Bridge Plating of Distal Radius Fractures

 

 

 

DEFINITION

High-energy fractures of the distal aspect of the radius with extensive comminution of the articular surface and extension into the diaphysis represent a major treatment challenge. Standard plates and techniques may be inadequate for the management of such fractures.

Before the introduction of the bridge plating technique, treatment of these injuries was limited to cast immobilization or external fixation with or without Kirschner wire augmentation. Both of these methods are associated with unacceptably high complication rates.

 

 

ANATOMY

 

The articular surface of the distal radius is tilted 21 degrees in the anteroposterior plane and 5 to 11 degrees in the lateral plane.

 

The dorsal cortex surface of the radius thickens to form the tubercle of Lister.

 

A central ridge divides the articular surface of the radius into a scaphoid facet and a lunate facet.

 

Because of the different areas of bone thickness and density, fractures tend to occur in the relatively weaker metaphyseal bone and propagate intra-articularly between the scaphoid and lunate facets.

 

The degree, direction, and magnitude of applied load may cause coronal or sagittal splits within the lunate or scaphoid facets.

 

PATHOGENESIS

 

Two subsets of patients with distal radius fractures continue to represent unique treatment challenges:

 

 

Patients with high-energy wrist injuries with fracture extension into the radial diaphysis

 

Patients with multiple injuries who require load bearing through the injured wrist to assist with mobilization and nursing care

 

NATURAL HISTORY

 

Lafontaine et al13 showed that the end results of comminuted distal radius fractures treated by closed methods resembled the prereduction radiographs more than any other radiographs during treatment, even when the reduction successfully restored wrist anatomy.

 

A number of studies clearly show that restoration of normal anatomy after distal radius fracture provides better function.4,6,7,8,10,11,12,14

 

Functional outcome scores in patients without anatomic reduction are poor.4,15

 

Malunion of the distal radius has been associated with pain, stiffness, weak grip strength, and carpal instability in a substantial percentage of patients.8 Long-term consequences include degenerative arthritis in up to 50% of patients with even minimal displacement in the young adult population.16

 

As surgical treatment (plating in particular) ensures more consistent correction of displacement and maintenance of reduction, there has been a trend toward operative treatment in both the elderly and the young population.

 

PATIENT HISTORY AND PHYSICAL FINDINGS

 

In the management of high-energy distal radius fractures, a complete history should include the mechanism of injury. These fractures are commonly the result of axial loading as opposed to the bending forces, which are all low-velocity fractures.

 

Examination of the soft tissue envelope of the wrist should be performed to rule out open fractures.

 

Because of the high-energy nature of these fractures, patients are at increased risk of neurovascular compromise. Careful examination for signs of impending compartment syndrome as well as median nerve dysfunction from an acute carpal tunnel syndrome should be clearly documented.

 

Associated injuries should be ruled out, and appropriate patient clearance according to advanced trauma life support guidelines should be obtained.

 

IMAGING AND OTHER DIAGNOSTIC STUDIES

 

Good-quality pre- and postreduction wrist radiographs should be obtained preoperatively to assess the fracture pattern and rule out associated injuries to the carpus or distal radioulnar joint (DRUJ).

 

Computed tomography (CT) scans may be helpful to assess complex intra-articular distal radius fractures.

 

NONOPERATIVE MANAGEMENT

 

There is no acceptable nonoperative management for high-energy comminuted distal radius fractures.

 

SURGICAL MANAGEMENT

 

The use of internal distraction plating or bridge plating for distal radius fractures was introduced by Burke and

Singer.3 The technique was expanded by Ruch et al,17 who described the use of a 12- to 16-hole 3.5-mm dynamic compression plate (DCP) (Synthes, Paoli, PA) placed in the floor of the fourth dorsal extensor

compartment to span from the intact radius diaphysis to the third metacarpal.5,17

 

The bridge plating technique provides strong fixation and allows for distraction across impacted articular segments.

 

The technique can be combined with a limited articular fixation approach for fracture patterns with intra-articular extension.

 

Bridge plating of the distal radius was further refined by Hanel et al.9 The authors described a variant of the bridge

 

P.316

plating technique using 2.4-mm AO plates passed extra-articularly through the second dorsal compartment and secured onto the dorsal radial aspect of the radius diaphysis and the second metacarpal (Table 1).

 

 

Table 1 Indications for Bridge Plating of Distal Radius Fractures

Indication

Explanation

Metadiaphyseal

comminution of the radius

Extensive comminution in metadiaphyseal region is difficult to treat with

standard implants used for distal radius fractures.

Need for weight

bearing through the upper extremity

Patients with associated lower limb injuries may require the need for early

weight bearing through the upper extremities.

Polytrauma

Nursing care of the multiply injured patient may be easier with spanning

internal fixation than with external fixation.

Augmented fixation

In osteoporotic bone, bridge plating can be used to augment tenuous

fixation.

Carpal instability

Carpal instability, particularly radiocarpal, isolated or in combination with a

distal radius fracture, may be held in a reduced position with the help of spanning internal fixation.

 

 

Preoperative Planning

 

A 22-hole 2.4-mm titanium mandibular reconstruction plate (Synthes) or a 2.4-mm stainless steel plate specifically designed for use as a distal radius bridge (DRB) plate (Synthes) is used for DRB plating.

 

The mandibular reconstruction plate is made of titanium and has square ends and scalloped edges and threaded holes to accept locking screws. The DRB plate that the authors currently use is made of stainless steel and has tapered ends to facilitate sliding the plate within the extensor compartment; it also has locking screws.

 

 

 

FIG 1 • Setup for this procedure, with longitudinal traction applied through finger traps and the C-arm coming in from above or below the hand table.

 

Positioning

 

With the patient anesthetized and supine on the operating table, the involved extremity is draped free and centered on a radiolucent hand table.

 

Finger traps are applied to the index and middle fingers and 4.5 kg of longitudinal traction is applied through a rope and pulley system.

 

A C-arm comes in from above or below the hand table (FIG 1).

 

Approach

 

Under image intensification, the closed reduction maneuver described by Agee1 is performed.

 

Plates are passed extra-articularly through the second dorsal compartment and secured onto the dorsal radial aspect of the radius diaphysis and the second metacarpal.

 

The interval between the extensor carpi radialis longus (ECRL) and extensor carpi radialis brevis (ECRB) is developed and the diaphysis of the radius exposed.

 

The DRB plate is introduced beneath the muscle bellies of the outcroppers extraperiosteally and advanced distally between the ECRL and ECRB tendons.

 

TECHNIQUES

• Closed Reduction Maneuver of Agee

Longitudinal traction is first used to restore length and to assess the benefit of ligamentotaxis for the

 

restoration of articular step-off (TECH FIG 1A,B).

 

Next, the hand is translated palmarly relative to the forearm to restore sagittal tilt and to assess the integrity of the volar lip of the radius (TECH FIG 1C-F).

 

 

Finally, pronation of the hand relative to the forearm is performed to correct the supination deformity. Once the initial reduction maneuver is completed, the bridge plate is then applied.

 

 

 

TECH FIG 1 • Radiographs show an anteroposterior (AP) projection of the wrist injury before (A) and after

(B) distraction is applied. (continued)

 

 

P.317

 

 

 

TECH FIG 1 • (continued) Clinical pictures show the wrist deformity before (C) and after (D) application of the Agee reduction maneuver, which is a combination of longitudinal traction and volar translation of the carpus. Radiographs show the wrist deformity before (E) and after (F) application of the Agee reduction maneuver.

• Approach and Plate Insertion

   

  The DRB plate is superimposed on the skin from the radial diaphysis to the distal metadiaphysis of the second metacarpal. The position of the plate is verified with image intensification and markings are placed on the skin at the level of the proximal and distal four screw holes of the plate (TECH FIG 2A-C).

   

  The subcutaneous tissues are infiltrated with 0.25% bupivacaine with epinephrine to promote hemostasis.

   

  A 5-cm incision is made at the base of the second metacarpal and continued along the second metacarpal shaft. In the depths of this incision, the insertions of the ECRL and ECRB are identified as they pass beneath the distal edge of the second dorsal wrist compartment to insert on the second and third metacarpal bases, respectively.

   

  A second incision is made just proximal to the outcropper muscle bellies (abductor pollicis longus and extensor pollicis brevis), in line with ECRL and ECRB tendons. The interval between the ECRL and ECRB is developed and the diaphysis of the radius exposed (TECH FIG 2D,E).

   

  The DRB plate is introduced beneath the muscle bellies of the outcroppers extraperiosteally and advanced distally between the ECRL and ECRB tendons (TECH FIG 2F).

   

   

   

  TECH FIG 2 • A. The plate is placed over the forearm and hand. Radiographs can be taken to confirm the position of the plate. The plate should be centered over the second metacarpal distally and the radius proximally. This will be along the course of the ECRL. B. Outline of the plate. C. Incisions are made over the second metacarpal and the radius. (continued)

   

   

  P.318

   

   

   

  TECH FIG 2 • (continued) D. The ECRL and ECRB tendons just proximal to the abductor pollicis longus in the forearm. E. Development of the interval between the ECRL and ECRB tendons to gain access to the radius shaft. F. The proximal aspect of the plate over the radius and in between the ECRL and ECRB. It is important to ensure that the plate runs within the second compartment and not superficial to the first and third compartment tendons. G. The plate is advanced proximal to distal and emerges distally over the second metacarpal. H. A third incision is marked out just ulnar to the tubercle of Lister. I. The extensor pollicis longus tendon has been released from its compartment, and bone graft is inserted through the dorsal fracture line just ulnar to the bridge plate.

   

   

  Some resistance may be encountered as the plate emerges distally but can usually be easily overcome with gentle manipulation of the plate (TECH FIG 2G).

   

  Occasionally, the plate will not pass through the compartment. In these cases, a guidewire or stout suture retriever is passed along the compartment from distal to proximal. The plate is secured to the distal end of the wire and delivered into the hand.

   

  In the rare instance that these measures fail, a third incision is made directly over the metaphysis of

  the radius, the proximal half of the second compartment is incised, and the plate is passed under direct vision.

   

  The third, or periarticular, incision may also be used to assess the articular surface, reduce die-punch fragments, and introduce bone graft (TECH FIG 2H,I).

• Plate Fixation and Articular Fixation

 

After the bridge plate is passed, it is then secured to the second metacarpal by placing a nonlocking fully threaded 2.4-mm cortical screw through the most distal plate hole. The proximal end of the plate is then identified in the forearm.

 

If the radial length has not been restored, then the plate, secured to the second metacarpal, is pushed distally until the length is reestablished and a fully threaded 2.4-mm nonlocking screw is placed in the most proximal plate hole. By using nonlocking screws, the plate is effectively lagged onto the intact bone.

 

P.319

 

Plate alignment along the longitudinal axis of the radius is guaranteed by securing the most distal and most proximal screw holes first.

 

The remaining holes are secured with fully threaded locking screws inserted with bicortical purchase.

 

It has been our experience that as the plate is passed along the radial diaphysis, through the second compartment and along the second metacarpal, extra-articular alignment, radial inclination, volar tilt, and radial length are restored.

 

Intra-articular reduction may be further adjusted by using limited periarticular incisions to allow for direct manipulation of articular fragments, placement of subchondral bone grafts, repair of intercarpal ligament injuries, and augmentation of fracture fixation with Kirschner wires and periarticular plates.

 

 

 

TECH FIG 3 • Final AP (A), oblique (B), and lateral (C) radiographic images.

 

 

Displaced volar medial fracture fragments that are not reduced with this technique require a separate volar incision and appropriate buttress support.

 

The biomechanical stability of spanning plates is strong and predictable. Behrens and Johnson,2 studying the rigidity of external fixator configurations, demonstrated that rigidity is directly proportional to how close the longitudinal fixator bar is to the bone and the fracture. A bridge plate, resting directly against the radius proximally and metacarpals distally, therefore optimizes the conditions to obtain the

strongest possible fixator construct.

A DRB plate fixed with a minimum of three screws at either end of the plate confers significantly more stability than would an external fixator used to stabilize a comparable fracture (TECH FIG 3).18

• Distal Radioulnar Joint Management

DRUJ stability is assessed after radius reconstruction. If the DRUJ is stable, the limb is immobilized in a long-arm splint with the forearm in supination for the first 10 to 14 days postoperatively.

If the DRUJ is unstable, and there are no contraindications to prolonging the operation, repair or reconstruction of DRUJ and triangular fibrocartilage complex is undertaken.

If, however, the patient's condition does not allow the operation to be prolonged, the ulnar head is reduced manually into the sigmoid notch and the ulna is transfixed to the radius with a minimum of two 1.6-mm Kirschner wires passed proximal to the DRUJ.

 

 

PEARLS AND PITFALLS

 

Hardware ▪ At the time of hardware extraction, if a mandibular reconstruction plate was used, removal the screws are removed and the plate is twisted axially 720 degrees to break up the

soft tissue adhesions and callus that tend to grow around and onto the scalloped edges of the titanium plate. This maneuver is not usually required when the smoothedged stainless steel DRB is used.

• A removable short-arm splint is worn for 2-3 weeks after plate removal. Hand therapy at this point is directed at regaining motion and strength.

 

 

 

 

POSTOPERATIVE CARE

P.320

 

Digit range-of-motion exercises start within 24 hours of surgery. Load bearing through the forearm and elbow is allowed immediately as well as the use of a platform crutch when the patient is physiologically stable. One month postoperatively, the platform is removed and weight bearing is allowed through the hand grip of regular crutches. Lifting and carrying are restricted to about 4.5 kg until fracture healing.

 

DRUJ stability and forearm motion are assessed 2 weeks after reduction. If the patient can supinate the forearm with little effort and the DRUJ is stable, then splinting is discontinued and axial loading through the extremity is allowed at this point.

 

If the patient has difficulty maintaining supination, or if the DRUJ was reconstructed acutely, a removable long-arm splint is fabricated.

 

If the DRUJ was transfixed with Kirschner wires, then the wires are removed on the third postoperative week and DRUJ stability is reassessed.

 

 

Supplemental Kirschner wires for articular fixation are removed 6 weeks postoperatively. The DRB plate and screws are removed usually no earlier than 12 weeks after injury.

OUTCOMES

 

The bridge plating technique for distal radius fractures was reviewed in a retrospective study consisting

of 62 consecutive patients treated in this fashion.9 The series represents the senior author's 10-year experience with the technique at a level 1 trauma center. Patients managed with bridge plating either for distal radius fractures with extensive metadiaphyseal comminution or for distal radius fractures associated with other injuries requiring weight bearing through the affected extremity represented 13% of distal radius fractures treated with operative fixation during this period. Fracture healing occurred in all 62 patients.

 

In each case, radial length was within 5 mm of neutral ulnar variance, radial inclination was greater than 5 degrees, and palmar tilt was at least neutral.

 

There were also no articular gaps or step-offs greater than 2 mm and the DRUJ was stable in all cases.

 

The plates were removed on average 112 days after placement.

 

Forty-one of the 62 patients have returned to their previous levels of employment. Of the remaining 21 patients, 8 were unemployed at the time of injury and remain so.

 

Thirteen patients sustained multiple injuries requiring considerable changes in occupation and lifestyle. Only 1 of these 13 patients considers the wrist fracture to be the limiting factor in failing to return to work.

 

Overall, these results compare favorably with the findings of Burke and Singer3 and Ruch et al.17

 

Similarly, Ruch et al17 showed that 64% of patients obtained excellent radiographic and functional results and another 27% of patients obtained good results in their prospective cohort of patients with comparable pathology.

 

The authors of each of these studies propose that distraction plating allows fracture reduction and fixation over a broad metadiaphyseal area while effectively diverting compression forces away from the fracture site.

 

The use of bridge plating in the treatment of distal radius fractures avoids the complications of external fixation. A bridge plate can remain implanted for extended periods without deleterious effects on functional outcome. All patients in our series went on to heal with acceptable metadiaphyseal and intra-articular alignment. In patients with multiple traumatic injuries, bridge plating allowed earlier postoperative load bearing across the affected wrist. This enabled independent transfers and the use of ambulatory aids. Application of bridge plates is simple and surgical time is comparable with the application of an external fixator.

 

COMPLICATIONS

There was one documented hardware failure in the series in a patient who initially refused to have the implant taken out and continued to work in heavy manual labor for 19 months before the bridge plate failed.

In addition, there were no cases of excessive postoperative finger stiffness or reflex sympathetic dystrophy.

This reflects the overall infrequent complications reported in the literature for bridge plating of the distal

 

radius. In fact, Burke and Singer3 reported no complications and Ruch et al17 reported no hardware failures and only three patients who developed long finger extensor lag of 10 to 15 degrees.

 

 

REFERENCES

1. Agee JM. Distal radius fractures. Multiplanar ligamentotaxis. Hand Clin 1993;9:577-585.

    

    

2. Behrens F, Johnson W. Unilateral external fixation. Methods to increase and reduce frame stiffness. Clin Orthop Relat Res 1989;(241):48-56.

    

    

3. Burke EF, Singer RM. Treatment of comminuted distal radius with the use of an internal distraction plate. Tech Hand Up Extrem Surg 1998;2:248-252.

    

    

4. Drobetz H, Bryant AL, Pokorny T, et al. Volar fixed-angle plating of distal radius extension fractures: influence of plate position on secondary loss of reduction: a biomechanic study in a cadaveric model. J Hand Surg Am 2006;31(4):615-622.

    

    

5. Ginn TA, Ruch DS, Yang CC, et al. Use of a distraction plate for distal radial fractures with metaphyseal and diaphyseal comminution. Surgical technique. J Bone Joint Surg Am 2006;88(suppl 1, pt 1):29-36.

    

    

6. Gradl G, Jupiter JB, Gierer P, et al. Fractures of the distal radius treated with a nonbridging external fixation technique using multiplanar K-wires. J Hand Surg Am 2005;30(5):960-968.

    

    

7. Graff S, Jupiter J. Fracture of the distal radius: classification of treatment and indications for external fixation. Injury 1994;25(suppl 4): S14-S25.

    

    

8. Handoll HH, Madhok R. Surgical interventions for treating distal radial fractures in adults. Cochrane Database Syst Rev 2003;(3):CD003209.

    

    

9. Hanel DP, Lu TS, Weil WM. Bridge plating of distal radius fractures: the Harborview method. Clin Orthop Relat Res 2006;445:91-99.

    

    

10. Hastings H II, Leibovic SJ. Indications and techniques of open reduction. Internal fixation of distal radius fractures. Orthop Clin North Am 1993;24:309-326.

     

     

11. Kamath AF, Zurakowski D, Day CS. Low-profile dorsal plating for dorsally angulated distal radius fractures: an outcomes study. J Hand Surg Am 2006;31:1061-1067.

     

     

12. Konrath GA, Bahler S. Open reduction and internal fixation of unstable distal radius fractures: results using the Trimed fixation system. J Orthop Trauma 2002;16:578-585.

     

     

13. Lafontaine M, Hardy D, Delince P. Stability assessment of distal radius fractures. Injury 1989;20:208-210.

     

     

14. McQueen MM. Non-spanning external fixation of the distal radius. Hand Clin 2005;21:375-380.

     

     

    P.321

     

15. McQueen MM, Simpson D, Court-Brown CM. Use of the Hoffman 2 compact external fixator in the treatment of redisplaced unstable distal radial fractures. J Orthop Trauma 1999;13:501-505.

     

     

16. Orbay JL, Touhami A. Current concepts in volar fixed-angle fixation of unstable distal radius fractures. Clin Orthop Relat Res 2006;445: 58-67.

     

     

17. Ruch DS, Ginn TA, Yang CC, et al. Use of a distraction plate for distal radial fractures with metaphyseal and diaphyseal comminution. J Bone Joint Surg Am 2005;87(5):945-954.

     

     

18. Wolf JC, Weil WM, Hanel DP, et al. A biomechanic comparison of an internal radiocarpal-spanning 2.4-mm locking plate and external fixation in a model of distal radius fractures. J Hand Surg Am 2006;31:1578-1586.