Introduction

Displaced intra–articular fractures of the distal radius are a unique subset of radius fractures. These fractures are usually the result of a high–energy injury and are usually associated with intra–articular soft–tissue injuries. These fractures are traditionally unstable, and are less amenable to closed manipulation and casting.

Lafontaine has described several radiographic features that signify when a fracture of the distal radius is unstable.¹ These include initial dorsal angulation greater than 20 degrees, extensive dorsal comminution, associated ulnar styloid fracture, significant intra–articular involvement, and older patients greater than the age of 60.

The prognosis for intra–articular fractures of the distal radius has been shown to depend on numerous factors.² These include the amount of radial shortening, residual extra–articular angulation, articular congruity of both the radiocarpal and radioulnar joints, and associated intra–articular soft–tissue injuries. Trumble et al., in their review of 52 intra–articular fractures, noted that factors that strongly correlated with a successful outcome included the amount of residual radial shortening and intra–articular congruity.³

The use of wrist arthroscopy as an adjunct in the management of displaced intra–articular distal radius fractures takes advantage of its ability to view the articular surface with bright light and magnified conditions with minimal surgical morbidity.⁴ Fracture hematoma and debris may be arthroscopically lavaged, which potentially can improve the patient’s final range of motion⁵ (Figure 17.1). In addition, associated intra–articular soft–tissue injuries may be detected and managed at the same sitting⁶ (Figure 17.2). Pathology not readily identified on plain radiographs is frequently discovered during arthroscopic–assisted reduction and internal fixation of distal radius fractures. In most instances, it is much easier to manage an acute soft–tissue injury that occurs with a distal radius fracture than chronic pathology. The purpose of this chapter is to review the rationale and technique in the application of wrist arthroscopy as a useful adjunct in the management of displaced intra–articular fractures of the distal radius.

FIGURE 17.1 Loose bodies are frequently seen during arthroscopic-assisted reduction of distal radius fractures, which are not readily apparent on plain radiographs. Removal of these loose fragments and cartilage debris may improve the patient’s final prognosis.

FIGURE 17.2 Partial and complete tears to the interosseous ligaments are frequently identified during the wrist arthroscopic procedure. Management of acute tears to the interosseous ligaments may have a better prognosis compared to chronic injuries.

Two millimeters of articular displacement has over the past several years become a well–established critical threshold for articular incongruity of the distal radius. Knirk and Jupiter, in their classic article, demonstrated the importance of an articular reduction within 2 mm or less.⁷ A patient whose articular reduction is greater than 2 mm at final follow–up visit has a significantly higher incidence of degenerative changes within the wrist. Bradway and Amadio further substantiated these findings in their study.⁸

In their series of 40 patients, Fernandez and Geissler noted that the critical threshold may be as low as 1 mm or less.⁹ They reported in their study that the incidence of complications was substantially lower and articular reduction was within 1 mm or less.

Edwards et al. described the advantage of viewing intra–articular reduction by wrist arthroscopy compared to monitoring under fluoroscopy alone.¹⁰ In their series, 15 patients underwent arthroscopic evaluation of the articular surface of the distal radius following reduction and stabilization under fluoroscopy. They found that 33% of the patients had an articular step–off of 1 mm or more as viewed arthroscopically. Frequently, the fragment was rotated. Wrist arthroscopy is particularly useful in judging the rotation of fracture fragments, which is not readily identifiable under fluoroscopy. Edwards et al. concluded that utilizing wrist arthroscopy as an adjunct may detect residual gapping not previously identified under fluoroscopy alone.

A high incidence of associated intra–articular soft–tissue injuries involving the triangular fibrocartilage complex and the interosseous ligaments has been shown by several studies of displaced intra–articular fractures of the distal radius.¹¹ Mohanti and Fontes, in two separate wrist arthrogram studies, noted a high incidence of tears of the triangular fibrocartilage complex associated with distal radius fractures. Fontes, in his series, noted a 66% incidence of tears of the triangular fibrocartilage complex in 58 patients.¹² Similarly, Mohanti noted an injury of the triangular fibrocartilage complex in 45% of 60 patients in his series.¹³

Several recent arthroscopic studies have documented incidences of associated intercarpal soft–tissue injuries with fractures of the distal radius. In three recent published studies, an injury to the triangular fibrocartilage complex seems to be the most common associated intra–articular soft–tissue injury. Geissler et al. reported their experience in 60 patients with displaced intra–articular fractures of the distal radius undergoing arthroscopic–assisted reduction and evaluation.¹⁴ The criterion for surgical stabilization in his series was an intra–articular fracture displaced 2 mm or more that cannot be reduced by closed manipulation. In Geissler et al.’s series, 49% of the patients had a tear of the triangular fibrocartilage complex. An injury to the interosseous ligaments was less common. Tears to the scapholunate interosseous ligament were present in 32% of patients, and injury to the lunotriquetral interosseous ligament was identified in 15%.

Lindau, in a similar arthroscopic study of 50 patients, noted that tears of the triangular fibrocartilage complex were present in 78% of patients, injuries to the scapholunate ligament were identified in 54% of patients, and tears of the lunotriquetral interosseous ligament were less common and seen in 16% of patients.¹⁵ Hanker, in a series of 65 patients, noted that tears of the triangular fibrocartilage complex were very common and were present in 55% of the patients in his series.¹⁶ Although it is clearly documented that associated soft–tissue injuries are common with displaced intra–articular fractures of the distal radius, how they may affect the final outcome in patients is still unknown.

Geissler et al. described an arthroscopic classification of an interosseous ligament injury based on their work on arthroscopic management of fractures of the distal radius.¹⁴ They noted that a spectrum of injury may occur to the interosseous ligament. The ligament attenuates, and then eventually tears, and the degree of rotation between the carpal bones increases. The scapholunate interosseous ligament appears to tear from volar to dorsal. This arthroscopic classification of carpal instability is based on observation of interosseous ligaments from both the radiocarpal and midcarpal spaces (Table 17.1).

Table 17.1 Geissler Arthroscopic Classification of Carpal Instability

The normal scapholunate and lunotriquetral interosseous ligaments have a concave appearance between the carpal bones as viewed from the radiocarpal space. The scapholunate ligament is best seen with the arthroscope in the 3–4 portal. The lunotriquetral interosseous ligament is best observed with the arthroscope placed in either the 4–5 or 6–R portal. The lunotriquetral interval will not be adequately seen with the scope in the 3–4 portal alone. In the midcarpal space, the scapholunate interval should be tight and congruent without any articular step–off. Similarly, the lunotriquetral interval should be congruent, but usually a 1–mm step–off or slightly increased play may be seen between the lunate and triquetrum as observed from the radial midcarpal space. A probe or needle may be inserted in the ulnar midcarpal space to evaluate the amount of play between the carpal bones.

In Geissler grade I injuries, there is a loss of the normal concave appearance between the carpal bones as the interosseous ligament attenuates and becomes convex (as seen in the radiocarpal space). Hemorrhage may be seen within the ligament itself in acute situations. However, in the midcarpal space the interval between the carpal bones will still be tight and congruent (with no step–off).

In Geissler grade II injuries, the interosseous ligament continues to become attenuated and becomes convex (as seen in the radiocarpal space, similar to grade I injuries). There is no gap between the carpal bones. However, in the midcarpal space the interval between the involved carpal bones is no longer congruent and a step–off is present. With scapholunate instability, there is slight palmar flexion of the dorsal edge of the scaphoid compared to the lunate. In lunotriquetral instability, the interosseous ligament again becomes attenuated as seen from the radiocarpal space with the arthroscope in the 6–R portal. In the radial midcarpal space, increased play will be seen between the lunate and triquetrum as palpated with a probe.

In Geissler grade III injuries, the interosseous ligament now starts to tear from volar to dorsal as seen with the arthroscope in the radial midcarpal space. A probe is frequently helpful to demonstrate the gap between the involved carpal bones. In the midcarpal space, a 2–mm probe may be placed between the carpal bones and twisted. The dorsal portion of the interosseous ligament is still intact, and complete separation of the carpal bones is not seen.

In Geissler grade IV injuries, the interosseous ligament is completely detached and the arthroscope may be passed freely from the radiocarpal space through the tear to the midcarpal space. This is the so–called “drive–through sign.”

It is felt that Geissler grade I injuries are consistent with a wrist sprain and usually respond to immobilization over a period of weeks. In Geissler grade II and grade III tears, these may be arthroscopically reduced and pinned in the acute situation. Pinning is not recommended for chronic injuries of the interosseous ligaments. In Geissler grade IV injuries, where there is complete detachment of the interosseous ligament, it is felt that open repair will have the best prognosis in an acute situation.

Large–joint instrumentation is not appropriate for arthroscopically assisted reduction of distal radius fractures. Smaller–joint arthroscopic instrumentation is essential. The small–joint arthroscope is approximately 2.7 mm, and even smaller scopes may be utilized if desired. When the arthroscope is initially placed in the wrist, it is usually full of fracture debris and hematoma. It is useful to irrigate out the fracture debris and utilize the shaver (3.5 mm or less) to clear the remaining hematoma to improve visualization, particularly to judge the rotation of the fracture fragments.

A traction tower is very useful in the arthroscopic–assisted management of intra–articular fractures of the distal radius. A traction tower allows the surgeon to flex, extend, and radial and ulnar deviate the wrist to help reduce the fracture fragments while maintaining constant traction to allow visualization. A new traction tower was designed to allow the surgeon to simultaneously evaluate arthroscopically the articular reduction and to monitor the reduction under fluoroscopy (Figure 17.3). The traction bar is uniquely placed at the side of the wrist rather than at its center, so that it does not block fluoroscopic evaluation and the surgeon does not need to work around a central bar. In addition, by having the traction bar at the side rather than centrally allows the surgeon to simultaneously arthroscope the wrist and stabilize the fracture while obtaining access through a standard volar approach.

FIGURE 17.3 A new traction tower was developed to allow for simultaneous arthroscopic reduction of the distal radius fracture and fluoroscopic examination. This greatly simplifies the procedure.

The surgeon can fluoroscopically evaluate the position of the plate and screw insertion during stabilization. This new traction tower allows a surgeon to perform arthroscopic–assisted fixation in both the vertical and/or horizontal planes, depending on the surgeon’s preference.(Figure 17.4). If a traction tower is not available, the wrist may be suspended with finger traps attached to a weight over the end of a hand table in the horizontal position, or with a shoulder holder in the vertical position. A small bump is useful to place under the wrist if weights are being utilized over the end of the table to maintain the wrist in slight flexion.

FIGURE 17.4 The new tower may be placed in a vertical or horizontal position for arthroscopic-assisted reduction of distal radius fractures, depending on the surgeon’s preference.

Thorough irrigation of the joint is necessary to wash out the fracture hematoma to improve visualization. Inflow is usually provided through a 14–gauge needle through the 6–U portal. In addition, it is important to provide outflow to limit fluid extravasation into the soft tissues. Outflow is provided through the arthroscope cannula. An intervenous extension tubing is connected to the arthroscope cannula, which drains then into a basin to limit fluid extravasation and not onto the surgeon’s lap or floor. It is felt that a separate inflow and outflow is necessary to improve irrigation of the joint rather than inflow through arthroscope cannula alone. The small–joint cannula in wrist arthroscopy does not allow much space between the cannula and the arthroscope itself, and this limits the amount of fluid irrigation through the arthroscope cannula. For this reason, it is felt that it is best to have a separate inflow through the 6–U portal.

A fracture of the distal radius wrist is frequently swollen. Because of this reason, it is fairly difficult to palpate the traditional extensor tendon landmarks for wrist arthroscopy. However, the bony landmarks can usually still be palpated and marked. These bony landmarks include the bases of the metacarpals, the dorsal lip of the radius, and the ulnar head. The traditional viewing portal is the 3–4 portal, which is made between the third and fourth dorsal extensor compartments. The 3–4 portal is made in line with the radial border of the long finger.

Precise portal placement is mandatory for arthroscopic–assisted reduction of distal radius fractures. If the portal is placed too proximal, the arthroscope may be placed within the fracture pattern itself. If it is placed too distally, it can injure the articular surface of the carpus. It is very useful to place an 18–gauge needle into the proposed location of the 3–4 portal prior to making a skin incision. The portal is made by pulling the skin with the surgeon’s thumb against the tip of a number 11 blade.

Blunt dissection is then continued with the hemostat to the level of the joint capsule, and the arthroscope with a blunt trocar is introduced into the 3–4 portal. The 3–4 portal is the primary viewing portal in wrist arthroscopy. The fracture hematoma and debris are then washed out to improve visualization with the inflow in the 6–U portal. A working portal is then made in the 6–R or 4–5 portal and the remaining hematoma is debrided out. Similarly to making the 3–4 portal, a needle is placed and viewed arthroscopically prior to making a skin incision for the working portal.

Ideal timing for arthroscopic–assisted reduction of distal radius fractures appears to be between 3 and 10 days. Earlier attempts at arthroscopic fixation may result in troublesome bleeding. Fractures that are over 10 days post–injury are more difficult to disimpact and elevate with arthroscopic–assisted reduction.

Fractures without extensive metaphysial comminution are most ideal for arthroscopic–assisted management. Radial styloid fractures, die punch fractures, three–part T fractures, and four–part fractures are all amenable to arthroscopic–assisted reduction and internal fixation.¹⁷ Some three–part fractures and most four–part fractures are managed through a combination of open reduction and arthroscopic–assisted fixation. In these instances, the fracture is stabilized by a volar plate through a volar approach (but the joint capsule is not incised). Articular reduction may be arthroscopically fine–tuned, and the distal screws inserted to stabilize the fracture. Associated soft–tissue injuries are detected and managed in the same sitting.

Radial Styloid Fractures

A radial styloid fracture is an ideal fracture pattern to manage arthroscopically, particularly if one is just beginning to gain experience in arthroscopic–assisted fixation of distal radius fractures. Several techniques are possible. A closed reduction and percutaneous fixation of the radial styloid fragment may be attempted under fluoroscopy. The fracture can be provisionally stabilized anatomically as possible as viewed under fluoroscopy.

The fracture then may be placed in traction, and the wrist arthroscopically evaluated. This allows the fracture hematoma and debris to be washed out and assessment made for any associated intra–articular soft–tissue injuries. The arthroscope is initially placed in the 3–4 portal, and the reduction of the radial styloid fracture is observed. However, the best portal to view rotation of the fracture fragment is by looking across the wrist. Therefore, it is best to place the arthroscope in either the 4–5 or 6–R portal to look across the wrist to judge the reduction of the radial styloid fragment and its rotation. Frequently, the articular reduction may look anatomical under fluoroscopy. However, the radial styloid fragment may still be slightly rotated as viewed arthroscopically.

If the radial styloid fragment is mal–rotated, the guide wires are then backed out of the radial shaft (leaving them only in the radial styloid fragment). They are then utilized as joysticks controlling the rotation of the fracture fragment and then advanced across the fracture site once the reduction is judged anatomical as viewed arthroscopically. In addition, a trocar may be introduced through the 3–4 portal to provide additional control of the radial styloid fragment as it is being manipulated with the joysticks and observed with the arthroscope in the 6–R portal. The positions of the guide wires are then checked under fluoroscopy. If the guide wires are appropriate, a cannulated screw may be placed over the guide wire through the radial styloid fragment into the radial shaft to stabilize the fracture fragment.

Early on in the author’s experience, only Kirschner wires were utilized to stabilize the radial styloid fragment. The author’s patients had to be further stabilized with a splint. In addition, the protruding Kirschner wires irritated the skin and potentially hampered rehabilitation. Now the author prefers headless cannulated screws, which limit any metal protruding from the skin and/or bone. New self–drilling headless screws have been recently introduced (Acutrak II, Hillsboro, OR), which eliminates a step of drilling and even further simplifies the procedure. The decrease in metal prominence exiting from the bone significantly decreases irritation of the thumb extensor tendons and promotes earlier range of motion and rehabilitation.

An alternative technique is to advance the guide wire or Kirschner wire under fluoroscopy into the radial styloid fragment alone, and not across the fracture site (Figure 17.5). The position of the guide wire in the radial styloid fragment and its angle in relation to the fracture is viewed directly under fluoroscopy. The wrist is then suspended in the traction tower and the standard wrist arthroscopy portals are made. Similar to before, the best view to judge rotation and reduction of the radial styloid fragment is through the 6–R portal. The previously placed Kirschner wires are then used as joysticks and the fracture is manipulated under direct observation and anatomically reduced to the distal radius (Figures 17.6 and 17.7).

FIGURE 17.5 Lateral view of a fracture dislocation of the distal radius involving the radial styloid.

FIGURE 17.6 Arthroscopic view with the arthroscope in the 6-R portal looking across the wrist in the displaced radial styloid fragment. A guide wire has been placed into the radial styloid fragment to act as a joystick.

FIGURE 17.7 Arthroscopic view of the radial styloid fragment as it is being reduced. A combination of the joystick into the radial styloid fragment and a trocar inserted into the 3–4 portal helps control the rotation and reduction of the displaced radial styloid fragment.

The guide wires are than advanced across the fracture site once the reduction is judged to be anatomical. It is vital to make a small skin incision over the radial styloid to insert the guide wires through a 14–gauge needle or through a cannula to prevent injury to the dorsal sensory branch of the radial nerve. An alternative technique is utilizing an oscillating drill to insert the guide wires. By use of an oscillating drill, the cutaneous nerves will not wrap around the Kirschner wire as it is being inserted. Once the position of the guide wires is checked under fluoroscopy, a headless cannulated screw may be inserted (Figures 17.8 and 17.9).

FIGURE 17.8 Fluoroscopic view of the reduced radial styloid fragment.

FIGURE 17.9 Lateral fluoroscopic view showing the radial styloid fragment and carpus to be anatomically reduced.

It is important to remember that radial styloid fractures have a high incidence of injury to the scapholunate interosseous ligament¹⁸ (Figures 17.10 through 17.12). The zone of injury may pass through the fracture and distally into the scapholunate interosseous ligament. Following arthroscopic reduction to the radial styloid fracture, the arthroscope is placed back in the 3–4 portal to evaluate the integrity of the scapholunate interosseous ligament (Figures 17.13 and 17.14). The arthroscope should also be placed in the radial midcarpal portal to evaluate the scapholunate interval from the midcarpal space. The potential for carpal instability should be thoroughly evaluated from both the radiocarpal and midcarpal spaces. In addition, the occasional loose body may be seen in the midcarpal space, which cannot be detected on plain radiographs. Loose bodies are usually associated with a fracture involving the lunate facet and arise from the hamate.

FIGURE 17.10 PA radiograph of an impacted fracture involving the scaphoid facet. In addition, a tear of the scapholunate interosseous ligament is apparent on plain radiographs.

FIGURE 17.11 Arthroscopic view of the impacted scaphoid facet fracture.

FIGURE 17.12 The impacted fracture of the scaphoid facet is elevated with a trocar in the 3–4 portal as viewed with the arthroscope in the 6-R portal.

FIGURE 17.13 A complete tear of the scapholunate interosseous ligament is identified arthroscopically. This is the Geissler “drive-through sign,” whereby the capitate is easily identified between the gap of the scapholunate as seen in the radial carpal space.

FIGURE 17.14 Anterior posterior view showing anatomical restoration of the joint surface from the impacted scaphoid facet fracture. A small open reduction was performed to repair the complete tear of the scapholunate interosseous ligament. It is felt that in complete Geissler grade IV tears open repair is preferable to arthroscopic reduction.

Three–Part Fractures

Three–part fractures involve a displaced fracture of the radial styloid and lunate facet. The radial styloid fracture may be closed reduced and percutaneously stabilized under fluoroscopic guidance. Again, it is vital to place the guide wires through a small incision to protect the dorsal sensory branch of the radial nerve when stabilizing the radial styloid fragment. The radial styloid fragment is then utilized as a landmark to which the depressed lunate facet fragment is reduced. Following percutaneous reduction and stabilization of the radial styloid fragment under fluoroscopic guidance, the wrist is suspended in the traction tower. The fracture debris and hematoma are then evacuated, and the depressed lunate facet fragment is best observed with the arthroscope in the 3–4 portal. An 18–gauge needle may be placed percutaneously directly over the depressed fragment and viewed arthroscopically as a landmark.

A large Steinmann pin is then placed approximately 2 cm proximal to the 18–gauge needle into the depressed lunate facet fragment, which is then elevated. Once the fragment is elevated back to the radial styloid fragment as judged arthroscopically, a bone tenaculum may be placed to further reduce the fracture gap between the radial styloid fragment and the depressed lunate facet fragment and to provide provisional stabilization. Once the fracture fragments are anatomically reduced as viewed arthroscopically, guide wires are placed transversely from the radial styloid subchondrally into the lunate facet fragment. If a dorsal die punch fragment is present, it is important that the guide pins be aimed dorsally to capture this fragment. Once the transverse pins are placed, it is important to pronate and supinate the wrist to ensure that the transverse pins have not violated the distal radioulnar joint.

Because of the concave nature of the distal radioulnar joint, the pins may appear under fluoroscopy to have not penetrated into the joint when in fact they have mechanically protruded into the joint. For this reason, pronate and supinate the wrist to evaluate the placement of the transverse pins. Previously, Kirschner wires were used to stabilize the fracture fragments alone. Now, headless cannulated screws are utilized if at all possible—not only to stabilize the radial styloid fragment but to stabilize the impacted lunate facet fragment. This decreases soft–tissue irritation during rehabilitation and promotes earlier range of motion. If extensive metaphysial comminution is present, a bone graft may be placed through a small dorsal incision between the fourth and fifth dorsal compartments to avoid late settling of the fracture fragments.

A volar plate may be utilized if metaphysial comminution is present. In this scenario, a standard volar approach is made over the radial side of the flexor carpi radialis. Dissection is continued down through the sheath where the flexor pollicis longus is identified and retracted ulnarly. The pronator quadratus is released off its radial border, exposing the fracture. The radial styloid fragment can be anatomically reduced back to the shaft as viewed directly through the incision. The lunate fracture fragment may be seen through the volar approach, and can be anatomically reduced and pinned through the volar approach. In this incidence, a volar plate is placed and the fracture is provisionally pinned through the plate. The wrist is then suspended in traction, and the articular reduction is viewed arthroscopically.

If the articular reduction is not anatomical, the pins may then be removed from the plate and the reduction may be fine–tuned as viewed arthroscopically. Once this reduction is felt to be anatomical, the pins are placed back through the plate to provisionally stabilize the fracture. The most distal screws are then placed through the plate into the distal articular fragment. In die punch fractures, it is particularly helpful to view the reduction while the distal screws are being placed through the plate (Figures 17.15 through 17.17). In this way, the dorsal die punch fragment can be arthroscopically viewed to be anatomical and the can be seen inserting into the fragment for stability (Figures 17.18 and 17.19).

FIGURE 17.15 CTscan showing an unstable dorsal lip fracture of the distal radius.

FIGURE 17.16 These fractures are typically difficult to reduce through a volar approach. However, the plate may be placed on the volar aspect and the reduction easily viewed arthroscopically.

FIGURE 17.17 Arthroscopic view of the reduction of the dorsal lip fragment. The very distal pins in the plate may be viewed directly arthroscopically as they capture the dorsal lip fragment. Direct arthroscopic observation ensures that the pins are capturing the dorsal lip fragment.

FIGURE 17.18 Fluoroscopic view confirming that the pin is capturing the small dorsal lip fragment through the volar distal radius plate.

FIGURE 17.19 PA radiograph showing stabilization of the dorsal fragment.

The dorsal die punch fragment is best seen with the scope in the 6–R portal, or through a volar radial portal as promoted by Slutsky. In this instance, a previous volar incision has been made and the arthroscope may be placed between the radioscaphocapitate ligament and the long radiolunate ligament.¹⁹ Particularly if any metaphysial comminution is present, plate stabilization is preferred. Volar plate fixation is very stable, and allows for earlier rehabilitation and range of motion.

Four–Part Fractures

In four–part fractures, the lunate facet is divided into volar and dorsal fragments (Figures 17.20 and 17.21). The volar ulnar fragment is unable to be reduced by closed manipulation. Traction on the volar wrist capsule rotates the volar ulnar fragment, causing it to be unable to be reduced by closed manipulation. The radial styloid fragment is again reduced by closed manipulation and is temporarily stabilized with Kirschner wires. A standard volar approach to the distal radius is performed as described previously. The reduction of the radial styloid fragment may be fine–tuned by direct observation of the fracture fragment and keying it into the shaft of the distal radius.

FIGURE 17.20 Comminuted metaphysial fractures with intra-articular involvement are best stabilized by a combination of arthroscopic-assisted reduction and plate stabilization.

FIGURE 17.21 Similarly, four-part fractures with a large volar ulnar fragment are best stabilized by a combination of open reduction through a volar approach and confirmation of the articular reduction by arthroscopy.

The volar ulnar fragment is then reduced under direct observation by reducing it back to the shaft and into the radial styloid fragment. It is then pinned provisionally transversely. The position of the reduction of the radial styloid and volar ulnar fragment provisionally stabilized is viewed under fluoroscopy. A volar distal radius plate is then utilized to stabilize the volar bone fragments (Figure 17.22). An initial screw is placed in the proximal portion of the plate to adjust the proximal–distal alignment of the plate in relation to the fracture fragments. The plate is then provisionally pinned to the articular fragments through the holes in the plate.

FIGURE 17.22 A standard volar approach is made to the distal radius and a volar plate is provisionally placed to stabilize the fracture. The fracture is provisionally stabilized with pins inserted through the plate.

The wrist is suspended in the traction tower and the arthroscope is placed in the 3–4 portal. Usually, the dorsal ulnar fragment is best viewed with the arthroscope in the 6–R portal or through the volar portal as described by Slutsky. The dorsal ulnar fragment is then percutaneously elevated back to the radial styloid and reduced to the volar ulnar fragment, which is utilized as a landmark (Figures 17.23 through 17.25). The distal screws may be inserted into the plate to stabilize the articular surface (once articular reduction of the distal radius is judged to be anatomical as viewed by the arthroscope). It is helpful that the first screw placed is a non–locking screw, which helps reduce the fragments back through the anatomically shaped distal radius plate. Particularly in small dorsal fragments, it is helpful to view the placement of the screws arthroscopically as they are seen inserted into these fragments to provide stability (Figure 17.26).

FIGURE 17.23 The wrist is then arthroscopically evaluated. Articular reduction can then be fine-tuned as viewed directly arthroscopically.

FIGURE 17.24 The comminuted intra-articular fracture is anatomically reduced as confirmed arthroscopically with the arthroscope in the 6-R portal.

FIGURE 17.25 The reduction of the dorsal lip fragment may be viewed with the arthroscope in the 6-R portal, or through the volar portal as popularized by Slutsky.

FIGURE 17.26 PA radiograph showing anatomical restoration to the joint surface of the four-part fracture.

Ulnar Styloid Fractures

Stabilization of an associated ulnar styloid fragment is usually controversial. Wrist arthroscopy provides some rationale as to when to stabilize an associate ulnar styloid fragment. Following anatomical reduction of the distal radius fracture, the tension of the articular disc is palpated arthroscopically. The arthroscope is placed in the 3–4 portal, and a probe is inserted through the 6–R portal. If there is good tension to the articular disc, the majority of the fibers of the triangular fibrocartilage complex is still attached to the base of the ulna and the ulnar styloid fragment is not stabilized. If the articular disc is lax by palpation, a peripheral tear of the triangular fibrocartilage complex is suspected. This may be covered with hematoma. It is important to debride the hematoma to obtain direct visualization of the periphery of the articular disc. A peripheral tear is then repaired arthroscopically if it is identified (Figure 17.27). The articular disc is repaired utilizing an outside–in technique to the base of the ulna with suture anchors.

FIGURE 17.27 Wrist arthroscopy also allows for rationale of when to stabilize the ulnar styloid fragment. Following reduction of the distal radius fracture, the articular disc is palpated. In this incidence, a peripheral tear was identified and repaired arthroscopically following the reduction to the distal radius.

Stabilization of a large ulnar styloid fragment is considered when the articular disc is lax when palpated and no peripheral tear is identified (Figure 17.28). In this incidence, the majority of the fibers of the articular disc is attached to the displaced ulnar styloid fragment. A small incision is then made between the interval of the extensor carpi ulnaris and flexor carpi ulnaris. Blunt dissection is carried down to protect the dorsal sensory branch of the ulnar nerve, which is running just volar to the incision. The ulnar styloid fragment is then cleared of fracture debris, and is stabilized by either tension band, Kirschner wire, or preferably by a small headless cannulated screw.

FIGURE 17.28 The patient had a large associated ulnar styloid fragment. Arthroscopic evaluation to the wrist showed laxity to the articular disc, and a peripheral tear of the triangular fibrocartilage complex was not seen. The ulnar styloid fragment was then stabilized by open reduction and internal fixation with a micro headless cannulated screw.

Discussion

The literature is relatively sparse regarding the results of arthroscopic–assisted fixation of displaced intra–articular fractures of the distal radius. Stewart et al. presented a comparison study of 12 open and 12 arthroscopic–assisted reductions of comminuted fractures of the distal radius.²⁰ These fractures were comminuted and were classified as AO type VII and VIII. In the arthroscopic group, they had five excellent, six good, and one fair result. The open group noted no excellent results. The authors concluded that the arthroscopic group had a significantly increased range of motion compared to the group that underwent open stabilization.

Similarly, Doi et al. reported their results in a comparison study of 38 patients who underwent arthroscopic–assisted fixation in comparison to those patients who underwent open reduction.²¹ The author similarly found that the arthroscopic group had improved range of motion compared to the open group.

Ruch reported his result of a comparison study of 15 patients who underwent arthroscopic–assisted reduction and 15 patients who underwent closed reduction and were stabilized by external fixation under fluoroscopy.²² In the 15 patients who underwent arthroscopic reduction, 10 patients had a tear of the triangular fibrocartilage complex. Seven of those tears were peripheral and underwent arthroscopic repair. No patients in the arthroscopic group had any signs of distal radioulnar joint instability at final follow–up visit. In the 15 patients who underwent closed reduction and external fixation, four patients continued to complain of instability of the distal radioulnar joint. Potentially, these patients had a peripheral tear of the triangular fibrocartilage complex—which could have been acutely repaired at the time of fracture stabilization.

Geissler and Freeland reviewed their results of 33 patients who underwent arthroscopic–assisted reduction of comminuted intra–articular fractures of the distal radius.²³ Their criteria were those fractures displaced 2 mm or more following a closed reduction. In their series, at final follow–up visit 25 patients had an anatomical reduction and eight patients had a 1–mm articular step–off. The patients were evaluated utilizing the modified Mayo wrist score and there were 20 excellent, 10 good, and 3 fair results in their series. Simple articular fractures had a better result compared to complex fracture patterns.

In addition, they analyzed their results based on associated soft–tissue injuries. They found when a Geissler grade II scapholunate interosseous ligament was present it did not affect the final prognosis. Geissler grade II injuries were evenly distributed throughout the patients’ series, and did not correlate with the final prognosis. However, when a Geissler grade III or IV tear was present in an AO type C fracture it significantly affected the final results. In the five patients with an AO type C fracture without an interosseous ligament tear, all five patients had an excellent result. However, in the five patients with an AO type C fracture with a Geissler grade III or IV interosseous ligament tear there were four good results and one fair result. It appeared that the presence of a Geissler grade III or IV interosseous ligament tear significantly affected the final prognosis in their study in AO type C fractures.

Summary

Wrist arthroscopy is a valuable adjunct in the management of displaced intra–articular fractures of the distal radius. It allows for evaluation of the articular reduction under bright light and magnified conditions. It has been previously reported that restoration of the articular surface is important and affects the patient’s final prognosis. Particularly, arthroscopy allows for detection of mal–rotation of fracture fragments—which is very difficult to judge under fluoroscopy. In addition, the washing out of fracture hematoma and debris may allow for improved range of motion (as shown by the comparison studies of Stewart and Doi).

Wrist arthroscopy also allows for the detection and management of associated intra–articular soft–tissue injuries, which have been shown to occur with a high incidence with intra–articular fractures of the distal radius. Arthroscopic detection of soft–tissue injuries allows for acute stabilization. It is felt that management of acute soft–tissue injuries has a better prognosis as compared to chronic reconstruction. Tears of the triangular fibrocartilage complex have been shown to be the most frequent associated soft–tissue injury with fractures of the distal radius. In addition, chondral defects or loose bodies that would not normally be seen with plain radiographs are frequently identified arthroscopically and can be removed from both the radiocarpal and midcarpal spaces.

Associated intra–articular soft–tissue injuries or loose bodies not detected on plain radiographs may be an explanation why some patients continue to complain of pain (particularly on the ulnar side of the wrist) for several months post–injury despite anatomical restoration of the fracture as seen on plain radiographs.²⁴ Last, wrist arthroscopy provides a rationale of when and when not to stabilize the displaced ulnar styloid fragment when it is associated with a fracture of the distal radius.