Elbow fracture dislocations are complicated injuries that are difficult to manage and fraught with complications. A complete series of radiographs is typically complemented with CT scan to evaluate the elbow and assist preoperative planning. Typically, operative intervention is necessary and a systematic approach to the elbow injuries should be chosen. This article addresses the coronoid and proceeds to the radial head, lateral soft tissues, and finally the medial ligaments if elbow instability persists. With a focused, systematic surgical approach, improved outcomes have been demonstrated and patients may recover full function and range of motion in the affected elbow.
Key points
- •
Complex elbow dislocations are typically high-energy injuries that present a challenge to the treating physician, almost always require surgery, and are commonly burdened with complications.
- •
Advanced imaging is often helpful to assess the extent of injury and to determine the approach and type of fixation necessary.
- •
A methodological surgical approach results in improved outcomes. The authors use an inside-out technique beginning with addressing any coronoid injuries if present, then proceed to the radial head, lateral ligament structures, and finally medial ligaments, if necessary.
- •
If elbow stability is in question after all bony and lateral ligamentous structures have been addressed, an external fixator may be applied with or without the repair of the medial ligaments.
- •
Early motion is crucial in avoiding postoperative stiffness and contractures; however, maintenance of a stable reduction is paramount.
Introduction
Adult elbow fracture dislocations present a significant challenge to the treating surgeon and are associated with a high complication rate. The elbow is a highly congruent trochoginglymoid joint with a significant amount of stability conferred from its bony structures. The elbow joint is comprised of articulations between the radial head and humeral capitellum, the olecranon and humeral trochlea, and the proximal radius and ulna. This construct is enhanced by the medial and lateral soft tissue constrains, which must also be addressed at the time of surgery.
Functional range of motion at the elbow is classically described as 50° of pronation and supination with a 100° arc of flexion, ranging from 30° to 130°. Contemporary studies using 3-D tracking techniques have found that required functional motion may be greater than previously reported. An important goal of treatment is to preserve or restore functional use of the elbow.
Dislocations of the elbow may be simple or complex, with simple dislocations representing a purely soft tissue injury of the elbow resulting in the dislocation. Complex dislocations are associated with a combination of fractures and soft tissue injuries, and for this reason may also be termed fracture dislocations .
In general, complex dislocations are described as anterior or posterior based on the translation of the ulna with respect to the distal humerus. Posterior dislocations are typically the result of an axial load applied through a supinated elbow with valgus stress. Conversely, anterior dislocations occur in the setting of a posterior force applied to the elbow in a flexed position or hyperextension trauma. The Horii circle, described by O’Driscoll and colleagues, outlines the typical pattern of soft tissue injury for elbow dislocations proceeding from lateral to medial ( Fig. 1 ).
Several classification systems have been proposed to group these fracture dislocations and guide treatment. Ring and Jupiter noted 4 common patterns of injury:
- 1.
Posterior dislocation of the elbow with fracture of the radial head
- 2.
Posterior dislocation with fracture of both the radial head and coronoid, described by Hotchkiss as the “terrible triad”
- 3.
Anterior transolecranon fracture dislocation
- 4.
Proximal Monteggia posterior fracture dislocations
Morrey further classified these injuries with the inclusion of soft tissue injury. Classification systems also exist for the patterns of injury to the individual components of the elbow, including radial head, coronoid, and olecranon fractures.
The most commonly used classification for radial head fractures was initially described by Mason in 1954, further modified by Broberg and Morrey in 1987, and finally Hotchkiss in 1997. Although the full details of the modified Mason classification are presented in Table 1 , generally, type 1 represents nondisplaced fractures, type 2 is a displaced (>2 mm) fractures, and type 3 is reserved for severely comminuted radial head fractures.
Type | Description |
---|---|
1 | Nondisplaced or minimally displaced fracture of head or neck; forearm rotation is limited only by acute pain and swelling, intra-articular fracture <2 mm, or marginal lip fracture. |
2 | Displaced (>2 mm) fracture of head or neck. Motion may be mechanically blocked or incongruous, without severe comminution (possible to repair by ORIF), or fracture involving more than marginal lip of radial head. |
3 | Severely comminuted fracture of head and neck that is nonreconstructible, usually requiring excision and/or replacement. |
Coronoid fractures are described using the Regan and Morrey classification, where type 1 involves the tip of the coronoid process, type 2 is a fracture of less than 50% of the coronoid height, and type 3 fractures include greater than 50% of the coronoid. The O’Driscoll classification describes coronoid fracture fragments of the tip, anteromedial, and basal region.
Finally, olecranon fractures are most commonly classified with the Schatzker, Mayo, or AO classification system. The Schatzker classification describes the pattern and location (intra/extra-articular) and is organized by mechanical construct needed for fixation. The Mayo classification simplifies the fracture pattern into type 1 nondisplaced stable fractures, type 2 displaced stable fractures, and unstable type 3 fractures, which are commonly comminuted.
Introduction
Adult elbow fracture dislocations present a significant challenge to the treating surgeon and are associated with a high complication rate. The elbow is a highly congruent trochoginglymoid joint with a significant amount of stability conferred from its bony structures. The elbow joint is comprised of articulations between the radial head and humeral capitellum, the olecranon and humeral trochlea, and the proximal radius and ulna. This construct is enhanced by the medial and lateral soft tissue constrains, which must also be addressed at the time of surgery.
Functional range of motion at the elbow is classically described as 50° of pronation and supination with a 100° arc of flexion, ranging from 30° to 130°. Contemporary studies using 3-D tracking techniques have found that required functional motion may be greater than previously reported. An important goal of treatment is to preserve or restore functional use of the elbow.
Dislocations of the elbow may be simple or complex, with simple dislocations representing a purely soft tissue injury of the elbow resulting in the dislocation. Complex dislocations are associated with a combination of fractures and soft tissue injuries, and for this reason may also be termed fracture dislocations .
In general, complex dislocations are described as anterior or posterior based on the translation of the ulna with respect to the distal humerus. Posterior dislocations are typically the result of an axial load applied through a supinated elbow with valgus stress. Conversely, anterior dislocations occur in the setting of a posterior force applied to the elbow in a flexed position or hyperextension trauma. The Horii circle, described by O’Driscoll and colleagues, outlines the typical pattern of soft tissue injury for elbow dislocations proceeding from lateral to medial ( Fig. 1 ).
Several classification systems have been proposed to group these fracture dislocations and guide treatment. Ring and Jupiter noted 4 common patterns of injury:
- 1.
Posterior dislocation of the elbow with fracture of the radial head
- 2.
Posterior dislocation with fracture of both the radial head and coronoid, described by Hotchkiss as the “terrible triad”
- 3.
Anterior transolecranon fracture dislocation
- 4.
Proximal Monteggia posterior fracture dislocations
Morrey further classified these injuries with the inclusion of soft tissue injury. Classification systems also exist for the patterns of injury to the individual components of the elbow, including radial head, coronoid, and olecranon fractures.
The most commonly used classification for radial head fractures was initially described by Mason in 1954, further modified by Broberg and Morrey in 1987, and finally Hotchkiss in 1997. Although the full details of the modified Mason classification are presented in Table 1 , generally, type 1 represents nondisplaced fractures, type 2 is a displaced (>2 mm) fractures, and type 3 is reserved for severely comminuted radial head fractures.
Type | Description |
---|---|
1 | Nondisplaced or minimally displaced fracture of head or neck; forearm rotation is limited only by acute pain and swelling, intra-articular fracture <2 mm, or marginal lip fracture. |
2 | Displaced (>2 mm) fracture of head or neck. Motion may be mechanically blocked or incongruous, without severe comminution (possible to repair by ORIF), or fracture involving more than marginal lip of radial head. |
3 | Severely comminuted fracture of head and neck that is nonreconstructible, usually requiring excision and/or replacement. |
Coronoid fractures are described using the Regan and Morrey classification, where type 1 involves the tip of the coronoid process, type 2 is a fracture of less than 50% of the coronoid height, and type 3 fractures include greater than 50% of the coronoid. The O’Driscoll classification describes coronoid fracture fragments of the tip, anteromedial, and basal region.
Finally, olecranon fractures are most commonly classified with the Schatzker, Mayo, or AO classification system. The Schatzker classification describes the pattern and location (intra/extra-articular) and is organized by mechanical construct needed for fixation. The Mayo classification simplifies the fracture pattern into type 1 nondisplaced stable fractures, type 2 displaced stable fractures, and unstable type 3 fractures, which are commonly comminuted.
Indications/contraindications
Simple elbow dislocations should be managed with concentric reduction as soon as possible. Stable range of motion should be assessed immediately after reduction and any subluxation or dislocation with extension or valgus stress documented. Typically, stable reductions are successfully managed nonoperatively with close monitoring and early range of motion. In patients who are morbidly obese, mentally impaired, or intubated, frequent examination and interval radiographs may be required to ensure that the initial closed reduction has not been lost.
Elbow dislocations with associated periarticular fractures (ie, complex dislocations); however, frequently necessitate surgical intervention, and the indications are predicated on the specific fracture pattern. For this reason, CT scan is often helpful in preoperative planning ( Fig. 2 ). With exception of a select pattern of injuries, nearly all fracture dislocations require some level of operative intervention.
- 1.
Radial head fractures: posterior elbow dislocations with associated isolated fracture of the radial head are rare injuries and a relative indication for surgical fixation. These injuries can be managed in a long arm cast, although conservative management may be associated with joint arthrosis and blocks to forearm rotation. When operative fixation is chosen, open reduction and internal fixation or acute radial head replacement are recommended because radial head excision in the presence of a traumatic elbow dislocation is contraindicated due to the risk of proximal migration. Elbow dislocation with a radial head fracture and a concomitant coronoid fracture ( Fig. 3 ) is nearly always an indication for surgery. Nonoperative treatment is reserved only for cases where concentric reduction is achieved, there are no blocks to motion, and fracture fragments are small and nondisplaced.
- 2.
Coronoid fracture: elbow dislocation with isolated fracture of the coronoid is rare and surgical intervention is, to some extent, based on the size and location of the coronoid fragment. Some investigators conservatively manage isolated fractures involving less than 10% of the coronoid height with a long arm cast. Surgical fixation is indicated for elbow dislocations with fractures greater than 10% of coronoid height as well as the well-known terrible triad injury of simultaneous elbow dislocation with coronoid and radial head fractures (see Fig. 3 ).
- 3.
Olecranon fracture: anterior transolecranon fracture dislocation necessitates operative intervention. The ulnar articular surface must be anatomically restored and any associated injuries to the coronoid, distal humerus, or radial head addressed at the time of fixation. Unlike a Monteggia fracture dislocation, the proximal radioulnar joint is not compromised with these injuries ( Fig. 4 ).
- 4.
Soft tissues: O’Driscoll and colleagues described the disruption of soft tissue structures from lateral to medial in elbow dislocations originating at the lateral ulnar collateral ligament (LUCL) and, in cases of high energy trauma, progressing to disruption of the medial ulnar collateral ligament (MUCL). After bony anatomy is restored, attention should be turned to the soft tissue structures for reconstruction. The annular ligament and LUCL should be repaired, because rotatory instability ensues with any deficit in the lateral collateral ligament (LCL) complex. The medial collateral ligament (MCL), however, needs only to be restored if the elbow remains unstable after all other fractures and soft tissue structures have been addressed. An alternative option is to place a hinged external fixator in this situation.
Surgical technique/procedure
Preoperative Planning
Preoperative planning begins with a thorough history, physical examination, and complete imaging, including standard anteroposterior (AP), lateral, and oblique views of the elbow. For elbow fracture dislocations, CT scanning is often helpful in recognizing complex intra-articular fracture patterns and can guide the surgical approach and treatment. MRI has limited utility in the acute setting, although it may prove helpful in cases of chronic elbow instability. Preoperative neurologic deficits must be carefully noted. All dislocations should be reduced and splinted at 90° until operative intervention.
A decision-making algorithm is demonstrated in Fig. 5 . Regardless of the fracture pattern, the surgeon should be prepared for several contingencies. A hinged external fixator should be available if the final reduction is deemed unstable. If the radial head is involved, the surgeon should be prepared to replace the radial head acutely.
Preparation and Patient Positioning
There are several options for positioning of the patient for adequate access to the elbow, which vary to some extent with the surgical approach chosen but are mostly based on surgeon preference. The procedure is typically performed under general anesthesia and adjunctive nerve blocks before or after surgery can assist in reducing postoperative pain.
The patient may be positioned supine with the arm adducted across the body to allow access to the posterior elbow ( Fig. 6 ). A bump placed under the ipsilateral scapula can assist arm positioning. Another option is to position the patient in the lateral decubitus position with the affected arm supported by bone foam or a bolster so that the elbow rests in a flexed position ( Fig. 7 ).
Regardless of the position chosen, the authors typically mark the ulnar and radial side of the elbow as well as the position of the ulnar nerve (see Figs. 6 and 7 ), because the surgeon can easily become disoriented when approaching the posterior elbow in this manner. A sterile tourniquet is applied after draping.
Surgical Approach
The approach to the elbow typically begins with a universal posterior skin incision, which provides circumferential access by raising full-thickness skin flaps while avoiding creating skin bridges. Some surgeons curve this incision around the olecranon to avoid postoperative pain with direct pressure on the subcutaneous bone. The posterior approach allows a panoramic view of the elbow, is convenient if a hinged external fixator is applied later in the procedure, and is conveniently accessed in the lateral decubitus position. Alternatively, separate medial and lateral skin incisions may be used that are beneficial in cases of medial soft tissue repair that must be performed, of an ulnar nerve that needs to be explored, or when visualization is not adequate through the posterior incision.
The lateral column can be approached through several deep intervals regardless of the skin incision chosen. The posterolateral (Kocher) approach ( Fig. 8 ) occurs between the extensor carpi ulnaris (ECU) and the anconeus, which provides direct access to the joint capsule; however, there is increased risk of injury to the LUCL. Alternatively the direct lateral (Kaplan) approach ( Fig. 9 ) accesses the joint at the muscular interval between the extensor digitorum communis (EDC) and the extensor carpi radialis brevis (ECRB). Although iatrogenic injury to the LUCL is less common, if the LUCL has been damaged, this approach does not allow for visualization for repair or reconstruction. In cases of elbow fracture dislocation, the soft tissues are often disrupted. Regardless of the interval chosen, dissection should be carried out with the elbow in pronation to reduce risk of injury to the posterior interosseous nerve (PIN).