Open Treatment of Radial Head Fractures and Olecranon Fractures

Julie E. Adams, MD, MS

Scott P. Steinmann, MD

Dr. Adams or an immediate family member has received royalties from DePuy; serves as a paid consultant to or is an employee of Arthrex, DePuy, and Articulinx; serves as an unpaid consultant to Synthes; and serves as a board member, owner, officer, or committee member of the American Association for Hand Surgery, the Minnesota Orthopaedic Society, the American Shoulder and Elbow Surgeons, the American Society for Surgery of the Hand, and the Arthroscopy Association of North America. Dr. Steinmann or an immediate family member has received royalties from DePuy; serves as a paid consultant to or is an employee of Arthrex, DePuy, and Articulinx; serves as an unpaid consultant to Synthes; and serves as a board member, owner, officer, or committee member of the American Association for Hand Surgery, the Minnesota Orthopaedic Society, the American Shoulder and Elbow Surgeons, the American Society for Surgery of the Hand, and the Arthroscopy Association of North America.

RADIAL HEAD FRACTURES

Patient Selection

Radial head fractures may be divided into three types according to the Mason classification (Figure 1). Type I fractures, which are minimally displaced or nondisplaced, have no mechanical block to motion. Appropriate treatment is a sling for comfort for a few days and then early mobilization. In this setting, the hematoma may be aspirated and the joint injected with local analgesic to facilitate pain relief by removing the hematoma and placing local anesthetic to allow early motion. Frequently, these patients present to the office or the emergency department with acute swollen elbow (hemarthrosis) and pain. It may be difficult to assess for any blocked motion because of the hemarthrosis and pain. Therefore, it is reasonable to consider an aspiration of the joint and injection of local analgesics. This may be done through the “soft spot,” which is the center of a triangle bordered by the lateral epicondyle, the tip of the olecranon, and the radial head. Alternatively, the anterolateral arthroscopy portal may be used, which is just anterior and distal to the radiocapitellar joint. The hematoma may be extracted using a 19-gauge needle and the syringe then exchanged for 1% lidocaine or other local anesthetic. Following this, the patient generally feels much more comfortable, and the surgeon can assess for any bony block to motion.

Mason type II fractures involve more than 2 mm of displacement and more than one third of the radial head. Mason type III fractures are comminuted, multi-fragmented fractures that are likely irreparable based on preoperative radiographs. Options for the management of radial head fractures are fragment excision, if there is a single fragment that is a bony block to motion; open reduction and internal fixation (ORIF); radial head excision; or arthroplasty.

Fragment excision may be considered if elbow stability is not compromised and is best considered for small fragments that are less than 25% of the head; are too small, osteoporotic, or comminuted for fixation; and do not articulate with the proximal radioulnar joint.

Radial head ORIF may be performed using screws or plate-and-screw constructs. Hardware should be placed in the safe zone (or the region that does not articulate with the proximal radioulnar joint), which is identified as the lateral region of the radial head and neck when the forearm is in a neutral position. This area is also bounded by the region between the Lister tubercle distally and the radial styloid.¹^,²^,³ For type III fractures, which preoperative radiographs suggest are irreparable based on the amount of comminution or multifragmentary pieces, replacement arthroplasty or excision may be considered. Excision should be avoided in the setting of instability. In addition, radial head excision is to be avoided in association with longitudinal instability of the forearm, such as an Essex-Lopresti injury.

Preoperative Imaging

Preoperative imaging should include three radiographic views of the elbow (Figure 2). If there has been an
associated dislocation, pre- and postreduction images should be reviewed. If there are other complicated bony injuries or suspected injuries, a CT scan with or without three-dimensional reconstructions may be obtained. Radiographs are examined for the presence of other bony injuries, the presence of joint subluxation suggesting instability, the number and size of fracture fragments, and associated osteopenia.

FIGURE 1 Illustration depicts the Mason classification of radial head fractures.

FIGURE 2 Lateral (A), AP (B), and oblique (C) radiographs of the elbow demonstrate a radial head fracture.

Procedure

Room Setup/Patient Positioning

The patient is positioned supine with an arm table or with the arm over the chest. A tourniquet is used to improve visualization. It is helpful to have a mini C-arm unit available for intraoperative imaging.

Either general or regional anesthesia may be used; however, general anesthesia provides the advantage of patient comfort during the procedure as well as the ability to immediately assess neurovascular status in the postoperative recovery room.

If there are other associated injuries, the surgeon could consider making a single posterior incision to one side of the olecranon tip, raising large full-thickness flaps to obtain deep access to the medial and lateral sides through this single incision. However, this may lead to seroma formation or other wound complications and requires making a larger incision. Generally, a separate lateral incision is preferred, and, if necessary, a separate medial incision can be made to address medial-side pathology.

Special Instruments/Equipment/Implants

In the setting of anticipated ORIF of the radial head, it is prudent to obtain a radial head replacement in the hospital in case fixation is found to be impossible or fails. A variety of small purpose-made implants is available for radial head fixation, including screws, headless screws, and plating systems. When plate fixation is anticipated, it is helpful to discuss with patients that commonly they may experience stiffness postoperatively and may require a second procedure for plate removal and/or manipulation of the elbow following adequate healing of the fracture. Provisional fixation with Kirschner wires (K-wires) is helpful before placing the definitive implants. Suture anchors may be helpful if collateral ligament repair is anticipated.

Surgical Technique

Either a single posterior incision or a separate lateral incision may be made, depending on the pathology to be addressed. In general, a lateral incision is made overlying the epicondyle and extending distally and longitudinally across the radial head. The deep dissection following the creation of full-thickness skin flaps depends on the pathology to be addressed. In the setting of ligamentous instability of the elbow, such as a radial head fracture in conjunction with a dislocation and perhaps a coronoid fracture, such as the terrible triad injury, there may be associated lateral ulnar collateral ligament (LUCL) avulsion, which creates a deep plane amenable for exposure of the radial head as well as for exposure and subsequent repair of the LUCL. In this setting, the avulsion is typically off the humeral epicondyle, and finger dissection will readily reveal a defect that may then be exploited, which is typically in the classic Kocher interval, between the anconeus and the extensor carpi ulnaris tendon (Figure 3). This allows for exposure of both the radial head and the LUCL for repair of the latter after the procedure is completed. On the other hand, there may not
be any ligamentous injury, in which case a good interval for exposure of the radial head may be using a muscle-splitting approach through the tendinous origin of the extensor digitorum communis (Figure 4). This allows for exposure of the radial head without any dissection below the midline of the radial head and does not endanger the LUCL, which lies more posterior to this area. This interval may be incised with the knife or cautery for exposure, and care should be taken distally to place the forearm in pronation to move the posterior interosseous nerve more distal from the surgical site. An arthrotomy is made, and the radial head and neck are exposed. The posterior interosseous nerve is in this region; its location varies from 2.2 to 5.2 cm distal to the radiocapitellar joint, depending on the size of the patient and the position of forearm pronosupination.⁴^,⁵

FIGURE 3 Intraoperative photograph shows the Kocher interval between the extensor carpi ulnaris and the anconeus, which is most useful for exposure in settings in which the radial head is injured in conjunction with an LUCL (lateral ulnar collateral ligament) injury.

FIGURE 4 Muscle-splitting approach. The radial head may be easily approached through a split in the tendon origin of the extensor digitorum communis (blue line). Dark blue line represents Kocher interval.

Following exposure of the radial head and the fracture, a determination is made as to whether the fracture is amenable to excision, ORIF, or radial head replacement. Provisional fixation may be obtained with small K-wires and then headless screws or plates placed. It is preferable to use screws and avoid plating if possible to allow for better motion postoperatively;⁶ however, fixation must be secure (Figure 5). Moreover, although it may be technically possible to fix a radial head fracture, it may be more advisable to consider replacement. A recent outcomes study suggests a high rate of unsatisfactory results following fixation in type III fractures and many type II fractures. The authors suggest that ORIF for radial head fractures should be restricted to those fractures with minimal comminution and three or fewer fragments and should be avoided in the setting of fracture-dislocations of the elbow.⁷

If fixation is not feasible and cannot be obtained, then the surgeon may consider either excision or radial head replacement. Radial head replacement is available using a wide variety of implants. Such implants can be intentionally loose, smooth-stemmed implants that are intended to act as a smooth spacer; implants that are either cemented or press-fit into the radial head and have an anatomic
head; or bipolar-type implants inserted into the radial neck and shaft and having an articulating head-neck junction allowing motion⁸ (Figure 6). Little information is available regarding the advantages of these implants, and the surgeon should use what he or she feels most comfortable with for the individual patient.

FIGURE 5 Open reduction and internal fixation of a radial head fracture using screws. A, Preoperative lateral radiograph demonstrates the fracture. Illustrations B through D demonstrate screw fixation. B, Provisional reduction and fixation. C, Insertion of a second screw for fixation in a crossed-screw fashion. D, The final construct. E, Postoperative AP radiograph demonstrates screw position.

In any case, for placement of the radial head, it is critical not to “overstuff” the joint. Sizing is difficult; however, a few guidelines include using the native resected radial head and its fragments assembled on the back table as a guide to the diameter and thickness of the radial head implant to be placed. Most systems have some element of modularity as well as size variance that allow for this. The dish of the radial head replacement should be approximately the same size as the inner dish of the native radial head surface. In general, there is a tendency to overstuff the joint and place a larger than necessary radial head, which can lead to radiocapitellar arthrosis and maltracking of the elbow. This is particularly problematic in the setting of ligamentous instability, which can be exacerbated by this.

In general, the radial head prosthesis is within 2 mm of the proximal radioulnar joint. On fluoroscopic images obtained in the operating room, the surgeon can assess if there is any asymmetric widening of the joint on the medial or lateral side and narrowing on the other side to see if the implant is too large or too small. If the implant is too large, the medial side of the joint will close down, or narrow—the so-called river delta sign; however, radiographic parameters are relatively insensitive, and overstuffing of up to 6 mm may be undetected on radiographs. A better determinant is visual inspection for any widening of the lateral ulnohumeral space or an attempt to match the lesser sigmoid notch.⁹^,¹⁰^,¹¹^,¹²^,¹³^,¹⁴ Most systems have a variety of trial implants that are available to ensure that the appropriate size is chosen before final implantation.

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