Fractures of the Olecranon and Proximal Ulna

The Problem

Fractures of the olecranon are classically the result of fall on the elbow with eccentric triceps contraction. These range from small extra-articular fragments to intra-articular comminuted fractures that may be associated with elbow dislocations.

Fractures of the proximal ulna are higher energy injuries and are associated with injuries to the proximal radio-ulnar joint; the radial head and the coronoid process; thus representing instability of either the elbow or the proximal radio-ulnar joint (Monteggia fracture dislocation). Commonly used classifications include Bado type based on direction of radial head replacement or Jupiter’ based on level of fracture of the ulna. These fractures are usually operative and require an anatomic fixation to allow for optimal outcome.

Clinical Presentation

Olecranon fractures are sustained secondary to a fall, usually on a flexed elbow; while proximal ulna fractures result from high-energy injuries including motor vehicle accidents or fall from height. The patient presents with pain and swelling with inability to extend the elbow; and a palpable defect at the fracture site in cases of displaced fractures. Swelling and ecchymosis (especially in the older patient on blood thinners) may make palpation of the defect difficult. Abrasions and wounds must be carefully evaluated to rule out an open fracture due to the superficial location of the proximal ulna.

Distal neuro-vascular checks are important with higher energy injuries, with attention to ulnar and posterior interosseous nerves.

Diagnostic Workup

Radiographs include an Antero-Posterior view; lateral view and oblique views if the radial head fracture is suspected. A CT scan is recommended for complex fractures to delineate the presence of a coronoid fracture or radial head fracture morphology to assist in treatment planning. If the elbow is dislocated, as may happen with high energy proximal ulna fractures, a closed reduction should be performed and the elbow splinted prior to further radiographic workup.

Non-Operative Management

Non-operative treatment is indicated for non-displaced or minimally displaced (<2-3mm) olecranon fractures; or those in medically unstable patients where the risk of surgery will outweigh the benefits.

The patient’ arm is placed in a long arm splint initially and is maintained for 1-2 weeks for pain control and then followed by protected range of motion with an elbow-hinged brace for 6-8 weeks. In displaced fractures, fibrous union will allow functional range in low demand patients.

Overall, this treatment option is suboptimal for displaced fractures and will result in weakness of extension and difficulty with overhead activities.

Indications for Surgery

Operative indications are:

• Intra-articular displacement or step-off of >2mm.

• Loss of active elbow extension (as tested with gravity eliminated) implying loss of extensor mechanism.

• Proximal ulna or olecranon fractures associated with elbow instability; and/or radial head or coronoid fractures which may require fixation.

• Open fractures.

Surgical Technique

Implants

Tension band wiring using two parallel K-wires and circlage or figure of eight wires (or sutures) passed through a bone tunnel distally is indicated for simple transverse intra-articular fractures and avulsion fractures (Figure 1). An intramedullary screw (6.5 or 7.3mm cancellous screw) may also be used in lieu of K-wires and is biomechanically superior, but screw head prominence may be an issue.

Figure 1.

Plating is best indicated for comminuted or oblique fracture patterns; the plate can be a one third tubular plate for simple fracture patterns (Figure 2); or a reconstruction type plate or pre-contoured locking plate for comminuted ones.

Figure 2.

Newer implants include olecranon nail which can be used for simpler fracture patterns as well.

For proximal ulna fractures, use of stronger implants, like commercially available pre-contoured plates with a proximal curve that goes around the olecranon and allows for increased proximal fixation are recommended to minimize chances of failure. Reconstruction type plates may also be used and contoured by the surgeon to fix the proximal ulna (Figure 3).

Figure 3.

Excision of smaller fragments (up to 40%) with tendon advancement is reserved for patients with limited function and may have little or no advantage over non-operative care.

Patient set up

The patient can be positioned supine with the arm across the chest; lateral or prone with the elbow flexed over a padded post. The position used is dependent on various factors including surgeon experience; presence of other injuries precluding certain positions, for example a spine injury may necessitate prone or supine position; the need for other concurrent surgeries like bilateral elbow fractures or acetabulum fractures may be performed in the prone position. I personally prefer the lateral position which allows easy access to the proximal ulna and extension to medial or lateral side as needed (Figure 4). A tourniquet applied to the upper arm is usually out of the surgical field; however, a sterile one may be used based on surgeon preference.

Figure 3.

Procedure

Surgical repair involves a posterior approach with the incision curved radially around the olecranon process to avoid painful scarring on the point of the elbow. For proximal ulna fractures, extended access may be needed to address radial head or coronoid fractures. Raising a flap underneath the fascia either laterally (Kocher interval between the ECU and Anconeus muscles) to approach the radial head or medially (sub-muscularly around the ulna) for the coronoid will allow access for fixation or replacement.

Once the exposure is completed, the fracture is cleared of in-folded periosteum and blood clots so the fracture ends can be visualized as well as the elbow joint. The articular surface is inspected for injuries and any depression or cartilage loss. Once the fracture pattern is understood, one can reduce the olecranon fracture using a pointed reduction clamp placed through a drill hole distally if needed and use k-wires for initial fixation. If the tension band technique is being used, the K-Wires should be inserted such that they are parallel and engage the anterior cortex distal to the olecranon. This will minimize the chances of them backing out and becoming prominent. The circlage or figure of eight wire is passed through a transverse drill hole distally and then around the base of the K-wires. Holding the elbow in extension these are tightened using one or two knots (Figure 2). The elbow is ranged to confirm adequate fixation. The same technique is used for suture (usually double strand of #5 ethibond or fiberwire); to facilitate passage of suture or wire through the triceps tendon proximally a cannula (angiocath) may be used.

If a plate is used, the initial K-wires must be inserted from either side of the midline of the olecranon to make room for the plate. The triceps tendon is split longitudinally in the midline without compromising its insertion to allow the plate to sit on bone. It is important to assess the plate position on the bone clinically and fluoroscopically before insertion of screws. The first screw inserted is usually the proximal one which goes across the fracture and may engage the anterior cortex similar to the K-wires or go into the canal to allow compression of the fracture as well as ‘uck’ the plate to the bone. Distal screws are then inserted with the fracture reduced and compressed if fracture pattern is amenable.

In proximal ulna fractures, similar techniques as above may be used, however, a few additional steps are required. Use of lag screws for intervening fracture fragments is useful in converting a complex fracture pattern to a simpler one. The coronoid process is fixed using either a screw or a suture passed from the capsule at the base and through drill holes in the ulna and then tied over a bony bridge over the subcutaneous surface or the plate. The plate is now affixed to the bone to regain length and alignment. Finally, the radial head is addressed for fixation or replacement as needed. For radial head fractures, presence of three or more fragments is an indication for radial head replacement; others can be fixed using mini-fragment or pre-contoured locking plates. These plates should be placed in the safe arc of motion to prevent impingement on the radio-ulna joint. Some authors advocate radial head surgery prior to ulna fixation; however, in my practice, I prefer to regain the ulna length and alignment first to help with the radial head.

If a locking plate is used, proximal fixation may be enhanced using locking screws, especially when near the joint and inserted unicortical. Distally, the bone quality in the diaphysis is sufficient for cortical screws and allow compression of the plate to the bone.

Fluoroscopy is useful in assessing reduction and hardware placement. Once fixation is complete the elbow should be taken through a range of motion to assess fracture fixation and elbow joint stability.

Pearls and Pitfalls of Technique

A lateral position with arm over the post allows easy exposure and extending it will help when doing the reduction. Use of a plastic bag (mayo stand cover) for the hand will provide a sterile cover, and a collection bag for irrigation fluid.

When marking the incision, also write out radial (R) and ulna (U) on the skin to aid with intra-operative orientation.

Articular impaction must be identified and elevated using the trochlea as a template; bone grafting (cancellous allograft; or bone graft substitutes) behind it and/or mini fragment screws are used to hold the reduction. In complex, comminuted fractures, use of additional mini-fragment plates will help in reducing small fragments to build up each segment and aid in overall reduction.

If the radial head is not reduced; check the ulna reduction; the most common reason is mal-reduction including shortening which may preclude the radial head from going back into the joint.

In the elderly patients with olecranon fractures, use of supplemental suture passed through the triceps tendon proximally and plate/bone distally will aid in the fixation and reduce failure rates from ‘pullout’ of the bone from the screws proximally due to the triceps contraction.

Potential Complications

The most common complication after olecranon fractures is hardware prominence which may necessitate removal. Wound breakdown secondary to the superficial position of the plate or wires also contributes to the problem.

For higher energy injuries, restriction of range of motion at the elbow and proximal forearm may be minimized by early range of motion and stable fixation. Non-union and implant failure may be seen in comminuted fractures with bone loss or inadequate reduction and fixation.

Post-operative Rehabilitation

The arm is splinted for 7-10 days to allow for soft tissue healing and range of motion at the elbow is allowed after that time; physical therapy is helpful as well. Weight bearing after simple ulna fractures is allowed if needed for use of assistive devices for ambulation. Complex fracture patterns including Monteggia fractures should be maintained non-weight bearing for 6 weeks or till healing is seen.

By 6 weeks, the patient is allowed most activities, once radiographic healing is noted. Return to impact exercises is restricted till bony union is completed, usually 3-4 months or longer (up to 6 months) in highly comminuted proximal ulna fractures with radial head involvement.

Outcomes/Evidence in the Literature

The expected range of motion is dependent on the severity of injury, the quality of the fixation, the post-operative rehabilitation and most patients tend to regain a functional range of motion. The outcome of Monteggia fractures is not as good as those with olecranon fractures and a higher incidence of non-union, restriction of range of motion, development of heterotopic ossification, especially when associated with elbow dislocation.

Villanueva, P, Osorio, F, Commessatti, M, Sanchez-Sotelo, J. “Tension-band wiring for olecranon fractures: analysis of risk factors for failure”. J Shoulder Elbow Surg. vol. 15. 2006. pp. 351-6. (Of the 37 patients reviewed, 17 required hardware removal; mild disability was common, with arthosis seen in those with elbow instability and associated coronoid or radial head fracture.)

Kloen, P, Buijze, GA. “Treatment of proximal ulna and olecranon fractures by dorsal plating”. Oper Orthop Traumatol. vol. 21. 2009. pp. 571-85. (Twenty-three patients with comminuted proximal ulna fractures were fixed with pre-contoured plate; 10 required hardware removal, all healed by 4.8 months and had an average arc of motion of 114 degrees at elbow.)

Ring, D. “Monteggia Fractures”. Orthop Clin North Am. vol. 44. 2013. pp. 59-66.

Ring, D, Jupiter, JB, Sanders, RW, Mast, J, Simpson, NS. “Trans-Olecranon Fracture dislocation of the elbow”. J Orthop Trauma. vol. 11. 1997. pp. 545-50. (Complex fracture patterns were treated in 17 patients with good to excellent results in 15 patients and the authors concluded that this was due to the fact that stable, anatomic fixation was achieved. Two failures were revised from one third tubular to dynamic compression plates.)

Anderson, ML, Larson, AN, Merten, SM, Steinmann, SP. “Congruent elbow plate fixation of olecranon fractures”. J Orthop Trauma. vol. 21. 2007. pp. 386-93.5. (Of 32 patients treated with a plate, five required hardware removal with good to excellent outcomes seen in 92% at 2 year follow-up. The average arc of motion was 120 degrees.)

Strauss, EJ, Tejwani, NC, Preston, CF, Egol, KA. “The posterior Monteggia lesion with associated ulnohumeral instability”. J Bone Joint Surg Br. vol. 88. 2006. pp. 84-9. (Twenty-three patients were reviewed and worse results were seen in the sub group with associated elbow dislocations.)

Summary

Olecranon and proximal ulna fractures span a wide spectrum of injuries and require treatment for repair and early range of motion. Most of these are intra-articular injuries and an anatomic reduction is important. Evaluation of associated injuries including those to the radial head and coronoid and addressing them at the same time will minimize the common complications of elbow and forearm stiffness.

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