Fractures of the olecranon in adults: classification and management

Fractures of the olecranon in adults: classification and management

Injury, 5, 121-129 121 Fractures of the olecranon in adults: classification and management C. L. Colton Royal National Orthopaedic Hospital. London ...

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Injury, 5, 121-129

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Fractures of the olecranon in adults: classification and management C. L. Colton Royal National Orthopaedic Hospital. London Summary A simple classification of fractures of the adult

olecranon process is proposed and used as a basis for making recommendations about .treatment. Possible mechanisms of injury are discussed. Surgical management varies according to the fracture type and certain modifications and applications of previously described techniques are recommended, together with a review of some of the relevant literature.

results of trauma to make a choice between a fully comprehensive grouping which, whilst including every possible variety of injury to the part, is too large and unwieldy for day-to-day use, and the alternative of a simpler classification which is easy to remember and use, accepting that a small proportion representing the rare types will remain unclassifiable. The second system has been adopted here.

PROPOSED C L A S S I F I C A T I O N FRACTURES of the olecranon are exceedingly rare in children (Maylahn and Fahey, 1958), almost certainly due to the shortness of the bony process in early years, and are well documented, especially in association with injury to the radial head (Wright, 1963; Theodorou, 1969; Pollen, 1973). However, the management of the adult olecranon fracture forms a significant part of general fracture practice and it is therefore surprising that there is no generally accepted classification of these injuries upon which to base rational treatment, although this need is universally recognized in the case of the majority of fracture types. This work proposes a simple classification of olecranon fractures, which serves as a basis for the selection and conduct of correct lines of surgical treatment for each injury type. It is a universal problem in the classification of the

Fig. l.--Diagram to show the typical site for the avulsion type of fracture of the olecranon process (Group 1).

Olecranon fractures can be divided into four main groups: 1. Avulsion group. 2. Oblique group. 3. Fracture-dislocation (Monteggia) group. 4. Unclassified group.

Fig. 2.--Radiograph of a typical, minimally displaced avulsion fracture in the arthritic elbow of an elderly male. Further displacement is prevented by the integrity of some of the more distally inserted fibres of the triceps tendon.

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1. Avulsion group In this pattern of injury a transverse fracture line separates a small proximal fragment of the olecranon process from the rest of the ulna

(Fig. 1). The fracture may be undisplaced (Fig. 2) or may be distracted by those fibres of triceps brachii which are inserted into the fragment (Fig. 3).

This type of fracture is more common in the elderly.

2. Oblique group This group comprises a range of comminution of the olecranon process in which the primary failure is represented by an oblique fracture plane starting near the deepest part of the trochlear notch and running dorsally and distally to emerge on the subcutaneous crest of the proximal part of the ulna (Fig. 4).

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Fig. 3.--Radiograph of a distracted avulsion fracture of the olecranon.

J A Fig,. 4.--A, Diagram to show how the oblique group of olecranon fractures (Group 2) comprises a spectrum of comminution from a single oblique fracture (Stage A) to those with a depressed (Stage C) or comminuted (Stage D) central articular segment. B, A sagittal split may occur in the proximal fragment in any of these injuries.

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In stage A this is the only fracture and the proximal half of the olecranon is then extended by triceps' action (Fig. 5). The second stage B of this injury is where following the oblique fracture the pressure of the trochlea separates off a cuneiform central fragment usually from the distal portion of the olecranon (Fig. 6).

depressed central fragment is comrninuted and impacted: stage D (Fig. 8). A further modification of the oblique type of injury is occasionally seen where the proximal portion of the olecranon is split by a fracture in the sagittal plane (Fig. 4) and this, combined with a depressed or comminuted central segment, is probably the commonest form of olecranon comminution.

Fig. 5.--Radiograph showing a single oblique

Fig. 6.--Radiograph of an oblique olecranon fracture associated with a minimallydepressed central articular segment (arrowed). This is only appreciable by observing the eccentricity of the curves of the central segment and the trochlea.

fracture (Stage B).

Fig. 7.--Radiograph showing an oblique fracture (type 2C) with a depressed central articular segment. Also a small central fragment remains associated with the main proximal fragment. The radiograph after incomplete reduction (Fig. 17) shows these fragments more clearly. Where the violence of injury has been greater, the compressive force of the lower humerus acting as a fulcrum about which the olecranon is bent, depresses this central cuneiform fragment and, at the same time frequently crushes the cancellous bone of the two main fragments: stage C (Fig. 7). In the more severe type the

Fig. 8.--Radiograph showing an oblique fracture with comminution of the central articular segment (type 2D).

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3. Fracture-dislocation (Monteggia) group Here the olecranon fracture is at, or fractionally proximal to, the level of the tip of the coronoid process (Fig. 9) so that a plane of instability is present through the fracture and the radiohumeral joint (Fig. 10). This may result in anterior fracture-dislocation of the elbow, rarely posterior, or valgus subluxation with secondary injury to the radial head (Fig. 11). I

4. Unclassified group The unclassified group includes those severely comminuted fractures of the olecranon process which usually result from major direct violence, frequently due to high velocity trauma. The multiple fracture planes are atypical, there is usually crushing of many of the fragments and they may be associated with fractures of the lower humerus and the shafts of the forearm bones (Fig. 12).

M E C H A N I S M OF INJURY Group 1 The avulsion injury is not frequently associated with direct violence to the point of the elbow and is usually seen in older subjects. It is generally agreed that this is a ' pull-off' fracture due to the action of the triceps with the elbow extended. Frequently a history of a fall on the outstretched hand is elicited.

Fig. 9.--Diagram of the Monteggia type of dislocation of the elbow associated with olecranon fracture (Group 3).

Fig. lO.--Radiograph showing a distally placed, comminuted fracture of the olecranon process with anterior dislocation of the elbow. This is due to a shearing force.

Fig. 11.--Radiograph showing subluxation of the radiohumeral joint associated with a distal olecranon fracture and a compression fracture of the radial head. This is caused by valgus deformation of the elbow.

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Group 2 Weber (1965) suggests that the oblique olecranon fracture is due to bending of the olecranon by hyperextension of the elbow but the observation of the frequent association with central fragment depression and cancellous bone compression by the trochlea negates this hypothesis. It is much more likely that the oblique group of fractures

force applied to a bone under axial compression o r distraction produces not a transverse fracture but an oblique one.

Group 3 In the anterior Monteggia type of injury with a transverse basal olecranon fracture the deforming force is probably of a shearing nature as in the ' side-swipe' type of violence. The association of compression fracture of the radial head with a number of fractures in this group, however, suggests that a valgus force has been applied to the elbow.

TREATMENT Groups 1 and 2 The principle of primary internal fixation and

Fig. 12.--Radiograph to show the grossly disorganized elbow due to a comminuted fracture of the olecranon and upper ulna caused by severe, direct violence.

early mobilization of those fractures where the action of a powerful muscle or ligament tends to distraCt the bony fragments is widely accepted. It is generally recognized, therefore, that surgery is the treatment of choice for displaced olecranon fractures. The basis of management of these types of olecranon fracture is to resist the deforming force which is not only one of distraction but of bending over the lower end of the humerus by the action of the elbow flexor and extensor muscles. In any bending moment applied to a



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A B Fig. 13.--A, Shows the forces generated in a solid body which is bent about a fulcrum. Compression forces act along the surface next to the fulcrum, whereas that opposite the fulcrum is subjected to a distraction force. B, Shows how a traction absorbing fixation on the surface opposite the fulcrum causes the deforming force to produce compression throughout the width of the body. result from a bending moment about the trochlea fulcrum caused by the sudden protective, synergistic contractions of the elbow flexors and extensors. Olecranon fracture has been reported in a weight-lifter during a snatch lift (Salpekar, 1966). The violence of this deformity would be increased by falling onto the flexed elbow at the same time. Aims (1961) has shown that a bending

rigid structure about a fulcrum there is an axial compression force along the surface adjacent to the fulcrum and a distraction force along the surface distant from and opposite to the fulcrum (Fig. 13A). Fixation by resistance of the distraction effect opposes the bending moment and also utilizes the bending forces to compress the fragments: the tension band principle (Fig. 13B).

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The most logical and practical form of fixation in accordance with this principle is that described by Weber and Vasey (1963). After reduction, the fragments are provisionally fixed with two parallel, intramedullary Kirschner wires and then a figure-of-eight loop of 20 S.W.G. stainlesssteel wire is passed through a coronal drill hole in the distal fragment. The loop is then crossed over on the dorsal surface of the olecranon,

tendency of the Kirschner wires to back out of the bone has been overcome by bending them over through 180° and driving the cut ends back into the proximal fragment (Fig. 14). Where a central cuneiform fragment is depressed, a frequent finding has been impaction of adjacent cancellous bone of the main fragments. This crushed surface is often seen to be smoothly curved corresponding to the form of the trochlea



Fig. 14.--Diagram of the Weber-Vasey tractionabsorption wiring technique• passed around the protruding Kirschner wires, then tightened and secured with a twist (Fig. 14). Weber (1970) has suggested that both limbs of the figure-of-eight should be twisted (Fig. 15) in order to increase the rigidity of the fixation but this has been found to be unnecessary. Furthermore this makes it much more difficult to remove the wire without wide exposure. The single twist wire can be withdrawn by division between the Kirsch.ner wires and traction on the limb of the figure-of-eight bearing the twist. In the double twist technique the second twist would jam in the drill hole and must be removed separately through a larger incision. The

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twist modification of the tractiontechnique suggested by Weber•

Fig. 16.--Diagram to show how impacted cancellous bone can leave a gap beneath an elevated central articular segment. This gap has curved surfaces due to the shape of the trochlea against which the bone was forced, and it may be filled with cancellous graft in order to stabilize the reduction of a depressed central fragment. and on elevation of the central fragment an underlying defect declares itself (Fig. 16). This gap may be packed with cancellous bone from the greater trochanteric region if the elevated fragment is unstable. The maintenance of the correct position of this fragment is difficult to achieve (Fig. 17) but is as essential as in any intra-articular fracture. The fact that the elbow joint does not normally bear weight does not

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mean that deformity of the joint surface will not lead to osteoarthritis, it simply delays by a few years its inevitable onset. In consequence, the younger the patient, the greater the need for anatomical reposition of the fragments. A severely comminuted central fragment cannot be reconstituted and has to be excised, leaving the gap to fill with fibrous tissue modelled on the trochlea (Fig. 18). This gap should not be filled with cancellous bone for fear of loosening

exploration, being rarely clearly visible on the original radiograph.

Fig. 17.--Radiograph showing an incompletely elevated central articular segment and the resultant deformity of the trochlear notch. This is the postreduction radiograph of the patient illustrated in

Fig. 18.--Radiograph taken after excision of a comminuted central segment in a typ.~ D injury (Fig. 8) and fixation with the Weber-Vasey technique.

Group 3 Where the olecranon fracture line is approximately level with the radiohumeral joint, even if the radial head is normally located on the original radiograph, the possibility of elbow-joint

Fig. 7.

Fig. 19.--Diagram to show the technique of excision of the central one-third of the olecranon process described by Barford (1972). a fragment of the graft and its escape as a loose body into the joint cavity. Barford (1972) describes an ingenious technique for the excision of the comminuted segment of the olecranon process as illustrated in Fig. 19. The orientation of the osteotomies is critical if a smoothly curved trochlear notch is to be reconstituted and they should be directed accurately along the radius of the trochlear curve at both sites. Where a sagittal split is present in the proximal olecranon, the Kirschner wires should be inserted not parallel but at an acute angle so that as the two proximal fragments slide down the wires when the figure-of-eight loop is tightened they are also approximated side-to-side (Fig. 20). Such sagittal splits may be appreciated only on surgical

instability must be considered and examination under anaesthesia is mandatory. If instability is present and shearing displacement of the fracture has to be prevented, the tension-band wiring principle cannot be applied. It is necessary, in this event, to use an intramedullary fixation device, such as the AO cancellous lag screw, which has proved most satisfactory (Fig. 21), or an ulnar plate. Deane's spike plate (Deane, 1970) may well be of value in this situation although the author has no personal experience of its use.

DISCUSSION Total excision of the proximal olecranon fragments has been advocated by a number of authorities (Rombold, 1934; Dunn, 1939;

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McKeever and Buck, 1947; Adler; May, and Macausland, 1959; Rowe, 1965). In excessively comminuted fractures it may be the only possible form of management, but because of loss

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of leverage for elbow extension and consequent triceps weakening (Hey-Groves, 1939), increased vulnerability of the ulnar nerve (McKeever and Buck, 1947) and possible instability of the elbow

Fig. 20.--Diagram to show the principle of angled Kirschner wires when using the Weber-Vasey fixation where ti3ere is a sagittal split in the proximal olecranon fragment. The radiograph shows this technique in use.

Fig. 21.--Radiographs showing the use of an AO cancellous screw for the intramedullaryfixation of a Group 3 injury. This is the post-fixation radiograph of the case illustrated in Fig. 11.

Colton : Fractures of the Olecranon in Adults

joint in more distally placed fractures it is not to be r e c o m m e n d e d as the treatment of first choice. It is absolutely contra-indicated in the G r o u p 3 injuries. The place for conservative treatment o f olecranon fractures is limited. In the small group where an avulsion type o f fracture remains undisplaced (Fig. 2) due to the integrity of the more distally inserted fibres of the triceps expansion, it is possible to achieve satisfactory union by plaster-of-Paris cast immobilization for three weeks. There is, however, frequently some loss o f the range of elbow-joint motion but it remains nevertheless the treatment o f choice in the elderly patient with this type of injury. Perkins (1936) recommended the early mobilization of even the distracted olecranon fractures and the acceptance of an elongated fibrous union. This management undoubtedly weakens triceps action (Watson-Jones, 1952), by no means results in painless function and is mentioned in order to condemn it, except in the elderly patient who refuses surgery. The immobilization of a distracted fracture in a plaster-of-Paris cast with the elbow fully extended usually produces troublesome hand swelling and stiffness, often results in fibrous union and always causes significant loss of elbow flexion (B/Shler, 1956). Troublesome ulnar nerve adhesion has been reported after conservative treatment o f fractured olecranon (Stewart, 1960).

REFERENCES ADLER, S., MAY, G., and MACAUSLAND,jun., W. R. (1959), 'Olecranon fractures ', J. Bone Jt Surg., 41A, 1540. ALMS, M. (1961), 'Fracture mechanics ', Ibid., 43B, 162.

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BARFORD, B. (1972), personal communication. BOHLER, L. (1956), The Treatment o f Fractures, vol. I, p. 733. New York: Grune & Stratton. DEANE, M. (1970), 'Comminuted fractures of the olecranon: an appliance for internal fixation', Injury, 2, 103. DUNN, N. (1939), ' An operation for fractures of the olecranon ', Br. reed. J., 1,214. HEY-GRoves, E. W. (1939), 'Fracture of the olecranon ', IBM., 1,296. MCKEEVER, F. M., and BucK, R. M. (1947), ' Fracture of the olecranon process of the ulna, treatment by excision of fragment and repair of triceps tendon ', Ibid., 135, 1. MAYLAHN, D. J., and FAHEY,J. J. (1958), ' Fractures of the elbow in children ', J. Am. mecl. Ass., 166, 220. PERKINS, G. (1936), 'Fractures of the olecranon ', Br. reed. J., 2, 668. POLLEN, A. G. (1973), Fractures attd Dislocations hz Children, p. 55. Edinburgh: Livingstone. ROMBOLD, C. 0934), 'Operation for suture of fracture of the olecranon ', J. Bone ,It Surg., 16, 947. Rowe, C. A. (1965), ' T h e management of fractures in elderly patients is different ', Ibid., 47A, 1043. SALPEKAR,P. D. 0966), ' Report of the visit of the 1965 North American Travelling Fellows to Great Britain ', Ibid., 42A, 386. STEWART, J. E. (1960), ' Silent ulnar nerve adhesions: a cause of limited elbow function ', Ibid., 42A, 537. THEODOROO, S. D. (1969), ' Dislocation of the head of the radius associated with fracture of the upper end of the ulna in children ', Ibid., 51B, 700. WATSON-JONES, R. (1952), Fractures and Joint hljuries, vol. 2, p. 519. Edinburgh: Livingstone. WEBER, B. G. (1965), in Technique ofhrternal Fixation o f Fractures (MULLER, M. E., ALLGOWER, M., and WILLENEGGER, H.), p. 167. Berlin: SpringerVerlag. - - - - (1970), personal communication. ----and VASEY, H. (1963), 'Osteosynthese bei olecranon fraktur', Revue Accid. Tray. Mal. Prot., 56, 90. WRIGHT, P. R. (1963), 'Greenstick fracture of the tipper end of the ulna with dislocation of the radiohumeral joint or displacement of the superior radial epiphysis ', J. Bone Jt Surg., 45B, 727.

Requests for reprints should be addressed to:--C. L. Coltort, Esq., F.R.C.S., OrthopaedicDept., Nottingham General Hospital, Nottingham.