Technique for unstable olecranon fracture-subluxations

TECHNIQUE FOR UNSTABLE OLECRANON FRACTURE-SUBLUXATIONS SHAWN W. O’DRISCOLL, PHD, MD, FRCS(C)

These fractures are This article presents a reliable method for treating unstable olecranon fracture-subluxations. not amenable to traditional AOlASIF methods of internal fixation with tension band wiring because of comminution and/or ulnohumeral subluxation. This injury can be successfully treated using a posterior 3.5 DC plate that is bent to an 80" angle at the proximal end. In a preliminary review of six patients so treated, a functional arc of motion was achieved in five of six patients. The range of motion was from 15”& 25”extension to 135” rf: 10” flexion with an arc of 120” +- 35”. The results were excellent(functional arc, no or minimal pain, excellent strength) in four cases. There were three reoperations:one for plate removal, one for ulnar nerve transposition (related to an open distal humerus fracture with soft tissue loss), and one for ligament repair and ORIF of a displaced coronoid fracture. This method of plating cornminuted proximal ulnar fractures with elbow subluxation has the advantages of stable fracture fixation, excellent purchase on even small proximal fragments, and buttressing against elbow subluxation-all of which permit immediate motion. KEY WORDS: elbow, subluxation, olecranon, fracture, dislocation, internal fixation

Complex fractures of the proximal

ulna including

com-

minuted fractures of the olecranon with ulnohumeral subluxation or dislocation are difficult to manage (Fig 1). Traditional forms of internal fixation using the AO/ASIF tension band technique require compression of the fracture site for stability. Compression causes distortion of the normal curvature of the semiulnar notch of the ulna and joint incongruity (Fig 1B). Inadequate compression permits ulnohumeral subluxation to occur when the fracture line or comminution extends anteriorly towards the coronoid (Fig lC,D). Therefore, tension band wiring is

not recommended for unstable cornminuted fracturesubluxations. l-3 SP ecial plates have been used to overcome this problem. The Zuelzer hook plate, originally designed for ankle fractures, was reported by Weseley to provide excellent results in proximal olecranon fractures including those with comminution.4 Deane designed a single spike-plate for cornminuted olecranon fractures5 Some authors have used an AO/ASIF l/3 tubular plate as a buttress plate on the posterior surface of the ulna.’ As this does not provide much fixation on the small proximal fragment, modifications have been suggested to the principle of buttress plating. Some surgeons have suggested bending a l/3 tubular plate and cutting off the plate at the proximal hole to create two sharp prongs that are inserted into or around the proximal olecranon6 The l/3 tubular plate is not particularly strong, and perFrom the Upper Extremity Reconstructive Service, St Michael’s Hospital, University of Toronto, Canada. Presented in part at the Annual Closed Meeting of the American Shoulder and Elbow Surgeons, Vail, CO, September 1992. Address reprint requests to Shawn W. O’Driscoll, PhD, MD, FRCS(C), Associate Professor, Department of Orthopedics, Mayo Clinic, Rochester, MN, 55905. Copyright 0 1994 by W. B. Saunders Company 1048-8888/94/0401-0008$05.00/0

Operative Techniques

in Orthopaedics,

sonal communication

with other surgeons has revealed

that plate breakage sometimes occurs. The goals of treatment of these unstable cornminuted olecranon fracture-subluxations are (1) stable fixation of the small proximal fragment, (2) buttressing of the ulnar shaft against the deforming pull of the anterior elbow flexors, (3) buttressing of the cornminuted fragments within the fracture site, (4) stable fixation of the ulnar shaft, (5) secure fixation of the coronoid, if fractured, and (6) early motion (Fig 2). The purpose of this article is to report a reliable method for stable internal fixation of cornminuted olecranon fracture-subluxations that accomplishes these goals, permits immediate active motion, is easy to perform, and uses standard AO/ASIF equipment that is readily available in the operating room.

MATERIALS AND METHODS Method For Internal Fixation The fracture is exposed with the usual subcutaneous incision and is reduced anatomically. Provisional stabilization is accomplished using K-wires as necessary, including one K-wire passed centrally down the canal of the ulna. Pointed reduction forceps are also helpful. A 7-, 8-, or lo-hole AOlASIF 3.5-dynamic compression (DC) plate is bent to an 80” angle at the proximal end so that one screw hole is over the triceps insertion on the tip of the olecranon when the plate is applied to the posterior surface of the proximal ulna. Contouring is performed with the bending pliers that come with the A0 small fragment set (Fig 3). This is hard on the hands but not difficult to perform. The proximal hole of the plate is then passed over the intramedullary K-wire, and the

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B

Fig 1. (A) Fractures of the olecranon can be unstable due to extension of the fracture toward the coronoid. Comminution increases this instability. The proximal ulna typically subluxates anteriorly due to the unopposed pull of the elbow flexors (brachialis, etc). These fractures behave quite differently from the usual olecranon fractures, are difficult to treat, and are associated with a poorer prognosis. (6) The traditional AO/ASIF method for internal fixation of olecranon fractures with intramedullary K-wires and tension banding relies on compression at the fracture site, which is not possible in cornminuted fractures. If compression is applied, the semiulnar notch of the ulna will be narrowed (arrows) resulting in joint incongruity. (C) If compression is not applied, the reduction is unstable and the fracture can displace. Anterior ulnohumeral subluxation occurs because of the unopposed pull of the anterior elbow flexors. (D) Radiograph of a patient who had been treated by K-wires and tension band technique for an unstable olecranon fracture-subluxation. Stability was not possible due to the comminution and distal fracture line, thus subluxation recurred. Careful inspection of the radiograph reveals that the ulna is still subluxated anteriorly, as indicated by the gap between the coronoid and the trochlea anteriorly (arrows).

plate is applied to the posterior surface of the proximal ulna. It is firmly compressed against the triceps and proximal ulna. It is held with reduction clamps while 4.0-mm fully threaded cancellous screws are inserted in the second and third holes pointing towards the medial and lateral sides of the proximal tip of the olecranon around the K-wire. After the K-wire is removed, a third 4.0-mm fully threaded cancellous screw is inserted in its place. These three screws are all at least 20-mm long and provide excellent fixation of even small proximal fragments. The reduction is confirmed once again, and the remaining screws are then inserted in the distal part of the plate. One or two can pass directly up into the coronoid, providing superb fixation. Interfragmentary compression screws are often useful. If the fracture can be converted to two main fragments by interfragmentary 50

compression, the plate can be used to compress the fracture site by eccentric screw placement. Its posterior location is optimal, as this is the tension side of the fracture. The wounds are closed routinely, a Jones compressive dressing is applied, and the arm is suspended for a day to prevent swelling. A light dressing is then applied and active motion is started on the second day. Special attention must be directed to the coronoid. Displacement of any coronoid fragments must by reduced and fixed. This is best done before reducing the olecranon itself, by working through the fracture site. Reduction of the coronoid is maintained with interfragmentary compression screws placed before application of the plate. After reduction of the olecranon and plate application, it is difficult to assess reduction of the coronoid. SHAWN W. O’DRISCOLL

vere elbow instability.7 In four patients an &hole plate was used, and in one patient a 7-hole plate was used. One patient who had extensive involvement of the coronoid and proximal ulna required a lo-hole plate.

RESULTS

Fig 2. The principals of treating these unstable cornminuted fracture-subluxations are to (1) obtain stable fixation of the small proximal fragment, (2) buttress the ulnar shaft against the proximal fragment to resist the deforming pull of the anterior elbow flexors (arrows), (3) buttress the cornminuted fragments within the fracture site, (4) obtain stable fixation of the ulnar shaft, and (5) secure fixation of the coronoid if fractured. This is best accomplished using a posterior 3.5 DC plate that has been contoured around the proximal olecranon. Plate breakage is extremely unlikely. Three screws can be Inserted into the small proximal fragment.

Patients This is a preliminary report of our clinical results. Six patients with unstable olecranon fracture-subluxations, mean age 46 years (20 to 65), were treated with this method and followed for 3 to 12 months (mean, 9). Follow-up is short, but the purpose of this article is to report the technique, rather than the clinical results. Five patients had anterior subluxation/dislocation of the ulna and radius; one had posterolateral rotatory subluxation. A typical example is illustrated in Fig 4. Five patients had open fractures---all were treated by immediate debridement and internal fixation. One patient had a severely comminuted open-grade 38 fracture of the distal humerus that was fixed during the same operation and received skin grafting 3 days later. Two had associated comminuted type III coronoid fractures with se-

All wounds and fractures healed within 12 weeks (Fig 4). At follow-up, range of motion was from 15” 2 25”extension to 135” + 10” flexion with an arc of 120” + 35”. A functional arc of motion as defined by Morrey et al8 (30 to 130” of flexion) was achieved in five of six patients. The results were excellent (functional arc, no or minimal pain, excellent strength) in four cases. One patient, who healed anatomically with full motion, complained of pain even after plate removal and remained off work on workers compensation. His x-ray showed mild arthritic changes. Removal of the plate did not affect his symptoms. Another patient had residual displacement of a type III coronoid fracture that caused permanent instability and early arthritis. There were three reoperations: one for plate removal, one for ulnar nerve transposition (related to an open distal humerus fracture with soft tissue loss), and one for ligament repair and open reduction and internal fixation (ORIF) of the displaced coronoid fracture. The latter had a poor result due to severe posttraumatic arthritis. None of the other patients required plate removal.

DISCUSSION This method of plating comminuted proximal ulnar fractures with elbow subluxation has the advantages of stable fracture fixation, excellent purchase on even small proximal fragments, buttressing against elbow subluxation with a strong plate that should not break, and can be performed with standard equipment readily available to all orthopedic surgeons. Immediate motion is possible SO posttraumatic stiffness is unlikely. Associated fractures of the coronoid and proximal ulnar shaft can be fixed by using a longer plate and additional interfragmentary compression screws as necessary. This method incorporates the advantages of modifications to the tension band technique proposed by others.4-6 It avoids most of

Fig 3. Contouring the 3.CDC plate. (A) The bending pliers that are used are supplied with the AO/ASIF small fragment set. (8) The proxlmal end of the plate is bent with the pliers to an 80” angle. UNSTABLE OLECRANON

FRACTURE-SUBLUXATIONS

51

Fig 4. (A) Lateral radiograph of a patient with an open cornminuted olecranon fracture-subluxation. The ulna is subluxated anteriorly. The coronoid is also fractured, which is best observed on the anteroposterior (postoperative) view (Fig 4C). (B,C) Postoperative radiographs. The wound was debrided and the fracture treated immediately with a contoured 35DC plate and interfragmentary compression screws. Stable anatomic reduction was possible despite the comminution. Active motion started when the wound was closed three days after debridement and ORIF. The fracture was healed in 6 weeks. (BE) Radiographs at 6 months.

their disadvantages such as the requirement for a special plate4T5or the possibility of plate failure (l/3 tubular plate). It was initially anticipated that plate removal might be

required, but this has not been necessary in most cases, perhaps because of its rounded contour and the fact that the screws sit completely flush with the surface of the plate (Fig 5A). In contrast, when a l/3 tubular plate is

Fig 5. The 3.5DC plate is strong and will not likely break although it is thick. (A) Plate removal has not generally been necessary, perhaps because of its smooth contour and the fact that the screws are recessed into the plate to decrease their prominence. (B) In contrast, although the l/3 tubular plate is thinner, the screw heads are much more prominent and likely to cause skln irritation when rubbed against hard surfaces.

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SHAWN W. O’DRISCOLL

used, the screw heads actually are more prominent because they project beyond the plate (Fig 5B). This gives the patient a “row of bumps” along the subcutaneous border of the ulna, and these prominences are more likely to strike or rub against tables and other surfaces. However, even if plate removal is required, it is a minor procedure with minimal morbidity and a small price to pay for the high likelihood of a good result from this difficult problem. Some have tried plating along the medial or lateral borders of the ulna. This method is not as reliable because it is only possible to place one or two short screws in the proximal fragment. Another reason that plating medially or laterally is less desirable is that the plate must be contoured exactly to meet the curvature of the proximal ulna or it will cause displacement. The posterior surface of the ulna is flat and contouring of the proximal end of the 3.5-DC plate as described in this article is easy and The fracture is will not cause fracture displacement. held reduced by the straight portion of the plate. Finally, the plate is best placed posteriorly for an optimum buttressing effect and to resist tension (fracture distraction) .

Indications

For Contoured

DC Plate

This plate is indicated for acute treatment of cornminuted olecranon fractures, olecranon fractures extending close to the coronoid, olecranon fractures with ulnohumeral subluxation, and olecranon nonunions. Open wounds are not a contraindication, although soft tissue defects should be reconstructed so that the plate, bones, and nerves are all covered.

UNSTABLE OLECRANON

FRACTURE-SUBLUXATIONS

SUMMARY In summary, this method of fixation for cornminuted unstable olecranon fracture-subluxations appears to accomplish all the goals of treatment and is biomechanically sound. It has been successfully used for olecranon nonunions as well and might be the treatment of choice for them. Cancellous bone graft can be compressed between the fracture ends. Shortening because of comminution or bone loss can be prevented by the use of an intercalary tricortical iliac crest bone graft that can still be compressed, permitting immediate motion.

ACKNOWLEDGMENTS I am grateful to Chantal Lichaa, BA, BSc, BMC, of the Division of Biomedical Communications, University of Toronto, for her detailed illustrations.

REFERENCES 1. Colton CL: Fractures of the olecranon in adults: Classification and management. Injury 5:121-129, 1973 2. Schatzker J, Tile M: Fractures of the olecranon, in Schatzker J, Tile M (eds): The Rationale of Operative Fracture Care: Berlin, SpringerVerlag, 1987, pp 91-95 3. Wolfgang G, Burke F, Bush D, et al: Surgical treatment of displaced olecranon fractures by tension band wiring technique. Clin Orthop 224:192-204, 1987 4. Weseley MS, Barenfeld PA, Eisenstein AL: The use of the Zuelzer hook plate in fixation of olecranon fractures. J Bone Joint Surg [Am] 58A:859-863, 1976 5. Deane M: Cornminuted fractures of the olecranon: An appliance for internal fixation. Injury 2103-106, 1970 6. Chapman MW: Operative Orthopedics. Nonunions and Malunions of the Upper Extremity. Philadelphia, PA, Lippincott, 1988, p 539 7. Regan W, Morrey B: Fractures of the coronoid process of the ulna. J Bone Joint Surg [Am] 71A:1348-1354, 1989 8. Morrey BF, Askew LJ, An K, et al: A biomechanical study of normal elbow motion. J Bone Joint Surg [Am] 63A:872-877, 1981

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