25 Olecranon and Monteggia Fractures
Fractures of the olecranon occur commonly in both young and elderly patients. This chapter will review important preoperative considerations as well as tactics employed in surgery. Monteggia fracture-dislocations are fractures of the ulna (usually proximal) associated with dislocation of the proximal radioulnar joint that pose unique treatment challenges.
Fractures of the Olecranon
History and physical exam
Direct injuries, such as a fall on the olecranon, can result in comminution along with ligamentous instability.
Indirect injuries, such as a fall on an outstretched hand, can result in tension failure of the olecranon. This often creates more simple fracture patterns.
A complete exam of the injured extremity should be performed. Nerve as well as vascular status should be documented.
A thorough inspection of the skin (especially in elderly patients) surrounding the injury should be performed to rule out open fractures and degloving injuries.
The semilunar notch (greater sigmoid notch) of the proximal ulna is composed of both the olecranon and the coronoid process (▶ Fig. 25.1 ).
Articulation of the semilunar notch with the distal humerus (trochlea) creates a hinge with approximately 180 degrees of motion.
A central groove in the semilunar notch interdigitates with the trochlea to assist with stability.
The bare area is a transverse ridge separating the distal cartilage of the coronoid from the proximal cartilage of the trochlear notch.
The radial notch laterally articulates with the radial head.
Three radiographic views (anteroposterior, oblique, lateral) are necessary to assist with fracture identification.
Unfortunately, obtaining quality imaging can be difficult secondary to the patient’s pain and altered anatomy.
A computed tomography scan can be useful in evaluating high-energy fracture patterns associated with instability or comminution.
Additionally, preoperative fluoroscopic imaging can be of use.
No universally accepted classification system.
Descriptive: Transverse, oblique, and comminuted.
The Mayo classification categorizes olecranon fractures based on three factors that affect the treatment (i.e., displacement, comminution, and stability; ▶ Fig. 25.2 ).
Initial treatment of olecranon fractures should be the placement of a well-padded posterior long-arm splint with the elbow in 45 to 90 degrees of flexion.
Reduction maneuvers should be performed for fractures associated with elbow instability.
Nonoperative treatment is rare, but reserved for patients with stable minimally displaced fractures, low functional demands, or injuries and comorbidities that may preclude surgery.
The stability of minimally displaced fractures can be determined by assessing displacement on flexion radiographs.
Patients amenable to nonoperative management should have a long-arm cast applied at 45 to 90 degrees of flexion for 3 to 4 weeks, followed by advancement of motion.
Most patients with displaced olecranon fractures will benefit from operative treatment.
Evaluation of the fracture pattern along with the patient’s clinical picture assists with determining appropriate fixation.
Direct posterior approach is most commonly used to treat olecranon fractures.
Arm adducted across the body.
Difficult without an assistant.
Beneficial in patients who must be supine for other reasons (multiple procedures).
ii. Lateral—arm rested over an arm holder (“hockey stick”), roll of blankets, or rested on a sterile, padded mayo stand.
iii. Prone—arm rested over an arm holder or on a table extension.
An incision is made along the subcutaneous border of the ulna and extended proximally to the olecranon.
A gentle lateral curve can be made when approaching the olecranon to avoid a potential site for skin irritation.
Full-thickness skin flaps are created to expose the underlying fascia. There is often a traumatic rent in the fascia at the level of the fracture.
Utilize the interval between flexor carpi ulnaris and extensor carpi ulnaris (ECU).
Reduction of the fracture is determined by the fracture morphology.
Simple fracture patterns with minimal comminution:
Direct healing can be achieved by obtaining compression at the fracture site.
The dorsal cortex can often provide an indirect read for the articular reduction.
Pointed bone reduction clamp can be used to reduce the fragments.
Crossing Kirschner (K) wires can be placed from proximal to distal to assist with reduction.
Lag screw fixation is used when the fracture is amenable; otherwise, compression can be obtained by eccentrically drilling through a plate.
Comminuted fractures present more of a challenge:
The plate is often used as a template in this scenario.
Length and rotation can often be judged radiographically and also by identifying bony landmarks such as the crest of the ulna.
Mini-fragment fixation can assist with temporary and/or definitive stabilization of smaller fragments.
Tension band (▶ Fig. 25.3 ):
One of the most common techniques used for fixation of olecranon fractures.
Must meet the following criteria:
i. A relatively transverse fracture pattern.
ii. Minimal articular comminution.
Tension band constructs are variable and can consist of K wires, cannulated screws, wire (18 gauge), and heavy suture—Some studies have suggested that using cannulated screws or heavy suture provides similar mechanical benefits with less hardware irritation than traditional constructs (K wires and 18 gauge wire).
When used in appropriate fractures, tension band fixation is a dependable, cost effective treatment option.
Plate and screws:
Typically used for fractures that are oblique, comminuted, or associated with elbow instability.
Precontoured locking plates, semitubular plates, and mini-fragment plates can be used for fixation (▶ Fig. 25.4 ).
Plates can be used as neutralization devices (when accompanied with lag screw fixation), as templates in comminuted fracture patterns, and as reduction tools to prevent displacement of proximal fracture segments.
Intramedullary nail or cancellous screw:
Biomechanical evidence demonstrates superior strength when compared to plates or tension band, however clinical data is limited.
Cannulated cancellous screw fixation:
i. Obtain the correct starting point on an anteroposterior and lateral image.
ii. Ensure the guidewire is inserted down the intramedullary canal.
iii. Following drilling, consider tapping prior to screw insertion.
Fragment excision and triceps advancement—typically used when extensive bone loss or poor bone quality prevents adequate fixation.
Hardware prominence—occurs in up to 85% of patients.
Loss of motion.
Common after any surgery around the elbow.
Can result from malreduction of the olecranon that results in a size mismatch with the trochlea.
Loss of pronation and supination can be caused by screws or K wires that are too long and abut the radius.
Failure of fixation—escape of the proximal fragment is most common and has been reported in locked plating constructs as well as tension bands.
Nonunion is rare.
Typically, early range of motion (ROM) can begin within 2 to 3 days if stable fixation has been obtained.
Consider a period of posterior splint immobilization of 7 to 10 days for comminuted fractures or in patients with osteopenia.
Non-weight-bearing of the injured extremity is usually maintained for 4 to 8 weeks. Progressive weight-bearing is permitted once signs of radiographic healing are observed.
Union rates up to 98% have been reported.
Often patients lose some strength and ROM compared to the contralateral side.