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External Fixation of Distal Radius Fractures
Orthop Clin N Am 38 (2007) 187–192
External Fixation of Distal Radius Fractures Jubin B. Payandeh, MD, FRCS(C), Michael D. McKee, MD, FRCS(C)* Division of Orthopaedics, Department of Surgery, 55 Queen Street East, Suite 800, Toronto, Ontario, Canada M5C 1R6
Fractures of the distal radius are the most common fractures that occur in patients between ages 15 and 75 years [1]. The mechanism of injury usually involves a fall onto the outstretched hand in an elderly patient whose bone quality is diminished by osteoporosis. In younger patients, high-energy injury mechanisms lead to wide displacement and marked comminution in bone of normal quality [2]. In either case, associated injuries (both systemic and of the upper extremity) must be identified and treated appropriately. Specifically, fractures of the distal radius may be associated with open wounds, tendon rupture, neurologic insult, or vascular injury. Treatment of these injuries must coincide with fracture care. Many methods for treating displaced distal radius fractures are available. All forms of treatment involve obtaining fracture reduction, which may then be maintained with casting, functional bracing, external fixation, percutaneous pinning, internal fixation, or a combination of these methods. This article discusses the indications and technique of fracture treatment with external fixation and, when required, adjuvant percutaneous pins. The authors believe that most fractures failing closed reduction and casting can be treated successfully with this method including those with a displaced articular component. Patient evaluation The initial evaluation of a patient who has a distal radius fracture begins with reviewing their pertinent medical history and screening for * Corresponding author. E-mail address: [email protected] (M.D. McKee).
associated injury. Physical examination must include an evaluation of the soft tissue injury, including the identification of open wounds and an assessment of neurovascular function. When a patient has been assessed, provisional splinting and high-quality radiographs should be obtained. The initial radiographs direct the surgeon toward the treatment method most likely to yield a successful outcome. Several classification schemes have been proposed for distal radius fractures, although their practical usefulness, reproducibility, and applicability are controversial [3]. Important points to consider are: Fracture displacement Intra-articular or partial articular involvement Associated ulna fracture or disruption of the distal radioulnar joint An overall assessment of bone quality and comminution In evaluating radiographs, the following parameters should be noted, which determine if the reduction is acceptable:
Radial length Radial inclination Lateral tilt Intra-articular step or gap
Table 1 outlines normal parameters and what is generally considered acceptable reduction criteria for young, active individuals. The acceptability of reduction varies with the physiologic health and functional demands of the patient [4]. The goals of treatment for a patient who has a distal radius fracture include obtaining and maintaining an acceptable reduction to bony
0030-5898/07/$ - see front matter Ó 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.ocl.2007.02.005
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PAYANDEH & MCKEE
Table 1 Acceptable reduction paramaters Radiographic parameter
Normal
Acceptable
Radial length
2 mm comparing level of lunate facet to ulnar head
Radial inclination
20 as measured from lunate facet to radial styloid 11 of volar tilt None
No more than 2 mm of shortening relative to ulnar head No less than 10
Lateral tilt Intra-articular step or gap
Neutral Less than 2 mm of either
Data from Knirk JL, Jupiter J. Intra-articular fracture of the distal end of the radius in young adults. J Bone Joint Surg Am 1986;68:647–59.
union as previously defined. Surgeons must also consider the soft tissue component of the injury. Open wounds that are typically on the volar side must be addressed with operative irrigation and debridement at injury and then followed up closely to ensure healing. The wrist and fingers are subject to stiffness after fracture treatment and must be mobilized when adequate bony stability is obtained. Occasionally in the acute setting an associated nerve injury occurs, most commonly median, that requires exploration and decompression.
achieved using the criteria specified in Table 1. If the reduction is not acceptable, a second reduction can be attempted. Adjuvants can be used to facilitate reduction, such as finger traps and a skilled assistant. If the second attempt fails, the patient should undergo operative treatment. Which fractures will fail closed treatment can often be predicted based on the initial fracture pattern. Severe comminution of the dorsal cortex usually leads to failure to obtain or maintain an acceptable reduction [5,6]. In these cases, a provisional reduction and splinting should be obtained while the patient is prepared for the operating room. For patients requiring operative treatment of displaced distal radius fractures, including intraarticular fractures, the authors advocate external fixation with percutaneous pins as first-line treatment. This recommendation is based on randomized, controlled trials that show a more rapid return of function and better functional outcome with this treatment compared with open reduction and conventional plate fixation for displaced fractures that fail closed reduction [7,8]. The caveat is that the goals of an acceptable reduction, including intra-articular step or gap, must be met during the procedure. The surgeon may have to resort to open reduction and internal fixation to achieve these goals in approximately 5% to 10% of cases. This recommendation does not apply to dorsal or volar shear fractures, which should be treated primarily with open reduction and plate fixation [9].
Treatment algorithm Treatment is initiated after the initial assessment. Displaced fractures of the distal radius, regardless of configuration, deserve an attempt at closed reduction and casting. Even fractures that require immediate operative treatment, such as those with open injuries, should be reduced closed in the emergency department. Decreasing the deformity will relieve pressure on the surrounding soft tissues and neurovascular structures and provide some pain relief. More information is gained from viewing postreduction radiographs, which help in planning the definitive treatment and fixation. The authors typically use a hematoma block with local anesthetic that can be supplemented with intravenous narcotics or conscious sedation in a monitored setting. An appropriate reduction maneuver is performed and a moulded plaster slab is applied. Postreduction radiographs are assessed to determine if an acceptable reduction has been
Operative technique The operative technique the authors use is closed reduction with the application of an external fixator that may be supplemented with percutaneous pins or bone grafting. The patient is positioned supine on the operating table and anesthetized. A hand table is used on the operative side and the authors apply, but not necessarily inflate, a tourniquet on the upper arm. The hand, wrist, and forearm are prepared and draped in a sterile fashion (Fig. 1). The authors use a small external fixator and 2-mm K-wires. Intraoperative image intensification is mandatory for this procedure. They prefer to use a small C-arm, which the surgeon can manipulate to obtain anteroposterior and lateral views once the patient has been draped. A small fragment set is available if closed reduction fails and an open procedure is required.
EXTERNAL FIXATION OF DISTAL RADIUS FRACTURES
Fig. 1. The patient is positioned supine with a hand table and tourniquet on the operative side.
Initially, a closed reduction maneuver should be performed to correct significant deformity. An assistant provides countertraction at the elbow and the surgeon manipulates the hand and wrist first with inline traction. Most fractures can be reduced with slight volar and ulnar deviation of the hand and wrist. Manipulating the fracture fragments directly with digital pressure is often helpful. A rolled towel can be placed under the wrist to act as a fulcrum with which the deformity can be corrected. If the fracture fragments are incarcerated, the deformity may need to be exaggerated initially to unlock the fragments [10]. The major fracture displacement must be reduced before the external fixator is applied because, once applied, the wrist is difficult to manipulate. Using the image intensifier during the reduction is invaluable.
189
When the provisional reduction has been achieved, the external fixator can be applied. Two pins are inserted into the radial shaft proximal to the zone of injury and another two pins are inserted into the second metacarpal. The plane of the pins should be varied to construct a quadrangular frame. For the radial pins, a small incision is made and the soft tissues are bluntly dissected down to bone. Right-angle retractors are used so the pins can be inserted under direct vision to protect surrounding structures. For the second metacarpal, the pins are radially based to avoid the extensor mechanism. Once the pins are in place, they should be checked for purchase and their length and position verified using the image intensifier. The frame assembly begins with two short bars between the radial and metacarpal pins, respectively. The connections can then be tightened. The authors use carbon-fiber bars, which are radiolucent, to facilitate adequate radiographs. Then a long bar connecting the radial and metacarpal pins is applied on one side with the connectors loosened. The reduction maneuver is then reapplied and an assistant tightens the connectors on the single bar. The reduction is verified using the image intensifier and, once achieved, a second bar is added to the frame construct and tightened (Fig. 2A, B). When applying an external fixator, extreme positions of the wrist should be avoided. The goal is to restore radiographic parameters, most importantly radial length, to an acceptable position (see Table 1). The reduction, especially residual intra-articular deformity, often must be fine-tuned using percutaneous pins or bone grafting.
Fig. 2. (A, B) This patient has had a fixator applied and percutaneous pins inserted for an open, displaced, and intraarticular distal radius fracture.
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Percutaneous K-wires are a useful adjuvant to external fixation for treating these fractures. The pins are inserted when the reduction has been achieved and the fixator applied. Commonly, pins are inserted in the radial styloid and dorsally. The fracture fragments can be manipulated either directly with the pin or indirectly by using them as a buttress. Although pins can be passed from the volar side, this is not recommended because of the proximity of important neurovascular structures. The authors insert the pins using the image intensifier to guide placement. If the fractured fragments are of sufficient size and the bone quality is good, the pins are passed through the distal fragment. Once the distal fragment is engaged with the pin, the authors use live image intensification to manipulate the captured fragment into the desired position. Once this position is gained, the pin is advanced proximally into the shaft, catching the opposite cortex. Typically, two or three pins are used. If the bone quality is poor or the distal fragments are small because of comminution, the K-wires can be used as a buttress. This procedure involves passing the wire through the fracture site and then using it as a lever to improve the fracture position with image control. The wire is then advanced proximally to either the opposite cortex or, if not possible, the medullary canal [11]. When the ulna is fractured distally, causing the carpus or distal radius to drift in the ulnar direction, an ulnar-sided pin can be used. This pin is inserted using image control through the ulnar styloid or fracture to act as a buttress. Ulnar styloid fractures are not routinely fixed. If obvious clinical or radiographic instability of the distal radioulnar joint occurs after radial fracture fixation, the ulnar styloid may require fixation. After the wires are passed and the fracture acceptably reduced, the wires are bent at the skin level to prevent migration and ease their removal. The skin should be relaxed with a small incision around the pin entry site if any tension is present. When a depressed articular fragment cannot be improved or manipulated with traction or a percutaneous pin, direct elevation and bone grafting is another option [12]. Where exactly the fragment is located should be determined from the anteroposterior and lateral views. A small incision is made below the fragment to be elevated and blunt dissection is performed to bone. An elevator is then used under image control to manipulate the articular fragment to an acceptable position. The defect created during this elevation is then filled
with either bone graft or graft substitute. Bone graft can be obtained from the iliac crest through a separate small incision. Alternatively, several bone graft substitutes are available, including calcium phosphate bone cements [13]. Before the conclusion of this procedure, the surgeon must determine if the goals of treatment have been achieved, which should be an acceptable reduction according to the criteria listed in Table 1. Rarely, in 5% to 10% of cases, achieving this goal is not possible using the methods described previously and the surgeon must consider converting to open reduction with internal fixation.
Case example Fig. 3 shows radiographs of an elderly woman who fell while at church and was brought to the emergency department with an isolated injury to her wrist. She had a 2-cm open wound on the volar/ulnar side of her wrist. The initial radiographs show significant radial shortening, loss of radial angulation, dorsal displacement, comminution, and intra-articular extension. The open wound demanded emergent operative treatment with debridement and reduction. An external fixator was applied after provisional reduction. In this case, the wrist tended to translate in an ulnar direction after the fixator was applied. The authors restored the ulnar buttress with an intramedullary K-wire.
Postoperative care The authors dress the pin sites with Vaselinecoated gauze followed by dry gauze, and then wrap the forearm and wrist in a soft bandage. They do not order a specific pin care regimen, other than keeping the sites clean and dry, and have found that minimal perturbation of the pin sites is ideal. Plain radiographs are obtained in the recovery room. Patients who have an isolated injury are discharged from the hospital the same day, whereas others stay longer depending on their associated injuries. Patients return to the clinic within 2 weeks and again 6 weeks postoperatively. At each visit, plain radiographs are taken. The frame and pins are usually removed in the clinic at 6 weeks if the radiograph shows fracture union and a supervised physiotherapy program is initiated to regain wrist motion and strength. Patients are encouraged to maintain motion of their shoulder, elbow, and fingers while the frame is in place. The authors
EXTERNAL FIXATION OF DISTAL RADIUS FRACTURES
191
Fig. 3. (A, B) Anteroposterior and lateral radiographs after open wrist injury. (C, D) Anteroposterior and lateral radiographs after operative treatment with external fixator application and percutaneous ulnar K-wire. (E, F) Anteroposterior and lateral radiographs 6 weeks after the removal of hardware.
then follow-up their patients at 3 and 6 months, or longer if specific problems associated with the injury are present. Results Treating displaced distal radius fractures, including those with an articular component, with external fixation and percutaneous pins typically yields good results [7,8]. A recent randomized controlled trial showed that percutaneous fixation had
superior results compared with open reduction and internal fixation; patients experienced improvement in function and pain scores at all points of follow-up. Those treated with indirect reduction scored a mean of 6 points better on the musculoskeletal function assessment. Grip strength is also superior in those treated with external methods, by a mean of 10.l lb. Outcomes were equivalent in terms of restoring radiographic parameters. Range of motion measurements were also the same with the injured wrist, losing on average 20 of flexion
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compared with the uninjured side [7]. This trial evaluated internal fixation using conventional, nonlocking plates. Whether the use of locking plates improves outcomes for these injuries has not been determined. Pin tract infections can occur with percutaneous fixation methods in 20% of patients. Most can be treated with an oral antibiotic prescription and local pin care. Occasionally, pin replacement, irrigation, and debridement are required for deep infections. Patients treated with either internal or external means may rarely develop a complex regional pain syndrome after treatment of a distal radius fracture [14]. The fractures are usually healed by 6 to 8 weeks. Fracture malunion, even when treated by expert surgeons, occurs in approximately 10% of cases. Although extra-articular deformity can be corrected with osteotomy, persistent articular step or gap deformity of more than 2 mm increases the risk for developing wrist arthritis by 10 times [15]. Discussion External fixation supplemented with percutaneous pins is an excellent option for treating displaced fractures of the distal radius, with reliably good results, a low reoperation rate, and a low complication rate. These fractures are common and this treatment method is familiar to orthopaedic surgeons. The key to success is to restore anatomic parameters of the distal radius while minimizing insult to the soft tissue envelope. All fractures, except shear fractures, failing closed treatment can be treated with external means. If these fail to produce an acceptable reduction, open reduction may rarely be required. Although locked plates are becoming increasingly popular for treating these fractures, whether they improve functional results compared with conventional implants or external fixation methods has not been determined in a direct comparative study. References [1] Emmett JE, Breck LW. A review and analysis of 11,000 fractures seen in a private practice of orthopaedic surgery. J Bone Joint Surg Am 1958;40:1169–75.
[2] Larsen CF, Lauritsen J. Epidemiology of acute wrist trauma. Int J Epidemiol 1993;22:911–6. [3] Kreder HJ, Hanel DP, McKee M, et al. Consistency of AO fracture classification for the distal radius. J Bone Joint Surg Br 1996;78:726–31. [4] Beumer A, McQueen MM. Fractures of the distal radius in low-demand elderly patients: closed reduction of no value in 53 of 60 wrists. Acta Orthop Scand 2003;74:98–100. [5] McQueen MM, Hajducka C, Court-Brown CM. Redisplaced unstable fractures of the distal radius: a prospective randomised comparison of four methods of treatment. J Bone Joint Surg Br 1996; 78:404–9. [6] McQueen MM, McLaren A, Chalmers J. The value of remanipulating Colles’ fractures. J Bone Joint Surg Br 1986;68:232–3. [7] Kreder HJ, Hanel DP, Agel J, et al. Indirect reduction and percutaneous fixation versus open reduction and internal fixation for displaced intraarticular fractures of the distal radius. J Bone Joint Surg Br 2005;87(6):829–36. [8] Kreder HJ, Agel J, Mckee MD, et al. A randomized, controlled trial of distal radius fractures with metaphyseal displacement but without joint incongruity: closed reduction and casting versus closed reduction, spanning external fixation, and optional percutaneous K-wires. J Orthop Trauma 2006; 20(2):115–21. [9] Jupiter JB, Fernandez DL, Toh CL, et al. Operative treatment of volar intra-articular fractures of the distal end of the radius. J Bone Joint Surg Am 1996;78(12):1817–28. [10] Handoll HH, Madhok R. Closed reduction methods for treating distal radial fractures in adults. Cochrane Database Syst Rev 2003;1:CD003763. [11] Kapandji A. [Intra-focal pinning of fractures of the distal end of the radius 10 years later]. Ann Chir Main 1987;6(1):57–63 [French]. [12] Axelrod T, Paley D, Green J, et al. Limited open reduction of the lunate facet in comminuted intra-articular fractures of the distal radius. J Hand Surg [Am] 1988;13(3):372–7. [13] Sanchez-Sotelo J, Munuera L, Madero R. Treatment of fractures of the distal radius with a remodellable bone cement: a prospective, randomized study using Norian SRS. J Bone Joint Surg Br 2000;82(6): 856–63. [14] Chaise F, Friol JP, Gainse E. [The post-fracture painful wrist]. Ann Chir 1994;48(1):88–90 [French]. [15] Knirk JL, Jupiter J. Intra-articular fracture of the distal end of the radius in young adults. J Bone Joint Surg Am 1986;68:647–59.
External Fixation of Distal Radius Fractures Jubin B. Payandeh, MD, FRCS(C), Michael D. McKee, MD, FRCS(C)* Division of Orthopaedics, Department of Surgery, 55 Queen Street East, Suite 800, Toronto, Ontario, Canada M5C 1R6
Fractures of the distal radius are the most common fractures that occur in patients between ages 15 and 75 years [1]. The mechanism of injury usually involves a fall onto the outstretched hand in an elderly patient whose bone quality is diminished by osteoporosis. In younger patients, high-energy injury mechanisms lead to wide displacement and marked comminution in bone of normal quality [2]. In either case, associated injuries (both systemic and of the upper extremity) must be identified and treated appropriately. Specifically, fractures of the distal radius may be associated with open wounds, tendon rupture, neurologic insult, or vascular injury. Treatment of these injuries must coincide with fracture care. Many methods for treating displaced distal radius fractures are available. All forms of treatment involve obtaining fracture reduction, which may then be maintained with casting, functional bracing, external fixation, percutaneous pinning, internal fixation, or a combination of these methods. This article discusses the indications and technique of fracture treatment with external fixation and, when required, adjuvant percutaneous pins. The authors believe that most fractures failing closed reduction and casting can be treated successfully with this method including those with a displaced articular component. Patient evaluation The initial evaluation of a patient who has a distal radius fracture begins with reviewing their pertinent medical history and screening for * Corresponding author. E-mail address: [email protected] (M.D. McKee).
associated injury. Physical examination must include an evaluation of the soft tissue injury, including the identification of open wounds and an assessment of neurovascular function. When a patient has been assessed, provisional splinting and high-quality radiographs should be obtained. The initial radiographs direct the surgeon toward the treatment method most likely to yield a successful outcome. Several classification schemes have been proposed for distal radius fractures, although their practical usefulness, reproducibility, and applicability are controversial [3]. Important points to consider are: Fracture displacement Intra-articular or partial articular involvement Associated ulna fracture or disruption of the distal radioulnar joint An overall assessment of bone quality and comminution In evaluating radiographs, the following parameters should be noted, which determine if the reduction is acceptable:
Radial length Radial inclination Lateral tilt Intra-articular step or gap
Table 1 outlines normal parameters and what is generally considered acceptable reduction criteria for young, active individuals. The acceptability of reduction varies with the physiologic health and functional demands of the patient [4]. The goals of treatment for a patient who has a distal radius fracture include obtaining and maintaining an acceptable reduction to bony
0030-5898/07/$ - see front matter Ó 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.ocl.2007.02.005
orthopedic.theclinics.com
188
PAYANDEH & MCKEE
Table 1 Acceptable reduction paramaters Radiographic parameter
Normal
Acceptable
Radial length
2 mm comparing level of lunate facet to ulnar head
Radial inclination
20 as measured from lunate facet to radial styloid 11 of volar tilt None
No more than 2 mm of shortening relative to ulnar head No less than 10
Lateral tilt Intra-articular step or gap
Neutral Less than 2 mm of either
Data from Knirk JL, Jupiter J. Intra-articular fracture of the distal end of the radius in young adults. J Bone Joint Surg Am 1986;68:647–59.
union as previously defined. Surgeons must also consider the soft tissue component of the injury. Open wounds that are typically on the volar side must be addressed with operative irrigation and debridement at injury and then followed up closely to ensure healing. The wrist and fingers are subject to stiffness after fracture treatment and must be mobilized when adequate bony stability is obtained. Occasionally in the acute setting an associated nerve injury occurs, most commonly median, that requires exploration and decompression.
achieved using the criteria specified in Table 1. If the reduction is not acceptable, a second reduction can be attempted. Adjuvants can be used to facilitate reduction, such as finger traps and a skilled assistant. If the second attempt fails, the patient should undergo operative treatment. Which fractures will fail closed treatment can often be predicted based on the initial fracture pattern. Severe comminution of the dorsal cortex usually leads to failure to obtain or maintain an acceptable reduction [5,6]. In these cases, a provisional reduction and splinting should be obtained while the patient is prepared for the operating room. For patients requiring operative treatment of displaced distal radius fractures, including intraarticular fractures, the authors advocate external fixation with percutaneous pins as first-line treatment. This recommendation is based on randomized, controlled trials that show a more rapid return of function and better functional outcome with this treatment compared with open reduction and conventional plate fixation for displaced fractures that fail closed reduction [7,8]. The caveat is that the goals of an acceptable reduction, including intra-articular step or gap, must be met during the procedure. The surgeon may have to resort to open reduction and internal fixation to achieve these goals in approximately 5% to 10% of cases. This recommendation does not apply to dorsal or volar shear fractures, which should be treated primarily with open reduction and plate fixation [9].
Treatment algorithm Treatment is initiated after the initial assessment. Displaced fractures of the distal radius, regardless of configuration, deserve an attempt at closed reduction and casting. Even fractures that require immediate operative treatment, such as those with open injuries, should be reduced closed in the emergency department. Decreasing the deformity will relieve pressure on the surrounding soft tissues and neurovascular structures and provide some pain relief. More information is gained from viewing postreduction radiographs, which help in planning the definitive treatment and fixation. The authors typically use a hematoma block with local anesthetic that can be supplemented with intravenous narcotics or conscious sedation in a monitored setting. An appropriate reduction maneuver is performed and a moulded plaster slab is applied. Postreduction radiographs are assessed to determine if an acceptable reduction has been
Operative technique The operative technique the authors use is closed reduction with the application of an external fixator that may be supplemented with percutaneous pins or bone grafting. The patient is positioned supine on the operating table and anesthetized. A hand table is used on the operative side and the authors apply, but not necessarily inflate, a tourniquet on the upper arm. The hand, wrist, and forearm are prepared and draped in a sterile fashion (Fig. 1). The authors use a small external fixator and 2-mm K-wires. Intraoperative image intensification is mandatory for this procedure. They prefer to use a small C-arm, which the surgeon can manipulate to obtain anteroposterior and lateral views once the patient has been draped. A small fragment set is available if closed reduction fails and an open procedure is required.
EXTERNAL FIXATION OF DISTAL RADIUS FRACTURES
Fig. 1. The patient is positioned supine with a hand table and tourniquet on the operative side.
Initially, a closed reduction maneuver should be performed to correct significant deformity. An assistant provides countertraction at the elbow and the surgeon manipulates the hand and wrist first with inline traction. Most fractures can be reduced with slight volar and ulnar deviation of the hand and wrist. Manipulating the fracture fragments directly with digital pressure is often helpful. A rolled towel can be placed under the wrist to act as a fulcrum with which the deformity can be corrected. If the fracture fragments are incarcerated, the deformity may need to be exaggerated initially to unlock the fragments [10]. The major fracture displacement must be reduced before the external fixator is applied because, once applied, the wrist is difficult to manipulate. Using the image intensifier during the reduction is invaluable.
189
When the provisional reduction has been achieved, the external fixator can be applied. Two pins are inserted into the radial shaft proximal to the zone of injury and another two pins are inserted into the second metacarpal. The plane of the pins should be varied to construct a quadrangular frame. For the radial pins, a small incision is made and the soft tissues are bluntly dissected down to bone. Right-angle retractors are used so the pins can be inserted under direct vision to protect surrounding structures. For the second metacarpal, the pins are radially based to avoid the extensor mechanism. Once the pins are in place, they should be checked for purchase and their length and position verified using the image intensifier. The frame assembly begins with two short bars between the radial and metacarpal pins, respectively. The connections can then be tightened. The authors use carbon-fiber bars, which are radiolucent, to facilitate adequate radiographs. Then a long bar connecting the radial and metacarpal pins is applied on one side with the connectors loosened. The reduction maneuver is then reapplied and an assistant tightens the connectors on the single bar. The reduction is verified using the image intensifier and, once achieved, a second bar is added to the frame construct and tightened (Fig. 2A, B). When applying an external fixator, extreme positions of the wrist should be avoided. The goal is to restore radiographic parameters, most importantly radial length, to an acceptable position (see Table 1). The reduction, especially residual intra-articular deformity, often must be fine-tuned using percutaneous pins or bone grafting.
Fig. 2. (A, B) This patient has had a fixator applied and percutaneous pins inserted for an open, displaced, and intraarticular distal radius fracture.
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PAYANDEH & MCKEE
Percutaneous K-wires are a useful adjuvant to external fixation for treating these fractures. The pins are inserted when the reduction has been achieved and the fixator applied. Commonly, pins are inserted in the radial styloid and dorsally. The fracture fragments can be manipulated either directly with the pin or indirectly by using them as a buttress. Although pins can be passed from the volar side, this is not recommended because of the proximity of important neurovascular structures. The authors insert the pins using the image intensifier to guide placement. If the fractured fragments are of sufficient size and the bone quality is good, the pins are passed through the distal fragment. Once the distal fragment is engaged with the pin, the authors use live image intensification to manipulate the captured fragment into the desired position. Once this position is gained, the pin is advanced proximally into the shaft, catching the opposite cortex. Typically, two or three pins are used. If the bone quality is poor or the distal fragments are small because of comminution, the K-wires can be used as a buttress. This procedure involves passing the wire through the fracture site and then using it as a lever to improve the fracture position with image control. The wire is then advanced proximally to either the opposite cortex or, if not possible, the medullary canal [11]. When the ulna is fractured distally, causing the carpus or distal radius to drift in the ulnar direction, an ulnar-sided pin can be used. This pin is inserted using image control through the ulnar styloid or fracture to act as a buttress. Ulnar styloid fractures are not routinely fixed. If obvious clinical or radiographic instability of the distal radioulnar joint occurs after radial fracture fixation, the ulnar styloid may require fixation. After the wires are passed and the fracture acceptably reduced, the wires are bent at the skin level to prevent migration and ease their removal. The skin should be relaxed with a small incision around the pin entry site if any tension is present. When a depressed articular fragment cannot be improved or manipulated with traction or a percutaneous pin, direct elevation and bone grafting is another option [12]. Where exactly the fragment is located should be determined from the anteroposterior and lateral views. A small incision is made below the fragment to be elevated and blunt dissection is performed to bone. An elevator is then used under image control to manipulate the articular fragment to an acceptable position. The defect created during this elevation is then filled
with either bone graft or graft substitute. Bone graft can be obtained from the iliac crest through a separate small incision. Alternatively, several bone graft substitutes are available, including calcium phosphate bone cements [13]. Before the conclusion of this procedure, the surgeon must determine if the goals of treatment have been achieved, which should be an acceptable reduction according to the criteria listed in Table 1. Rarely, in 5% to 10% of cases, achieving this goal is not possible using the methods described previously and the surgeon must consider converting to open reduction with internal fixation.
Case example Fig. 3 shows radiographs of an elderly woman who fell while at church and was brought to the emergency department with an isolated injury to her wrist. She had a 2-cm open wound on the volar/ulnar side of her wrist. The initial radiographs show significant radial shortening, loss of radial angulation, dorsal displacement, comminution, and intra-articular extension. The open wound demanded emergent operative treatment with debridement and reduction. An external fixator was applied after provisional reduction. In this case, the wrist tended to translate in an ulnar direction after the fixator was applied. The authors restored the ulnar buttress with an intramedullary K-wire.
Postoperative care The authors dress the pin sites with Vaselinecoated gauze followed by dry gauze, and then wrap the forearm and wrist in a soft bandage. They do not order a specific pin care regimen, other than keeping the sites clean and dry, and have found that minimal perturbation of the pin sites is ideal. Plain radiographs are obtained in the recovery room. Patients who have an isolated injury are discharged from the hospital the same day, whereas others stay longer depending on their associated injuries. Patients return to the clinic within 2 weeks and again 6 weeks postoperatively. At each visit, plain radiographs are taken. The frame and pins are usually removed in the clinic at 6 weeks if the radiograph shows fracture union and a supervised physiotherapy program is initiated to regain wrist motion and strength. Patients are encouraged to maintain motion of their shoulder, elbow, and fingers while the frame is in place. The authors
EXTERNAL FIXATION OF DISTAL RADIUS FRACTURES
191
Fig. 3. (A, B) Anteroposterior and lateral radiographs after open wrist injury. (C, D) Anteroposterior and lateral radiographs after operative treatment with external fixator application and percutaneous ulnar K-wire. (E, F) Anteroposterior and lateral radiographs 6 weeks after the removal of hardware.
then follow-up their patients at 3 and 6 months, or longer if specific problems associated with the injury are present. Results Treating displaced distal radius fractures, including those with an articular component, with external fixation and percutaneous pins typically yields good results [7,8]. A recent randomized controlled trial showed that percutaneous fixation had
superior results compared with open reduction and internal fixation; patients experienced improvement in function and pain scores at all points of follow-up. Those treated with indirect reduction scored a mean of 6 points better on the musculoskeletal function assessment. Grip strength is also superior in those treated with external methods, by a mean of 10.l lb. Outcomes were equivalent in terms of restoring radiographic parameters. Range of motion measurements were also the same with the injured wrist, losing on average 20 of flexion
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compared with the uninjured side [7]. This trial evaluated internal fixation using conventional, nonlocking plates. Whether the use of locking plates improves outcomes for these injuries has not been determined. Pin tract infections can occur with percutaneous fixation methods in 20% of patients. Most can be treated with an oral antibiotic prescription and local pin care. Occasionally, pin replacement, irrigation, and debridement are required for deep infections. Patients treated with either internal or external means may rarely develop a complex regional pain syndrome after treatment of a distal radius fracture [14]. The fractures are usually healed by 6 to 8 weeks. Fracture malunion, even when treated by expert surgeons, occurs in approximately 10% of cases. Although extra-articular deformity can be corrected with osteotomy, persistent articular step or gap deformity of more than 2 mm increases the risk for developing wrist arthritis by 10 times [15]. Discussion External fixation supplemented with percutaneous pins is an excellent option for treating displaced fractures of the distal radius, with reliably good results, a low reoperation rate, and a low complication rate. These fractures are common and this treatment method is familiar to orthopaedic surgeons. The key to success is to restore anatomic parameters of the distal radius while minimizing insult to the soft tissue envelope. All fractures, except shear fractures, failing closed treatment can be treated with external means. If these fail to produce an acceptable reduction, open reduction may rarely be required. Although locked plates are becoming increasingly popular for treating these fractures, whether they improve functional results compared with conventional implants or external fixation methods has not been determined in a direct comparative study. References [1] Emmett JE, Breck LW. A review and analysis of 11,000 fractures seen in a private practice of orthopaedic surgery. J Bone Joint Surg Am 1958;40:1169–75.
[2] Larsen CF, Lauritsen J. Epidemiology of acute wrist trauma. Int J Epidemiol 1993;22:911–6. [3] Kreder HJ, Hanel DP, McKee M, et al. Consistency of AO fracture classification for the distal radius. J Bone Joint Surg Br 1996;78:726–31. [4] Beumer A, McQueen MM. Fractures of the distal radius in low-demand elderly patients: closed reduction of no value in 53 of 60 wrists. Acta Orthop Scand 2003;74:98–100. [5] McQueen MM, Hajducka C, Court-Brown CM. Redisplaced unstable fractures of the distal radius: a prospective randomised comparison of four methods of treatment. J Bone Joint Surg Br 1996; 78:404–9. [6] McQueen MM, McLaren A, Chalmers J. The value of remanipulating Colles’ fractures. J Bone Joint Surg Br 1986;68:232–3. [7] Kreder HJ, Hanel DP, Agel J, et al. Indirect reduction and percutaneous fixation versus open reduction and internal fixation for displaced intraarticular fractures of the distal radius. J Bone Joint Surg Br 2005;87(6):829–36. [8] Kreder HJ, Agel J, Mckee MD, et al. A randomized, controlled trial of distal radius fractures with metaphyseal displacement but without joint incongruity: closed reduction and casting versus closed reduction, spanning external fixation, and optional percutaneous K-wires. J Orthop Trauma 2006; 20(2):115–21. [9] Jupiter JB, Fernandez DL, Toh CL, et al. Operative treatment of volar intra-articular fractures of the distal end of the radius. J Bone Joint Surg Am 1996;78(12):1817–28. [10] Handoll HH, Madhok R. Closed reduction methods for treating distal radial fractures in adults. Cochrane Database Syst Rev 2003;1:CD003763. [11] Kapandji A. [Intra-focal pinning of fractures of the distal end of the radius 10 years later]. Ann Chir Main 1987;6(1):57–63 [French]. [12] Axelrod T, Paley D, Green J, et al. Limited open reduction of the lunate facet in comminuted intra-articular fractures of the distal radius. J Hand Surg [Am] 1988;13(3):372–7. [13] Sanchez-Sotelo J, Munuera L, Madero R. Treatment of fractures of the distal radius with a remodellable bone cement: a prospective, randomized study using Norian SRS. J Bone Joint Surg Br 2000;82(6): 856–63. [14] Chaise F, Friol JP, Gainse E. [The post-fracture painful wrist]. Ann Chir 1994;48(1):88–90 [French]. [15] Knirk JL, Jupiter J. Intra-articular fracture of the distal end of the radius in young adults. J Bone Joint Surg Am 1986;68:647–59.