6 Both Bone Forearm Fracture

10.1055/b-0040-174129

6 Both Bone Forearm Fracture

M. Wesley Honeycutt and Daniel Kim

Summary

Diaphyseal fractures of both the radius and ulna are aptly named both bone forearm fractures. There is no role for nonoperative management of these injuries in the adult population as it will consistently result in an unacceptable loss of forearm rotation. ¹ The goals of treatment are fracture union, restoration of anatomic forearm geometry, and functional return of forearm rotation. This chapter describes how to surgically treat both bone forearm fractures with a volar approach to the radius and a direct approach to the ulna. It provides a detailed look at both approaches, thoroughly addresses the important subtleties of the approaches, and describes the essential tricks to consistently achieve anatomic reduction of the forearm.

6.1 Introduction

Both bone forearm fractures refer to diaphyseal fractures of both the radius and ulna. In adults, open reduction internal fixation of these fractures is essential to restore the anatomic radial bow and forearm rotational function (▶Fig. 6.1). There are two historic descriptions of approaches to the radial shaft: the anterior approach, described by Henry, ² and the posterior approach, described by Thompson. ³ Typically, the order of fixation relies on the degree of comminution of either bone; the more simple fracture pattern is fixed first to restore reliable length, alignment, and rotation. However, the radius is often fixed first regardless of fracture pattern. The radius is fixed with the elbow extended to create a stable post for ulnar fixation, when the elbow is subsequently flexed. Fixation is done using two separate incisions to decrease the risk of synostosis associated with a single incision. ⁴

**Fig. 6.1 (a)** Lateral radiograph of a mid-diaphyseal both bone forearm fracture with radial comminution. **(b)** Anteroposterior radiograph of a mid-diaphyseal both bone forearm fracture with a *red line* demarcating the loss of the natural radial bow.

6.2 Preop

Surgical table. Surgeon-specific flat table with radiolucent hand table
Patient position. Supine. Position the shoulder at the edge of the bed to allow for complete visualization of the forearm with intraoperative fluoroscopy.
Operating room setup. The bed should be rotated 90 degrees from anesthesia, with the C-arm parallel to the hand table, and the monitor on the contralateral side of the room from the surgeon.
Surgical prep. A nonsterile tourniquet is placed on the ipsilateral arm above the elbow, and the arm is sterilely prepped below the level of the tourniquet to the hand. Exsanguination is done with a 4-inch Esmarch bandage after sterile prep is performed.
Patient exam. Perform a complete neurovascular and motor exam, which includes the assessment of sensation and motor function of the median, ulnar, and radial nerves. Evaluate distal radial and ulnar pulses, hand perfusion, and capillary refill time. Palpate forearm compartments to rule out compartment syndrome.

6.3 Radius Fixation

The radial shaft is often fixed first to create a stable post for ulnar fixation.

6.4 Volar Approach

The elbow is extended and the forearm is rotated in a supinated position on the hand table.
The landmarks for the incision are the lateral edge of the biceps tendon insertion and the radial styloid. The length of the incision varies, but it must allow for adequate visualization proximal and distal to the fracture to allow for a minimum of two screws on each side.
Sharp incision is performed with a scalpel through skin, and bovie electo-cautery is used to dissect through subcutaneous tissue to the level of the forearm fascia. Proximally, avoid the lateral antebrachial cutaneous nerve of the forearm, which courses at this depth.
Forearm fascia may be incised with scissors, scalpel, or bovie.
Proximally, blunt dissection can be performed to find the interval between the brachioradialis (BR) and the flexor carpi radialis (FCR) muscle bellies. This plane is developed proximally between the pronator teres (PT) and the BR.
The BR is retracted laterally using Army-Navy retractors. The superficial radial nerve courses underneath this muscle and should be identified and protected with retractors or vessel loops.
The radial artery must be identified medial and deep to the BR in the proximal forearm, just lateral to the PT. This vessel then courses between the BR and the FCR muscle bellies in the middle third of the forearm. Retract the radial artery medially in these portions.
Small venae comitantes from the radial artery will feed the BR throughout its length and can be ligated to assist lateral retraction of the muscle.
Deep dissection is performed by continued blunt dissection between the BR and the PT down to the radial aspect of the biceps tendon on the radius. Dissection through the tendon bursa should result in a rush of fluid, which aids in identification of the correct location. The supinator muscle should run obliquely from lateral to medial on the proximal surface of the bone at this level.
Fully supinate the forearm to bring the supinator insertion anteriorly. This should also displace the posterior interosseous nerve posteriorly as it pierces the supinator muscle from proximal and medial to distal and lateral.
At this point, a self-retaining retractor is placed submuscular to help with visualization of the fracture and deep structures.
Incise through the supinator muscle longitudinally along its broad insertion with a bovie. Continue subperiosteal dissection laterally to expose the bone surface.
In the middle third of the radius, pronate the forearm to visualize the insertion of the PT on the lateral aspect of the radius (▶Fig. 6.2). Subperiosteal dissection of the PT is performed using a periosteal elevator, from lateral to medial. The PT is retracted medially, and the self-retainers are moved deeper.
In the distal third, the forearm should again be supinated to visualize the volar surface of the radius. The radial artery is lateral at this part of the dissection and can be safely retracted laterally with the brachialis. Bluntly dissect lateral to the flexor pollicis longus. The pronator quadratus may be dissected off the surface of the radius from lateral to medial with an elevator or bovie.
Once subperiosteal dissection is performed at the fracture site, the fracture ends are delivered using lobster clamps on both proximal and distal segments. All fracture hematoma and fibrous tissue is dissected carefully from the fracture site with a curette and pickups.

**Fig. 6.2** Illustration demonstrating the deep dissection of the volar approach in the middle third of the radius. The supinator has been incised on the radial shaft, the flexor carpi radialis and radial artery are retracted medially, and the brachioradialis and superficial branch of the radial nerve are retracted laterally. At this level, the pronator teres insertion on the radial shaft is visualized. (Modified from illustration by Daniel Zieman.)

6.4.1 Fracture Reduction and Fixation

Ensure that anesthesia has provided maximal pharmacologic muscle relaxation, as it will significantly aid in fracture manipulation and reduction.
Fracture edges are reduced under direct visualization and held using pointed reduction forceps. Alternatively, a 3.5-mm compression plate may be placed on the volar surface of the radius, and the reduction is held through the plate using Kirschner wires (K-wires), pointed reduction forceps, or Verbrugge clamps.
Reduction is visualized using C-arm fluoroscopy in multiple planes. When anatomic reduction is achieved, fixation is completed with at least two screws on either side of the fracture. Typically, three bi-cortical nonlocking crews are used on both sides of the fracture. Army-Navy retractors placed on either the distal or proximal extent of the incision may help achieve another few centimeters of visualization for screw placement.

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