Surgery can be performed under regional or general anesthesia. The patient is typically positioned supine using a arm board or “lazy” lateral with the arm brought over the chest. A nonsterile tourniquet can be applied under the final drapes or a sterile tourniquet can be placed depending on the size of the patient’s arm. Preoperative imaging and fluoroscopy should be available for use intraoperatively. Two types of incisions may be used, either an extensile posterior skin incision or a lateral skin incision. With the posterior incision full-thickness fasciocutaneous flaps are raised starting on the lateral side. The medial flap is only developed if medial exposure is required for medial collateral ligament repair or ulnar nerve release.

The injury is initially exposed via a lateral arthrotomy. The injured structures are identified from superficial to deep. The deep lateral approach is performed either through Kocher’s (Fig. 5.7) or Kaplan’s interval or a combination of both. Typically the lateral collateral ligament complex with the common extensor is avulsed off the lateral epicondyle and either the Kaplan or Kocher interval or both can be developed distally to gain access to the radial head and coronoid [25, 27]. Although usually not necessary, releasing a portion of the extensor origin from the lateral supracondylar ride of the humerus can improve lateral exposure. Distally, the annular ligament is incised and later repaired. Deep to the common extensor tendon , the origin of the lateral ligament complex is assessed. Often, the common extensor and the lateral ligament complex are detached as a unit and do not need separation but rather are repaired en mass. Commonly a bare lateral epicondyle is encountered, consistent with a complete proximal avulsion of the LUCL [25]. Next the radial head is assessed. The decision to proceed with either radial head fracture fixation or replacement with arthroplasty is made based on the age of the patient, the degree of comminution and bone quality. If the radial head fracture is deemed repairable attention is turned to fixation of the coronoid process. However, if arthroplasty is planned then a radial neck osteotomy is performed in preparation for the prosthetic implant. The radial neck osteotomy and removal of the remaining head fragments have the benefit of dramatically improving exposure of the fracture bed of the coronoid process from the lateral side.

When the radial head is amenable to fixation , visualization of the coronoid injury can be challenging. Several maneuvers can assist with visualization and exposure from the lateral arthrotomy. The fragments of the radial head, if loose, can be temporarily removed from the wound. Alternatively, the fragments can sometimes be hinged distally on their intact soft tissue attachments. If additional exposure is still required the elbow joint can be subluxed posterolaterally to deliver the coronoid into the field of view. In some cases, a separate medial approach will be needed for adequate exposure and internal fixation of the coronoid fracture. This is more common in cases where the radial head fracture fragments are small and reparable precluding good coronoid exposure and/or the coronoid fracture is large, comminuted, or preferentially involves the anteromedial facet.

Surgical repair and stabilization are carried out from deep to superficial, and the coronoid injury is addressed first. Fixation of the coronoid fracture depends on its size and degree of comminution [21, 22, 24]. Small O’Driscoll type 1 fractures can often be ignored as there is minimal bony compromise and the benefits of anterior capsular repair are minimal. If fixation is needed for stability this can be accomplished with sutures passed through drill holes from the dorsal aspect of the proximal ulna into the fracture bed and can be facilitated by utilizing a targeting guide (Fig. 5.8). This device can typically be found in any anterior cruciate ligament (ACL) reconstruction tray. In Type 1 fractures with only a small osseous fragment, sutures provide more reliable fixation than screws.

The requirement for fixation of small coronoid tip fractures remains controversial. Recent research has called into question the need for coronoid fracture fixation [28]. Terada et al. [29] and Josefsson et al. [30] both reported that chronic elbow instability was more common in patients with smaller fractures of the coronoid process. The authors suggested that even small coronoid fractures should be repaired to reconstruct the anterior buttress provided by the anterior capsule. However, a recent biomechanical study suggests that fixation of small type I coronoid tip fractures contributes little to stability in spite of this anterior capsular attachment [31]. Repair of the collateral ligaments was found to be more critical than suture fixation of the coronoid process in the treatment of small type I coronoid fractures [31]. However, because the overwhelming majority of published protocols still support coronoid or anterior capsule fixation, repair of even small coronoid fractures is currently the standard [6, 12, 21, 32].

For larger transverse fragments the suture is passed through drill holes in the fragment and is also passed through the capsule. With larger osseous fragments screw fixation can be performed with a large pointed reduction forceps to hold the fracture reduced while an ACL drill guide is utilized to pass a guide wire from the proximal posterior ulna into the coronoid fragment. A partially threaded cannulated screw can then be advanced over the guide wire and the fracture is compressed. If the size of the coronoid fragment allows, a second screw is placed in the same manner. Anatomic reduction of the fracture is often challenging and is likely unnecessary as long as the anterior buttress and capsular attachments are securely restored [21].

A medial approach offers excellent visualization of the entire coronoid, including the base. Fixation from the medial side can also be achieved with targeted screws into the coronoid through the dorsal surface of the ulna . Larger fracture fragments or fractures with medial comminution can be repaired using fracture specific plates or mini-fragment plates molded to the contour of the medial coronoid. Various medial approaches are available including a split of the flexor pronator, a flexor carpi ulnaris splitting approach through the bed of the ulnar nerve or the Taylor-Scham approach between the ulnar shaft and the ulnar head of the flexor carpi ulnaris. Each of the these approaches has been previously described in Chap. 3.

The goals of treatment for the fracture of the radial head are to have a stable construct allowing the radial head to function both as an elbow stabilizer and also permitting early protected mobilization. In general, aggressive operative treatment of radial head injuries restoring the load bearing capacity of the lateral column is preferred in patients with terrible triad injuries. Because the radial head is an important secondary stabilizer, excision in the setting of complex elbow instability is contraindicated acutely [33]. The radial head resists valgus load when the MCL is injured and acts as a buttress to posterior instability with a deficient coronoid [34, 35]. Additionally, it restores the lateral column of the elbow, acting to tension the repaired lateral ligaments resisting varus and posterolateral rotatory instability. Previous studies have demonstrated elbow instability and posttraumatic arthrosis following resection of the radial head in complex elbow dislocations [7]. Therefore, the preferred surgical treatment options in the setting of terrible triad injuries include open reduction and internal fixation (ORIF) or radial head arthroplasty .

The decision between performing open reduction and internal fixation is based upon several factors including fracture location, number of fragments, and comminution. Previous studies have demonstrated inferior outcomes in radial head fractures with greater than three articular fragments treated with open reduction and internal fixation [30]. In a series of 56 radial head fractures treated with ORIF, 13 of the 14 Mason Type III fractures with more than three fragments had unsatisfactory results in contrast to all 15 Mason type II fractures which had satisfactory results [36]. A recent study compared radial head fractures treated with ORIF versus radial head arthroplasty in patients with terrible triad injuries [31]. All patients were managed with a standard algorithm consisting of either repair or replacement of the radial head, repair of the lateral ligaments and repair of the coronoid fracture. The decision to replace or repair the radial head was based on the number of articular fragments; patients with three or less fragments underwent internal fixation. With a minimum of 18 months of follow-up no differences were found in DASH score, Broberg-Morrey index, or in overall range of motion. All patients that underwent arthroplasty at the index procedure had a stable elbow at final follow-up where as 3 or 9 patients in the ORIF group were found to have residual instability. However, 37 % of the patients in the arthroplasty group demonstrated radiographic signs of arthritis compared to none in the ORIF group [37]. Based upon this data, open reduction internal fixation will likely reduce the long-term chance of developing arthritis but should only be considered in patients in whom stable fixation can be achieved with good bone, no comminution, and a limited number of fragments. Otherwise, arthroplasty provides a more reliable outcome in terms of restoring stability.

Open reduction and internal fixation is reserved for radial head fractures with three or fewer fragments, good bone quality, minimal comminution, and ideally when there is not complete disruption at the radial neck. Advances in contemporary techniques have improved surgical outcomes using internal fixation [36]. Variable pitch headless screws, 1.5 or 2.0 mm cortical mini-fragment screws, pre-contoured radial rim and neck plates, T-plates, mini-condylar plates, and absorbable pins have all been described for the restoration of the fractured radial head and neck.

The articular surface should be reduced under direct visualization using a dental pick or small point-to-point reduction forceps, and should be confirmed with fluoroscopic imaging. Provisional fixation is obtained with small diameter Kirschner wires. Hardware is then placed with the goal of achieving enough stability to allow postoperative functional mobilization (Fig. 5.9). Headless or countersunk screws are utilized to avoid radiocapitellar chondrolysis. Additionally, careful attention to screw lengths will avoid radioulnar joint penetration and avoid painful rotation, diminished range of motion and osteoarthritis. If the fracture pattern involves extension into the radial neck, then operative fixation usually requires the addition of a plate. The nonarticulating portion of the radial head is referred to as the “safe zone” [38–40] which is the preferred region of plate placement. The safe zone corresponds to an approximately 90–110° arc of radial head surface and is defined as the lateral portion of the radial head/neck that lies between perpendicular axes through the radial styloid and Lister’s tubercle [40]. Application of the plate to the radial side of the neck with the forearm in neutral rotation ensures placement in the “safe zone”. Care should be taken to avoid plating distally past the bicipital tuberosity as distal dissection places the posterior interosseous nerve at risk for injury.