Bridge Plating of Distal Radius Fractures

Paul A. Martineau

Kevin J. Malone

Douglas P. Hanel

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
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.