Surgical indications for radial head fractures is an area of controversy. In general, ORIF is offered to patients with radial head fractures that are displaced ≥2 to 3 mm and involve >30% of the articular surface, even if they do not impede forearm rotation. Radial head fractures that cause a mechanical block to motion should be fixed, regardless of their size. Fixation is also indicated during the surgical treatment of complex elbow fracture-dislocations to provide additional stability. The radial head is described as a secondary elbow stabilizer; however, when injuries occur to the primary stabilizers (medial collateral ligament [MCL] and lateral collateral ligament [LCL] and ulnohumeral articulation), its importance is elevated. Isolated nondisplaced and minimally displaced radial head fractures generally do not cause any mechanical blocks to rotation, thus can be treated nonoperatively.

A relative contraindication to ORIF is a comminuted radial head fracture with more than three displaced articular fragments. Although ORIF can be attempted, radial head arthroplasty is often preferred in these cases.

The patient is typically positioned supine, with the affected arm placed over the chest or extended on an arm table. A “universal posterior” or lateral skin incision can be used, depending on surgeon preference and associated injuries. Deep dissection can be performed laterally through different intervals, depending on the status of the LCL. In cases of an isolated radial head fracture, we recommend a common extensor tendon-splitting approach, since it protects the LCL and provides a more direct exposure for fixation of partial articular radial head fractures, which are typically located in the anterolateral quadrant with the forearm in neutral rotation (Figure 22.1). If the LCL is ruptured, a classic Kocher approach (extensor carpi ulnaris-anconeus interval) may be preferable. The posterior interosseous nerve (PIN) is at risk with lateral exposures of the elbow; it can be protected by avoiding excessive distal dissection and placing the forearm in a pronated position.

Displaced fracture fragments should be carefully reduced and secured using small headless or countersunk headed interfragmentary screws. An obliquely oriented screw inserted from the radial head into the radial neck is a described technique to avoid placement of plates for fractures involving the entire articular surface or extending into the radial neck. Plate-and-screw constructs are avoided if possible because they are associated with postoperative stiffness, need for subsequent hardware removal, and disruption of periosteal vascularization of the radial head. However, if a plate is considered necessary for additional stability, it should be contoured to the patient’s anatomy and placed on the nonarticular portion of the radial head.

Repair of associated injuries is carried out as indicated, including collateral ligaments or other bony structures, such

as the coronoid. All injuries, repaired or not, should be documented and communicated to collaborating therapists, since this will influence postoperative rehabilitation. Specifically, the status of the MCL (repaired or not) and the status of the LCL (solid repair or poor-quality repair) should be documented. The wound is then closed in layers. The elbow is typically immobilized and elevated after surgery for a brief period to decrease swelling and pain prior to therapy.

Elbow stiffness is a common complication after ORIF of the radial head. Possible etiologies include prominent hardware, capsular scarring and adhesions, heterotopic ossification (HO), prolonged immobilization, or noncompliance with postoperative rehabilitation. Physical examination should assess whether the end ROM is firm or soft. The latter finding may be managed successfully with therapy using stretching and static-progressive splinting. However, firm endpoints should be investigated to determine the cause. Mature capsular scarring and adhesions may require open or arthroscopic capsular releases.

Other less common complications may include infection, ulnar nerve or PIN injury, malunions, nonunions, and persistent elbow instability.

Radial head arthroplasty is indicated for comminuted, displaced fractures for which stable internal fixation cannot be achieved. For complete articular radial head fractures, there is some evidence that arthroplasty is superior to ORIF.

Patient positioning and surgical approach are similar to ORIF. Arthroplasty is typically performed using metallic implants. Although the specific technique will vary depending on the prosthesis used, optimal sizing of all implants is critical to avoiding complications, such as pain, postoperative stiffness, and arthrosis. Articular fragments should be retained and reassembled to help determine the appropriate implant diameter and length. The diameter can be chosen based on the minimum outer diameter of the native radial head. The use of the lesser sigmoid notch for implant diameter sizing may be unreliable. An alternative method is to use the ipsilateral capitellar dimensions on preoperative radiographs to estimate radial head diameter. Similarly, implant length can be approximated using the excised radial head. When the prosthesis is inserted, its articular surface should be even with the proximal edge of the lesser sigmoid notch. Contralateral elbow radiographs can further aid in identifying over- or under-lengthening of the radial head prosthesis. Inappropriate length can be difficult to diagnose using radiographs of the injured elbow only. Local landmarks have been shown to be inaccurate, including the lateral ulnohumeral joint space, which can be nonparallel on anteroposterior radiographs in normal patients due to anatomic variability. The medial ulnohumeral joint space is also unreliable because it may not demonstrate widening on anteroposterior radiographs until significant over-lengthening has occurred.

Once a trial implant is inserted, the elbow is placed through ROM, with stability testing and fluoroscopic assessment. The tracking of the radial head implant on the capitellum is observed to ensure that it is congruent. As in the case of ORIF, the associated injuries are repaired, if required, and documented.

Possible complications after radial head replacement include infection, loosening, radial head “over-lengthening” or “overstuffing,” radiocapitellar arthritis, instability, HO and fractured components. In a retrospective review of 47 failed metallic radial head arthroplasties, 31 (66%) were caused by aseptic loosening. Other causes included stiffness, instability, and deep infection. Prophylaxis against HO remains controversial. In the authors’ opinion, prophylaxis may be unnecessary in isolated radial head fractures with minimal soft-tissue trauma.

Prior to initiating postoperative rehabilitation, the therapist must be aware of the following:

These important details allow the therapist to create a custom-tailored rehabilitation program (Figure 22.2). Ideally,

patients should be seen in specialized outpatient therapy 48 to 72 hours following surgery.

Isolated radial head fractures managed with a lateral ulnar collateral ligament (LUCL)–sparing approach can be placed in a sling or a collar and cuff (Figure 22.3) with the elbow maintained at 80° to 90° of flexion. These are used for comfort during the day and in between exercise sessions.

Patients with associated ligamentous injuries or fractures should be placed in a posterior elbow resting orthotic, with the elbow positioned in approximately 80° to 90° of flexion. The forearm rotation should be specific to the injury pattern to provide optimal ligament protection:

Although the optimal time for initiation of ROM after radial head fracture is unknown, the stability of fixation is critically important. We usually advocate that patients begin controlled active and passive mobilization 2 to 5 days postoperatively. Modifications to the exercise regime are made in cases with associated injuries: