The incidence of fracture of the coronoid varies from less than 1% to 2% of elbow fractures.57 Because most fractures of the coronoid process occur with dislocations of the elbow, it seems logic that they would happen in older children. However, in a review of 23 coronoid fractures in children, Bracq9 found that the injuries occurred in two peak age groups: One was between 8 and 9 years of age and the other between 12 and 14 years.
ASSESSMENT OF FRACTURES OF THE PROXIMAL RADIUS
Mechanisms of Injury for Fractures of the Proximal Radius
Most fractures of the proximal radius occur at the neck. Fractures of the proximal radius most commonly occur after a fall on an outstretched arm with elbow extended and valgus stress at the elbow.33,40,43,68,69,117 The immature radial head is primarily cartilaginous and intra-articular radial head fractures in children and adolescents are rare. The cartilaginous head absorbs the force and transmits it to the weaker physis or metaphysis of the neck.117 These fractures characteristically produce an angular deformity of the head with the neck (Fig. 13-1A). The direction of angulation depends on whether the forearm is in a supinated, neutral, or pronated position at the time of the fall. Vostal showed that in neutral, the pressure is concentrated on the lateral portion of the head and neck. In supination, the pressure is concentrated anteriorly, and in pronation it is concentrated posteriorly.117
Proximal radial fractures also may occur in association with elbow dislocation. The fracture will occur either during the dislocation event, typically displaced anterior. Alternatively, the fracture may occur during spontaneous reduction of the distal humerus, driving the displacement of the proximal radius posterior (Fig. 13-2).
Associated Injuries with Fractures of the Proximal Radius
Proximal radius fractures can occur concomitantly with distal humerus, ulna, radial shaft, or distal radius fractures.33,43,44,69,102 Fractures in combination with ulnar fractures often are part of the Monteggia fracture pattern detailed in Chapter 14. Presence of associated fractures portends a poor prognosis for patients with proximal radius fractures with higher rates of persistent stiffness and pain compared to those with isolated proximal radius fractures.104 As detailed further in Chapter 18, proximal radius fractures can also occur during traumatic elbow dislocations. The posterior interosseous nerve (PIN) wraps around the proximal radius and occasionally can be injured in association with proximal radius fractures. More typically, however, the nerve is at risk during percutaneous manipulation or open reduction of proximal radius fractures.
Signs and Symptoms of Fractures of the Proximal Radius
Following a fracture, palpation over the radial head or neck is painful. The pain is usually increased with forearm supination and pronation more so than with elbow flexion and extension. Displaced fractures frequently result in visible bruising or ecchymosis on the lateral aspect of the elbow with significant soft tissue swelling. Neurologic examination should in particular evaluate the PIN, which can be affected by fractures of the proximal radius.
In a young child, the primary complaint may be wrist pain, and pressure over the proximal radius may accentuate this referred wrist pain.2 The wrist pain may be secondary to radial shortening and subsequent distal radioulnar joint dysfunction. The misdirection of such a presentation reinforces the principle of obtaining radiographs of both ends of a fractured long bone and complete examination of the entire affected extremity.
Imaging and Other Diagnostic Studies for Fractures of the Proximal Radius
Displaced proximal radius fractures are usually easy to identify on standard anteroposterior (AP) and lateral radiographs. Some variants in the ossification process can resemble a fracture. Most of these involve the radial head, although a step-off also can develop as a normal variant of the metaphysis. There may be a persistence of the secondary ossification centers of the epiphysis. Comparison views of the contralateral elbow are useful for evaluation of unusual ossification centers after an acute elbow injury.
If the elbow cannot be extended because of pain, special views are necessary to see the AP alignment of the proximal forearm and distal humerus. A regular AP view with the elbow flexed may not show the fracture because of obliquity of the beam. One view is taken with the beam perpendicular to the distal humerus, and the other with the beam perpendicular to the proximal radius. The perpendicular views show the proximal radial physis in clear profile.
With a minimally displaced fracture, the fracture line may be difficult to see because it is superimposed on the proximal ulna, and oblique views of the proximal radius may be helpful.10,117 One oblique view that is especially helpful is the radiocapitellar view suggested by Greenspan et al.37,38 and Hall-Craggs et al.39 This view projects the radial head anterior to the coronoid process (Fig. 13-3) and is especially helpful if full supination and pronation views are difficult to obtain because of acute injury (Fig. 13-4).
The diagnosis of a partially or completely displaced fracture of the radial neck may be difficult in children whose radial head remains unossified.88 The only clue may be a little irregularity in the smoothness of the proximal metaphyseal margin (Fig. 13-5). The full extent of the injury was appreciated only by magnetic resonance imaging (MRI). Displacement of the supinator fat pad may also indicate fracture of the proximal radius90; however, this fat pad and the distal humeral anterior and posterior fat pads are not always displaced with occult fractures of the radial neck or physis.41,93,95 Arthrogram, ultrasound, or MRI are helpful to assess the extent of the displacement and the accuracy of reduction in children with an unossified radial epiphysis (Fig. 13-6).17,42,51
In the preossification stage, on the AP radiograph, the edge of the metaphysis of the proximal radius slopes distally on its lateral border. This angulation is normal and not a fracture. In the AP view, the lateral angulation varies from 0 to 15 degrees, with the average being 12.5 degrees.113 In the lateral view, the angulation can vary from 10 degrees anterior to 5 degrees posterior, with the average being 3.5 degrees anterior.10
Recently described posterior radiocapitellar subluxation following what appeared to be fairly innocuous radial head fractures have been attributed to undiagnosed ligamentous injury associated with the fracture. Kasser includes this in lesions he describes as “The radiographic appearance seemed harmless (TRASH).”119 MRI provides excellent anatomic detail of the elbow joint and should be considered when evaluating displaced radial head fractures, particularly if change in position is noted on serial radiographs.
Classification of Fractures of the Proximal Radius
Chambers Classification of Proximal Radial Fractures
TABLE 13-2 Classification of Fractures Involving the Proximal Radius
• Group I: The radial head is primarily displaced (most common type)
• Group II: The radial neck is primarily displaced
Head-Displaced Fractures (Group I). With valgus elbow injuries, the fracture pattern can be one of three types (A, B, or C) (Fig. 13-7). In the first two types, the fracture line involves the physis. Type A represents either a Salter–Harris type I or II physeal injury. In a Salter–Harris type II injury, the metaphyseal fragment is triangular and lies on the compression side. In type B fractures, the fracture line courses vertically through the metaphysis, physis, and epiphysis to produce a Salter–Harris type IV fracture pattern (Fig. 13-7). This is the only fracture type that involves the articular surface of the radial head. In type C fractures, the fracture line lies completely within the metaphysis (Fig. 13-8), and the fracture can be transverse or oblique. Type B fractures, intra-articular radial head fractures, are rare. These can have poor long-term results if posterior radiocapitellar subluxation develops (Fig. 13-9).114,119 The incidences of types A and C fractures are approximately equal.102
In two rare types of fractures of the radial neck associated with elbow dislocation, the head fragment is totally displaced from the neck.5,12,29,43,68,118 Fractures occurring during spontaneous reduction of elbow dislocation generally drive the radial head dorsal as the capitellum applies a dorsally directed force to the radial neck during reduction (type D) (Fig. 13-2A).43,118 Fractures occurring during the dislocation event generally drive the radial head volar as the capitellum applies a volarly direct force during the process of dislocating (type E) (Fig. 13-2B).5,68,113 Even with spontaneous or manipulative elbow reduction the radial head fragment will usually remain volar to the radial shaft with the fractured radial neck articulating with the capitellum.
Regardless of the type of fracture pattern, displacement can vary from minimal angulation to complete separation of the radial head from the neck (Fig. 13-10). With minimal angulation, the congruity of the proximal radioulnar joint is usually retained. If the radial head is displaced in relation to the radial neck, the congruity of the proximal radioulnar joint is lost. Completely displaced fractures are often associated with more severe injuries.
Neck-Displaced Fractures (Group II). Rarely, angular or torsional forces cause a primary disruption or deformity of the neck while the head remains congruous within the proximal radioulnar joint. Treatment of these fractures is manipulation of the distal neck fragment to align it with the head. For the neck-displaced fractures, there are two subgroups: Angular and torsional.
An angular fracture of the radial neck may be associated with a proximal ulnar fracture. This association is recognized as a Monteggia variant. A Monteggia type III fracture pattern is created when a varus force is applied across the extended elbow, resulting in a greenstick fracture of the olecranon or proximal ulna and a lateral dislocation of the radial head.124 Occasionally, however, the failure occurs at the radial neck (Monteggia III equivalent) and the radial neck displaces laterally, leaving the radial head and proximal neck fragment in anatomic position under the annular ligament (Fig. 13-11).70
Rotational forces may fracture the radial neck in young children before ossification of the proximal radial epiphysis. This has been described only in case reports with a supination force.33,40 Reduction was achieved by pronation of the forearm. Diagnosis of these injuries is difficult and may require arthrography or an examination under general anesthesia. This injury should be differentiated from the more common subluxation of the radial head (“nursemaids elbow”), in which the forearm usually is held in pronation with resistance to supination.
Stress Injuries (Group III). A final mechanism of injury is chronic repetitive stress, both longitudinal and rotational, on either the head or the proximal radial physis. These injuries are usually the result of athletic activity in which the upper extremity is required to perform repetitive motions. Repetitive stresses disrupt growth of either the neck or the head with eventual deformity. A true stress fracture is not present.
In the United States, the popularity of organized sports has produced a number of unique injuries in children related to repetitive stress applied to growth centers. Most elbow stress injuries are related to throwing sports such as baseball. Most of this “Little League” pathology involves tension injuries on the medial epicondyle. In some athletes, however, the lateral side is involved as well because of the repetitive compressive forces applied to the capitellum and radial head and neck. Athletes involved in sports requiring upper extremity weight bearing, such as gymnastics or wrestling, are also at risk. In the radial head, lytic lesions similar to osteochondritis dissecans may occur (Figs. 13-12 and 13-13).24,110,123 Chronic compressive loading may cause an osteochondrosis of the proximal radial epiphysis, with radiographic signs of decreased size of the ossified epiphysis, increased radiographic opacity, and later fragmentation. If the stress forces are transmitted to the radial neck, the anterior portion of the physis may be injured, producing an angular deformity of the radial neck (Fig. 13-3).25
Judet Classification of Radial Neck Fractures
Radial neck fractures, the most common type of proximal radius fracture, (Group IA and IC) have also been classified based on angulation by Judet (Table 13-3).59 Increasing grade has generally been associated with poorer outcomes with both nonoperative and operative care as discussed in the section on treatment outcomes.
TABLE 13-3 Judet Classification of Radial Neck Fractures
Outcome Measures for Fractures of the Proximal Radius
Most previously published literature on the outcomes of pediatric proximal radius fractures have used nonvalidated functional outcome measures. Various iterations of “excellent,” “good,” “fair,” and “poor” with individualized descriptions have been utilized. The growing emphasis in orthopedics on critical functional assessments following injury or surgery should improve the quality of future evidence on this topic. It is hoped that validated functional measures for upper extremity function and global pediatric and adolescent function be utilized in future research efforts in this area.
Range of motion following treatment of proximal radius fractures is a critical component of outcome. Usually assessments have been done manually using a goniometer. The wider availability of digital motion capture technology will hopefully provide more accurate measures of range of motion following extremity trauma in future studies.
PATHOANATOMY AND APPLIED ANATOMY RELATING TO FRACTURES OF THE PROXIMAL RADIUS
In the embryo, the proximal radius is well defined by 9 weeks of gestation. By 4 years of age, the radial head and neck have the same contours as in an adult.69 Ossification of the proximal radius epiphysis begins at approximately 5 years of age as a small, flat nucleus (Fig. 13-14). This ossific nucleus can originate as a small sphere or it can be bipartite, which is a normal variation and should not be misinterpreted as a fracture.10,58,95
No ligaments attach directly to the radial neck or head. The radial collateral ligaments attach to the annular ligament, which originates from the radial side of the ulna. The articular capsule attaches to the proximal third of the neck. Distally, the capsule protrudes from under the annular ligament to form a pouch (recessus sacciformis). Thus, only a small portion of the neck lies within the articular capsule.117 Because much of the neck is extracapsular, fractures involving only the neck may not produce an intra-articular effusion, and the fat pad sign may be negative with fracture of the radial neck.10,41,95
The proximal radioulnar joint has a precise congruence. The axis of rotation of the proximal radius is a line through the center of the radial head and neck. When a displaced fracture disrupts the alignment of the radial head on the center of the radial neck, the arc of rotation changes. Instead of rotating smoothly in a pure circle, the radial head rotates with a “cam” effect. This disruption of the congruity of the proximal radioulnar joint (as occurs with displaced fractures of the proximal radius) may result in a loss of the range of motion in supination and pronation (Fig. 13-15).121
Table 13-4 lists the proposed mechanisms for fractures of the radial head and neck in children.
TABLE 13-4 Fractures of the Radial Head and Neck. Proposed Mechanisms in Children
TREATMENT OPTIONS FOR FRACTURES OF THE PROXIMAL RADIUS
Nonoperative Treatment of Fractures of the Proximal Radius
Nonoperative treatment is indicated for the majority of proximal radius fractures. A great deal of remodeling of the proximal radius can be expected in skeletally immature children. Based on multiple retrospective case series, radial neck angulation of 30 to 45 degrees generally remodels and conservative treatment will lead to good results.22,66,68,102,113 It is critical to assess forearm rotation, and if a block to full rotation is appreciated operative treatment should be considered. Intra-articular aspiration of hematoma and injection of local anesthetic can assist with pain relief and assessment of range of motion.
In the case of nondisplaced radial head fractures (Salter–Harris IV, Group 1B in the Chambers classification) close follow-up with serial radiographs is warranted to monitor radiocapitellar alignment. If subluxation is suspected, advanced imaging with ultrasound or MRI along with consideration of operative treatment should be considered.
Closed reduction techniques should be attempted if there is displacement or unacceptable angulation at the fracture site. The goal should be to restore the alignment to accepted indications below with full forearm rotation. Internal fixation is usually not necessary if successful closed reduction can be accomplished.
Patients not requiring closed reduction should be immobilized for comfort for a short period of time to allow for comfort and soft tissue healing. This is generally 1 to 3 weeks based on extent of injury and age. After fracture pain has subsided patients should work on progressively increasing range of motion and resumption of activities as symptoms allow. Immobilization can be accomplished with a sling, posterior arm splint, or long-arm cast based on surgeon and patient preference (Table 13-5).
TABLE 13-5 Proximal Radius Fractures: Nonoperative Treatment
Closed Reduction Techniques
Several closed reduction techniques for proximal radius fractures have been described in the literature. All have generally good reported results and the surgeon should be familiar with multiple techniques and apply them as needed because closed treatment of proximal radius fractures generally has been shown to have improved results compared to open treatment. No technique has been demonstrated to have superiority over another. Techniques are variations on either manipulating the proximal fragment to the fixed radial shaft or manipulating the radial shaft to the fixed proximal fragment.
Patterson74 described a reduction technique for the radial neck in 1934. Conscious sedation or general anesthesia is recommended in children to allow for adequate relaxation for the procedure. The annular ligament should be intact to stabilize the proximal radial head fragment.58 An assistant grasps the arm proximal to the elbow joint with one hand (Fig. 13-16) and places the other hand medially over the distal humerus to provide a medial fulcrum for the varus stress applied across the elbow. The surgeon applies distal traction with the forearm supinated to relax the supinators and biceps. A varus force is then placed on the elbow with added direct lateral pressure on the radial head in an attempt to reduce the fracture. Kaufman et al.45 proposed another technique in which the elbow is manipulated in the flexed position. The surgeon presses his or her thumb against the anterior surface of the radial head with the forearm in pronation.
Although forearm supination relaxes the supinator muscle, supination may not be the best position for manipulation of the head fragment. Jeffrey43 pointed out that the tilt of the radial head depends on the position of the forearm at the time of injury. The direction of maximal tilt can be confirmed by radiograph and is also when fracture deformity will be most palpable clinically. The best position for reduction is the degree of rotation that places the radial head most prominent laterally. If the x-ray beam is perpendicular to the head in maximal tilt, it casts an oblong or rectangular shadow; if not, the shadow is oval or almost circular.43 With a varus force applied across the extended elbow, the maximal tilt directed laterally, and the elbow in varus, the radial head can be reduced with the pressure of a finger (Fig. 13-16, right). An alternative technique with the elbow in extension was described by Neher and Torch. An assistant uses both thumbs to place a laterally directed force on the proximal radial shaft while the surgeon applies a varus stress to the elbow. Simultaneously, the surgeon uses his other thumb to apply a reduction force directly to the radial head (Fig. 13-17).65
The Israeli technique involves stabilization of the proximal fragment with the thumb anteriorly while rotating the forearm into full pronation to reduce the shaft to the proximal fragment.45 The elbow should be flexed to 90 degrees for the manipulation (Figs. 13-18 and 13-19). Another technique emphasizing reduction of the shaft to the proximal fragment was recently described by Monson. After adequate sedation or anesthesia the elbow is flexed to 90 degrees and forearm fully supinated. The proximal radial fragment should be stabilized in place by the annular ligament. A directly applied force to the radial shaft is applied to reduce the shaft to the head (Figs. 13-20 and 13-21). Initial experience with this technique in six children has been reported with excellent results and no need for additional procedures.61
Lastly, use of an Esmarch bandage wrap as is done for limb exsanguination prior to tourniquet use in extremity surgery has been described to serendipitously promote fracture reduction (Fig. 13-22).15 This can be utilized as an easy adjunct in nearly all of the described closed reduction techniques.
Regardless of the technique chosen alignment should be assessed by fluoroscopy. Radial neck angulation should be reduced to less than 45 degrees in children under 10 years of age and less than 30 degrees in children greater than 10 years of age. The radiocapitellar joint should be congruent. The elbow joint must be stable to stress. Immobilization for a short duration is recommended for pain control and soft tissue healing. Early range of motion should be encouraged once the acute pain has resolved, generally within 1 to 3 weeks.
Operative Treatment of Fractures of the Proximal Radius
Surgical treatment is indicated in situations where acceptable alignment cannot be achieved with closed means, or if there is persistent elbow instability or restricted range of motion after closed treatment. Most fractures of the proximal radius present to the surgeon with minimal deformity and do not require treatment other than a short period of immobilization. Operative treatment should be considered when displacement remains over 2 mm, angulation is greater than 45 degrees (age < 10) or greater than 30 degrees (age < 10), and for open injuries. Nerve palsy is generally not an indication for surgery because most will recover function over time.
Instrument-Assisted Closed Reduction
Preoperative Planning (Table 13-6)
TABLE 13-6 Instrument-Assisted Closed Reduction of Proximal Radius Fractures
Positioning. The patient should be positioned supine on the operating table with a radiolucent hand table attached to the operating bed. The affected extremity should be placed directly in the middle of the hand table. The entire operating table should be rotated 90 degrees from standard position to place the injure extremity opposite the anesthesiologist. Fluoroscopy will be brought in directly in line with the injured extremity with surgeon and assistant on either side of the hand table (Fig. 13-23). The patient should be brought to the lateral edge of the bed and head secured to the operating room table. We suggest a towel or blanket draped over the head surrounded by strong tape from one edge of the table to the other (Fig. 13-24). This is especially important for small patients to allow for the fluoroscopy unit to be able to image the area of interest and not be blocked by the table. Torso should be secured to the table with a safety strap. A nonsterile tourniquet should be applied to the humerus. Surgeons may be standing or seated per their preference.
Surgical Approach. Percutaneous direct lateral approach is utilized as described in the technique below to minimize risk of injury to the PIN.
Technique. Simple steel K-wires generally are appropriate to assist with closed reduction. Size will range from 2 to 2.7 mm based on the size of the child. Other instruments utilized include Steinmann pins, periosteal elevators, or a double-pointed bident.3,30,87 Fluoroscopy is used to localize the fracture site and intended entry site of the wire. This should be along the direct lateral cortex of the radial shaft to decrease risk of injury to the PIN. Pronating the forearm further moves the PIN away from the surgical field. Skin is incised with a small stab wound and a small curved clamp is utilized to bluntly dissect through the muscle to the radial cortex. The sharp end of the wire is cut for surgeon safety and the blunt end is inserted down to the radial cortex. Fluoroscopic guidance is used to localize the fracture site and the blunt end of the wire can be used to push the distal fracture fragment back into an appropriate position (Fig. 13-25). Arthrography can be helpful to assess congruency of the elbow joint. (Dormans 1994)19 Once the fracture is reduced to within appropriate guidelines the pin is removed and stability and range of motion are assessed. If the fracture remains stable through a normal arc of motion no internal fixation is needed.7,68,121 If instability is noted then internal fixation can be placed. Small antegrade K-wires can be placed percutaneously to transfix the fracture.20,28,44 (Fig. 13-26). Pins should stay lateral to minimize injury to the PIN. Pins traversing the capitellum into the proximal radius should be avoided because they have a high rate of migration and/or pin breakage.28,68,93,121 Various iterations of this technique have been described in the literature.3,6,20,76,101
Alternatively, the sharp end of the wire can be retained and introduced to the fracture site and the wire used as a lever to correct angulation.14 Once corrected, the pin can be driven from proximal to distal across the radial cortex and serve as a buttress against recurrent angulation of the distal fragment. In this instance, the wire is introduced through the skin closer to the fracture site than in the prior described technique to prevent soft tissue from blocking appropriate leverage of the distal fracture fragment. The pin is cut short but left out of the skin and underneath postoperative immobilization. It may be removed in 1 to 3 weeks when the surgeon is comfortable allowing range of motion at the elbow (Fig. 13-27).
A modification described by Wallace utilizes an instrument to provide counterforce on the radial shaft. Fluoroscopy in an AP projection is used to determine the forearm rotation that exposes the maximum amount of deformity of the fracture, and the level of the bicipital tuberosity of the proximal radius is marked. A 1-cm dorsal skin incision is made at that level just lateral to the subcutaneous border of the ulna. A periosteal elevator is gently inserted between the ulna and the radius, with care not to disrupt the periosteum of the radius or the ulna. The radial shaft is usually much more ulnarly displaced than expected, and the radial nerve is lateral to the radius at this level. While counterpressure is applied against the radial head, the distal fragment of the radius is levered away from the ulna. An assistant can aid in this maneuver by gently applying traction and rotating the forearm back and forth to disengage the fracture fragments. The proximal radial fragment can be reduced either manually with thumb pressure or assisted by a percutaneous instrument as described (Table 13-7, Figs. 13-28 and 13-29).
TABLE 13-7 Instrument-Assisted Closed Reduction of Proximal Radius Fractures
Intramedullary Nail Reduction/Fixation
Preoperative Planning. Implant size should be estimated prior to surgery. The technique was initially described using K-wires which are readily available and inexpensive. Some prefer using titanium flexible nails that also work well but are more costly. The isthmus of the radius should be measured on both AP and lateral views and implant size should be chosen to easily pass. Generally an implant 60% to 70% of the width of the isthmus will pass without too much difficulty. In adolescents this will usually be a 2- or 2.4-mm K-wires. It is advised to have one size larger and smaller than planned available if needed (Table 13-8).
TABLE 13-8 Intramedullary Nail Reduction/Fixation of Proximal Radius Fractures
Positioning. Same as for instrument-assisted closed reduction.
Surgical Approach(es). The implant is inserted at the distal radius via a radial entry. The distal radial physis should be localized with fluoroscopy. A direct lateral incision of 1 to 2 cm is made just proximal to the physis of the distal radius. Careful scissor dissection to the lateral radial cortex is made with care taken not to injure the superficial radial nerve. It is not required to search for the nerve, however, if encountered it should be gently retracted. Extensor tendons from the first dorsal compartment may also be encountered and should be retracted.
Alternatively, the implant may be inserted via a direct dorsal approach over the dorsal tubercle of the radius. Either longitudinal or transverse incisions may be utilized. Extensor tendons will be encountered and should be protected during opening of the radial cortex at the dorsal tubercle.
Technique. Intramedullary reduction and fixation of proximal radius fractures was described by Metaizeau in 1980.60 After selection of an appropriate-sized implant (K-wire or titanium flexible nail) the distal 3 to 4 mm of the implant should be bent sharply about 40 degrees. Either a dorsal or radial approach can be utilized at the entry site of the distal radius. The wire is advanced through the radial canal to the fracture site. If necessary, closed maneuvers should be used to improve alignment at the fracture site to allow for successful passage of the distal tip of the implant into the proximal fragment. The implant should be impacted into the epiphysis to achieve maximal fixation prior to reduction attempts with the implant. Once advanced appropriately, the nail should be rotated 90 to 180 degrees as needed to reduce the proximal fragment. The forearm should be held by the assistant to prevent the radial shaft from rotating with the implant (Fig. 13-30). Stability at the elbow joint and range of motion are assessed. The implant should be cut distally balancing need for ease of recovery during implant removal with soft tissue irritation from implant prominence at the distal radius. Rigid immobilization is not necessary with use of an intramedullary implant; however, most surgeons will immobilize the extremity in a long-arm splint or cast for 7 to 10 days for pain relief and to allow for soft tissue healing. Early range of motion is encouraged to minimize postoperative stiffness (Table 13-9).
TABLE 13-9 Intramedullary Nail Reduction/Fixation of Proximal Radius Fractures
Open Reduction Internal Fixation
Preoperative Planning. Appropriate implants should be available if rigid internal fixation is planned. These may include mini fragment screws, mini-fragment plates, or specialty proximal radius plates. Small fragment screws and plates are too large for fixation of the proximal radius. Specialty plates are produced by numerous manufacturers, but are designed for adult patients. Many will be too large for children and young adolescents, however, they may fit appropriately in the older adolescent (Table 13-10).
TABLE 13-10 Open Reduction Internal Fixation of Proximal Radius Fractures
Positioning. Same as for instrument-assisted closed reduction.
Surgical Approach(es). A lateral approach to the proximal radius should be utilized for open reduction of proximal radius fractures. The lateral Kocher approach provides appropriate exposure. Dissection should occur between the anconeus and extensor carpi ulnaris. Usually the interval is easier to identify distally and can be traced back proximally. The muscle fibers will be seen to run in divergent directions distally which assist with location of the interval. Often the annular ligament will be traumatically disrupted and also the joint capsule will be disrupted. Care should be taken to stay superior to the lateral collateral ligament of the elbow to prevent adding iatrogenic instability. Distally the supinator may be released if needed for plate application.
When exposing the proximal radius the forearm should be kept in a pronated position to move the PIN further away from the surgical field. Vigorous retraction should be avoided anteriorly to limit traction on the PIN.
Technique. After adequate exposure of the fracture site the anatomy of the fracture should be evaluated. Radial neck fractures are more common and can be reduced using manual pressure or instrumented manipulation. Often a dental pick is useful to hold a reduced position after manual reduction. The fracture can be either definitively or provisionally fixed at this point with small K-wires. Radial head fractures are usually more complex and may have multiple fragments. Attempts should be made to reduce the radial head in children and adolescents with use of small pins or bone clamps to hold provisional reduction. Radial head excision is generally a salvage operation but can be considered as a primary treatment if there is extensive comminution prohibiting reconstruction. Results have been uniformly poor after excision with high incidence of cubitus valgus and radial deviation at the wrist.21,40,44 Radial head replacement has not been described for children or adolescents but is increasingly utilized for adults.
When proceeding with open reduction, most surgeons elect to place more rigid fixation to allow for early range of motion. Screw fixation with minifragment screws or small headless screws provides stable fixation of radial head and neck fractures (Figs. 13-31 and 13-32).97 Plates have been utilized for fixation of radial neck fractures requiring open reduction (Fig. 13-33). They should be placed in the “safe zone” of the proximal radius. This is an area of about 100 to 110 degrees of the circumference of the proximal radius that does not articulate with the proximal ulna during forearm rotation. With the forearm in 10 degrees of supination the “safe zone” is directly lateral.99 (JOT 1998 12:291-293)100 Screws should be kept unicortical to prevent perforation into the proximal radioulnar joint. Plate application requires more extensive dissection than isolated screw fixation and has led some authors to strongly advocate for multiple screw fixation alone for radial head and neck fractures. There is no good quality evidence supporting one form of internal fixation over another in the treatment of fractures of the proximal radius.