Treatment of Distal Humerus Fractures

The Problem

Distal humerus fractures comprise of groups of complex articular injuries. These relatively uncommon fractures represent one of the most challenging fracture fixations with complication being commonplace. The failure of anatomical restoration of the complex articular anatomy, the limited areas for fixation, the tendency for intra-articular comminution and osteoporosis, all render a treatment challenge.

Providing anatomical reduction with a stable fixation is the fundamental goal of treatment allowing for early active motion. Preservation of the extensor mechanism and minimizing soft tissue injury will enhance a more favorable clinical outcome. The common complications include elbow stiffness, heterotopic ossification, ulnar neuropathy, and nonunion.

Clinical Presentation

History

The mechanism of injury mostly occurs from high-energy trauma in young patients, in which the soft tissue condition and associated injuries are often severe. In contrast, the low-energy fracture in elderly patients may present with complex fracture patterns where pre-existing arthritic changes, comorbidity, and functional status, are considered in decision-making whether internal fixation or elbow arthroplasty is suitable.

Physical Examinations

• Soft tissue: Small open wounds may present on the posterior aspect as the distal end of the humeral shaft has penetrated through the skin. The high-energy open fractures are often more contamination than the size of the apparent wound and there may be comminution and bone loss.

• Distal vascular status must carefully be assessed and documented. If abnormal or questionable, Doppler ultrasound or angiography is considered.

• Neurological examination: Pre-existing ulnar nerve dysfunction substantially influences the development of late ulnar neuropathy. The ulnar neuropathy findings may not be as clinically apparent as radial nerve dysfunction and may be incomplete injury, thus specific pre-operative motor and sensory functions must be documented. Two-point discrimination is important for diagnosis and follow-up.

• Associated injury: The subtle forearm and wrist injuries can be overlooked from the obvious elbow deformity. The detailed examination of the injured extremity is necessary, especially in the high-energy injury patients.

Diagnostic Workup

Imaging Studies

• The standard anteroposterior and lateral radiographs are generally appropriate for initial diagnosis and simple fractures.

• Gentle traction radiograph may provide more information for the more complex intra-articular fractures.

• Computed tomography (CT) scans with three-dimensional reconstruction will help improve the reliability of fracture classification and characterization compared to the conventional CT. The CT is useful in assessing the presence of coronal plane fracture, and also supporting for decision-making if total elbow arthroplasty may be needed in the elderly patient.

Classifications

• The AO/ASIF comprehensive classification system includes three major types of fractures: Type A (extra-articular), type B (partial articular), and type C (complete articular). Each type is subdivided into three groups and three subgroups based on the fracture patterns and comminution.

• The Mehne and Matta classification system includes three levels of surgical anatomy:

  Extracapsular fractures

  Extra-articular intracapsular fractures

  Intra-articular fractures are divided into 4 groups including single columnar injury, bicolumnar injury, capitellar fractures, and trochlea fractures.

  Single columnar injuries are divided into medial or lateral column fractures, and subdivided into high and low fractures.

  Bicolumnar injuries are classified by the location and slope of the fracture lines, as well as the orientation of the intra-articular fragments. The main patterns include the following: high and low “T”, “Y”, “H”, medial, and lateral Lambda patterns. This classification system helps to predict the possibility of the internal fixation by the size and feature of the fragments. The fractures occur below the level of the olecranon and coronoid fossae and can include small articular fragments, which are more difficult to achieve secure fixation with and have the potential risk for avascular necrosis.

• The articular shearing fractures of capitellum and trochlea are classified according to the Association for Osteosynthesis/Association for the Study of Internal Fixation (AO/ASIF) classification as B3: With the subtype B3.1 indicating isolated capitellar fractures; B3.2, trochlear fractures; and B3.3, combined capitellar-trochlear fractures. The specific classification systems of the capitellum includes:

  Type 1 (Hahn-Steinthal fracture), consisted of coronal shear fractures of the capitellum with little or no involvement of the trochlea.

  Type 2 (Kocher-Lorenz fracture), superficial shear fracture of the capitellar cartilage with minimal attached subchondral bone.

  Type 3, comminuted fractures of the capitellum.

  Type 4, shear fracture of the distal end of the humerus extending in the coronal plane across the capitellum to include most of the lateral trochlear ridge and the lateral half of the trochlea. The latter can demonstrate in the lateral radiograph a “double arc sign”. One arc is provided by the subchondral bone of the capitellum and the other by the lateral ridge of the trochlea. (Figure 1)

Figure 1.

Non–Operative Management

• Non-operative management is unlikely to achieve accurate reduction of displaced fractures with high likelihood for fracture displacement, elbow stiffness, malunion, and nonunion.

• It can be cautiously used in stable non-displaced extra-articular fractures. Patient compliance and close monitoring are crucial due to the tendency of secondary displacement.

• The “bag of bones” technique may be employed for intra-articular fractures, if patients are medically unfit for surgery. A brief period of immobilization is applied for the first few days until pain and swelling subside. Gentle active motion is initiated under supervision and gradually increased for 6-8 weeks until early fracture healing.

• Resistive exercise should not be started before radiographic union is appreciated, which is generally in 3 months.

Indications for Surgery

• Displaced fractures

• Associated ipsilateral fractures such as forearm or wrist injuries

• Nerve or vascular injuries

• Preliminary spanning external fixation may be indicated in open fractures with severe soft tissue injuries or polytrauma patients

Surgical Technique

Necessary Equipment and Instrumentation

• Fluoroscopy

• 3.5 mm reconstruction plates or anatomical pre-contoured plates

• Headless compression screws are prepared for articular shearing fractures or coronal plane fractures.

• Total elbow arthroplasty should be prepared for elderly patients with severely comminuted fractures or pre-existing arthritic changes.

Patient Positioning

• The proper position depends on the planned surgical exposure, fracture type, associated injuries, as well as the surgeon’s preference.

• The patient with multiple trauma or associated brachial artery injury may need to be in a supine position. In this circumstance, if the posterior incision is planned for fracture fixation, the patient’s forearm will be held across the chest by a dedicated assistant or a positioner device.

• For most distal humerus fractures, we prefer a lateral decubitus or prone position. For the lateral decubitus position, the patient is positioned closed to the rim of an operating table with the affected arm supported on a padded bolster, which allows the elbow to be flexed beyond 100 degrees and will permit access for the image intensifier.

• The surgical field is draped up to the axilla, and the iliac crest should be prepared and draped in comminuted fractures. The use of a sterile tourniquet and general anesthesia are recommended because the procedure may be lengthy, and later airway management can be a struggle due to the patient positioning.

• For the articular shearing fractures of capitellum and trochlea, for which a lateral extensile exposure is planned, the patient should be in a supine position with the arm extended on a hand table.

Incision

• The straight posterior skin incision or a curving incision around the olecranon to the radial side are useful for the posterior exposure.

• Full thickness medial and lateral subcutaneous flaps are sharply elevated from the fascia of the triceps and anconeus muscles.

Ulnar nerve

• The ulnar nerve is released from the medial intermuscular septum at least 8 cm proximal from the medial epicondyle, and distally until it passes through the two heads of the flexor carpi ulnaris.

• The nerve can be either left in its position or transposed into an anterior subcutaneous position, depending on how much work is anticipated on the medial column and the pre-existing ulnar nerve dysfunction.

Surgical Exposures

• The fracture site can be approached by various methods, including the olecranon osteotomy, paratricipital exposure (Alonso-Llames), triceps-splitting exposure, triceps sparing elevation (Bryan-Morrey), and triceps-reflecting anconeus pedicle (TRAP).

• The selections of these exposures are dependent on the intra-articular fracture complexity, the necessity of anterior articular component exposure, the anticipated plan for elbow arthroplasty, and, in part, the surgeon’s preference.

Paratricipital Exposure

• This approach involves developing windows along the medial and lateral borders of the triceps without violating the extensor mechanism.

• It can be used in extra-articular or simple intra-articular fractures of the distal humerus.

• The conversion to the olecranon osteotomy or total elbow arthroplasty can be done if needed.

Olecranon Osteotomy

• The olecranon osteotomy provides the greatest exposure of the articular surface. In a cadaveric study of non-fractured models, almost 60% of the total articular surface could be seen.

• The anconeus is partly elevated from the ulnar to directly visualize the trochlear notch. The distally apex chevron osteotomy is performed at the deepest part of the trochlear notch.

• The proximal olecranon fragment and triceps are then elevated from the humerus.

• The fixation of the osteotomy is done by double tension-band wiring technique. (Figure 2)

• Two 0.045-inch Kirschner wires are drilled from the dorsal aspect of the proximal ulnar, angled anteriorly and slightly medially, to exit just medial to the ventral ridge of the ulnar, aiming to prevent the wires backing out and radial impingement.

• Each of two 20- or 22-gauge stainless steel wires are passed through the transverse drill holes in the distal ulnar fragment, about a centimeter apart. Each wire is bent into a figure-of-eight and passed beneath the attachment of the triceps against the very tip of the proximal olecranon; a 16-gauge needle can be used to facilitate the passage. The wires are tensioned on each side of the ulnar, and then trimmed and bent into the adjacent soft tissues.

• The Kirschner wires are cut and bent into 180 degree fashion with wire bending forceps or pliers, and then hammered in to the olecranon.

Figure 2.

Lateral Extensile Exposure

• The lateral exposure is considered in lateral column fractures, and the articular shearing fracture of the capitellum.

• The patient is in the supine position with the arm supported on a hand-table. Either the lateral skin incision or posterior skin incision can be used.

• The dissection starts just proximal to the lateral epicondyle. The origin of the extensor carpi radialis longus is elevated from the lateral supracondylar ridge, and then the anterior capsule is elevated with sharp dissection.

• The fibers of the common extensor origin and lateral collateral ligament complex, which are located posterior to the imaginary line that bisects the capitellum, should be preserved attached to the lateral epicondyle.

• The lateral aspect of the triceps is elevated from the distal humerus and proximal olecranon.

• If the extensile exposure needs to be done, the lateral epicondyle osteotomy can be elevated with an osteotome to hinge open the articular surface. The lateral epicondyle fragment must be carefully repaired with the transosseous sutures.

Fracture Reduction and Internal Fixation

• A triangular shape of the medial and lateral bony columns and the intervening articular trochlea have to be adequately stabilized.

• The medial and lateral ridge of the trochlea should be realigned as close as possible to its original width and provisionally fixed using a smooth Kirschner wire. If a structural defect exists in the articular fragments of the trochlea, bone graft is required, in order to preserve the anatomical width and stability of the trochlea.

• With associated coronal plane fractures, the provisional fixation with small Kirschner wires should be considered, as it will be difficult to visualize later on. The definitive fixation may require the use of headless screws or threaded Kirschner wires.

• The articular fragments are then temporarily fixed to each bony column with 0.062 Kirschner wires.

• The definitive fixation using plates and screws may have the implants either at 90 degrees or parallel to each other. The proper plate configuration depends mainly on the fracture pattern and the direction and position of the screws that can securely fix the articular fragments.

• The plate fixation may start on the side with the larger articular fragment first, given that the implant may be more easily contoured to the distal fragment, maximizing the distal screw purchase through the plate.

• On the medial column, either the precontoured or reconstruction type plates can be placed medially on the crest of the medial supracondylar ridge.

• On the lateral column, the posterior plate can extend distally to the posterior articular border of the capitellum. When inserting the most distal screw, great care must be taken not to penetrate the anterior articular surface of the capitellum. Alternatively this screw can be directed proximally and laterally to engage the lateral supracondylar ridge.

• Another option is applying the plate on the lateral aspect of the lateral column, which can be used as a single or combined with the posterolateral plate. The plate should be positioned distally enough that the most distal screw can be directed across the trochlea and engage all articular fragments. (Figure 3)

• After the definite fixation of the articular fragments has been done, the supracondylar compression can be applied with a pointed reduction forceps, before tightening the eccentric-loaded screw to the humerus shaft.

Figure 3.

Pearls and Pitfalls of Technique

Pearls

If the proximal fixation has to extend up to the mid-shaft of the humerus, approximately 10-14 cm proximal to the lateral epicondyle, the radial nerve should be identified and protected.

The olecranon osteotomy should be started by oscillating saw, and later finished by small osteotome for cracking the subchondral bone, in order to create an uneven surface that will enhance later realignment and fixation.

The medial column plate can be contoured to cradle around the medial epicondyle, as the most distal two screws can be placed at 90 degrees to each other, or a long screw is placed distally from the cradle to engage proximally on the lateral column.

Pitfalls

The interfragmentary screws outside the plate should not be inserted before the distal plate fixation to maximize screw fixation of the distal articular fragments through the plate.

Excessive interfragmentary compression should be avoided in the osteoporotic bone or very comminuted fractures.

Always fill the bony defect with bone graft to enhance the stability and healing.

Plates must be extended proximally enough to provide at least 2 or 3 screws on each plate engaging the shaft of the humerus.

Potential Complications

Ulnar Neuropathy

• The reported incidence of ulnar neuropathy following distal humerus fracture fixation ranges from 7-38%.

• The factors that may influence include the preexisting ulnar nerve dysfunction, intraoperative nerve management, excessive traction, impingement with implant, range of motion, scar formation, and fracture healing response.

• During the post-operative rehabilitation, if the patient is unable to gain motion and has increasing pain around the elbow, the detailed examination of the ulnar nerve should be done to rule out the ulnar neuritis.

• There remains no clear consensus as to when an ulnar nerve is transposed during surgery. If there is preoperative palsy, possible implant irritation, or intra-operative traction, the anterior transposition should be considered.

Nonunion

• Nonunion of fractures of the distal humerus has been reported to occur approximately in 0-7% of cases.

• Most of the nonunions will occur at the supracondylar region, primarily the consequence of inadequate fixation. Other factors may include high-energy injuries, extensive comminution, and poor bone quality.

• Pain, loss of motion, and associated late ulnar neuropathy are common symptoms associated with nonunion.

Elbow Stiffness

• The functional arc of motion can usually be achieved in patients with adequate stable fixation that will allow the range of motion exercise within the first few days.

• The factors that may risk elbow stiffness include polytrauma patients, high-energy injury, significant delay before definitive management, multiple surgeries, and an open fracture. The incidence of heterotopic ossification may be increased in patients treated beyond 24 hours after injury.

• If the range of motion reaches a plateau and is still below the functional arc of motion of 100 degrees, surgical capsular release may be considered. However this should not be done before 4 months after the surgery.

• Currently, the authors have not found heterotopic ossification prophylaxis to be necessary.

Post–operative Rehabilitation

• The elbow is splinted in full extension and elevated on pillows for the first 24-48 hours.

• When the fixation is secure, the gravity-assisted active range-of-motion exercise should be initiated within 24-48 hours postoperatively. In the supine position, the patient holds the arm vertical and then actively flexes the elbow with the gravity assist. For extension, position the arm at side of the body and allow the gravity to extend the elbow.

• Gradual increasing of the motion is anticipated within 4-6 weeks post surgery. Static progressive splint and night extension splint can be used if the range-of-motion is not appreciated.

• Resistive exercise begins after radiographic healing is seen, at approximately 12 weeks.

Outcomes/Evidence in the Literature

Doornberg, J, Lindenhovius, A, Kloen, P, van Dijk, CN, Zurakowski, D, Ring, D. “Two and three-dimensional computed tomography for the classification and management of distal humeral fractures. Evaluation of reliability and diagnostic accuracy”. J Bone Joint Surg Am. vol. 88. 2006. pp. 1795-1801. (This study reported that the CT with 3-dimensional reconstruction would help improve the reliability of fracture classification compare to the conventional CT.)

Brown, RF, Morgan, RG. “Intercondylar T-shaped fractures of the humerus. Results in ten cases treated by early mobilisation”. J Bone Joint Surg Br. vol. 53. 1971. pp. 425-428. (This study described the “bag of bones” technique used in T-shaped fractures of the humerus. Ten patients with an average age of 49 years achieved fracture healing with the average arc of motion of 98 degrees.)

Scharplatz, D, Allgower, M. “Fracture-dislocations of the elbow”. Injury. vol. 7. 1975. pp. 143-159. (A series of 20 comminuted distal humerus fractures were treated with ORIF with plates, lag screws, and Kirschner wires. Very good results were seen in 45% of the patients.)

Jupiter, JB, Neff, U, Holzach, P, Allgower, M. “Intercondylar fractures of the humerus. An operative approach”. J Bone Joint Surg Am. vol. 67. 1985. pp. 226-239. (A report of the AO principle and techniques applied to 34 intra-articular distal humerus fractures. Excellent and good results were achieved in almost 80% of the patients.)

Ring, D, Gulotta, L, Chin, K, Jupiter, JB. “Olecranon osteotomy for exposure of fractures and nonunions of the distal humerus”. J Orthop Trauma. vol. 18. 2004. pp. 446-449. (A series of 45 olecranon osteotomies used in distal humerus fractures. All osteotomies healed within 6 months, except one patient that disrupted the osteotomy in a fall 4 weeks after surgery. Thirteen percent of the patients had wire removal for symptoms related directly to the wires.)

Erpelding, JM, Mailander, A, High, R, Mormino, MA, Fehringer, EV. “Outcomes following distal humeral fracture fixation with an extensor mechanism-on approach”. J Bone Joint Surg Am. vol. 94. 2012. pp. 548-553. (This study reported the results in 37 fractures that were fixed via the paratricipital approach. The median arc of elbow motion was 126 degrees, and the mean DASH score indicated excellent scores with mild impairment. The median percent loss of triceps strength was 10% (range, 0-49%) compared with the contralateral elbow.

Kaiser, T, Brunner, A, Hohendorff, B, Ulmar, B, Babst, R. “Treatment of supra- and intra-articular fractures of the distal humerus with the LCP Distal Humerus Plate: a 2-year follow-up”. J Shoulder Elbow Surg. vol. 20. 2011. pp. 206-212. (This study reported results using anatomically pre-contoured orthogonal plates in 22 distal humerus fractures. All fractures were healed with the mean range of motion of 129 degrees in flexion and -16 degrees in extension. There were no cases of secondary fracture displacement, even in elderly patients.)

Sanchez-Sotelo, J, Torchia, ME, O’Driscoll, SW. “Complex distal humeral fractures: internal fixation with a principle-based parallel-plate technique”. J Bone Joint Surg Am. vol. 89. 2007. pp. 961-969. (This study reported the outcome of the parallel-plate technique in 32 complex distal humeral fractures. Fracture union was achieved in 31 patients with the average flexion-extension arc of 99 degrees.)

McKee, MD, Veillette, CJ, Hall, JA, Schemitsch, EH, Wild, LM. “A multicenter, prospective, randomized, controlled trial of open reduction–internal fixation versus total elbow arthroplasty for displaced intra-articular distal humeral fractures in elderly patients”. J Shoulder Elbow Surg. vol. 18. 2009. pp. 3-12. (This study reported the results of randomized trial between ORIF and total elbow arthroplasty in patients with average an age of 77 years. At 2 years follow-up the functional results were not significantly different. With 15 patients in the ORIF group, the mean final motion arc was 95 degrees, 27% had incongruent reduction > 2 mm, and 1 patient (6%) had nonunion. However 25% of the patients that were assigned to the ORIF group, needed to be converted in to arthroplasty.)

Ruan, HJ, Liu, JJ, Fan, CY, Jiang, J, Zeng, BF. “Incidence, management, and prognosis of early ulnar nerve dysfunction in type C fractures of distal humerus”. J Trauma. vol. 67. 2009. pp. 1397-1401. (This study randomized 29 distal humerus fracture patients who had preoperative ulnar nerve symptoms to either subfascial transposition or in situ decompression of the ulnar nerve. Complete recovery occurred in 12 of 15 patients in the transposition group and 8 of 14 patients in the in situ release group, however the difference is not statistically significant.

Summary

Improved surgical techniques and contemporary implants enhance outcomes for the surgical treatment of complex distal humerus fractures. Stable internal fixation is necessary to rebuild the triangular-shaped construct of the distal humerus. Patients are encouraged to start early active motion in the first few days after the operation. Surgeons have to be alert for all of the potential complications, and provide intervention in the proper time.

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