Treatment principles in the management of open fractures

The management of open fractures continues to provide challenges for the orthopedic surgeon. Despite the improvements in technology and surgical techniques, rates of infection and nonunion are still troublesome. Principles important in the treatment of open fractures are reviewed in this article. Early antibiotic administration is of paramount importance in these cases, and when coupled with early and meticulous irrigation and debridement, the rates of infection can be dramatically decreased. Initial surgical intervention should be conducted as soon as possible, but the classic 6 h rule does not seem to be supported in the literature. All open fractures should be addressed for the risk of contamination from Clostridium tetani . When possible, early closure of open fracture wounds, either by primary means or by (cid:223) aps, can also decrease the rate of infection, especially from nosocomial organisms. Early skeletal stabilization is necessary, which can be accomplished easily with temporary external (cid:222) xation. Adhering to these principles can help surgeons provide optimal care to their patients and assist them in an early return to function.


INTRODUCTION
I t has been estimated that between 3.5 and 6 million fractures occur in the United States annually. 1,2 Extrapolating from European data, we can estimate that more than 3%, i.e., 150,000, of these are open fractures. 3,4 When adjusting for population differences, we predict that more than 4.5 million open fractures occur per year in India. This figure may be an underestimation, given the high population density in the large urban centers in India. These fractures can involve significant morbidity and are inherently worrisome, as the body's protective skin barrier has been broken and the potential for contamination is high. The correct and timely management of these injuries can benefit our patients and lead to more favorable outcomes.
When deciding on the treatment strategy, the treating surgeon must consider the patient's condition, the mechanism of injury, and the fracture type. Although some of the most impressive injury patterns are from high-energy mechanisms, more commonly, patients present with an open fracture from a simple low-energy mechanism such as a fall. Each fracture could conceivably be treated quite differently, ranging from external fixation and delayed closure or fixation to immediate irrigation, debridement, and primary closure. The status of the soft tissues surrounding the fracture site is of paramount importance in this decision-making process, which usually influences the initial management.
Goals of open fracture management are well known and include the prevention of infection, achievement of bony union, and the restoration of function. Current treatment strategies in the care of open fractures are continuously studied, improved, and adjusted as our literature base expands. Important principles include antibiotic utilization, timing of initial surgical intervention, type of wound closure, antibiotic delivery methods, tetanus coverage, wound irrigation, and adjunctive therapies to assist with fracture union. This review aims to provide current information and references for further reading on these topics and provide a framework for decision-making when presented with an open fracture in the acute setting.
accurate prognosis for more severe injuries (i.e., Type III injuries). 6,9 There has been some concern in the literature regarding the interobserver reliability of this system. 10 In this study, the surgeons interpreted color movies of examinations and radiographs of patients and then classified the injuries based on that screening. Overall, they demonstrated 60% agreement. We contend that classification of the injury should be made in the operating room at the conclusion of the initial irrigation and debridements (see Table 1 for details). The second classification system, the MESS, was originally designed as an objective tool to assist the surgeon in decisionmaking for amputation vs limb salvage in complex lower extremity trauma. 8 This rating scale takes into consideration the skeletal and soft tissue damage, limb ischemia time, presence of shock, and the patient's age. Multiple studies have examined the efficacy of the MESS both retrospectively and prospectively and have found it to correlate well with the treatment of major limb trauma. It has been suggested that a score of greater than or equal to 7 is predictive of amputation with nearly 100% accuracy [ Table 2]. 8,[11][12][13][14][15][16][17][18][19] More recent information has emerged in the management of severe lower extremity trauma and the effectiveness of the MESS and other lower extremity trauma scoring systems, including the Limb Salvage Index and the Predictive Salvage Index. In one of the largest multicenter, prospective outcome studies pertaining to lower extremity trauma, the Lower Extremity Assessment Project (LEAP), found in a study of more than 500 patients with lower extremity trauma that injury factors with the highest significance in the decision for limb salvage were not solely the measures listed in the above scoring systems. The LEAP group found that the most significant factors were tibial fracture pattern, presence of an open foot fracture, bone loss, muscle injury, vein injury, arterial injury, and the absence of plantar sensation. Severe muscle injury had the highest impact on the surgeon with loss of plantar sensation being second. 20 More recent followup data have challenged the importance of the insensate foot in the decision for amputation. 21 Interestingly, this study found more than one-half of the patients presenting with an insensate foot treated with reconstruction ultimately regained sensation in two years.
The decision for amputation or limb salvage should be made with careful consideration of multiple factors to include not only the MESS parameters and those from the LEAP study, but also the emotional impact, social impact, and psychological recovery necessary for physical recovery. 20,22 The assistance of the patient and their family is also encouraged. We ultimately advise initial surgical exploration prior to decision-making in the severely injured extremity. 17

CONTAMINATION OF OPEN FRACTURE AND USE OF ANTIBIOTICS
All open fractures are by definition contaminated and must be treated as such. The treatment methods may differ depending on the type of fracture. Infection risks also differ by fracture type and have been reported to be ranging from Type III fracture with extensive soft-tissue loss and periosteal Above patterns but usually very contaminated stripping and bone damage. Usually associated with massive contamination. Will often need further soft-tissue coverage procedure (i.e. free or rotational ß ap) IIIC Type III fracture associated with an arterial injury requiring repair, Above patterns but with vascular injury irrespective of degree of soft-tissue injury.
needing repair Antibiotic treatment with open fracture management should be automatic with early administration being paramount [ Table 3], ideally within 3 h of injury. The risk of infection has been shown to decrease six-fold with this practice. 24,26 With the propensity for gram-positive infections with Type I and II fractures, a first-generation cephalosporin is generally recommended. Some authors have advocated adding gram-negative coverage as well. 24,25,27 Type III fractures often have contamination from gram-negative organisms, and in the case of soil-contaminated wounds (i.e., farm injuries), additional coverage should be added for anaerobic bacteria. Typically, this would include penicillin for the risk of a Clostridial infection. In the treatment of open fractures in the hospital setting, the surgeon must also be concerned for nosocomial infections, namely by Staphylococcus aureus and aerobic gram-negative bacilli such as Pseudomonas. 25 Specific antibiotic coverage for these organisms may be indicated. The duration of antibiotic therapy in the treatment of open fractures has been suggested to be between 1 and 3 days without any solid agreement on a firm end point. 25,26,[28][29][30] We typically maintain antibiotic coverage until the wound is closed. Our recommended treatment regimen is detailed in Table 3.
Local antibiotic delivery must be considered when extensive contamination is present. This is commonly done with an "antibiotic bead-pouch" construct formed with antibiotic powder and polymethylmethacrylate (PMMA) cement. These constructs are available commercially or can also be easily made in the operating room with readily available equipment. A recommended technique we follow includes forming beads over 24-gauge wire with 3.6 g of tobramycin mixed with 40 g of PMMA cement. 31 The beads are counted and then placed into the wound and covered with an impermeable dressing (i.e., Ioban, 3M, Minneapolis, MN). This simple technique when used in conjunction with systemic antibiotics has been shown to decrease infection rates from 12 to 3.7% in severe open fractures [ Figure 1]. 32 At our institution, this bead-pouch technique is occasionally used after preliminary debridement when surgical plans dictate a return to the operating room within 48 h for further debridement.
Wound contamination with dirt, saliva, or feces; puncture wounds, including unsterile injections; missile injuries; burns; frostbite; avulsions; and crush injuries must raise concerns for Clostridium tetani, the anaerobic gram-positive bacterial species responsible for tetanus. 33 Prophylaxis and treatment for tetanus should be considered for every patient with an open fracture. In the United States, the Centers for Disease Control and Prevention recommend tetanus immunization via tetanus toxoids at 2, 4, and 6 months, 12-18 months, 5 years, 11-12 years, and then at 10-year intervals for maintenance immunization. Any patient presenting with an open fracture who has not completed the tetanus toxoid immunization 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 250-500 IU of human tetanus immune globulin (HTIG). Furthermore, if more than 10 years has elapsed since the last tetanus booster or the patient's immune system is compromised, both the tetanus toxoid and HTIG should be given. 33 The HTIG will offer most patients 3 weeks of protection [ Table 4].

INITIAL SURGICAL DEBRIDEMENT
The timing of initial surgical intervention has wide variance within the literature. Historically, the 6-hour rule has been employed as the time limit within which an open fracture should be taken to the operating room for initial debridement. 5 Many factors influence this parameter including the operating room availability, surgeon availability, and the patient's physiologic status. 34 Challenges can arise when striving to adhere to this time limit including operating under conditions that are less than ideal (i.e., nonorthopedic surgical teams, poor implant availability, surgeon and personnel fatigue, etc.). This unfortunately can result in adverse events with patient outcomes. The optimal environment for surgical care of the orthopedic trauma patient involves surgical teams that are well-rested and experienced with the procedures being performed. Strict adherence to the emergent 6-h rule does not seem to be justified based on empiric evidence available in the literature. [34][35][36][37][38][39][40][41][42][43][44] Open fractures should be taken to the operating room in an urgent manner using appropriate surgical judgment. There are certain scenarios when more emergent debridements may be needed. These may include Type III injuries with vascular injury and/or gross fecal or soil contamination. If surgery for an open fracture is to be delayed, temporizing treatment should include sterile and antiseptic coverage (i.e., with Technicare soap solution or iodine-derivative) and provisional splinting with attention paid to basic length, rotation, and alignment. A preliminary fracture reduction may need to be performed in the emergency room. Once the wound is dressed and splinted, the covering should not be lifted until the patient is delivered to the operating room as this practice can increase the infection rate by a factor of 3-4. 45-46 Ideally, a digital photograph can be taken at the initial evaluation and used for further communication between providers. We find this to be especially helpful in academic trauma centers where residents and fellows initially evaluate the patients and communicate findings to the attending surgeon.

IRRIGATION AND DEBRIDEMENT PRINCIPLES
Perhaps the most important aspect in the treatment of open fractures is the initial surgical intervention with irrigation and meticulous debridement of the injury zone. In fact, we believe that the surgeon should spend as much time for planning and performing the debridement as for the fixation of the fracture. This initial debridement should include a sequential evaluation of skin, fat, fascia, muscle, and bone [ Table 5]. The propensity to excise as little possible should be avoided in open fracture management given the relatively high contamination rate of these injuries, especially in Type III injuries. 6 Our approach with open fracture management is to remove any obvious devitalized tissue (including bone) at the initial debridement. If a second debridement is warranted, some questionable muscle may be left until the next scheduled debridement. Ideally, coverage of the open fracture should take place after one to two formal

Tetanus immunization status Recommended dosing
Tetanus booster within last 5 years No further treatment necessary More than 5 years since booster or Tetanus toxoid (if wound has not completed immunization series tetanus prone, give HTIG) More than 10 years since booster Tetanus toxoid and HTIG or immune system compromised HTIG: Human tetanus immune globulin.

TIMING OF WOUND CLOSURE
Options for wound closure in the treatment of open fractures include primary closure of the skin, split-thickness skin-grafting, and the use of either free or local muscle flaps. The timing of open wound closure has proponents in the immediate, early, and delayed categories. Although these terms are used frequently in the literature, their use has yet to gain universal acceptance. 54 Traditionally, immediate closure is defined as wound closure at the time of the initial surgical intervention. Early closure is within the 24-72 h window, and delayed or late closure extends beyond 3 days. Historically, surgeons have opted to delay closure because of the perceived risks of clostridial infections and gas gangrene. This concern is certainly present in the grossly contaminated open fracture. Current treatment strategies correctly emphasize the importance of debridement and irrigation, and adhering to these principles has allowed surgeons to consider earlier closure and immediate primary closure in some cases when certain criteria are met. These have been suggested to include debridement performed within 12 h, no excess skin loss primarily or secondarily during debridement, skin approximation possible without tension, no gross soil or other similar contamination, and no vascular insufficiency. 55  Our recommendation is toward primary closure of Type I, Type II, and a few selected Type IIIA fractures. The most important factors in our decision-making process is the adequacy of the initial debridement and the degree of wound contamination. If there is any doubt regarding the safety of primary closure, we opt to wait until the second surgical debridement and make further treatment decisions at that time. If a primary closure is conducted and there is questionable tissue viability noted postoperatively, we have a very low threshold for reopening the wound 48-72 h after initial closure. If possible, we aim to have coverage completed within 72 h preferably with primary closure. Particular attention must be paid to tension across the wound closure site. Tension may interfere with wound healing by decreasing the vascularity across the incision. Close relationships with plastic and tissue reconstructive teams can facilitate early closure if flap coverage is necessary. A valuable adjunct to wound closure has been the wound vacuum-assisted closure device (VAC; KCI, San Antonia, TX). 65-69 It has been shown that this device aids in wound healing by reducing edema, enhancing granulation tissue formation, and increasing local blood flow [ Figure 2]. 70,71 We utilize this vacuum-assisted closure concept often when immediate closure is not possible although it is important to realize that this method does not necessarily reduce infection rates or allow a permissible delay in wound closure. 69,72 The choice between the wound vacuum-assisted closure device and the antibiotic bead-pouch depends on the degree of wound contamination and surgeon preference.

SKELETAL STABILIZATION
Early stabilization of open fractures provides many benefits to the injured patient. It protects the soft tissues around the zone of injury by preventing further damage from mobile fracture fragments. It also restores length, alignment, and rotation-all vital principles of fracture fixation. This restoration of length also helps decrease soft tissue dead spaces and has been shown in studies to decrease the rates of infection in open fractures. 40,73,74 Lastly, early fixation allows improved access to soft tissues surrounding the injury and facilitates the patient's early return to normal function. 75 The surgeon has many choices when deciding on fixation constructs: skeletal traction, external fixation, and intramedullary nails and plates. The choice of fixation involves the bone fractured and the fracture location (intraarticular, metaphyseal, diaphyseal), the extent of the soft-tissue injury and the degree of contamination, and the physiologic status of the patient. 23 There are also certain situations in which more than one method may be used (i.e., fibula plating of a Pilon fracture in which fibula fixation helps restore length and rotation in conjunction with an external fixator placed across the tibial-talar joint).
Skeletal traction and external fixation are the quickest fixation constructs to employ.  results. [92][93][94][95] Conclusions from these studies seem to indicate that conversion from external fixation to an intramedullary nail is safe given two parameters: conversion in less than 2 weeks and absence of pin site infections. Conversion after pin site infections may require additional time and antibiotic treatment after removing the external fixator and placement of the intramedullary nail. 92 We use this conversion frequently for complex trauma and Type III open fractures.

ADJUNCTIVE THERAPIES
An inherent risk in the treatment of open fractures is the occurrence of a nonunion. This is typically defined as a lack of osseous union across three cortices as seen by radiographs 9 months postoperatively. Prophylactic bone grafting can also be used in the early treatment of open fractures. The literature has several examples of studies pertaining to immediate or early prophylactic bone grafting, and this practice has reported to shorten the time to fracture union and reduce the rate of delayed union by more than 11 weeks. 103-106 The utilization of prophylactic bone grafting is not routine at our hospital, and we do not typically intervene before 6 months postoperatively.

CONCLUSIONS
The above review provides a framework that the surgeon can reference when treating patients with open fractures.
The management of open fractures involves the adherence to principles discussed earlier. Using a principle-based treatment regimen can help improve patient outcomes while avoiding complications and adverse events. Ultimately, this is the surgeon's goal, and patients will benefit from the early return to normal function.