External Fixation of Tibial Fractures

Transcription

1 15 External Fixation of Tibial Fractures Nirmal C. Tejwani, MD David Polonet, MD Philip R. Wolinsky, MD Abstract External fi xation for defi nitive or initial management of tibial fractures has a long history, with pin-to-bar external fi xation being the standard of care for defi nitive management. However, the use of this method has lessened because of the increased popularity of intramedullary nailing and drawbacks associated with external fi xation. This method is still commonly used in the military environment and can be used for temporary stabilization of tibial fractures, especially in the setting of periarticular injuries. These fi xators also may be useful for salvage of open and/or infected fractures that are unsuitable for internal fi xation. Definitive Management of Tibial Shaft Fractures Pin-to-Bar External Fixation In the past, pin-to-bar external fixation was used extensively for definitive management of tibial shaft fractures, particularly open fractures. This method of external fixation was the standard of care for these injuries until it was largely supplanted by the use of internal fixation. As the use of intramedullary (IM) nailing has become Instr Course Lect 2015;64: mainstream and comparative studies of external fixation and internal fixation outcomes have become available, the disadvantages associated with the use of external fixation for definitive management of these fractures have become clear. These drawbacks include deep and superficial pin-tract infections; an increased rate of malunion; the same deep infection rate as a reamed, minimally reamed, or unreamed IM nail; and an increased incidence of infection Dr. Tejwani or an immediate family member has received royalties from Biomet; is a member of a speakers bureau or has made paid presentations on behalf of and serves as a paid consultant to Zimmer and Stryker; and serves as a board member, owner, offi cer, or committee member of the American Academy of Orthopaedic Surgeons, the Orthopaedic Trauma Association, and the Foundation of Orthopaedic Trauma. Dr. Polonet or an immediate family member serves as a paid consultant to Biomet. Dr. Wolinsky or an immediate family member is a member of a speakers bureau or has made paid presentations on behalf of Zimmer; serves as a paid consultant to Biomet and Zimmer; has received research or institutional support from Synthes; and serves as a board member, owner, offi cer, or committee member of the Orthopaedic Trauma Association, the American Academy of Orthopaedic Surgeons, the American Orthopaedic Association, and the American College of Surgeons. when placing an IM nail after an external fixator has been in place for 10 days to 3 weeks. 1 Patient dissatisfaction is another important factor in the decreased use of external fixation for definitive management of tibial shaft fractures. The external fixator often needs to remain in place for 3 to 4 months or longer. Currently, pin-to-bar external fixation for tibial shaft fractures is used more often for initial temporizing stabilization (that is, damage-control orthopaedics) when the patient is too sick for definitive fixation or when the injury to the soft-tissue envelope is too severe to permit definitive fixation (the too sick limb; Figure 1). External fixation is still commonly used in the military environment. In this setting, contaminated wounds are the norm, and the ability to place an IM nail is compromised by the injury and an austere environment, with limited resources available in the battlefield. For pin-to-bar external fixation, insertion of no less than two half pins on either side of the fracture is recommended. Placement of pins in two 2015 AAOS Instructional Course Lectures, Volume

2 Trauma Figure 1 A and B, Intraoperative photographs demonstrating the use of pin-to-bar external fi xation for management of lower extremity fractures in the setting of damage-control orthopaedics. The 19-year-old patient was involved in a motor vehicle crash and required a thoracotomy. He eventually required extracorporeal membrane oxygenation. The bilateral tibial fractures and left femoral fracture were initially stabilized with external fi xation. different planes improves the strength of the construct. Overall strength also may be improved by using a pin or a bar with a larger diameter, placing the bar/clamps as close to the skin as the swelling allows, and spreading the pins appropriately (near-near-far-far technique). Pin care technique, although important, is not universally agreed on. This chapter s authors prefer to allow the patient to shower and keep the pin sites free of scabs. Application of an antibiotic dressing is not recommended unless indicated for pin-site infection. External Fixation With Circular Frames The biomechanics of circular frames are unique and differ from those of the familiar pin-to-bar frames. The circular fixators need to be built properly to be effective. To increase the stiffness of a circular frame, several factors should be considered, including the size of the rings. The smallest rings possible should be used, although room must be left to allow for soft-tissue swelling to prevent impingement of the ring on the soft tissue. The largest diameter wire possible should be used, and the wires must be maximally tensioned. Wire placement affects frame stiffness. Shear stiffness depends on the interwire angle and loading direction. Stiffness decreases dramatically when the interwire angle is less than 60. Placing opposed olive wires to maximize the interwire angle can increase shear stiffness, although doing so can be limited by soft-tissue, safe corridor constraints. 2-4 Bending stiffness can be increased by placing a drop wire, which is a wire spaced more than 4 cm away from the other wires. This increases bending stiffness to a 90 interwire angle. In addition, frames with two levels of periarticular fixation are stiffer than frames with all the wires placed close together. 2-4 If the periarticular fragment is too short to allow adequate wire spacing, then temporary joint spanning for 6 to 8 weeks may be needed. 2-5 The use of circular frames for managing tibial fractures is useful for several reasons. These frames can be used for periarticular fractures with long extensions into the tibial shaft. 6,7 Circular frames allow immediate weight bearing, which is beneficial for patients with bilateral and/or multiple injuries and aids in earlier mobilization, thus diminishing the potential for complications associated with recumbancy. In patients with soft-tissue defects, these frames may be used to close the defects by deliberately malreducing the fracture or shortening it and then gradually reestablishing reduction and/or length. The frames are useful for pediatric patients as well. The presence of an open physis may dictate the type of fixation that can be used, and the condition of the soft tissues may not allow for an open and/ or an acute correction of a deformity. Hybrid External Fixation A hybrid fixator is a combination of a circular wire frame and the more AAOS Instructional Course Lectures, Volume 64

3 External Fixation of Tibial Fractures Chapter 15 Figure 2 Photograph of a hybrid frame used for management of a distal tibial fracture. The two-level ring/wire portion of the frame is used for fi xation of the short distal fragment, whereas the pin-to-bar portion is used for fi xation of the long fragment. familiar half-pin frame. The joint surface is reduced through small incisions, and fixation of the smaller periarticular block is achieved with thin, tensioned wires. Fixation of the long fragment is achieved using pin-to-bar frames with half pins. This limits the soft-tissue dissection required for the fixation of tibial shaft fractures by avoiding the long portion of the open incision needed for plate placement versus joint reduction (Figure 2). Hybrid fixation is still used successfully to manage tibial fractures. This technique was controversial for several reasons. One reason was the inconsistent use of open reduction and internal fixation for fractures of the articular surface. Another issue was the potential lack of attention to proper frame construction based on the biomechanics of hybrid frames. In the literature, the results of hybrid fixation are good, with a substantial reduction in the reported incidence of soft-tissue complications compared with the results of acute open reduction and internal fixation using large incisions However, the patient is still required to wear a large, bulky external fixator on the leg for variable lengths of time. Figure 3 A, Intraoperative photograph demonstrating placement of an external fi xation frame across the knee for reduction of a proximal tibial fracture. Note the black external guide for percutaneous insertion of screws into the plate. B, Intraoperative photograph of the lower extremity demonstrating the smaller incisions that can be used for percutaneous plate fi xation with a medial external fi xator. External Fixation as an Intraoperative Reduction Tool Plating and IM nailing techniques have evolved over the years to protect the soft-tissue envelope and the blood supply to bone. Minimally invasive percutaneous osteosynthesis (MIPO) techniques allow surgeons to place plates using smaller incisions, resulting in less soft-tissue damage. However, maintaining the reduction while passing the plate and placing screws is difficult. The use of an external fixator is helpful to maintain gross length, rotation, and alignment (Figure 3). A frame also can be helpful for placing an IM nail in the tibia, particularly for fractures of the proximal or distal third of the tibia, where the canal flares out and there is a mismatch between the diameter of the canal and that of the IM nail 11 (Figure 4). Several different types of temporary frames can be used. One type is a joint-spanning frame that is placed such that it crosses a joint (typically the knee or the ankle joint). A knee-spanning frame can be used to stabilize distal femoral or proximal tibial fractures, whereas an ankle-spanning frame is typically used for distal tibial fractures (Figure 5). Frames also can be placed without crossing a joint. Often a very simple frame with only one pin inserted on either side of the fracture will provide sufficient stability when the frame is used as an intraoperative reduction tool. More pins can be added if further stability is required. Although a femoral distractor also can be used for temporary stabilization, this chapter s authors prefer to use an external fixator because the frame is not constrained at all. The pins are in serted, and the clamps and bars are loosely attached. The limb is then pulled to use ligamentotaxis for reduction. The reduction is checked with the C-arm and, if it is satisfactory, the clamps are tightened. The use of the distractor is reserved for situations in which the fracture is shortened and has been short for more than 2 to 3 days. The distractor is helpful for regaining length before reduction and definitive fixation are performed. Temporary Management of Periarticular Tibial Fractures Acute management of complex tibial plateau fractures with dual lateral and medial plating that is placed via a single anterior incision (referred to as the deadbone sandwich) has resulted in a high 2015 AAOS Instructional Course Lectures, Volume

4 Trauma Delaying the definitive procedure in addition to the use of MIPO techniques for placement of the diaphyseal portion of the fixation plate or plates has led to a lower incidence of soft- tissue complications and infections, with the added benefit of having permanent implants buried within the soft-tissue envelope Both techniques can be used to manage tibial fractures. Each technique is associated with complications such as soft-tissue breakdown and the risk of nonunion Figure 4 A, Intraoperative photograph of the lower extremity demonstrating placement of a nonspanning external fi xation frame on the tibia to provide stability during intramedullary nailing. The frame is used for reduction during the procedure. AP fl uoroscopic images of the ankle (B) and knee (C) joints demonstrating insertion of a half pin parallel to the joint to assess reduction in the AP plane. If the intramedullary nail meets the distal pin at a 90 angle, then the reduction is acceptable. A Bovie cord also can be used to assess reduction. If the cord crosses the proximal and distal pin at 90, then the reduction is acceptable in the AP plane. Figure 5 A and B, Intraoperative photographs of the lower extremity demonstrating the use of a knee-spanning external fi xation frame to stabilize a bicondylar tibial plateau fracture with associated lower leg compartment syndrome. rate of soft-tissue complications Management of acute intra-articular pilon fractures that result from a highenergy axial load applied to the distal tibia also has been associated with a high rate of soft-tissue complications Thus, management of these fractures has evolved. Currently, injuries can be temporarily stabilized with pin-to-bar external fixation frames while the definitive procedure is delayed until the soft-tissue injury has been resolved. Rules for Temporary Pinto-Bar Fixation Frames Because the frames will be used for only several weeks, the biomechanical rules used to construct temporary spanning pin-to-bar external fixation frames are not required to construct definitive half-pin/bar frames. The methods of increasing the stiffness of the pin-tobar frame, particularly the placement of pins as far from and as close to the fracture site as possible, may lead to infection if a pin is placed within the fracture hematoma. Temporary pin-to-bar frames can be constructed in many ways. The key is to build a frame that is simple, inexpensive, and easy to apply. Incisions should be planned and marked on the skin where the external fixator will be placed. The pins should be kept as far away from the incisions as possible. Clamps must be kept away from the fracture site because they are not radiolucent and will block visualization of the fracture in the fixator. Typically, the placement of two pins on either side of the fracture is sufficient to create traction and hold the fracture out to length. The goal is to allow for restoration of length, alignment, and rotation to facilitate final fracture fixation and management. Unless the AAOS Instructional Course Lectures, Volume 64

5 External Fixation of Tibial Fractures Chapter 15 fixator is used for definitive management of the fracture, external fixation should be converted to internal fixation within 2 weeks to reduce the risk of pinsite infection. Summary The use of external fixation for tibial fractures varies from a simple fracturespanning frame to complex reconstructive frames, including those used to manage bone defects and nonunions. The appropriate and judicious use of external fixation is an important adjunct in the management of tibial fractures. The use of external fixation is based on a surgeon s familiarity with the equipment and procedure. References 1. Della Rocca GJ, Crist BD: External fixation versus conversion to intramedullary nailing for definitive management of closed fractures of the femoral and tibial shaft. J Am Acad Orthop Surg 2006; 14(10 Spec No.):S131-S Geller J, Tornetta P III, Tiburzi D, Kummer F, Koval K: Tension wire position for hybrid external fixation of the proximal tibia. J Orthop Trauma 2000;14(7): Kummer FJ: Biomechanics of the Ilizarov external fixator. Clin Orthop Relat Res 1992;280: Orbay GL, Frankel VH, Kummer FJ: The effect of wire configuration on the stability of the Ilizarov external fixator. Clin Orthop Relat Res 1992;279: Pugh KJ, Wolinsky PR, Dawson JM, Stahlman GC: The biomechanics of hybrid external fixation. J Orthop Trauma 1999;13(1): Giotakis N, Panchani SK, Narayan B, Larkin JJ, Al Maskari S, Nayagam S: Segmental fractures of the tibia treated by circular external fixation. J Bone Joint Surg Br 2010;92(5): Oztürkmen Y, Karamehmetoğlu M, Karadeniz H, Azboy I, Caniklioğlu M: Acute treatment of segmental tibial fractures with the Ilizarov method. Injury 2009;40(3): Babis GC, Kontovazenitis P, Evangelopoulos DS, Tsailas P, Nikolopoulos K, Soucacos PN: Distal tibial fractures treated with hybrid external fixation. Injury 2010;41(3): Marsh JL, Bonar S, Nepola JV, Decoster TA, Hurwitz SR: Use of an articulated external fixator for fractures of the tibial plafond. J Bone Joint Surg Am 1995;77(10): Ristiniemi J, Flinkkilä T, Hyvönen P, et al: Two-ring hybrid external fixation of distal tibial fractures: A review of 47 cases. J Trauma 2007;62(1): Wysocki RW, Kapotas JS, Virkus WW: Intramedullary nailing of proximal and distal one-third tibial shaft fractures with intraoperative two-pin external fixation. J Trauma 2009;66(4): Mallik AR, Covall DJ, Whitelaw GP: Internal versus external fixation of bicondylar tibial plateau fractures. Orthop Rev 1992;21(12): Moore TM, Patzakis MJ, Harvey JP: Tibial plateau fractures: Definition, demographics, treatment rationale, and long-term results of closed traction management or operative reduction. J Orthop Trauma 1987;1(2): Young MJ, Barrack RL: Complications of internal fixation of tibial plateau fractures. Orthop Rev 1994;23(2): Barei DP, Nork SE, Mills WJ, Coles CP, Henley MB, Benirschke SK: Functional outcomes of severe bicondylar tibial plateau fractures treated with dual incisions and medial and lateral plates. J Bone Joint Surg Am 2006;88(8): Boraiah S, Kemp TJ, Erwteman A, Lucas PA, Asprinio DE: Outcome following open reduction and internal fixation of open pilon fractures. J Bone Joint Surg Am 2010;92(2): Egol KA, Tejwani NC, Capla EL, Wolinsky PL, Koval KJ: Staged management of high-energy proximal tibia fractures (OTA types 41): The results of a prospective, standardized protocol. J Orthop Trauma 2005;19(7): Patterson MJ, Cole JD: Two-staged delayed open reduction and internal fixation of severe pilon fractures. J Orthop Trauma 1999;13(2): Sirkin M, Sanders R, DiPasquale T, Herscovici D Jr: A staged protocol for soft tissue management in the treatment of complex pilon fractures. J Orthop Trauma 1999;13(2): Barei DP, Nork SE, Mills WJ, Henley MB, Benirschke SK: Complications associated with internal fixation of high-energy bicondylar tibial plateau fractures utilizing a two-incision technique. J Orthop Trauma 2004;18(10): Canadian Orthopedic Trauma Society: Open reduction and internal fixation compared with circular fixator application for bicondylar tibial plateau fractures: Results of a multicenter, prospective, randomized clinical trial. J Bone Joint Surg Am 2006;88(12): Hall JA, Beuerlein MJ, McKee MD; Canadian Orthopaedic Trauma Society: Open reduction and internal fixation compared with circular fixator application for bicondylar tibial plateau fractures: Surgical technique. J Bone Joint Surg Am 2009;91(suppl 2 pt 1): Krupp RJ, Malkani AL, Roberts CS, Seligson D, Crawford CH III, Smith L: Treatment of bicondylar tibia plateau fractures using locked plating versus external fixation. Orthopedics 2009;32(8). 24. Richards JE, Magill M, Tressler MA, Shuler FD, Kregor PJ, Obremskey WT; Southeast Fracture Consortium: External fixation versus ORIF for distal intra-articular tibia fractures. Orthopedics 2012;35(6):e862-e AAOS Instructional Course Lectures, Volume

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