Julie E. Adams
Scott P. Steinmann
The subcutaneous location of the olecranon makes it vulnerable to injury, and fractures are not uncommon following low-energy trauma. Fractures of the olecranon are generally amenable to treatment and usually have a favorable prognosis.
Pathogenesis
Epidemiology, Etiology, and Pathophysiology
Isolated fractures of the olecranon constitute approximately 10% of fractures about the elbow, with an estimated incidence of 1.08 per 10,000 person-years. Most olecranon fractures follow low-energy trauma such as a fall from a height of <2 meters, a direct blow to the elbow, or from forced hyperextension. A fall on a partially flexed elbow may generate an avulsion fracture of the olecranon from the pull of the triceps. Amis and Miller investigated variable-impact mechanisms and the resultant fracture patterns in a cadaveric model. Whereas radial head and coronoid fractures tended to occur with forearm impacts with the elbow in ≤80 degrees of flexion, olecranon fractures followed direct blows at 90 degrees of flexion, and injuries occurring with the elbow in >110 degrees of flexion tended to result in distal humerus fractures. The olecranon and coronoid process constitute the semilunar or greater sigmoid notch of the ulna, which articulates with the trochlea. The constraints of this articulation confer stability to the elbow joint and facilitate anterior-posterior motion. A transverse “bare area” devoid of cartilage is found at the midpoint between the coronoid and the tip of the olecranon. An appreciation of this anatomic structure is necessary to avoid inadvertently discarding structurally significant portions of the olecranon when reconstructing the fractured olecranon. The ossification center of the olecranon generally appears by 9 to 10 years of age and fuses to the proximal ulna by age 14 years. Persistence of the physis into adulthood may occur and can be confused with a fracture; clues to this condition include its commonly bilateral nature and often familial tendency. In addition, patella cubiti, an accessory ossicle embedded in the distal triceps, may be present and likewise be mistaken for a fracture.
Classification of Olecranon Fractures
Morrey classified olecranon fractures according to criteria regarding stability, comminution, and displacement (Fig. 56-1). The Mayo Classification thus divides olecranon fractures into three types, provides a basis for a rational treatment algorithm by fracture type and subtype, and conveys prognostic value.
Mayo Type I
Mayo type I fractures are undisplaced fractures characterized by displacement of <2 mm with separation remaining <2 mm with flexion of the elbow to 90 degrees or with extension against gravity. Patients with these fractures are able to actively extend the elbow against gravity. Type I fractures may be further subdivided into type IA, noncomminuted fractures, and type IB, comminuted fractures. Since these fractures are nondisplaced by definition, the degree of comminution is not practically significant, and types IA and IB may essentially be regarded as and treated as the same lesion.
Mayo Type II
Mayo type II fractures are the most common type. These fractures, which are stable fractures with >3 mm of displacement, may be noncomminuted (type IIA) or comminuted (type IIB). Because the collateral ligaments are intact, the forearm is stable relative to the humerus.
Mayo Type III
Mayo type III fractures are unstable, displaced fractures and represent fracture-dislocations. Like types I and II, type III
P.386
fractures may be subclassified into noncomminuted (IIIA) or comminuted (IIIB) types.
|
Figure 56-1 Mayo Classification of olecranon fractures. Type I fractures are nondisplaced noncomminuted (IA) or comminuted (IB) fractures. Type II fractures are stable displaced fractures and may be noncomminuted (IIA) or comminuted (IIB). Type III fractures are unstable, displaced fractures and may be noncomminuted (IIIA) or comminuted (IIIB). (From Cabenela ME, Morrey BF. Fractures of the olecranon. In: Morrey BF, ed. The Elbow and Its Disorders. Philadelphia: WB Saunders; 2000 , with permission.) |
Avulsion-Type Fractures
Avulsion-type fractures do not fit into the Mayo Classification categories well but are common in the elderly and may result from forces generated by the triceps. In general, little comminution is present.
Complex Olecranon Fracture-Dislocations
Olecranon fractures associated with subluxation of the radial head and or the coronoid process are typically multifragmentary, complex injuries that may be adequately described by the Mayo Classification scheme. Anterior fracture dislocations are often referred to as transolecranon fracture-dislocations, as the mechanism of injury appears to involve anterior displacement of the forearm resulting in the trochlea being driven through the olecranon process. The radial head is displaced anteriorly. This injury, unlike the Bado type I Monteggia fracture, is characterized by instability of the ulnohumeral joint with a preserved radioulnar relationship. Posterior fracture dislocations of the olecranon are more similar to type II Monteggia fractures, with posterior dislocation of the radial head, an apex posterior fracture of the ulna, and similar implications for the stability and function of both the ulnohumeral joint as well as the forearm. These fractures may be considered a variant of the posterior Monteggia lesion. Both posterior and anterior variants are commonly associated with basal fractures of the coronoid. In anterior olecranon fracture dislocations, reduction of the olecranon and coronoid fracture fragments results in restoration of stability with little implications for forearm dysfunction. Posterior olecranon fracture dislocations, in contrast, have important implications with elbow instability and forearm dysfunction common despite fracture reduction.
Diagnosis
Physical Examination and History
Clinical Features
Because the olecranon is subcutaneous, the fracture may often be felt as palpable crepitation. With the exception of some avulsion-type fractures of the olecranon, the fracture
P.387
by nature is intra-articular, so hemarthrosis is frequently present in conjunction with olecranon fracture. Although this sign may be obfuscated by pain caused by the injury, inability to actively extend the elbow against gravity may be an important indication of triceps discontinuity. Because of the proximity of the ulnar nerve, the first and each subsequent examination should document the status of the ulnar nerve.
|
Figure 56-2 Flow chart representing the evaluation and decision-making processes involved in the workup and treatment of olecranon fractures. |
Radiologic Features
Anteroposterior and true lateral radiographs should be obtained to aid in diagnosis and treatment considerations. The true lateral film should be examined to determine the extent and nature of the fracture pattern and to evaluate for the presence of other lesions such as a radial head fracture or dislocation, or distal humerus or coronoid fractures. A radiocapitellar view may be helpful to assess concomitant pathology.
Diagnostic Workup Algorithm
Figure 56-2 presents a diagnostic workup algorithm.
Treatment
Surgical Indications/Contraindications and Postoperative Management
For Mayo type I fractures, conservative nonoperative management is preferred. The patient is placed in sling immobilization for comfort with early active gentle range of motion exercises commencing no later than 7 to 10 days postinjury. Close follow-up (weekly) with radiographs is essential to rule out displacement and need for alternative treatment. Restrictions on active resisted elbow extension and weight bearing should be maintained for 6 to 8 weeks with gradual increases in these activities as tolerated. Rarely, in select patients, type I fractures may benefit from open reduction and internal fixation to allow immediate motion and stability. Some type I fractures may be treated with immobilization in a long arm cast at 90 degrees of flexion for 3 to 4 weeks. Thereafter, protected range of motion with avoidance of flexion >90 degrees until radiographic evidence of bony healing occurs, usually at 6 to 8 weeks, is recommended. Range of motion exercises may be commenced at an earlier time point in select patients, such as the elderly, in whom stiffness occurs more frequently.
Displaced fractures (Mayo types II and III) are best treated surgically with either excision or open reduction and internal fixation. Goals of surgical management include restoring the articular congruity and stability of the elbow, maintaining extension power, and providing stable anatomic fixation such that early range of motion is possible, thereby lessening the risk of postoperative stiffness. Options include tension band wiring, intramedullary screw placement, plate-and-screw constructs, bioabsorbable pins, or excision. Tension band wiring using standard AO technique is generally accepted and widely used as treatment for most olecranon fracture patterns amenable to this fixation technique (Fig. 56-3).
P.388
Tension band wiring converts tensile forces across the fracture to compressive forces that, with motion, exert compression across the fracture site. It may be favored over plate-and-screw fixation due to requirements for less soft tissue dissection and less periosteal stripping. However, this fixation technique may have technical challenges and be associated with undesirable postoperative sequelae. Because of the subcutaneous nature and location of the elbow, prominent hardware may be problematic, with many patients in one series reporting hardware-related pain (24%) and functional difficulties (32%) relieved by hardware removal. Hardware removal rates are ≤81% in some series. Nevertheless, ≤97% good to excellent results have been widely reported with use of tension band wiring using proper technique. However, for fractures with fragments distal to the coronoid, plate-and-screw osteosynthesis is preferred, as these more distal fragments are usually not adequately fixed by tension band wiring. Likewise, more comminuted
P.389
fractures or oblique patterns are best treated with plate-and-screw fixation to optimize stability. In the authors' experience, plate-and-screw osteosynthesis provides the optimal fixation stability with minimal complications.
|
Figure 56-3 Line drawing demonstrating optimal AO technique for tension band wiring. Reduction of the fracture is performed with pointed forceps (A), and parallel Kirschner wires are driven obliquely from proximal to distal until the volar cortex is penetrated (B). A 2.5-mm drill is used to create a transverse hole distally to accept the tension wire (B). The 1.0- or 1.2-mm wire with a prefabricated loop is introduced under the triceps and the two K-wires, then through the transverse hole (C). As an alternative, two separate wires may be used (C). The wires are grasped at the base and twisted together and the twists laid down flat on the bony surfaces (D′ and F′). Subsequently, the K-wires are pulled back slightly, cut obliquely, and bent into hooks. The hooks are then impacted into bone over the tension band (E, E′, and F′). (From Heim U. Forearm and hand/mini-implants. In: Muller ME, et al., eds. Manual of Internal Fixation: Techniques Recommended by the AO-ASIF Group. 3rd ed. New York: Springer-Verlag; 1991 , with permission.) |
|
Figure 56-4 This 84-year-old right hand–dominant woman experienced a syncopal episode and fell down the stairs at home. She sustained concomitant fractures of the left proximal humerus, left distal radius, left ulnar styloid, and a fracture of the left olecranon(A) treated with excision of the proximal fragment (B and C). At 6 months postoperatively, she was painfree and her range of motion in the flexion extension arc was from 20 to 135 degrees; pronation was to 70 degrees and supination was to 70 degrees. |
Excision of fracture fragments with advancement and reinsertion of the triceps is preferred for elderly, low-demand patients (Fig. 56-4A, B), for nonunions, in those with poor soft tissue viability, for avulsion-type extra-articular fractures, and in cases with severe comminution as in Mayo type IIB, or rarely, type IIIB fractures (Fig. 56-4). Disadvantages of excision include subsequent risks of triceps weakness, instability, stiffness, and a theoretical risk for increased arthrosis. Biomechanical studies suggest that decreased extension strength may be minimized with reattaching the triceps at a more posterior site. McKeever and Buck determined that one may excise ≤80% of the olecranon without sacrificing stability if the coronoid and anterior soft tissues are intact. If anterior damage is present or if comminution extends as far distally as the coronoid process, instability is a sequela if too much proximal ulna is excised. In addition, An et al. noted increasing instability of the elbow with olecranon excision. However, satisfactory clinical outcomes (Fig. 56-4A, B) have been described for treatment of olecranon fracture by excision when used in appropriate patient populations. The nature of the procedure, in which hardware is absent, may lead to decreased local complications and need for subsequent procedures relative to other surgical treatment options. Despite documented satisfactory outcomes with excision, some speculate that excision may lead to development of arthrosis. Biomechanical studies document increased forces across the ulnohumeral joint following excision relative to fixation with tension band wiring, suggesting that abnormal joint forces that may predispose to arthrosis may follow excision.
P.390
Intramedullary screw or nail fixation is generally not recommended because of their less reliable fixation stability in vivo. In addition, potentially problematic with intramedullary nailing are fracture malreduction secondary to off-axis placement of the nail, possible damage to the triceps muscle or the ulnar nerve during locking-screw placement, and the effect of cyclical loading as well as union rate.
Bioabsorbable fixation may be desirable because of the potential to avoid future operations for hardware removal. Satisfactory outcomes in a few patients have been noted; however, further clinical experience is needed to determine the role that bioabsorbable fixation techniques will assume in the future.
Plate-and-screw constructs are preferred by the authors for most fractures and are necessary to treat all oblique fractures, fractures with extensive comminution, and fractures with fragments distal to the coronoid.
Mayo type IIA fractures are usually adequately treated with tension band wiring. Intramedullary fixation has also been described for selected patients, although reported outcomes have been variable and biomechanical data is less supportive of this technique.
Type IIB fractures are treated according to the age and activity level of the patient. In patients younger than 60 years of age, anatomic reduction of fracture fragments followed by plate-and-screw fixation is the treatment of choice. Care should be taken to avoid shortening the articular groove of the ulna between the olecranon process and the coronoid process, as doing so may lead to early arthritis. In older patients, or when comminution is severe, excision of proximal fragments with advancement and reinsertion of the triceps tendon may be preferred.
Mayo type III fractures, displaced unstable fractures, represent the most difficult treatment challenge of all olecranon fractures and are associated with the highest complication rates and least satisfactory outcomes. Type III fractures are associated with a high incidence of concomitant pathology, such as ligamentous trauma or bony injuries of the radial head or coronoid or distal humerus; these should be addressed at the time of olecranon fixation. Type III olecranon fractures typically require plate fixation and ligamentous reconstruction. One may consider application of a hinge fixator if stability is not restored.
Noncomminuted (IIIA) fractures may be treated with a plate-and-screw construct and anatomic reduction. Comminuted (type IIIB) fractures may likewise be treated with plate osteosynthesis or very rarely be treated with excision of fracture fragments, although instability is likely.
Olecranon fracture dislocations require special considerations for treatment. Because of inherent instability of these fracture patterns, they are best treated with plate-and-screw osteosynthesis. Contoured plates are preferred; one-third tubular plates lack the stiffness necessary to withstand early range of motion and have been associated with early loosening or fatigue fractures. If a concomitant anteromedial coronoid fracture fragment is present, it should be fixed to optimize stability of the elbow. The integrity of the lateral collateral ligament (LCL) and the anteromedial coronoid are important factors in stability of the fracture.
When comminution is extensive, a skeletal distractor or temporary external fixation device may be helpful to facilitate reduction; after satisfactory reduction is obtained, definitive fracture fixation using plate and screws with or without augmentation with tension band wiring is usually possible. If extensive comminution is present such that plate and screw fixation does not provide sufficient fracture stability, augmentation with tension band wiring through the triceps insertion may facilitate stable fixation.
Surgical Technique
A dorsal midline longitudinal incision curving over the olecranon is recommended to avoid placing the incision over the subcutaneous bone. Medial and or lateral flaps may be raised to access other bone or ligamentous structures; alternatively, concomitant radial head or coronoid fractures may be treated through the window created by the olecranon fracture.
Excision may be performed by sharp dissection of fracture fragments from the triceps aponeurosis, and longitudinal drill holes made through the proximal ulna to secure the triceps tendon down to bone (Fig. 56-4).
Tension band wiring may be performed using the standard AO technique (Figs. 56-3 and 56-5). Bone reduction clamps are used to reduce the fracture. A superficial drill hole in the distal fragment may be useful to give a traction site for the jaws of the bone reduction forceps. Following reduction, two parallel 1.6-mm K-wires are introduced from the posterior aspect of the olecranon aiming anteriorly and obliquely just through the anterior cortex. A 2.5-mm hole is
P.391
drilled transversely in the distal fragment for placement of a 1.0-mm or 1.2-mm cerclage wire with a prefabricated loop; alternatively, two cerclage wires may be used. The wire is then routed under the triceps tendon and K-wires to create a figure-of-8 construct. Tensioning is performed symmetrically on each side. The K-wires are pulled back slightly, cut and bent, and finally the bend ends are impacted into bone.
|
Figure 56-5 This 60-year-old nurse practitioner fell while running and sustained a type IIA olecranon fracture (A and B). She underwent open reduction and internal fixation with tension band wiring (C and D). Subsequently, at latest follow-up she had range of motion from 10 to 100 degrees in the flexion/extension arc. She complained of prominent hardware and underwent hardware removal at 20 months after her fracture fixation. |
Plate osteosynthesis is likewise performed using standard AO technique (Fig. 56-6). The plate may be applied over part of the triceps insertion without muscle or periosteal elevation to optimize bone healing, or the triceps may be split longitudinally and mobilized. If a concomitant anteromedial coronoid fracture fragment is present, it should be fixed to optimize stability of the elbow. When comminution is extensive, a skeletal distractor or temporary external fixation device may be helpful to facilitate reduction; after satisfactory reduction is obtained, definitive fracture fixation using plate and screws with or without augmentation with tension band wiring is usually possible. If extensive comminution is present such that plate-and-screw fixation does not provide sufficient fracture stability, augmentation with tension band wiring through the triceps insertion may facilitate
P.392
stable fixation. Restoration of the olecranon and coronoid facets is key as the intervening segment, the transverse ridge of the olecranon, contributes little surface contact area to the articular interface.
|
Figure 56-6 This 66-year-old right hand–dominant retired laboratory technician slipped on the ice and fell, sustaining a direct blow to her left elbow and this Mayo type IIA fracture of the olecranon (A and B). She underwent plate-and-screw osteosynthesis (C and D). At 18 months postoperatively, she was painfree and her range of motion was 0 to 140 degrees, with supination to 70 degrees and pronation to 80 degrees. |
The wound is then closed in the standard fashion and a posterior plaster dressing is applied in full extension. The arm should be elevated overnight and the initial dressing changed on the second day. Active and passive motion is then initiated. Alternatively, if for any reason the operative fixation was felt to be less than optimal, splinting may be continued for 3 to 4 weeks to allow for some bony healing. Protected use of the extremity is maintained with minimal weight bearing and no resistance greater than that of gravity for 6 weeks or until radiographic evidence of healing is seen.
Complications
Complications of olecranon fracture include nonunion or malunion, infection, loss of motion, ulnar nerve symptoms, arthrosis, and need for additional procedures, such as hardware removal. Loss of motion may be problematic, particularly a 10- to 15-degree extension lag. This appears to be
P.393
related to immobilization. Radiographic evidence of degenerative changes in the ulnohumeral joint has been documented in 20% to 50% of patients ≤15 to 25 years following olecranon fracture, but is generally asymptomatic. Symptomatic hardware is the most frequent complication, requiring removal in 11.4% to 81% of patients. Hardware prominence is more common in tension band wiring relative to other fixation techniques, such as figure-of-8 wiring or plate-and-screw constructs. The risk of problematic hardware with tension band wiring is decreased if attention to proper AO technique is observed and wires are bent 180 degrees and impacted into bone with the triceps securely sutured over the wires.
Results and Outcomes
Outcomes following olecranon fracture are generally good to excellent, with most series noting satisfactory outcomes and restoration of normal or near-normal function in >95% of patients.
In conclusion, olecranon fractures are commonly seen in orthopedic practice and with appropriate treatment, generally have good to excellent outcomes with little adverse sequelae. Decreased range of motion, radiographic evidence of degenerative changes, and requirement for hardware removal are common but generally are not devastating complications, and may be obviated by attention to proper technique, anatomic reduction, and proper postoperative management.
Suggested Readings
Amis AA, Miller JH. The mechanisms of elbow fractures: an investigation using impact tests in vitro. Injury. 1995;26(3):163–168.
An KN, Morrey BF, Chao EY. The effect of partial removal of the proximal ulna on elbow restraint. Clin Orthop. 1986;209:270–279.
Bailey CS, MacDermid J, Patterson SD, Outcome of plate fixation of olecranon fractures. J Orthop Trauma. 2001;15:542–548.
Bostman OM. Metallic or absorbable fracture fixation devices. A cost minimization analysis. Clin Orthop. 1996;329:233–239.
Boyer MI, Galatz LM, Borrelli J, Jr, et al. Intra-articular fractures of the upper extremity: new concepts in surgical treatment. Instr Course Lect. 2003;52:591–605.
Bucholz RW, Heckman JD, eds. Rockwood and Green's Fractures in Adults. 5th ed. Philadelphia: Lippincott, Williams & Wilkins; 2001.
Cabenela ME, Morrey BF. Fractures of the olecranon. In: Morrey BF, ed. The Elbow and Its Disorders. Philadelphia: WB Saunders; 2000.
Colton CL. Fractures of the olecranon in adults: classification and management. Injury. 1973;5(2):121–129.
Compton R, Bucknell A. Resection arthroplasty for comminuted olecranon fractures. Orthop Rev. 1989;18(2):189–192.
Didonna ML, Fernandez JJ, Lim TH, et al. Partial olecranon excision: the relationship between triceps insertion site and extension strength of the elbow. J Hand Surg Am. 2003;28(1):117–122.
Doornberg JD, Ring JD, Jupiter JB. Effective treatment of fracture-dislocations of the olecranon requires a stable trochlear notch. Clin Orthop. 2004;429:292–300.
Estourgie RJ, Tinnemans JG. Treatment of grossly comminuted fractures of the olecranon by excision. Neth J Surg. 1982;34(3):127–129.
Evans MC, Graham HK. Olecranon fractures in children. Part 1: a clinical review; Part 2: a new classification and management algorithm.J Pediatr Orthop. 1999;19:559–569.
Fern ED, Brown JN. Olecranon advancement osteotomy in the management of severely comminuted olecranon fractures. Injury. 1993; 24(4):267–269.
Fyfe IS, Mossad MM, Holdsworth BJ. Methods of fixation of olecranon fractures. An experimental mechanical study. J Bone Joint Surg Br. 1985;67(3):367–372.
Gartsman GM, Sculco TP, Otis JC. Operative treatment of olecranon fractures. Excision or open reduction with internal fixation. J Bone Joint Surg Am. 1981;63:718–721.
Hak DJ, Golladay GJ. Olecranon fractures: treatment options. J Am Acad Orthop Surg, 2000;8(4):266–275.
Heim U. Forearm and hand/mini-implants. In: Muller ME, et al., eds. Manual of Internal Fixation: Techniques Recommended by the AO-ASIF Group. 3rd ed. New York: Springer-Verlag; 1991.
Helm RH, Hornby R, Miller SW. The complications of surgical treatment of displaced fractures of the olecranon. Injury. 1987;18(1):48–50.
Horne JG, Tanzer TL. Olecranon fractures: a review of 100 cases. J Trauma. 1981;21(6):469–472.
Horner SR, Sadosivan KK, Lipka JM, et al. Analysis of mechanical factors affecting fixation of olecranon fractures. Orthopedics. 1989;12:1469–1472.
Kamineni S, Hirahara H, Pomianowski S, et al. Partial posteromedial olecranon resection: a kinematic study. J Bone Joint Surg Am. 2003;85-A(6):1005–1011.
Karlsson MK, Hasserius R, Kailsson C, et al., Fractures of the olecranon: a 15- to 25-year followup of 73 patients. Clin Orthop. 2002;403:205–212.
Karlsson MK, Hasserius R, Besiakov J, et al. Comparison of tension-band and figure-of-eight wiring techniques for treatment of olecranon fractures. J Shoulder Elbow Surg. 2002;11(4): 377–382.
McKay PL, Katarincic JA. Fractures of the proximal ulna olecranon and coronoid fractures. Hand Clin. 2002;18(1):43–53.
McKeever FM, Buck RM. Fracture of the olecranon process of the ulna: treatment by excision of fragment and repair of triceps tendon.JAMA. 1947;135:1–5.
Moed BR, Ede DE, Brown TD. Fractures of the olecranon: an in vitro study of elbow joint stresses after tension-band wire fixation versus proximal fracture fragment excision. J Trauma. 2002;53:1088–1093.
Molloy S, Jasper LE, Elliott DS, et al. Biomechanical evaluation of intramedullary nail versus tension band fixation for transverse olecranon fractures. J Orthop Trauma. 2004;18(3): 170–174.
Morrey BF. Current concepts in the treatment of fractures of the radial head, the olecranon, and the coronoid. Instr Course Lect. 1995;44:175–185.
Morrey BF. Master techniques in orthopaedic surgery. In: Morrey BF, ed. The Elbow. 2nd ed. Philadelphia: Lippincott Williams & Wilkins; 2001.
Mullett JH, Shannon F, Noel J, et al. K-wire position in tension band wiring of the olecranon—a comparison of two techniques. Injury. 2000;31(6):427–431.
Nowinski RJ, Nork SE, Segina DN, et al. Comminuted fracture-dislocations of the elbow treated with an AO wrist fusion plate. Clin Orthop Relat Res. 2000;378:238–244.
O'Driscoll SW, Jupiter JB, Cohen MS, et al. Difficult elbow fractures: pearls and pitfalls. Instr Course Lect. 2003;52:113–134.
Ring D, Jupiter JB, Sanders RW, et al. Transolecranon fracture-dislocation of the elbow. J Orthop Trauma. 1997;11:545-550.
Rommens PM, Schneider RU, Reuter M. Functional results after operative treatment of olecranon fractures. Acta Chir Belg. 2004;104(2):191–197.
Wolfgang G, Burke F, Bush D, et al. Surgical treatment of displaced olecranon fractures by tension band wiring technique. Clin Orthop. 1987;224:192–204.