Review Article Open Tibial Shaft Fractures: I ... - Orthobullets

[Pages:10]Review Article

Open Tibial Shaft Fractures: I. Evaluation and Initial Wound Management

J. Stuart Melvin, MD Derek G. Dombroski, MD Jesse T. Torbert, MD Stephen J. Kovach, MD John L. Esterhai, MD Samir Mehta, MD

From the Department of Orthopaedic Surgery (Drs. Melvin, Dombrowski, Torbert, and Esterhai), the Division of Plastic Surgery (Dr. Kovach), and the Orthopaedic Trauma and Fracture Service (Dr. Mehta), University of Pennsylvania, Philadelphia, PA.

Dr. Mehta or an immediate family member is a member of a speakers' bureau or has made paid presentations on behalf of AO and Smith & Nephew, and has received nonincome support (such as equipment or services), commercially derived honoraria, or other non?research-related funding (such as paid travel) from Wolters Kluwer Health?Lippincott Williams & Wilkins. None of the following authors or an immediate family member has received anything of value from or owns stock in a commercial company or institution related directly or indirectly to the subject of this article: Dr. Melvin, Dr. Dombroski, Dr. Torbert, Dr. Kovach, and Dr. Esterhai.

J Am Acad Orthop Surg 2010;18: 10-19

Copyright 2010 by the American Academy of Orthopaedic Surgeons.

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Abstract

Open fractures of the tibial diaphysis are often associated with severe bone and soft-tissue injury. Contamination of the fracture site and devitalization of the soft-tissue envelope greatly increase the risk of infection, nonunion, and wound complications. Management of open tibial shaft fractures begins with a thorough patient evaluation, including assessment of the bone and soft tissue surrounding the tibial injury. Classification of these injuries according to the system of Gustilo and Anderson at the time of surgical d?bridement is useful in guiding treatment and predicting outcomes. Administration of antibiotic prophylaxis as soon as possible after injury as well as urgent and thorough d?bridement, irrigation, and bony stabilization are done to minimize the risk of infection and improve outcomes. The use of antibiotic bead pouches and negative-pressure wound therapy has proved to be efficacious for the acute, temporary management of severe bone and soft-tissue defects.

The subcutaneous location of the anteromedial tibial surface is the reason for the high proportion of diaphyseal fractures that are open. These fractures are associated with severe bone and soft-tissue injury. The often high-energy nature of these injuries can lead to gross contamination of the bone and soft tissue, thereby greatly increasing the risk of infection, nonunion, and wound complications.

Appropriate initial management of open tibial shaft fractures can profoundly affect the overall outcome. The first step in treatment is assessment of the patient and the involved extremity. The goals of initial treatment are to accurately define the extent of the injury and minimize the risk of infection through prompt administration of antibiotics as well as urgent d?bridement and copious irrigation.

Epidemiology and Patient Evaluation

Fractures of the tibial diaphysis are the most common long bone fracture, and approximately 24% of these fractures are open.1 Road traffic accidents are the mechanism of injury in more than half of all open tibial shaft fractures, with most of the remainder caused by falls, sportsrelated injuries, and direct blows.1 The high-energy nature of most of these fractures contributes to the increased proportion of Gustilo type III (ie, high-energy open) injuries. In their large epidemiologic study, Court-Brown et al2 found that nearly 60% of open tibial shaft fractures were Gustilo type III.

Because more than half of patients with open tibial shaft fracture present

Journal of the American Academy of Orthopaedic Surgeons

J. Stuart Melvin, MD, et al

with other injuries, the initial evaluation should follow the guidelines of the Advanced Trauma and Life Support protocol.2,3 After initial resuscitation, a detailed history of the injury should be sought, with a focus on the mechanism and setting. Tetanus immunization status should also be determined. During physical examination of the injured extremity, special attention should be paid to the neurovascular examination, status of the compartments, and the extent of soft-tissue injury and contamination. It is important to compare pulses between legs and to observe for capillary refill. In all patients with an abnormal vascular examination, the fracture should be reduced and the extremity evaluated using the anklebrachial index or Doppler ultrasonography. A patient with an ankle-brachial index of 3 hours after injury compared with 12 hours.

The effect of irrigation pressure has also been evaluated. Evidence indicates that high-pressure pulsatile lavage (HPPL) (nozzle pressure 50 psi) is effective in removing bacteria and debris from wounds.31 However, recent animal studies have suggested that HPPL may be detrimental to bone and soft-tissue structure as well as bone healing and that it may drive bacteria into wounds.27,31-33 Hassinger et al32 evaluated fresh ovine muscle specimens contaminated with bacteria and demonstrated deeper bacteria penetration and greater bacterial retention with HPPL compared with low-pressure lavage. In a similar model, Boyd and Wongworawat33 showed that HPPL penetrates and disrupts soft tissues to greater a degree than does low-pressure lavage. Dirschl et al31 demonstrated a detrimental effect of HPPL on early new bone formation in New Zealand white rabbits that underwent osteotomy of the medial femoral condyle and subsequent HPPL. In that study, HPPL was compared with control and bulb syringe irrigation groups. A follow-up study showed that early new bone formation is inhibited by HPPL pressure 50 psi.34

We have found that continuous gravity irrigation via cystoscopy tubing using 6 to 9 L of normal saline (with a soap solution for heavy contamination) provides excellent wound irrigation without the potential detrimental effects of HPPL, antiseptic, or antibiotics. A prospective multicenter international study is under way to examine the effects of both fluid pressure (high versus low) and solution type (normal saline versus normal saline with soap) on the infection rate of open fractures.

Immediate Primary Wound Closure

Immediate primary closure of an open wound is possible when an adequate amount of viable soft tissue is available to allow closure of an open wound without tension. With modern antibiotic prophylaxis and surgical techniques, immediate primary wound closure is safe and may decrease nosocomial infection by sealing open wounds and providing biologic coverage. DeLong et al35 managed 87 of 119 open fractures with immediate primary wound closure after irrigation and d?bridement. The authors found no difference in infection or nonunion rates compared with delayed closure. No cases of gas gangrene were reported. Hohmann et al36 found no difference in infection rates among type I, II, and IIIA open tibia fractures managed with primary versus delayed wound closure.

In the setting of timely antibiotic prophylaxis and thorough d?bridement and irrigation in a healthy host, we recommend that type I through type IIIA fracture be closed primarily at the time of initial d?bridement provided that it is possible to achieve a tension-free closure. We advocate the use of DonatiAllg?wer sutures to minimize the amount of cutaneous vascular compromise. The Allg?wer modification of the Donati vertical mattress suture technique was shown in a porcine model to have the least effect on cutaneous blood flow compared with simple, horizontal mattress and vertical mattress sutures37 (Figure 2). In wounds with limited soft-tissue viability, lack of soft-tissue coverage, or severe contamination, other methods of wound coverage should be considered, such as a bead pouch or vacuum-assisted closure.

Local Antibiotics

Local antibiotic-impregnated delivery vehicles can be a useful adjunct

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J. Stuart Melvin, MD, et al

to systemic antibiotic prophylaxis in managing large open tibial wounds. Polymethylmethacrylate (PMMA) cement is the most commonly used antibiotic delivery vehicle. Commercially prepared PMMA beads are not available in the United States, so they must be made by the surgeon. Typically, 40 g PMMA is mixed with 3.6 g tobramycin, molded into 5- to 10-mm spheres, and strung on suture or wire. Alternatively, a cement block spacer may be formed for placement in a segmental defect. Most often, aminoglycosides are used because of their broad spectrum of activity and heat stability; however, vancomycin and cephalosporins have also been employed. With the support of the hospital pharmacy, these beads can be prepared sterile and peel-packed for immediate use.

For wounds with inadequate softtissue coverage, local antibiotics are often administered through the creation of a bead pouch. The area is d?brided and irrigated, the antibiotic-impregnated PMMA beads are placed into an open fracture defect, and the defect is sealed with a semipermeable sterile covering. Use of a bead pouch allows for high local concentrations of antibiotic (10 to 20 times higher than systemic administration) and reduces the potential for nosocomial contamination. The use of drains in addition to a bead pouch is controversial. We prefer not to use drains in combination with the bead pouch so as to maintain higher levels of antibiotics locally. In addition, the frequency of surgical intervention in a patient with an open tibia fracture may minimize the impact of drains.

In a series of 1,085 open fractures, Ostermann et al38 found an infection rate of 3.7% for those treated with the bead pouch technique and systemic antibiotics compared with a 12% infection rate for fractures managed with systemic antibiotics alone (P < 0.001). Keating et al39 retrospectively compared the use of the

bead pouch technique at the time of reamed intramedullary nailing with delayed wound closure. A notably lower rate of deep infection was found in the group managed with a bead pouch and delayed primary closure than in the group managed with no bead pouch and with delayed wound closure (4% versus 16%, respectively). The bead pouch technique appears to be a useful temporizing option for severely contaminated open fractures of the tibial shaft with inadequate tissue for immediate closure.

Local antibiotics have also been used successfully in the management of large segmental bone loss in open tibia fractures. Masquelet et al40 and Pelissier et al41 used a two-stage protocol in which antibiotic-impregnated PMMA cement spacers were inserted into segmental defects to maintain length and induce a synovium-like foreign-body membrane. This membrane provides a contained space for future cancellous bone grafting and has been shown to secrete transforming growth factor-1, vascular endothelial growth factor, and bone morphogenetic protein-2. Ristiniemi et al42 used a similar two-stage technique in the management of 23 open tibia fractures with substantial bone loss (mean, 52 mm). Septopal beads (Merck, Damstadt, Germany) were placed at the time of wound coverage and bone stabilization to preserve the volume of the bone loss and to induce a foreign-body membrane. They were removed at a mean of 8 weeks after the soft-tissue cover procedure and were replaced with iliac crest bone graft within the foreign-body membrane. Twentytwo of the 23 fractures healed after a mean of 40 weeks.

More recently, delivery of local antibiotics through bioabsorbable vehicles such as calcium sulfate, demineralized bone matrix, and fibrin clots has shown promise in preventing in-

fection in animal models.43,44 These delivery vehicles eliminate the need for removal of PMMA cement and may reduce the number or volume of autografts while providing osteoconductive and/or osteoinductive material to aid in fracture healing. Beardmore et al43 created in a goat model a 12-mm?diameter unicortical defect in the proximal tibial metaphysis and contaminated the defect with an infecting dose of S aureus. Tobramycin-impregnated calcium sulfate pellets combined with demineralized bone matrix was found to be as effective as tobramycin-impregnated PMMA cement beads in preventing infection.

Negative-pressure Wound Therapy

The Vacuum-Assisted Closure device (VAC; Kinetic Concepts, San Antonio, TX) uses continuous subatmospheric pressure (typically, 125 mm Hg) applied through an open-cell foam dressing sealed over a wound to decrease edema, rapidly increase the amount of granulation tissue, and reduce wound size.45 The popularity of the VAC device has increased tremendously since its introduction, and the device appears to be a versatile tool in wound management. Parrett et al46 observed a shift in their treatment patterns for open fractures of the lower extremity over a 12-year period. Significantly fewer free flaps were placed in the last 4 years of their series than in the first 4 years (5% versus 20%, respectively). Additionally, there was an increase in the use of negative-pressure wound therapy (NPWT), from 7% during the middle 4 years (when NPWT was introduced) to 49% during the final 4-year period, even though there was no change in the severity of open fracture. With this shift in wound management, a decrease in reoperation rates was noted, from 19% in

January 2010, Vol 18, No 1

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