Fig. 10.1
Serendipity radiographic view of bilateral SC joints. A malunion of the right medial clavicle is present although difficult to appreciate
The interpretation of medial clavicle fractures using plain radiographs is often challenging and computed tomography (CT) is the preferred modality (Fig. 10.2). Axial CT imaging of bilateral SC joints can better delineate fracture displacement and the proximity of close neurovascular structures for surgical planning. CT scans can also differentiate medial physeal separations from true SC joint dislocations which may have treatment and prognosis implications. These are often Salter-Harris II physeal injuries with posterior displacement of the lateral fragment. CT scans are essential in identifying the often small, poorly visualized metaphyseal bone fragment still aligned with the sternum [20, 21]. These injuries can be a diagnostic challenge often having a delayed presentation and diagnosis in as many as 57% of cases [22–25]. As an alternative, MRI (magnetic resonance imaging) affords good visualization without the risk of radiation exposure associated with CT. Assessment of the sternoclavicular joint congruity and underlying mediastinal compression are best viewed in the axial plane [26]. A high clinical suspicion is required when evaluating for medial physeal injuries as they are commonly misdiagnosed as SC joint dislocations despite advanced imaging [27].
Fig. 10.2
(a) Radiograph of bilateral full-length clavicles demonstrating subtle fracture of the left proximal clavicle. (b) Axial CT scan of same patient demonstrating physeal fracture of medial clavicle with significant posterior displacement of lateral fragment in close proximity of mediastinal structures
In the high-energy trauma patient , careful radiological assessment of the shoulder girdle is necessary to rule out concomitant injuries to the scapula and glenoid [28]. An AP chest film is critical as part of a trauma series and may identify associated rib fractures or potentially life-threatening intrathoracic injuries such as pneumo or hemothoraces. A CT angiogram is also a valuable adjunct when a distal vascular deficit is detected following a high-energy clavicle fracture.
Management
Traditionally, fractures of the medial clavicle have been treated nonoperatively, even when significantly displaced. The risk of damage to neurovascular and airway structures combined with the relative infrequency of the injuries has led many authors to advocate for conservative measures [12, 15, 29–33]. This typically includes a brief period of shoulder immobilization for 2–6 weeks followed by a structured rehabilitation program. The results of nonsurgical treatment for medial clavicle injuries are in general satisfactory although the low prevalence of these fractures and retrospective nature of most reports precludes a detailed analysis [4, 9]. In addition, confounding variables including severe neurovascular or visceral injuries in polytrauma patients complicate the analysis of clinical outcomes [18].
Nonunion rates between 4 and 8% have been reported; however, the nonunion rate for patients with displaced medial-end fractures may be as high as 14% [4, 5] (Fig. 10.3). Nonunion has been associated with significant pain, loss of function, limb weakness, and pectoral muscle dysfunction [4, 9, 34]. Therefore, in select clinical settings, open reduction and internal fixation of displaced medial fractures has been described and recommended [8, 10, 24, 35–37]. This also includes retrosternal SC dislocations or adolescent medial epiphyseal separations compromising mediastinal structures [7, 24, 35, 38] and case reports of highly unstable bipolar clavicle injuries with segmental fractures involving both the medial and lateral thirds of the clavicle [8, 10].
Fig. 10.3
(a) Radiograph of bilateral full-length clavicles demonstrating right medial clavicle nonunion. (b) Axial CT scan of same patient demonstrating nonunion of right medial clavicle
Adult-type displaced medial fractures are typically treated with anatomic reduction with plate and screw fixation. Excellent functional outcomes and low complication rates have been reported in this population [25, 39, 40]. Cases of hardware failure are rare although patients often have mild symptoms of plate irritation [25]. Open reduction and transosseous suture techniques are used in the operative treatment of displaced physeal injuries [25]. This avoids significant disruption to the physis and does not typically have the issues with hardware irritation, migration, and subsequent removal as previous techniques using Kirschner wires or metal sutures [41–43]. Excellent long-term functional results with low complications have been reported using transosseous suture techniques [24, 25, 36].
Preferred Surgical Technique
The senior author’s treatment of choice for displaced fractures of the medial clavicle is anatomic reduction and plate fixation. Fracture pattern and the size of the medial fragment determine whether the fixation spares or spans the SC joint. A cardiac surgeon is present and available in the event of an intrathoracic vascular injury
After a general anesthetic, the patient is placed in the modified beach-chair position with the head secured on a headrest. The entire chest and upper portion of the abdomen are prepared and draped to allow for possible sternotomy in an emergency situation. The authors do not routinely free-drape the arm. The incision is made directly over the SC joint at the level of the fracture and extended laterally in line with the shaft of the clavicle. A single, thick subcutaneous tissue flap is elevated exposing the underlying myofascial layer. This layer is divided sharply down to the clavicle and SC joint and is elevated off the bone as a single layer that can be later closed over the plate. If a traumatic tear or “rent” exists in the fascia, this instead is utilized and extended.
The fracture site is then exposed and inspected. Hematoma and interposed soft tissue are carefully debrided. Depending on fracture type, a medial fracture fragment is usually attached to the SC joint with adjacent displacement of the shaft portion of the clavicle. Tissue is carefully released using blunt dissection from the inferior and superior boarders of the displaced fragment. A sharp reduction forcep is used to gently reduce the lateral clavicle to the medial portion. The reduction is held provisionally with fracture reduction forceps.
If a large proximal fragment exists, adequate fixation may be achieved with multiple 3.5 mm cancellous screws secured through a 3.5 mm non-locking plate. When a small medial fragment is encountered or additional fixation is required, the construct should span the SC joint . Bicortical screws in the sternum and clavicle are desired and uncontrolled plunging with the drill or depth gauge must be avoided. Since the procedure is typically reserved for young, active patients, bone quality is rarely an issue, and the authors have not found locking plates to be required or useful in this setting. A one-third tubular plate is typically used.
If damaged, the anterior capsuloligamentous attachments of the SC joint should be repaired using a strong nonabsorbable suture. The surgical site is thoroughly irrigated and a two-layer closure of the soft tissues is performed to maximize local resistance to infection and minimize the potential for hardware irritation. The myofascial layer is sutured with #1 absorbable suture and the skin with 3-0 monofilament sutures. Absorbable subcutaneous sutures are avoided to minimize the risk of tissue reaction or stitch abscesses.
The patient wears a simple sling for comfort and can begin range-of-motion (ROM) exercises in the immediate postoperative period . The use of the sling is discontinued after 10–14 days and strengthening exercises are initiated at 6 weeks postoperatively.
Illustrative Cases
Case 1
An 18-year-old male was seen in consultation for a left shoulder girdle injury he sustained while snowboarding. He landed on his left shoulder from a height of 10 ft when attempting a jump. He complained of isolated left chest discomfort and denied any difficulty breathing or swallowing. Upon physical examination, there was an anterior prominence of the proximal left clavicle with a significant amount of swelling and ecchymosis. The area was tender and he is neurologically intact.
CT scan of bilateral SC joints identifies an anterior fracture -dislocation of the left SC joint with anterior displacement of the residual shaft fragment (Fig. 10.4).
Fig. 10.4
(a) Axial CT scan of bilateral sternoclavicular joints demonstrating an anterior fracture-dislocation on the left side. (b) 3D CT scan reconstruction of same patient demonstrating left SC fracture-dislocation
Management options included nonoperative treatment with a period of sling immobilization followed by early ROM and then strengthening at 6 weeks. This would include accepting the current deformity and asymmetry of the chest wall and the potential for a symptomatic nonunion. Open reduction and internal fixation would aim to correct the deformity and minimize the risk of nonunion. In additional to routine surgical risks of an open procedure, there was the remote possibility life-threatening hemorrhage.
The patient was managed operatively with open reduction and internal fixation with plate and screw fixation. A “T-shaped” plate was utilized and screw purchase in the large medial fragment was sufficient and therefore the SC joint was spared (Fig. 10.5).
Fig. 10.5
(a) Postoperative radiograph of chest after open reduction and internal fixation with plate and screw fixation of the left medial clavicle. (b) AP radiograph of left clavicle after open reduction and internal fixation
Case 2
A 13-year-old male was seen in consultation for a right shoulder girdle injury he sustained while playing tackle football. He was hit from standing height and forcefully landed on his left shoulder with his arm adducted. He had pain along his right medial chest wall and was reluctant to move his right shoulder. He denied difficulty breathing or swallowing. Upon physical examination, there was an obvious asymmetry in the appearance of his right medial clavicle and his right shoulder appeared internally rotated. There was no significant swelling or ecchymosis and he was neurovascular intact distally.
Right clavicle radiographs and axial CT scan of the SC joint demonstrated a significantly displaced fracture of the medial clavicle with the residual epiphyseal fragment attached to the SC joint (Fig. 10.6).
Fig. 10.6
(a) Right clavicle radiograph of subtle posterior physeal separation of medial clavicle. (b–d) Unilateral CT scan demonstrating posteriorly displaced physeal separation of right medial clavicle
Given the degree of displacement resulting in shortening and deformity of the shoulder girdle and the close proximity of mediastinal structures to the displaced fragment, operative treatment was chosen.
The patient underwent open reduction and internal fixation with plate and screw fixation. Due to the small size of the epiphyseal fragment, an SC spanning construct was utilized for adequate fixation (Fig. 10.7).
Fig. 10.7
(a) Postop chest radiograph after open reduction and internal fixation of the right medial clavicle. (b) AP of right clavicle after open reduction and internal fixation with plate and screws
Distal Clavicle Fractures
Distal clavicle fractures account for 10–30% of all clavicle fractures [1, 2, 4, 5, 16]. The majority of these fractures are nondisplaced or minimally displaced, extra-articular, and are typically managed nonoperatively [1, 4]. A particular subset of distal clavicle injuries are inherently unstable, prone to displacement, and are at risk for delayed or nonunion [44]. Distinguishing the subtle variations in fracture pattern stability can be challenging and ultimately guides treatment decisions. However, nonunions are often asymptomatic, particularly in elderly and sedentary individuals, and the preferred operative fixation remains controversial [34, 45].
Applied Anatomy
The clavicle widens along its acromial end and the lateral third contains the apex of the superior bow of the clavicle. The clavicle acts as a strut connecting the shoulder girdle to the axial skeleton and scapulothoracic motion is dependent on the stable relationship between the distal clavicle and scapula [44]. The distal clavicle is anchored solidly to the scapula by the AC capsuloligament and the coracoclavicular (CC) ligaments. The AC capsuloligament complex spans the AC joint and attaches to the distal aspect of the clavicle 6 mm medial to the AC joint [4]. The AC ligament and joint capsule are important stabilizers in the horizontal plane of motion [46]. The CC ligaments consist of the trapezoid and conoid ligaments which originate from the base of the coracoid process and attach on the inferior boarder of the distal clavicle and provide vertical stability. The trapezoid ligament originates more lateral attaching to the clavicle approximately 2 cm from the AC joint while the conoid ligament attaches to the medial clavicle approximately 4 cm from the AC joint [4].
Muscular attachments of the lateral third of the clavicle include the anterior fibers of the deltoid and trapezius as well as the clavicular head of the pectoralis major. The pectoralis major and weight of the arm provide the chief deforming force on the lateral fragment, causing inferomedial and anterior displacement in fractures of the middle third of the clavicle [47].
Classification
Neer and later Craig defined lateral-third fractures based on the relationship of the fracture line to the CC ligaments and the AC joint [30, 48] (Fig. 10.8). Type I fractures occur lateral to the CC ligaments and spare the AC joint. These fractures are often minimally displaced as the proximal fragment is stabilized by the CC ligaments and the distal fragment by the deltotrapezial fascia. Type III fractures are also minimally displaced as the ligaments remain intact, but have an intra-articular component. Type II fractures are inherently unstable as the proximal fragment is detached from the CC ligaments while the distal fragment remains attached to the scapula via the AC joint capsule. Type II fractures are differentiated into those where the fracture occurs medial to the conoid ligament (Type IIA) and those where the fracture lies between the conoid and trapezoid ligaments (Type IIB). Determination of the precise location of the fracture and the integrity of the CC ligaments can be difficult to determine on plain radiographs [44]. Type IV fractures are rare injuries involving epiphyseal separation in pediatric patients [49]. Type V injuries are comminuted and unstable as neither the proximal or distal fragments have ligamentous continuity with the coracoid [49]. An investigation using shoulder fellowship-trained observers demonstrated overall fair agreement for the Neer classification, but only slight agreement for the Type IIB pattern, which is thought as the most important determining factor for surgery [50].
Fig. 10.8
Illustration of the Neer Classification of distal clavicle fractures
A more recent classification was introduced by Robinson in which fractures are subdivided according to displacement, angulation, comminution, and intra-articular involvement [4] (Fig. 10.9). Distal clavicle fractures were classified as Type 3, with subgroups into A and B based on displacement of the major fragments. The subgroups are further divided according to articular involvement. Although complicated, the classification system demonstrated excellent interobserver and intraobserver reliability among orthopedic trainees [4].
Fig. 10.9
Illustration of the Robinson classification for distal clavicle fractures (type 3)
Clinical Evaluation
Most distal clavicle fractures occur as the result of either a direct blow or a fall on shoulder with the arm in the adducted position [5, 51]. The force from the impact at the acromion is transmitted through the AC joint to the CC ligaments and the distal clavicle [44].
Physical examination findings include ecchymosis, swelling, and tenderness at the level of the distal clavicle. A bony protuberance under the skin may be present caused by fracture displacement of the proximal fragment with an appearance similar to that of a high grade AC joint separation. As with medial clavicle injuries, a thorough neurological examination of the shoulder and the upper extremity should be performed and documented, particularly in high-energy clavicle fractures.
Radiographic Evaluation
Radiographic assessment should include routine views of the shoulder girdle to identify associated scapular or glenoid fractures. An axillary view is particularly useful in identifying subtle injuries of the distal clavicle including posterior displacement. The Zanca view is centered over the AC joint with a 10–15° cephalic tilt and can be helpful in evaluating intra-articular involvement [38] (Fig. 10.10). A single radiograph including bilateral clavicles and AC joints can also useful in assessing overall fracture pattern and displacement.
Fig. 10.10
Zanca radiographic view of the right shoulder demonstrating a nonunion of the distal clavicle
Management
Most fractures of the lateral third of the clavicle are nondisplaced or minimally displaced and can be treated successfully nonoperatively [1, 4]. The rehabilitation regimen is similar to that of medial and midshaft clavicle fractures. After a period of sling immobilization for 2–6 weeks where supine passive and active-assisted ROM are initiated, active ROM is then allowed. Strengthening is initiated when signs of fracture consolidation are present radiographically.
The integrity of the CC ligaments plays an important role in the stability of the medial fragment and a smaller proportion of fractures involving the lateral third of the clavicle are at risk for delayed or nonunion. The nonunion rate ranges from 22 to 37% for displaced Neer type II fractures, and the absence of cortical contact is an independent risk for nonunion [4, 34, 52]. The risk of nonunion has also been reported to increase with advancing patient age and fracture displacement [53, 54]. Thus, the Neer classification has been traditionally used to determine fracture stability which is the driving factor for surgical decision-making and displaced type II, type IV, and type V fracture patterns in active healthy patients are typically managed surgically. However, only fair agreement between observers for the Neer classification has been demonstrated in the literature and only slight agreement for the type IIB Neer pattern [50].
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