I. Radial Head Fractures
A. Epidemiology/overview
1. Approximately 20% of all elbow fractures involve the radial head.
2. Radial head fractures are often associated with more complex injuries, including associated elbow fractures and soft-tissue injuries.
3. The radial head is increasingly recognized as an important secondary stabilizer of the elbow; therefore, radial head excision alone is contraindicated in clinical settings where there is extensive damage to the primary stabilizers.
B. Pathoanatomy
1. Radial head fractures typically result from a fall on an outstretched hand with the forearm in pronation, which results in an axial load on the elbow.
2. 30% of patients with radial head fractures have other soft-tissue and skeletal injuries, including carpal fractures, distal radioulnar joint (DRUJ) and interosseous membrane disruption, coronoid fractures, Monteggia fracture-dislocations, capitellar fractures, and medial and lateral collateral ligament injuries.
C. Evaluation
1. History
a. Fractures of the radial head typically occur following a fall on the outstretched hand.
b. Question the patient carefully about concomitant wrist, forearm, or shoulder pain (eg, wrist pain may indicate an Essex-Lopresti lesion [DRUJ injury with radial head fracture]).
2. Physical examination
a. Lateral elbow pain and tenderness or limitation in elbow or forearm motion should alert the examiner to the possibility of a radial head fracture.
Michael David McKee, MD, FRCSC, or the department with which he is affiliated has received research or institutional support from Zimmer and Stryker Biotech.
b. Examine the forearm and elbow for tenderness along the course of the interosseous membrane (Essex-Lopresti lesion), instability of the DRUJ, pain at the medial side of the elbow (medial collateral ligament), and a block to rotation or flexion/extension.
3. Imaging
a. AP and lateral radiographs of the elbow are routine.
b. Nondisplaced fractures of the radial head may be diagnosed by elevation of the anterior and posterior fat pads (the so-called "sail sign") by an intra-articular hemarthrosis.
c. The radiocapitellar view is accomplished by positioning the patient as for a lateral view but angling the tube 45° toward the shoulder.
d. For comminuted fractures, CT can delineate the location, number, and size of the fragments.
4. Joint aspiration—Aspiration of the intra-articular hematoma and injection of a local anesthetic can be helpful when assessing mechanical blocks to motion.
D. Classification—Mason classification of radial head fractures (
Table 1)
[Table 1. Mason Classification of Radial Head Fractures]
[
Figure 1. Radiographs of a Monteggia variant injury in a 37-year-old patient following a fall. A, AP view of an angulated fracture of the proximal ulna with a comminuted posterolateral fracture-dislocation of the radial head. AP (B) and lateral (C) radiographs following open reduction and internal fixation of the ulnar shaft, radial head replacement with a modular, metallic prosthesis, and repair of the lateral collateral ligament with suture anchors in the lateral column.]
E. Treatment
1. Nonsurgical—Most minimally displaced (<3 mm) radial head fractures can be treated nonsurgically with a brief period of immobilization (7 to 10 days maximum) in a sling or posterior splint for pain relief followed by early range-of-motion exercises.
2. Surgical—Radial head fractures that are significantly displaced, block motion (especially rotation), or are part of more complicated injury patterns are candidates for surgical repair.
3. Surgical procedures
a. Open reduction and internal fixation options
i. Screws
ii. Plates (safe zone)
iii. Herbert screws
b. Radial head replacement for severe fractures
F. The "terrible triad" of the elbow
1. The terrible triad is defined as a posterior elbow dislocation associated with radial head fracture, coronoid process fracture, and lateral collateral ligament tear.
2. Stability is achieved through open reduction and internal fixation of the coronoid fracture and/or repair of the anterior capsule, fixation or replacement of the radial head, and repair of the lateral collateral ligament complex.
G. Complications of radial head fractures
1. Fracture displacement occurs in less than 5% of cases.
2. Infection
3. Loss of fixation
4. Stiffness (especially forearm rotation)
5. Radiocapitellar arthritis
H. Pearls and pitfalls
1. Isolated fractures do best with early mobilization, not prolonged casting.
2. Radial head fractures with three or more fragments (Figure 1) have a higher incidence of unsatisfactory results with fixation. Consider replacement, rather than fixation, for such fractures.
3. Radial head excision alone is contraindicated in the presence of other destabilizing injuries.
4. Hardware should be applied to the safe zone, the part of the radial head that does not articulate with the proximal ulna. This is the arc between lines drawn through the radial styloid and Lister's tubercle (
Figure 2).
I. Rehabilitation—Immobilization for 7 to 10 days in a posterior splint followed by early range-of-motion exercises is recommended for nonsurgically treated stable fractures as well as surgically treated fractures.
II. Olecranon Fractures
A. Epidemiology/overview
1. The olecranon and the coronoid process form the greater sigmoid notch, which articulates with the
[Figure 2. AP (A) and lateral (B) radiographs of a comminuted, displaced, intra-articular radial head and neck fracture in an active 32-year-old woman. The patient had minimal painful forearm rotation preoperatively. C, Intraoperative photograph following countersunk screw fixation of the head fracture and initial lag screw fixation of the neck fracture. The fixation was placed in the "safe zone," the nonarticular portion of the neck, in an arc subtended by lines through the radial styloid and Lister's tubercle. A mini-fragment plate was subsequently applied. D, Postoperative AP radiograph.]
trochlea of the distal humerus. The intrinsic anatomy of this articulation allows for flexion/extension movement of the elbow joint and provides for stability of the elbow.
2. The olecranon also serves as the insertion for the triceps tendon, which blends with the periosteum of the proximal ulna.
3. The exposed position of the olecranon renders it vulnerable to both direct trauma and violent muscular contractions (from the triceps).
B. Pathoanatomy
1. Olecranon fractures can result from several different mechanisms, including a direct blow, a fall on an outstretched hand with the elbow in flexion, or high-energy trauma that is associated with radial head fractures or elbow dislocation.
2. Sudden and violent triceps muscle contraction can produce an avulsion fracture of varying size of the olecranon tip.
C. Evaluation
1. History
a. The history may be helpful in distinguishing a triceps avulsion from an actual direct blow to the elbow.
b. Pain is usually localized to the posterior part of the elbow.
2. Physical examination
a. Given the subcutaneous location of the olecranon, the fracture itself may be palpable.
b. Extensive posterior swelling is typical.
c. A careful examination of the integrity of the extensor mechanism (with gravity eliminated) can aid surgical decision making.
d. If present, open wounds are typically posterior and result from direct impact of the posterior
[
Table 2. Colton Classification of Olecranon Fractures]
surface of the elbow against an unyielding structure.
3. Imaging
a. Plain radiographs are usually sufficient for isolated fractures of the olecranon.
b. A true lateral radiograph is necessary to accurately identify the plane of the fracture and the number of fracture fragments.
D. Classification—Table 2 lists the Colton classification of olecranon fractures.
E. Treatment
1. Goals—The goals of treatment of olecranon fractures include articular restoration, preservation of the extensor mechanism, elbow stability, avoidance of stiffness, and minimizing complications.
2. Nonsurgical—Nondisplaced fractures (Colton type I), although uncommon, can be effectively treated by immobilization of the limb in a long-arm splint or cast with the elbow flexed at 90° for 4 weeks.
3. Surgical
a. Displaced fractures (Colton type II and its subtypes) require surgical fixation in healthy, active patients to preserve the strength of the extensor mechanism and to maintain intraarticular incongruity.
b. Contraindications include active infection and severe medical comorbidities.
4. Surgical procedures
a. Tension band wiring technique over two Kirschner wires
i. Indications—Isolated, noncomminuted fractures that are not associated with ligamentous instability. It is important that there be minimal comminution and no elbow instability present when using this technique.
[
Figure 3. Lateral radiograph of the elbow of a 42-year-old man who sustained an early, recurrent posterior subluxation of the elbow following attempted fixation of a proximal ulnar fracture using a tension band technique. The coronoid fragment has not been stabilized and the associated fracture of the radial head has not been addressed.]
ii. The tension band wiring technique does not resist angular forces or effectively stabilize complex fracture patterns.
iii. Contraindications—Tension band wiring is contraindicated for comminuted fractures of the proximal ulna (Figure 3), especially those that have associated elbow instability. It cannot reliably hold comminuted fragments and is unable to withstand the increased bending and rotational forces seen in this situation.
iv. Insertion of Kirschner wires into the anterior cortex of the ulna distal to the fracture line enhances fixation strength and may help prevent backing out.
b. Contoured plate application to the posterior aspect of the proximal ulna (
Figure 4)
i. Contoured plate application is the preferred fixation method if comminution or associated ligamentous injury with instability is present.
ii. The terminal aspect of the triceps insertion can be elevated and then repaired following plate application to minimize prominence.
c. Fragment excision and triceps reattachment
i. May be beneficial for elderly (older than age 70 years), low-demand patients whose bones are so osteoporotic as to compromise fixation
ii. This procedure cannot be performed if there is associated ligamentous instability.
5. Complications
a. Loss of motion, typically terminal extension
b. Loss of reduction is rare.
[Figure 4. Preoperative and postoperative radiographs of the elbow of a 17-year-old boy who sustained an elbow dislocation associated with olecranon (black arrow), coronoid (white arrowhead), and radial head (white arrow) fractures. A, Preoperative lateral view. B, Lateral view following open reduction and internal fixation of the radial head fragment with a single countersunk Herbert screw, plate fixation of the ulna, and repair of the lateral collateral ligament through drill holes in the lateral column. A concentric reduction of both the radiocapitellar and ulnohumeral joints was achieved, with sufficient stability to initiate immediate motion, enhancing the functional result.]
c. Nonunion is rare, but malunion (especially of unreduced, impacted articular fragments) may lead to posttraumatic arthritic change and stiffness.
6. Pearls and pitfalls—The tension band technique should be used only for noncomminuted transverse fractures that are proximal to the base of the coracoid.
7. Rehabilitation
a. Nonsurgically treated fractures that are minimally displaced with an intact extensor mechanism can be treated in a long-arm splint with radiographic monitoring and mobilized at 4 weeks.
b. Surgically treated fractures are splinted for up to 1 week for pain control and to allow swelling to subside.
i. Active and gentle passive motion is then instituted, but resisted extension is specifically restricted until clinical and radiographic evidence of fracture healing is apparent (usually 6 weeks).
ii. Older patients who typically use forceful elbow extension to rise from a chair or a toilet should be advised to avoid this activity until fracture union occurs.
III. Proximal Ulnar Fractures
A. Epidemiology/overview
1. Although they may seem complex, proximal ulnar fractures tend to fall into one of three basic injury patterns.
a. Monteggia fractures and variants
b. Simple olecranon fractures (see section II, Olecranon Fractures)
c. Olecranon fracture-dislocations
2. Most of these injuries require surgical intervention.
3. Posterior fracture-dislocations of the proximal ulna are associated with a high incidence of radial head fractures and lateral collateral ligament injuries.
B. Pathoanatomy
1. A fall directly on the elbow can produce a transolecranon fracture-dislocation as the distal humerus acts as a pile driver and drives through the trochlear notch of the ulna.
2. A fall on an outstretched hand results in a posteriorly directed force vector to the elbow and can produce a posterior fracture-dislocation or a (posterior) Monteggia fracture.
C. Evaluation
1. History
a. The history should include a clarification of the exact mechanism of injury, any sensation of dislocation with spontaneous reduction, and any associated upper extremity pain or discomfort.
b. Any reports of wrist and/or forearm pain should alert the treating surgeon to the possibility of a more complex injury pattern.
2. Physical examination
|
a. |
The elbow is typically swollen, especially posteriorly. |
[
Table 3. Bado Classification of Monteggia Fractures]
|
b. |
If present, open wounds are usually posterior or posterolateral. |
|
c. |
A careful neurologic examination, especially of the ulnar nerve, should be performed. |
|
d. |
The wrist should be examined to determine if there is any evidence of a distal radioulnar injury (the so-called "bipolar forearm injury"). If there is gross malalignment, a gentle closed reduction and splinting can be performed before radiographs are obtained. |
3. Imaging
a. Radiographs
i. Plain radiographs are the mainstay of imaging; they usually show the general injury pattern.
ii. Repeat radiographs obtained after a gentle reduction and splinting can provide more detailed information. It is important to look for associated bony injuries in this situation; radial head fractures, coronoid fragments, and collateral ligament avulsions are common.
b. CT may be helpful in defining the size and location of fracture fragments and in confirming associated injuries.
D. Classification—The Bado classification defines four types of Monteggia fractures according to the direction of displacement of the radial head and other characteristics (Table 3).
E. Treatment
1. Nonsurgical—Stable, noncomminuted fractures of the proximal ulna that are not associated with other injuries about the elbow can be treated nonsurgically. However, this injury pattern is relatively rare; most require surgical intervention.
2. Surgical
a. Complex proximal ulnar fractures often contain a significant coronoid fragment, which is typically triangular and involves 50% to 100% of the coronoid process. This fragment is important for recreating the anterior buttress of the greater sigmoid notch of the proximal ulna.
b. Coronoid reduction and fixation is a critical component of elbow stability.
c. Once the main proximal-distal fragment fracture line of the ulna is reduced, visualization (and repair) of the coronoid becomes difficult. Thus, it is important to fix the coronoid fragment (usually with lag screws) to the distal ulnar fragment before reducing the primary ulnar fracture line.
d. Fixation of the proximal ulnar fracture should be performed with a small fragment compression plate contoured to project proximally around the tip of the olecranon.
e. A similar approach is used for Monteggia fracture patterns: open reduction and internal fixation of the ulna with a 3.5-mm compression plate through a posterior approach.
f. Ulnar fracture malreduction is the usual cause of any residual subluxation or dislocation of the radiocapitellar joint.
g. Contraindications include active infection and medical comorbidities.
F. Complications
1. The complication rate for fractures of the proximal ulna is reported to be quite high.
2. Simple fractures tend to heal well, but the treatment of complex fractures has been hampered by a poor understanding of injury patterns and deforming forces, inadequate fixation, and prolonged immobilization of tenuously repaired fractures (see Figure 3).
3. The risk of proximal radioulnar synostosis is increased by multiple surgeries, extensive soft-tissue damage or dissection, exposure of the radius and ulna together, and concomitant radial head injuries.
G. Pearls and pitfalls
1. Failure to recognize associated radial head and lateral collateral ligament injuries can lead to recurrent instability.
2. Loss of fixation from inadequate plate selection, length, or placement is exacerbated by the osteoporotic bone of older individuals.
3. Extensive soft-tissue damage, the use of surgical approaches that expose radial and ulnar fracture sites together (often necessary), prolonged immobilization, or concomitant radial head injury can lead to radioulnar stiffness or even synostosis.
4. Ulnar fracture malreduction is the most common cause of residual radial head malalignment in a Monteggia fracture-dislocation.
H. Rehabilitation
1. Postsurgical rehabilitation is largely dependent on the fracture/ligament fixation obtained intraoperatively as well as the results of stability testing at the conclusion of the procedure.
2. Typically, a well-padded posterior splint is applied with the elbow at 90° and the forearm in pronation (to protect a lateral-sided ligament repair).
3. If adequate stability has been achieved, early motion with active and gentle passive exercises is instituted within 1 week after surgery, and the patient is weaned from the splint.
4. Strengthening is instituted at 6 to 8 weeks. Even in marginally repaired fractures, active muscle contraction of the dynamic stabilizers, such as the flexor-pronator mass and the common extensor origin, may improve concentric stability of the ulnohumeral joint, analogous to active deltoid exercises in a shoulder with inferior subluxation after trauma.
IV. Coronoid Fractures
A. Epidemiology/overview
1. The coronoid acts as the anterior buttress of the greater sigmoid notch of the olecranon, and it is the primary resistor of posterior elbow subluxation or dislocation.
2. The coronoid is typically fractured as the distal humerus is driven against it during an episode of posterior subluxation or severe varus stress.
3. A coronoid fracture (identified in as many as 10% to 15% of elbow injuries) is pathognomonic of an episode of elbow instability.
4. Fractures at the base of the coronoid can exacerbate elbow instability because the sublime tubercle is the attachment site for the anterior bundle of the medial collateral ligament and the tip of the coronoid is the attachment site for the middle part of the anterior capsule.
5. Associated injuries are common.
B. Pathoanatomy
1. Previously, type I and even some type II coronoid fractures (see Classification) were considered avulsion fractures produced by the anterior capsule; however, this does not describe the mechanism of injury, which is primarily a shearing force.
2. An intact coronoid resists posterior elbow displacement.
3. The medial facet is important for varus stability, and it provides insertion for the medial collateral ligament.
4. Anteromedial facet fractures occur from a primarily varus force, are often associated with a lateral collateral ligament injury, and represent a distinct subtype of injury.
[
Figure 5. AP radiograph of the elbow of a young male patient with a posteromedial rotatory elbow injury from a varus deforming force. The varus position of the joint, with an avulsion of the lateral collateral ligament and a compression fracture of the anteromedial facet of the coronoid, is clearly seen. This injury pattern will require buttress plate fixation of the coronoid fracture and lateral ligament repair for optimal outcome.]
5. Posterolateral rotatory instability is associated with injury to the lateral collateral ligament; it is often associated with radial head fracture and coronoid tip fracture.
6. Posteromedial rotatory instability results from anteromedial coronoid fracture and disruption of the lateral collateral ligament.
C. Evaluation
1. History
a. A history of dislocation with spontaneous reduction may be elicited.
b. Pain in the forearm or wrist may be a sign of associated injuries that require further evaluation and imaging.
2. Physical examination
a. Examination for instability is difficult but important for an accurate diagnosis.
b. A varus attitude of the elbow and pain on varus stress indicate a posteromedial rotatory injury (Figure 5).
3. Imaging
a. Standard AP and lateral radiographs should be obtained; however, the amorphous structure of the coronoid and overlap of adjacent structures can make interpretation difficult.
b. CT can be useful in this setting, especially for higher grades of comminuted coronoid fractures.
[
Table 4. Regan and Morrey Classification of Coronoid Fractures]
D. Classification
1. The Regan and Morrey classification is shown in Table 4.
2. O'Driscoll classification—O'Driscoll has proposed a more comprehensive classification scheme that subdivides the coronoid injury based on the location and the number of coronoid fragments; this scheme is important because it recognizes fractures of the anteromedial facet caused by a varus posteromedial rotatory force (Figure 5).
E. Treatment
1. Nonsurgical
a. The decision to treat a coronoid fracture surgically or nonsurgically is based as much on the associated injuries (radial head fracture, collateral ligament tears) and the evaluation of elbow joint stability as it is on the morphology and displacement of the fracture fragments themselves.
b. A minimally displaced type I or II fracture with no associated injuries and a stable elbow on examination may be treated with a brief period of immobilization for pain control followed by early range-of-motion exercises. Most elbow dislocations are more stable with the forearm in pronation.
c. Most elbows with a coronoid fracture require surgical stabilization.
2. Surgical
a. Small type I or II fractures can be repaired with suture fixation.
b. Larger type II or III fractures may require retrograde screws or plate insertion.
c. Fractures involving the medial facet can be repaired with plates or pins for rigid fixation.
d. Concurrent injuries (radial head fracture, ligament tears) must be addressed.
e. Hinged external fixation may be used to help maintain stability in difficult or revision cases.
F. Complications
1. Complication and repeat surgery rates are high.
2. Complications include stiffness of the elbow, recurrent instability of the elbow, posttraumatic arthritic degeneration, and heterotopic ossification.
3. Failure to appreciate (and surgically repair) the underlying associated elbow instability leads to early failure (see Figures 3 and 5).
G. Pearls and pitfalls
1. In the setting of a complex proximal ulnar fracture, the coronoid fragment is an important bulwark against recurrent posterior subluxation.
2. Larger coronoid fragments are also important, in that they include the insertion of the medial collateral ligament.
3. In the setting of a complex proximal ulnar fracture, the coronoid fragment should be repaired before the main ulnar fracture is reduced.
4. Fixation of the coronoid fragment can be performed with cannulated screws from the posterior surface of the ulna.
H. Rehabilitation
1. Rehabilitation is dependent on an intraoperative examination at the conclusion of the procedure.
2. A thermoplastic resting splint is applied with the elbow at 90° and the forearm in the neutral position.
3. The terminal 30° of extension is restricted for the first 2 to 4 weeks.
4. Shoulder abduction, which places a varus moment on the arm, is avoided for the first 4 to 6 weeks.
5. There is increasing evidence that some residual ulnohumeral "sagging" or gapping after the surgical repair of elbow injuries may rapidly improve under the influence of dynamic muscle contraction that early active motion provides.
Bibliography
Bryan RS, Morrey BF: Extensive posterior exposure of the elbow. Clin Orthop Relat Res 1982;166:188-192.
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Frankle MA, Koval KJ, Sanders RW, Zuckerman JD: Radial head fractures with dislocations treated by immediate stabilization and early motion. J Shoulder Elbow Surg 1999;8:355-356.
Hotchkiss R, Green D: Fracture dislocation of the elbow, in Rockwood and Green's Fractures in Adults, ed 4. Philadelphia, PA, Lippincott Raven, 1996, pp 929-995.
Johnson GW: A follow-up of one hundred cases of fracture of the head of the radius with a review of the literature. Ulster Med J 1962;31:51-56.
Judet T, Garreau de Loubresse C, Piriou P, Charnley G: A floating prosthesis for radial head fractures. J Bone Joint Surg Br 1996;78:244-250.
Macko D, Szabo RM: Complications of tension-band wiring of olecranon fractures. J Bone Joint Surg Am 1985;67:1396-1401.
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Top Testing Facts
Radial Head Fractures
1. The forearm and wrist should be examined carefully in all cases of radial head fracture.
2. Most radial head fractures can be treated nonsurgically.
3. Isolated radial head fractures do best with early mobilization, not prolonged casting.
4. Radial head excision alone is contraindicated in the presence of other destabilizing injuries.
Olecranon Fractures
1. The integrity of the extensor mechanism should be examined carefully.
2. The tension band technique is indicated for isolated, noncomminuted olecranon fractures without ligamentous instability.
3. Insertion of Kirschner wires into the anterior cortex of the ulna distal to the fracture line enhances fixation strength and may help prevent backing out.
4. Plate fixation is preferred for comminuted fractures, fractures with coronoid extension, or any associated elbow instability.
5. Fragment excision and triceps reattachment may be beneficial for elderly, low-demand patients whose bones are so osteoporotic as to compromise fixation.
Proximal Ulnar Fractures
1. Posterior fracture-dislocations of the proximal ulna are associated with a high incidence of radial head fractures and lateral collateral ligament injuries.
2. Type II (posterior radial head displacement) Monteggia fractures comprise the majority (70% to 80%) of Monteggia fractures in adults.
3. Complex proximal ulnar fractures often contain a significant coronoid fragment, which is typically triangular and involves 50% to 100% of the coronoid process. This fragment is important to recreate the anterior buttress of the greater sigmoid notch of the proximal ulna.
4. Coronoid reduction and fixation is a critical component of elbow stability.
5. The risk of proximal radioulnar synostosis is increased by multiple surgeries, extensive soft-tissue damage or dissection, and concomitant radial head injuries.
6. Ulnar fracture malreduction is the most common cause of residual radial head malalignment in a Monteggia fracture-dislocation.
Coronoid Fractures
1. The presence of a coronoid fracture is pathognomonic of an episode of elbow instability, and associated injuries are common.
2. A coronoid fracture is not typically an avulsion fracture but is caused by a shearing mechanism.
3. Anteromedial facet fractures occur from a primarily varus force, are often associated with a lateral collateral ligament injury, and represent a distinct subtype of injury.
4. Fractures involving the medial facet can be repaired with plates or pins for rigid fixation.
5. Hinged external fixation may be used to help maintain stability in difficult or revision cases.
6. In the setting of a complex proximal ulnar fracture, the coronoid fragment is an important bulwark against recurrent posterior subluxation.
7. Larger coronoid fragments are also important, in that they include the insertion of the medial collateral ligament.
8. In the setting of a complex proximal ulnar fracture, the coronoid fragment should be repaired before the main ulnar fracture is reduced.
9. Fixation of the coronoid fragment can be performed with cannulated screws from the posterior surface of the ulna.