury


  • 2.

    Arterial injury without ischemia


  • 3.

    Arterial injury with distal ischemia

Contamination

  • 1.

    None or minimal


  • 2.

    Superficial contamination


  • 3.

    (A) Deep contamination; (B) high-risk environment (ie, farm, fecal, dirty water)

Bone loss

  • 1.

    No bone loss


  • 2.

    Some bone loss but cortical contact between fragments remains


  • 3.

    Segmental bone loss


From Orthopedic Trauma Association: Open Fracture Study Group. A new classification scheme for open fractures. J Orthop Trauma 2010;24:460; with permission.




Initial management


The management of an open fracture begins in the emergency department. Antibiotics and tetanus prophylaxis should be administered in a timely fashion as early as possible. Any patient presenting with an open fracture who has not completed the tetanus toxoid immunization series or has not had their booster in the last 5 years should be given a tetanus toxoid booster. If the wound is prone to contamination with Clostridium tetani , the tetanus toxoid should be combined with human tetanus immune globulin. If more than 10 years have elapsed since the last tetanus booster or the patient has a compromised immune system, both tetanus toxoid and human tetanus immune globulin should be administered.


After an initial evaluation of the soft tissue injury and neurovascular status, the wound should be covered with a sterile dressing and the limb immobilized in a well-padded splint. The splint will assist in stabilizing the fracture and limit further shear forces across the soft tissue by limiting excessive motion of the bone fragments. Repeated uncovering and covering of the wound has been shown to increase the rate of infection by 3- to 4-fold, so a sterile or betadine-soaked dressing should be applied and not removed until the patient is in the operating room. If there is obvious debris or contamination this should be removed and irrigation at the bedside with a gentle normal saline lavage considered, but deeper debridement should be avoided at the risk of further contamination of the tissues with nosocomial organisms.




Antibiotic administration


The urgent administration of antibiotics is a well-established critical step in preventing infection of open fractures. A systematic review of antibiotic administration in open fractures by the Eastern Association for the Surgery of Trauma produced several recommendations for treatment. This review found Level 1 evidence for 4 statements:


Feb 23, 2017 | Posted by in ORTHOPEDIC | Comments Off on Timing of Operative Debridement in Open Fractures
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