You are in: eMedicine Specialties > Orthopedic Surgery > ELBOW Olecranon FracturesArticle Last Updated: Dec 29, 2006AUTHOR AND EDITOR INFORMATIONSection 1 of 12
  Author: James W Pritchett, MD, FACS, Clinical Associate Professor of Orthopedic Surgery and Sports Medicine, University of Washington School of Medicine Coauthor(s): Margaret A Porembski, MD, Research Fellow, Department of Surgery, Massachusetts General Hospital, Shriner's Burns Hospital, Harvard Medical School Editors: Mark D Lazarus, MD, Associate Professor of Orthopedic Surgery, Medical College of Pennsylvania-Hahnemann University, Chief of Shoulder and Elbow Service, Department of Orthopedic Surgery, Hahnemann University Hospital; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Michael Yaszemski, MD, PhD, Associate Professor, Departments of Orthopedic Surgery and Bioengineering, Mayo Foundation, Mayo Medical School; Dinesh Patel, MD, FACS, Associate Clinical Professor of Orthopedic Surgery, Harvard Medical School; Chief of Arthroscopic Surgery, Department of Orthopedic Surgery, Massachusetts General Hospital; Harris Gellman, MD, Consulting Surgeon, Broward Hand Center, Voluntary Clinical Professor of Orthopedic Surgery and Plastic Surgery, Departments of Orthopedic Surgery and Surgery, University of Miami School of Medicine Author and Editor Disclosure Synonyms and related keywords: elbow fractures, tension band wiring, tension-band wiring, AO-ASIF, Arbeitsgemeinschaft fur Osteosynthesefragen-Association for the Study of Internal Fixation INTRODUCTIONSection 2 of 12
  The human's unique prehensile skill largely depends on the integrity of the bones, ligaments, and muscles around the elbow joint. The elbow not only bends the arm but also permits pronation and supination of the hand. Fractures of the olecranon are common and are usually detected easily. For excellent patient education resources, visit eMedicine's Breaks, Fractures, and Dislocations Center. Also, see eMedicine's patient education article Broken Elbow. History of the ProcedureSee Treatment, Intraoperative details. ProblemThe olecranon is the proximal bony projection of the ulna at the elbow. Olecranon fractures are a diverse group of injuries, ranging from simple nondisplaced fractures to complex fracture dislocations of the elbow joint. FrequencyDespite the fact that the olecranon is a very heavy, strong process of bone, it is fractured rather frequently in adults. This is due partly to its exposed position on the point of the elbow, where most direct injuries to the elbow occur, and partly to the tremendous cross strain put on the olecranon during falls on the flexed forearm. The olecranon process is rarely broken in children, because in early life, it is short, thick, and relatively much stronger than the lower end of the humerus. Usually, children sustain supracondylar fractures of the humerus instead. Open fractures occur in 2-31% of cases. Neurologic injuries to median, radial, or ulnar nerves may occasionally occur. Ulnar neurapraxia has been reported in 2-5% of cases. Generally, symptoms resolve with conservative treatment, but late neurolysis or transposition may occasionally be required. EtiologyThe most common mechanism of an olecranon fracture is a fall on the semiflexed supinated forearm. As the hand strikes the ground, muscles are tensed to break the fall, and the powerful triceps snaps the olecranon over the lower end of the humerus, which acts as a fulcrum. The next most frequent cause of this injury is direct trauma, as in falls on, or blows to, the point of the elbow. Occasionally, the olecranon may be fractured by hyperextension injuries, such as those resulting in elbow dislocation in adults or supracondylar fractures in children. Very rarely is the olecranon broken by muscular violence, as in throwing. ClinicalMost olecranon fractures are isolated. However, additional injuries to the same extremity are possible. Careful examination, including that of the shoulder, clavicle, humerus, wrist, hand, and forearm, is essential. Typically, the elbow incurs both soft tissue injury and joint effusion. Examine the skin, radial and ulnar pulses, and function of the ulnar, median, and posterior interosseous nerves. Carefully assess isolated injuries, as fracture of the coronoid process of the radial head and Monteggia fracture dislocations have a significant impact on elbow stability. When a supracondylar humerus fracture occurs in conjunction with an olecranon fracture, exposure of the humerus can be obtained by using the olecranon fracture site. Similarly, when an associated coronoid and/or radial head fracture exists, reduction and fixation can be achieved via a direct posterior approach through the displaced olecranon fragment. Although olecranon fractures generally are isolated injuries, a high index of suspicion for associated injuries is warranted in the evaluation of patients with multiple trauma. Twenty percent of patients with high-energy trauma have associated injuries (eg, long bone fracture, skull fracture, splenic injury, pulmonary contusion, axillary artery rupture). A transverse or slightly oblique break near the base of the olecranon is the usual fracture. In oblique fractures, the fracture line tends to slope down and back and emerges on the posterior border of the olecranon. In other instances, a small piece of bone is pulled off of the proximal end of the olecranon. INDICATIONSSection 3 of 12
Fractures with significant displacement (>2 mm) or comminution may require surgical intervention. RELEVANT ANATOMYSection 4 of 12
The elbow is a complex hinge joint. The major stabilizers to valgus stress (ie, bending away from the body) are the medial (ulnar) collateral ligament and the radial head. The major stabilizer to varus stress (ie, toward the body) is the lateral collateral ligament complex. The coronoid process stabilizes the humerus against the distal ulna. The olecranon also prevents anterior translation of the ulna with respect to the distal humerus. The anterior surface of the ulna is covered with articular cartilage. Therefore, all fractures (except the rare tip fractures) are intra-articular fractures. The olecranon articulates with the trochlea of the humerus. The triceps inserts into the posterior third of the olecranon and proximal ulna. The periosteum of the olecranon blends with the triceps. The ulnar nerve lies on the posterior aspect of the elbow, posterior to the medial collateral ligament. The ulnar nerve sweeps anteriorly to join the ulnar artery. The ulnar neurovascular bundle may be at risk during Kirschner wire (K-wire) fixation. Fracture displacement is largely due to the pull of the triceps muscle, which tends to pull a separated fragment upward but is resisted by the strong fibrous covering on the olecranon (see Image 1). The blending of fibers in the lateral ligaments, the elbow capsule, and some triceps fibers that blend with the periosteum form this fibrous covering. If the fracture force does not tear this fibrous sheath, little or no tendency toward displacement exists, even in the presence of comminution. Most olecranon fractures exhibit little or no displacement. Fragment displacement of more than 1.5 cm is uncommon, even with complete bony and soft tissue injury. Usually, wide separation of fragments indicates an old fracture with extensive tearing of the fibrous sheath in which the unopposed triceps is contracted gradually, drawing the separated fragment upward. CONTRAINDICATIONSSection 5 of 12
Nonoperative treatment is often desirable in patients with significant associated medical conditions. Contused soft tissue healing is of paramount importance. Nonoperative treatment of even significantly displaced olecranon fractures in patients with severe medical illness, steroid use, or dementia is reasonable. WORKUPSection 6 of 12
Imaging Studies
StagingSeveral classification systems have been suggested.
TREATMENTSection 7 of 12
Medical therapyThe goals of olecranon fracture treatment must be individualized to the needs of the patient. In young active individuals, restoration of the articular surface, preservation of motor power, restoration of stability, and prevention of joint stiffness are important. In older patients, minimization of morbidity is the most important goal. An understanding of the extent of associated injuries is critical prior to initiating treatment. Additional fractures or disruptions of collateral ligaments render the elbow unstable. Nonoperative treatment As stated in Contraindications, nonoperative treatment is often desirable in patients with significant associated medical conditions. Contused soft tissue healing is of paramount importance. Nonoperative treatment of even significantly displaced olecranon fractures in patients with severe medical illness, steroid use, or dementia is reasonable. Skillful neglect is the treatment of choice for these patients. An Ace wrap with sufficient padding to protect the elbow is the only requirement. Patients with wide separation of fracture fragments lose significant, but not complete, elbow extension power. Late pain from an ununited displaced olecranon fracture generally is not a problem, but the extensor power is compromised. Approximately 70% of the extensor power is estimated to be lost when the fracture is displaced more than 1.5 cm. Nondisplaced fractures with intact extensor mechanisms may be treated nonoperatively. Three weeks of casting usually is sufficient. The elbow can be placed at any degree of flexion. Displacement generally can be reduced by placing the elbow in more extension. Patients can be comfortable with the elbow extended 135°. However, it is often more convenient to immobilize the elbow at 90°. Regaining both flexion and extension can be difficult. At first, patients are cautioned to limit flexion to 90°, at least until evidence of radiographic healing is satisfactory. Surgical therapyNonoperative care for simple fractures is usually successful. However, fractures with significant displacement (>2 mm) or comminution may require surgical intervention. Excision and triceps advancement may be indicated for severely comminuted fractures or for patients with osteoporotic bone. Open reduction and internal fixation is preferred for displaced intra-articular fractures. Intramedullary screw fixation, with or without a wire or cable, is the most secure. Plate fixation is recommended for extensive comminuted or unstable oblique fractures not amenable to other types of treatment. Plate fixation also may be preferable in the face of an associated coronoid fracture. Preoperative detailsWhen determining the appropriate surgical approach, consider patient age, health, bone quality, fracture pattern, and ligamentous stability. Intraoperative detailsExcision of fragment and triceps advancement Excision of the fracture fragment and reattachment of the triceps tendon may be indicated in a select group of elderly patients with osteoporotic bone in whom the olecranon fracture involves less than 50% of the joint surface or when the fragment is too small or comminuted for successful internal fixation. Integrity of the collateral ligaments, intraosseous membrane, and distal radioulnar joint must be established before considering excision; otherwise, instability can result. The triceps is reattached with nonabsorbable sutures that are passed through drill holes in the proximal ulna. The drill holes are placed such that the triceps will insert just off the articular margin of the olecranon articular surface, in essence extending the articular margin. Weakening of the extensor mechanism is a drawback of excision and triceps advancement. However, comparison of the isometric strength of patients treated by excision with those who had internal fixation showed no differences. Excision and triceps advancement may be followed by immediate motion if the suture repair of the triceps is secure. Tension band wiring A tension band wire is the most common fixation technique for simple fractures. The goal is to convert the extensor force of the triceps to a dynamic compression force along the articular surface. In this technique, a direct straight posterior incision is used with the patient supine with the arm across the chest or, occasionally, in the prone position. Two smooth K-wires are placed through the triceps tendon into the olecranon with great care made to bury the wires beneath the tendon and firmly impact them into the bone. Otherwise, the wires certainly will migrate posteriorly and can become an irritant or possibly a source of infection. The key is to place the tension band wire as dorsally as possible on the surface of the olecranon (see Image 2). K-wires help to hold the tension band wire in place as it loops around the tip of the olecranon. A drill hole through the ulna at 1-2 cm distal to the articular surface provides the distal fixation point. Placing 2 knots in the 18-gauge wire results in more rigid fixation than a single knot and provides symmetrical tension at the fracture site. Plate fixation Plate fixation is most commonly recommended for comminuted fractures for which tension band wire fixation is not feasible. It also is indicated for fractures that involve the coronoid process and for those associated with Monteggia fracture dislocations of the elbow. Some authors have used one-third tubular, dynamic compression, or pelvic reconstruction plates for comminuted fractures. The proximal end of the one-third tubular plate can be modified to make a hook-plate that provides additional fixation for small fragments. The subcutaneous location of the hardware raises concerns about prominence necessitating subsequent removal of fixation. Do not narrow the olecranon-to-coronoid distance. Restore it to within a few millimeters of the correct anatomic distance. Bone grafting sometimes is necessary. The last hole in the plate where it has been bent to make a hook provides a good location for an intramedullary screw. Intramedullary screw fixation Use of a single large-diameter cancellous screw for repair of olecranon fractures has been advocated for a long time. The Rush brothers wrote that intramedullary insertion of a Steinmann pin was the beginning of the Rush pin technique of fracture fixation in 1936. They claimed this to be the first American case of intramedullary pinning. They found that Steinmann pins were difficult to use and designed their own pins. When 6.5-mm AO-ASIF screws became available, they were used more commonly. In the frontal plane, 4° of valgus angulation exists between the ulnar shaft with respect to the sigmoid notch (see Image 3). When intramedullary screws are used, take care to properly place the screw along the intramedullary shaft axis to avoid displacement of the fracture. With the advent of cannulated screws, it is much easier to correctly place the screw in the medullary canal of the ulna simultaneously, accommodating for the bow in the ulna and achieving anatomic reduction. The 7.3-mm cannulated AO screws are the most secure. Also, screw fixation is probably the easiest technique. Biomechanically, screw fixation does not provide as secure a fixation as tension-band wiring. However, by adding a tension band around the screw, excellent fixation can be obtained. The most secure technique is placement of a large-diameter cannulated screw with a braided cable (see Images 4-5). A 1.6-mm cable is adequate and much stronger than an 18-gauge wire. Postoperative detailsOperative management of olecranon fractures should provide sufficient fixation for immediate motion. Typically, patients are immobilized for only a brief time to assist wound healing and are then started on range-of-motion exercises at 10 days. However, muscle strengthening is not emphasized until bone healing is visualized radiographically. Patients may return to work involving vigorous use of the extremity at 3-4 months postoperatively. COMPLICATIONSSection 8 of 12
Symptomatic hardware requiring removal is the most frequent complication following internal fixation. Hardware problems have occurred in up to 80% of patients with Kirschner tension band wires. Wire migration with soft tissue irritation, wire breakage, or fracture displacement may occur with tension-band wiring. Counsel patients about the possibility of symptomatic hardware when internal fixation is offered. Hardware complications generally occur less frequently with intramedullary screw fixation. Plate and screw fixation carries a moderate risk of subsequent need for hardware removal. Loss of motion is a common problem following fractures of the elbow but is usually not a significant issue for olecranon fractures. Generally, patients lose 15° of extension and, occasionally, a small amount of supination. Motion tends to improve progressively with time for up to 2 years. Heterotopic ossification occurs in 13-14% of patients. The range of reported rates of infection following operative treatment is 0-6%. Reflex sympathetic dystrophy occurs on rare occasions. Generally, nonunion occurs in fewer than 5% of patients. When nonunions are treated by internal fixation and bone grafting, good to excellent results occur in approximately two thirds of cases. OUTCOME AND PROGNOSISSection 9 of 12
The best outcomes are observed in patients who have nondisplaced or minimally displaced fractures treated nonoperatively. Evaluation criteria are degree of pain, range of motion, and radiographic findings. In patients treated operatively, excision with triceps repair has the lowest rate of complications. In controlled studies, pain, subjective function, isometric strength, isokinetic work, range of motion, stability, and incidence of degenerative change were similar for patients treated with internal fixation and patients treated with excision. The preferred treatment appears to be excision when possible. Patients treated with internal fixation using an intramedullary screw plus wire or cable yield the fewest complications and best results when internal fixation is necessary. Occasionally, fixation removal is required. Of patients with plate fixation, 70-80% have good to excellent results, as compared with more than 90% of patients with tension band wiring. This probably is because simple fractures are usually treated with tension band wiring, whereas less favorable fracture patterns are treated with plate fixation. FUTURE AND CONTROVERSIESSection 10 of 12
Controversy exists regarding the amount of acceptable articular displacement for closed treatment. Certainly, several millimeters of displacement are usually well tolerated. Degenerative changes occur in fewer than 20% of these patients. The method chosen for open treatment of olecranon fractures is also controversial. Decisions regarding fragment excision versus internal fixation often are based on percentage of joint space involvement. McKeever and Buck in 1947 stated that as much as 80% of the trochlear notch can be excised without compromising elbow stability, provided that the coronoid and distal trochlea are preserved. One patient developed anterior instability following excision of 75% of the articular surface. The consensus certainly suggests that at least 50%, but likely less than 80%, of the articular surface can be excised, and a good result can still be obtained. Future treatment of olecranon fractures may very well involve percutaneous fixation accompanied by arthroscopic assistance. MULTIMEDIASection 11 of 12
REFERENCESSection 12 of 12
Article Last Updated: Dec 29, 2006 | |||||||||||||||||||||||||||||||||||
