Open Reduction and Internal Fixation of Distal Humerus Fractures

Michael David McKee, MD, FRCSC

Dr. McKee or an immediate family member has received royalties from Stryker; is a member of a speakers’ bureau or has made paid presentations on behalf of Synthes and Zimmer; serves as a paid consultant to or is an employee of Synthes and Zimmer; has received research or institutional support from Wright Medical Technology and Zimmer; and serves as a board member, owner, officer, or committee member of the American Shoulder and Elbow Surgeons, the Orthopaedic Trauma Association, and the Canadian Orthopaedic Association.

PATIENT SELECTION

The overall incidence of distal humerus fractures in adults has been reported to be 5.7 per 100,000 people per year.¹ Treatment usually requires surgical fixation, which can be technically demanding. Many issues regarding the management of distal humerus fractures have not been clarified sufficiently to allow surgeon consensus. The optimum surgical approach, plate configuration, indications for arthroplasty, the need for ulnar nerve transposition, and the use of prophylaxis for the prevention of heterotopic ossification (HO) continue to be debated.

The AO/Orthopaedic Trauma Association (AO/OTA) classification for distal humerus fractures is widely used and is helpful for treatment planning.² The classification divides distal humerus fractures into three categories: type A, nonarticular fractures; type B, partial articular fractures; and type C, complete articular fractures.

Paramount features of the treatment goals are to obtain an anatomic reduction with adequate stability to allow early range of motion. Achieving these goals is advantageous for optimizing the patient’s recovery time and function. A preoperative discussion about the risks and benefits of surgical versus nonsurgical treatment is key. In particular, outlining that the return of completely normal preinjury range of motion is rarely achieved after such an injury is important. This, combined with informing patients that transient ulnar nerve paresthesias are relatively common secondary to injury and from manipulation of the nerve intraoperatively, can temper expectations to a realistic level.

Contraindications

Contraindications to ORIF include a patient’s poor health precluding the ability to tolerate an operation, active infection, lack of appropriate soft-tissue coverage, poor compliance, and extreme osteoporosis not amenable to stable fixation. In patients older than 70 years with extreme osteoporosis and intra-articular fracture comminution, a linked semiconstrained total elbow arthroplasty is likely the best surgical option.³

Nonsurgical treatment is appropriate for stable, nondisplaced fractures and patients with preexisting conditions creating a nonfunctional extremity. Vigilant follow-up is necessary to recognize potential fracture displacement. Institution of early physical therapy will minimize posttraumatic elbow stiffness.

PREOPERATIVE IMAGING

Imperative investigations include AP, lateral, and oblique radiographs of the elbow and, when indicated, shoulder and wrist radiographs. Traction radiographs and CT scans can be very helpful for preoperative planning and hardware templating⁴ (Figure 1).

PROCEDURE

Room Setup/Patient Positioning

Room setup should be comfortable for the patient and the surgical team. Positioning should allow access to the surgical site for imaging. There are many described techniques for patient positioning; however, placing the patient in the lateral decubitus position with the affected extremity over an arm bolster provides excellent access to the distal humerus and allows gravity to be a reduction aid (Figure 2). Supine positioning of multiple trauma patients, particularly those with chest injuries, is preferable; the affected arm is placed across the chest on a pad or bolster.

Positioning should allow for intraoperative radiographs to be obtained or the use of an image intensifier (mini C-arm). A radiolucent arm bolster is helpful but not a necessity. Although the reduction of fracture fragments can be directly visualized, the fluoroscope can be useful for observing dynamic joint alignment and anterior fragments that can be difficult to directly visualize, as well as to ensure that there is no intra-articular screw penetration.

FIGURE 1 AP (A) and lateral (B) preoperative radiographs demonstrate an intra-articular distal humerus fracture. Evidence of air is also seen, as this was an open fracture. C, CT reconstruction of the same injury. The CT scan was extremely useful in this particular instance because a proximal ulnar fracture was identified that is not readily evident on the radiographs. This fracture was an avulsion of the ulnar insertion of the medial collateral ligament.

Special Instruments/Equipment/Implants

Special equipment needed for this procedure includes small fragment plates (including malleable reconstruction plates or precontoured periarticular plates), mini fragment plates and screws, Herbert screws, Kirschner wires (K-wires), sterile tourniquet, reduction clamps/osteotomes, oscillating saw (for olecranon osteotomies and bone-graft retrieval), wire set (for olecranon osteotomy fixation), bone-graft set, and mini C-arm fluoroscope or plain intraoperative radiography.

Plates must be strong enough to support early range of motion exercises following fixation. One third tubular plates are not strong enough and are contraindicated. Although not a necessity, precontoured locking plates have increased the strength of fixation constructs and reduced surgical time dedicated to contouring plates.⁵ Plates with variable axis-locking holes support capturing small or comminuted distal fragments while avoiding joint penetration and enhancing fixation strength.

FIGURE 2 Photograph shows a patient secured in the lateral decubitus position via a beanbag and safety strap, with the affected arm placed over a padded bolster. All bony prominences are padded appropriately. This patient had been transferred from a peripheral facility, where he had undergone an irrigation and débridement of an open distal humeral fracture.

Surgical Technique

A complete surgical briefing should be done with the entire surgical team and should include the surgeon initialing the surgical site and reviewing the procedure with the patient and the team, as well as the administration of prophylactic antibiotics, before the induction of anesthesia.

All bony prominences should be padded appropriately to avoid iatrogenic nerve palsy or pressure sores. The patient is placed and secured in the lateral decubitus position with the affected extremity over a padded arm bolster allowing 90° of flexion at the elbow. The posterior iliac crest should be prepared if it is anticipated that bone graft will be required. The upper extremity is prepared beyond the shoulder and draped to allow access to the proximal arm. An extremity stockinette is wrapped to midforearm. A sterile tourniquet is applied to the proximal arm. The extremity is exsanguinated with an Esmarch bandage before the inflation of a pneumatic tourniquet.

Although different approaches have been described, typically a direct posterior incision is used, exposing the triceps as well as the proximal olecranon⁶ (Figure 3). Some surgeons curve this incision laterally around the olecranon to avoid a scar directly over the olecranon. It is mandatory to identify, protect, and mobilize the ulnar nerve. It should be released sufficiently to allow safe exposure and fixation of the fracture. Flagging the nerve with a Penrose drain/vessel loop serves as a visual reminder of the nerve’s position throughout the procedure and facilitates very gentle retraction (Figure 4).

FIGURE 3 Intraoperative photographs show the straight posterior approach for open reduction and internal fixation of a distal humerus fracture. The patient’s open fracture wound (A) was incorporated into the incision, and the skin edges were excised (B). The large rent in the triceps and skin was created by the humeral shaft as it protruded at the time of injury. More than 90% of open wounds in this type of injury are posterior.

Extensor Mechanism

Different options exist for dealing with the extensor mechanism.

Paratricipital Approach

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