Floating Shoulder 

Updated: Mar 11, 2019
Author: Mohit N Gilotra, MD; Chief Editor: S Ashfaq Hasan, MD 

Overview

Background

The term floating shoulder was used in 1992 by Herscovici et al to describe their series of ipsilateral fractures of the clavicle and scapular neck.[1] Although some have questioned the accuracy of this definition, the term floating shoulder, in contemporary use, usually refers to ipsilateral fractures of the clavicle and scapular neck but can also apply to any combined injury to the superior shoulder suspensory complex (SSSC).[2]

Floating shoulder injuries are rare. They result from high-energy trauma and have a high incidence of associated injuries, which likely contribute to their underdiagnosis and undertreatment. Understanding the pathologic anatomy and instituting appropriate treatment are important for minimizing the sometimes significant morbidity from this injury.[3, 4, 5, 6]

Although this unstable injury tends to have a better outcome in patients in whom the clavicle fracture is surgically stabilized (particularly more distal clavicle fractures), the injury should be assessed in the context of the whole patient. Consideration of the age, demands, associated injuries, and the severity and displacement of the fracture may make nonoperative treatment preferable, with an expectation of a good result.[7]

Anatomy

The upper extremity is suspended primarily from the axial skeleton by a bony and ligamentous ring (ie, the SSSC).[8]  The ring consists of the middle and distal clavicle, coracoclavicular and acromioclavicular ligaments, acromion, coracoid process, and glenoid. Of these, the clavicle is the primary support to the axial skeleton. The musculotendinous attachments from the spine, sternum, ribs, and medial clavicle to the scapula, distal clavicle, and proximal humerus provide the secondary support.

Pathophysiology

A double disruption of the SSSC ring results in an unstable construct and is the most accurate description of a floating shoulder.[8]  The most common double disruption of this ring is the combined fracture of the clavicle and scapular neck, and the terms are usually equated. However, the term floating shoulder can apply to any combined injury to the SSSC.

The deforming forces acting on this unstable construct include the weight of the arm and the force of the muscles acting on the proximal humerus, both of which pull the glenoid fragment distally and anteromedially.

Etiology

Ipsilateral fractures of the clavicle and scapular neck typically occur after high-energy trauma, such as the following:

  • Motor vehicle accidents
  • Falls from a height
  • Crush injuries
  • Gunshot wounds

With the exception of those occurring from gunshot wounds, most such fractures are closed injuries.

Epidemiology

Ipsilateral fractures of the clavicle and scapular neck are exceedingly rare, constituting approximately 0.1% of all fractures.[1]

Prognosis

Displaced ipsilateral fractures of the clavicle and scapular neck are rare. These patients often have significant associated injuries because of the severity of the initial trauma. Initial treatment of these patients involves assessment and stabilization of the often life-threatening associated injuries.

The prognosis for injuries treated nonsurgically often depends on the predicted rotator cuff dysfunction. Excessive glenoid displacement from combined injuries will alter the normal lever arm of the rotator cuff and the surrounding musculature.[9] In patients who do not have contraindications for surgical treatment, the best outcomes are achieved most predictably with reduction and stabilization of at least one part of the SSSC.[10] ​

 

Presentation

History and Physical Examination

The assessment of patients with ipsilateral fractures of the clavicle and scapular neck includes not only evaluation of the injury but also, more important, evaluation of the whole patient. An emergency physician and, often, a trauma surgeon (depending on the associated injuries) are usually the first to see these patients.

As with most scapular fractures, ipsilateral fractures of the clavicle and scapular neck have a high incidence of associated injuries, which may result in underdiagnosis as attention is drawn to more life-threatening injuries.[11, 12]

In series in which associated injuries specifically are reported, the incidence ranges from 40% to 96%.[11, 13]  In one series, five of 36 patients died from their associated injuries, and four of 36 had severe head trauma that precluded shoulder rehabilitation for more than 3 months.[14]

Closed head injuries and pulmonary injuries (eg, pneumothorax, multiple rib fractures, hemothorax) each constitute approximately one third of associated injuries. Cervical spine injuries and long bone fractures each constitute another 10-20%. Other reported injuries include brachial plexus and subclavian artery injury, liver lacerations, and other forms of intra-abdominal injury secondary to blunt trauma.

Specific clinical findings in the involved upper extremity can vary with the severity of the trauma and the presence and severity of associated injuries. However, some findings are common. Pain is much greater than that observed with isolated upper-extremity fractures, not only because of the additional fracture but also because of the resulting displacement and secondary muscle spasm.

Traction neuritis of the brachial plexus also can increase the pain. The patient's limb usually hangs lower than the limb on the uninjured side. Some of this effect is attributable to the inferior displacement of the distal fracture fragments, and some is secondary to postural changes assumed by the patient to increase comfort. The scapula usually appears to be protracted as part of the postural changes. A loss of the normal concavity at the anterior aspect of the shoulder is likely to occur as the distal glenoid fragment and humeral head are displaced anteriorly.

Routine complete history and physical examination of the patient are followed by appropriate laboratory and radiographic studies (see Workup).

 

Workup

Laboratory Studies

Laboratory studies that may be helpful include the following:

  • Complete blood count (CBC)
  • Basic metabolic profile
  • Urinalysis

Imaging Studies

Chest radiography, a cervical spine series, and electrocardiography (ECG) often are also indicated on the basis of the history and physical examination findings.

Specific radiographic evaluation of the shoulder injury should include plain radiographs of the clavicle and the shoulder trauma series (true anteroposterior view of the glenohumeral joint, axillary view, and scapular lateral view). If concern exists regarding an intra-articular extension of the scapular neck fracture or if the scapular neck fracture is inadequately depicted on the plain films, a computed tomography (CT) scan of the scapula should be obtained.

 

Treatment

Approach Considerations

For floating shoulder, as for other rare injuries, no large series studies have been reported with matched patient groups in which two or more treatments were compared. Instead, information to arrive at and support treatment recommendations has come mainly from the following two sources[1, 14, 15, 16] :

  • Understanding of the anatomy and function of the superior shoulder suspensory complex (SSSC) and concern for a potential poor result if the injury is not stabilized when excessive displacement is present
  • Data provided by several small series of patients

Treatment recommendations have included most available options, such as the following[1, 13, 14, 15] :

  • Nonoperative care with early mobilization
  • Nonoperative care with delayed mobilization at 1 month
  • Open reduction and internal fixation (ORIF) of the clavicle alone
  • ORIF of both fractures

For most patients, and barring specific contraindications, ORIF of the clavicle is recommended for displaced ipsilateral fractures of the clavicle and scapular neck. However, in patients with nondisplaced fractures and in those in whom underlying medical status or severe associated injuries create excessive surgical risk, nonoperative treatment can often yield an acceptable result.

Concomitant injuries may preclude surgery for floating shoulder.

Nonoperative Therapy

Nonoperative management may consist of a 1-month period of immobilization followed by return to active assisted range of motion (ROM) with physical therapy.

Results of nonoperative therapy

Edwards et al reported on 20 patients treated with a sling or shoulder immobilization for comfort with early instigation of pendulum exercises.[14]  Fifteen of the scapula neck fractures were displaced less than 5 mm; nine of the clavicle fractures were displaced less than 1 cm. The patient was weaned from the sling or shoulder immobilization, and active and passive ROM exercises were started as comfort allowed. This occurred over a 3- to 8-week period. Follow-up averaged more than 2 years, and results were assessed based on pain, strength, range of motion, stability, and radiographic assessment.

Edwards et al used several rating systems to classify results,[14] including the system used by Herscovici.[1]  On final follow-up, no further displacement from the original radiographs was noted. One clavicle nonunion was observed. The remainder of the fractures healed. Two patients had a 20° loss of elevation. Five patients (25%) complained of moderate-to-severe pain, three were unhappy with the appearance of their shoulder, and four were dissatisfied with their result. The least generous rating systems used gave 17 patients an excellent result and three a good result.

Ramos et al reported on 13 patients treated by immobilization for 1 month followed by physical therapy.[15]  Results were assessed by using the scoring system of Herscovici.[1]  Results were rated excellent in 11 patients, good in one, and fair in one. All fractures united. Four patients had elevation limited to 80-120°. Three patients had significant weakness on examination. Nine of 13 patients returned to their sedentary occupations, two others returned to heavy physical work, and two had to give up their previous heavy physical occupation.

A closer review of these reports suggests that the results of nonoperative treatment may be less positive than the conclusions suggest. In the series by Edwards et al, a group of patients had relatively nondisplaced or minimally displaced injuries.[14] An additional 16 patients were eliminated from this study because of serious associated injuries and failure of follow-up.

The rating systems used assign considerable weight to factors such as muscle strength and stability, which are less likely to be affected by this injury. No value is assigned for deformity. For example, a patient with severe pain (eg, at rest, requiring daily medication), deformity, total disability from work, and an ability to elevate the shoulder to 130° is allotted a good result in this system. In the series by Edwards et al,[14] patients with more pain and dissatisfaction tended to have fractures involving the distal third of the clavicle.

Surgical Therapy

Indications for surgical therapy

The literature is relatively limited, and validated indications for surgical management remain unclear. It appears that good outcomes can be achieved with ORIF of the clavicle fracture only[17] and nonoperative treatment of the scapular neck fracture, particularly if the fracture involves the distal third of the clavicle (see Results of Operative Therapy below). ORIF of the clavicle all but eliminates the risk of deformity or asymmetry of the involved shoulder, and it also likely results in the improved comfort, ROM, and strength found in patients treated in this manner. Nevertheless, if significant displacement of the glenoid persists, it is recommended that the scapular neck fracture be addressed surgically.[3]

Despite the lack of large systematic studies, it is commonly recommended that scapular neck fractures be treated with operative intervention when they are displaced more than 1 cm, when the glenopolar angle is less than 26º or more than 55º, when the angular displacement of the fragment is 40º or more in either the coronal or the sagittal plane, or when there is an open fracture requiring surgical irrigation and debridement.[3, 18, 19] These parameters may be reassessed after surgical stabilization of the clavicle.

Operative details

Clavicle fixation

For clavicle fixation, the patient is positioned in the semirecumbent position. A Mayfield (ring) type headrest is useful for positioning and facilitates intraoperative imaging of the shoulder. The neck is slightly tilted and rotated toward the contralateral side for better access to the medial aspect of the surgical exposure. The field is widely draped from the base of the neck and the entire upper extremity is draped free. Intraoperative manipulation of the upper extremity can be useful in reducing the fracture.

An incision can be made in line with the clavicle, anterior to the clavicle or obliquely along Langerhans lines. Supraclavicular nerves are often identifiable and should be protected as much as possible. The junction of the aponeurosis of the trapezius superiorly and the deltoid and pectoralis inferiorly is split to expose the fracture. Commonly, the displaced fracture already has exposed the plane of dissection. This split is repaired at the completion of the procedure. Reduction and stabilization are carried out by using standard internal fixation techniques.

The 3.5-mm reconstruction plate works well for this injury because it is easy to contour to the S-shaped clavicle. Precontoured clavicular plates may be used as well. The plate can be placed superiorly or anteriorly on the clavicle, depending on the orientation of the fracture. Placement of a blunt elevator deep to the clavicle during drilling of the screw holes protects against risk of pneumothorax and neurovascular injury.

A short longitudinal split in the deltoid can be made over the coracoid process. To minimize the risk of injury to the axillary nerve, the split should not exceed 5 mm. Access to the coracoid can be useful in facilitating reduction of the fractures.

Some surgeons have advocated intramedullary fixation of the clavicle. This is a reasonable approach for middle third fractures of the clavicle but is more technically demanding than plate and screw fixation and is less familiar to most surgeons.[20]

After the procedure, the patient is placed in a sling, and the shoulder is mobilized as the stability of the fracture and the patient's medical status allow. Fracture healing should be complete in 6-12 weeks, with comfort, mobility, and strength improving over 6-9 months.

Scapular neck fixation

Surgical fixation for scapular neck fractures employs a Judet posterior approach to the shoulder with the patient in the lateral position. The classic Judet incision is a curved one that starts at the posterolateral corner of the acromion, runs along the scapular spine, and then curves around the medial border of the scapula. A more limited straight incision, made from the tip of the acromion posteriorly and directed toward the scapular angle, has also been described; however, exposure and fixation of an inferior glenoid neck fracture may be more difficult through this approach.

The deltoid is exposed and sharply dissected from its insertion on the scapular spine and acromion. It is then reflected laterally, exposing the interval between the infraspinatus and the teres minor. A fat stripe is commonly found here, to be distinguished from a separate fat stripe located in the middle of the infraspinatus. This interval is used to expose the posterior capsule, which is then incised to allow visualization of the intrarticular extension of the fracture; this helps facilitate anatomic reduction of the joint surface.

If additional exposure is necessary the infraspinatus tendon can be tagged and cut approximately 1-2 cm medial to to its insertion on the greater tuberosity.The lateral pillar of the scapula can then be exposed by developing the plane proximally between the infraspinatus and the teres minor.

After reduction, final fixation is accomplished with with contoured 2.7 mm or 3.5 mm reconstruction plates or a 3.5 semitubular plate applied along the lateral border of the scapula. Fixation can be augmented with lag screws if the fracture pattern allows this.[3, 18] When a posterior deltoid-off approach to the shoulder is taken, it is critical to repair the deltoid back to the scapular spine by using drill holes and nonabsorbable sutures.

Alternatively, for fractures involving only the posterior glenoid rim, a posterior deltoid-splitting approach may be employed, followed by an infraspinatus split to expose the posterior capsule. The utility of the infraspinatus split, as opposed to the infraspinatus–teres minor interval, is that it bisects the posterior glenoid rim at its midpoint. Care should be taken to limit medial extension of the infraspinatus split to a maximum of 15 mm medially from the glenoid rim so as to avoid iatrogenic injury to branches of the suprascapular nerve to the infraspinatus, which are located at the spinoglenoid notch 22 mm medial to the glenoid rim.[21]

It is important to note that this approach should be reserved for fractures of the posterior glenoid rim only, with no medial or proximal extension. It is not an extensile approach.

Results of surgical therapy

Herscovici et al reported on seven patients treated with ORIF of the clavicle and two patients treated nonoperatively.[1] Surgical treatment consisted of plate and bicortical screw fixation. The scapular neck fracture was not exposed. Active ROM exercises began 3-5 days postoperatively. Pain, lifestyle changes, range of motion, and muscle strength were scored for results reporting. All fractures in each treatment group healed.

All of the seven patients who were treated surgically had excellent results; five had no pain, and two had mild pain on exertion.[1] Two patients failed to return to their prior occupation or sporting activity. No patient in the operative group had a significant deformity of the shoulder. Of the two patients treated nonoperatively, one had a good result, and the other had a poor result (though the poor result largely was caused by severe associated injuries). Both patients treated nonoperatively had significant asymmetry of their shoulders.

Leung et al reported on 15 patients with ipsilateral fractures of the clavicle and scapular neck treated with ORIF of both fractures.[13, 12] In this study,[13] eight patients had elevation higher than 150°, and seven had elevation higher than 120º. Eight patients had normal strength, two had good strength, and five had fair strength. Three patients considered their shoulders normal, 11 had mild limitations, and one had moderate limitations that resolved after the prominent scapular plate was removed. All 15 patients returned to their jobs doing manual labor.

Gilde et al reported on 13 patients with combined ipsilateral clavicle and scapular fractures, all resulting from high-energy mechanisms and treated with only clavicle reduction and fixation with a minimum of 12 months' follow-up.[9] Passive ROM was begun 1-2 weeks postoperatively, and active ROM and strengthening were begun 6 weeks postoperatively.

In this study, clavicle union was seen in 92.3% of patients, and final pain was reported as minimal in 11 cases, moderate in one, and high in one. Eight patients had 180º of flexion and abduction, and three had sufficient ROM and function to perform activities of daily living (ADLs). None of the patients required reconstruction of scapular malunion after nonoperative treatment, and 12 returned to their previous work without restrictions.

Complications

Complications can be quite varied in this group of patients, with a relatively high incidence of associated injuries. Complications specific to the surgical treatment of these patients are rare but may include the following:

  • Infection
  • Nonunion of the fractures
  • Neurovascular injury [22]
  • Deltoid dehiscence

Some numbness just distal to the incision can be expected and may improve over time.