Acromioclavicular (AC) dislocations and displaced fractures of the middle third of the clavicle rarely occur together. Isolated AC joint separation is often treated nonoperatively with internal coracoclavicular (CC) fixation or reconstruction considered for type IV-VI AC dislocations and some type III injuries.1 Isolated clavicle fractures traditionally have been treated nonoperatively. The current trend is toward internal fixation for displaced and shortened fractures.2 There have been only a handful of reports of concomitant AC dislocation and midshaft clavicle fracture.3-6 Previous treatments have included nonoperative treatment, AC fixation, or internal fixation of the clavicle with ligamentous reconstruction.
We present a previously undescribed technique for internal fixation of this rare shoulder injury. The patient provided written informed consent for print and electronic publication of this case report.
Case Report
While driving an all-terrain vehicle, a healthy 19-year-old right-hand–dominant man hit a bridge and sustained direct impact to his right shoulder. He presented to the emergency department complaining of right shoulder pain and deformity without skin disruption, vascular insufficiency, or neurologic symptoms. Anteroposterior (AP) radiograph showed an oblique, displaced, middle-third clavicle shaft fracture (Figure 1). An associated type IV AC dislocation was confirmed on axillary radiograph (Figure 2) and on an axial cut from a trauma chest computed tomography (CT) scan (Figure 3). The patient was discharged home from the trauma service the next day with a sling for comfort and plans for delayed, elective operative fixation 1 week later.
The patient was placed in a beach-chair position. Through a longitudinal incision extending laterally over the AC joint, the clavicle was exposed for fracture reduction, with care taken to retain soft-tissue attachments. The distal clavicle was buttonholed posteriorly through the trapezius muscle and fascia. The distal fracture fragment was devoid of any remaining CC ligamentous attachment. After satisfactory reduction, a low-profile precontoured clavicle plate (Superior Midshaft Clavicle Plate; Acumed, Hillsboro, Oregon) was placed superiorly; the fracture was compressed through the plate and internally fixed with three 3.5-mm bicortical screws on both sides of the fracture. Approximately 5 mm of the distal clavicle was resected at the AC joint to facilitate adequate AC and CC reduction without disruption of the clavicle fracture. With an adequate CC reduction, a 3.5-mm fully threaded cortical screw was placed through the most distal hole in the clavicle plate, clavicle, and coracoid.
After surgery, the patient was placed into an ARC shoulder immobilizer (Bledsoe, Grand Prairie, Texas) for 6 weeks, removing the immobilizer only for elbow and wrist range of motion (ROM) exercises. Radiographs at 3-month follow-up (Figure 4) showed a healed fracture with no loss of AC or CC reduction. Three months after surgery, another procedure was performed to remove the CC screw. One year after the initial surgery, the patient complained of intermittent soreness over the lateral shoulder but was not limited in his activities and was back to performing manual labor without difficulty. He had full ROM in forward flexion, abduction, internal rotation, and external rotation without weakness, tenderness, or any neurovascular deficit. After CC screw removal, no deformity returned at the shoulder. Radiographs showed a healed fracture with minimal superior subluxation at the AC joint without significant change from the 3-month follow-up (Figure 5).
Discussion
The combined injury pattern of a type IV AC dislocation and a displaced middle-third clavicle shaft fracture is rare. The usual mechanism of injury, as seen in the present case, is a direct blow to the shoulder at the tip of the acromion, though indirect forces from a fall on an outstretched hand are also described.7 Disruption of the CC ligaments with AC separation likely dissipates the stress necessary to create a clavicle fracture in most cases,1 explaining the rarity of this injury. It is imperative to evaluate patients for injury to both the osseous and ligamentous structures.
Previous case reports of concomitant AC separation and midshaft clavicle fracture have described a variety of treatment options, but to date our case represents the only episode in which both the clavicle fracture and the AC joint were treated with open reduction and internal fixation (ORIF). Wurtz and colleagues5 reported on a series of 4 patients with AC disruption and middle-third clavicle fracture. Three of the 4 patients had type IV AC separation; all 3 were treated, 2 acutely and 1 chronically, with open reduction of the AC and CC joints; 2 of these patients had CC screw fixation only after reduction, and the third had 2 Steinmann pins placed across the AC joint without CC screw fixation. All hardware was removed after 12 weeks. The fourth patient had a type II AC dislocation and was treated with closed reduction of the clavicle with no intervention for the AC joint. None of the clavicle fractures in this series were treated with internal fixation. All patients had full and pain-free ROM at 1- to 3-year follow-up.