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Acromioclavicular joint injuries ("separated" shoulder)

Acromioclavicular joint injuries ("separated" shoulder)
Literature review current through: Jan 2024.
This topic last updated: Nov 01, 2023.

INTRODUCTION — The acromioclavicular (AC) joint is situated at the distal end of the clavicle forming an articulation with the acromion of the scapula (picture 1). The AC joint complex is strong, but its location makes it vulnerable to injury from direct trauma. Injuries to the AC joint are classified according to the position of the clavicle with respect to the acromion and coracoid. Treatment is based upon the extent of injury. AC joint injuries are sometimes referred to as sprains or a "separated" shoulder.

The evaluation and management of AC injuries will be reviewed here. Chronic pain after injury, arthritic and atraumatic conditions of the acromioclavicular joint, as well as a general approach to the patient with shoulder pain and discussions of other specific shoulder injuries are found separately. (See "Acromioclavicular joint disorders" and "Evaluation of the adult with shoulder complaints" and "Multidirectional instability of the shoulder" and "Rotator cuff tendinopathy" and "Clinical manifestations and diagnosis of osteoarthritis", section on 'Shoulder'.)

ANATOMY AND BIOMECHANICS — A more complete discussion of shoulder anatomy and biomechanics is found separately. The structure and function of the acromioclavicular (AC) joint is described below. (See "Evaluation of the adult with shoulder complaints", section on 'Anatomy and biomechanics'.)

The AC joint is supported by ligaments that span its anterior, superior, posterior, and inferior aspects (picture 1). These ligaments also envelop the distal 1 to 2 cm of the clavicle. In addition to the AC ligaments, the distal clavicle is held in alignment with the acromion by the strong coracoclavicular (CC) ligaments. These ligaments consist of the conoid ligament medially and the trapezoid ligament laterally. The AC joint itself has a cartilaginous disk and synovial membrane.

Joint motion is limited, but the clavicle can rotate a few degrees, and small amounts of translation and slight angulation are possible. The clavicle and scapula tend to move in unison, and investigators have shown fully preserved shoulder range of motion (ROM) with fusion of the AC joint [1]. Anatomic drawings of the shoulder are provided (figure 1 and figure 2 and figure 3).

At physiologic loads, the AC ligaments primarily resist anteriorly and posteriorly directed forces while the CC ligaments resist superiorly and axially directed forces [1]. The AC ligaments also serve as a secondary restraint to superior displacement. These roles change if excessive loading forces cause injury to the AC joint. As the AC ligaments begin to fail, the CC ligaments bear a greater proportion of the load from anterior and posterior forces, increasing the susceptibility of the CC ligaments to injury.

The following provide additional support for the AC joint:

The attachments and fascia of the deltoid and trapezius muscles.

The coracoacromial ligament, which provides secondary stability to the joint and absorbs some impact during AC joint trauma.

The clavicle, which acts as a strut that holds the scapula and shoulder girdle away from the thorax to improve the leverage and position of the glenohumeral joint.

In addition to direct physiologic loads on the AC joint, forces from the upper extremity are partially transferred through the AC joint. As an example, compressive forces are increased with adduction of the arm. The stout ligamentous complex described above is necessary to withstand these forces.

EPIDEMIOLOGY, MECHANISM, AND CLASSIFICATION — The acromioclavicular (AC) joint is involved in 9 to 12 percent of shoulder girdle injuries [2,3]. Incomplete AC joint injuries (Type I or II) occur twice as often as more severe injuries (Type III to VI) [2]. The great majority occurs in men in their 20s, often during contact sports (eg, American football, ice hockey, rugby) [3-5].

Injury to the AC joint usually occurs from direct trauma to the superior or lateral aspect of the shoulder (acromion) with the arm adducted, such as a direct blow or falling onto the shoulder (figure 4). Force correlates with injury. Low force typically causes an AC sprain. Progressive increases in force cause AC ligament rupture, and then sprain and rupture of the stronger coracoclavicular (CC) ligaments.

Direct trauma to the shoulder can displace the acromion and scapula inferiorly with respect to the clavicle. This displacement increases the load on the AC ligaments, which stretch and then fail, leading to increased loads on the CC ligaments. Surrounding muscles are unable to support the joint during injury by this direct mechanism.

Less often, the AC joint is injured by an indirect force, such as a fall onto an outstretched arm or elbow, which drives the humeral head into the acromion and damages the AC joint. Injury can also occur from forceful adduction of the humerus across the chest.

The sequential injury pattern of the AC joint stabilizers has led to an injury classification system that reflects the progression. An initial classification system developed in the 1960s described basic injuries (Types I-III), and was expanded by Rockwood to include more severe injuries (Types IV-VI) [3]. This system is widely used and described in the accompanying table (table 1). Each injury type is also described below. (See 'Specific AC injuries: Description and radiograph appearance' below.)

In the classification system, the AC injury type should be distinguished from the more general injury grading scale designation used for all ligaments. Injury type refers to the specific AC injury pattern, while grade refers to the extent of injury and applies to any ligament. For instance, grade one ligament injuries involve a sprain or overstretching without disruption; grade two refers to gross tears with weakness, but without complete ligament disruption; and grade three represents complete ligament disruption.

HISTORY AND EXAMINATION — The clinician should ask about the mechanism of injury, any previous shoulder injuries or procedures, and any associated neurovascular or cervical spine symptoms. The patient typically gives a history of sustaining direct trauma to the superior or lateral aspect of the shoulder (acromion) with the arm adducted, such as a direct blow or falling onto the shoulder (figure 4) (see 'Epidemiology, mechanism, and classification' above). Evaluation of patients with a history of chronic pain in the acromioclavicular (AC) joint region is discussed separately. (See "Acromioclavicular joint disorders" and "Evaluation of the adult with shoulder complaints".)

The physical examination often provides clues to the extent of injury. The patient with an AC injury typically exhibits tenderness directly over the AC joint, possibly associated with deformity. A systematic approach to shoulder inspection and palpation helps the clinician to identify the injuries sustained. Palpation should include: the sternoclavicular (SC) joint, entire length of the clavicle, AC joint, acromion, spine of the scapula, coracoclavicular (CC) ligaments, the coracoid process, and the humerus. Focal tenderness suggests injury to the involved structure.

If injuries are not severe and the diagnosis is in doubt, the clinician can perform passive cross-body adduction of the arm to compress the AC joint (so-called AC compression or crossover test) (picture 2). If this maneuver elicits pain, it helps to confirm the diagnosis of AC joint injury. The AC shear test and other maneuvers are typically only necessary if the diagnosis is in doubt. Other tests for assessing the AC joint and a complete evaluation of the shoulder joint are described in detail separately. (See "Acromioclavicular joint disorders", section on 'Special maneuvers for the AC joint' and "Physical examination of the shoulder".)

A careful distal neurologic and vascular examination of the involved extremity and screening cervical spine examination should be performed in all cases of suspected AC joint injury. Particularly in patients who have sustained significant trauma to the neck, cervical spine injury must be ruled out. (See "Cervical spinal column injuries in adults: Evaluation and initial management" and "Initial management of trauma in adults".)

DIAGNOSTIC IMAGING

Plain radiographs — Initial radiographic evaluation of a suspected acromioclavicular (AC) joint injury can be pursued using either of two approaches: a single anterior-posterior (AP) view including both AC joints; or, two AP radiographs, one of the involved shoulder and a comparison film of the uninvolved side. Using two separate AP radiographs provides a more detailed view of the AC joints. The patient's arm should be internally rotated when radiographs are obtained, which increases the sensitivity of plain radiographs for detecting Type III injuries [6]. (See 'Specific AC injuries: Description and radiograph appearance' below.)

If the initial views are limited, either an AP of the glenoid or a Zanca view can be used for a second view. Stress views (ie, radiographs taken with the patient holding weights) are no longer recommended [7,8].

The Zanca view (AP with a 10 to 15 degree cephalic tilt) of the involved shoulder highlights the AC joint, which is projected above the scapula (picture 3 and image 1 and image 2). This allows the entire AC joint to be seen without overlying images. A Zanca view is especially helpful when any of the following are suspected: a Type II AC injury, a distal clavicle fracture, or injury to the physis of the distal clavicle in children.

The normal width of the AC joint in adults is 1 to 3 mm. Children and adolescents have a slightly wider joint space, while older adults a somewhat narrower space. By the age of 60, the joint space is often less than 1 mm [1]. Although the normal coracoclavicular (CC) distance ranges from 11 to 13 mm, it is the comparative difference with the contralateral CC joint space that is most important. An increase in CC distance of 25 to 50 percent indicates a complete CC ligament disruption [3]. If coracoid tenderness is present, an axillary view radiograph is needed to rule out any associated coracoid fracture. The axillary view also helps to confirm anterior-posterior position of the distal clavicle with injury Types III-VI. (See 'Specific AC injuries: Description and radiograph appearance' below.)

The majority of upper extremity surgeons no longer routinely obtain stress views of the shoulder [7]. Stress views are taken while the patient holds, or has attached, 5 or 10 pound weights in each hand. They were used to differentiate between Type II and Type III injuries. Physical examination and AC joint views are generally adequate to determine the type of injury and appropriate treatment. Due to the added discomfort and radiation exposure, stress views should be reserved for cases in which the physical examination and standard radiographs leave a specific management dilemma unresolved [8].

Ultrasound — Although high quality studies are lacking, ultrasound appears to be an effective tool for the diagnosis of AC joint injuries based on broad clinical experience. In the hands of an experienced ultrasonographer, the presence and degree of a number of AC joint injuries can be assessed (image 3) [9]. Dynamic maneuvers performed during the ultrasound examination (eg, crossover test) can provide insights into the degree of injury, such as the degree of AC joint subluxation or separation, and these findings can be compared to the uninjured joint. (See "Musculoskeletal ultrasound of the shoulder".)

Additional ultrasound resources — Instructional videos demonstrating proper performance of the ultrasound examination of the shoulder and related pathology can be found at the website of the American Medical Society for Sports Medicine: sports US shoulder pathology. Registration must be completed to access these videos, but no fee is required.

SPECIFIC AC INJURIES: DESCRIPTION AND RADIOGRAPH APPEARANCE

Type I acromioclavicular (AC) injuries represent a sprain or partial tear of the AC ligaments, and manifest as a tender AC joint that often has mild swelling but no deformity (image 4). The coracoclavicular (CC) ligaments are nontender and the clavicle is typically nontender, with the exception of the distal-most 1 to 2 cm. Active overhead range of motion (ROM) and cross-body ROM are usually limited by pain. If passive cross-body adduction of the arm to compress the AC joint elicits pain, this helps to confirm AC joint injury if the diagnosis is in question.

Type II AC injuries represent a complete tear of the AC ligaments with no injury or partial injury of the CC ligaments (figure 5). They typically manifest as a prominent and tender AC joint, often with significant swelling. There is minimal tenderness of the CC ligaments reflecting the absence of significant injury. The stable CC ligaments prevent further superior translation of the clavicle, but there may be instability of the distal clavicle in the horizontal plane. Radiographs show partial elevation of the distal clavicle with no or minimal widening of the CC distance (image 5). Although the normal CC distance ranges from 11 to 13 mm, it is the comparison to the opposite CC joint space that is most important. An increase in CC distance of 25 to 50 percent indicates a complete CC ligament disruption [3].

Type III AC injuries involve complete disruption of both the AC and CC ligaments (figure 6). Deformity of the AC joint is clearly visible, although swelling may obscure the degree of injury (picture 4). There is marked tenderness of the CC ligaments, which helps distinguish Type III from Type II injuries. There is usually partial to complete reduction of the separation when the examiner gently pushes down on the distal clavicle. Radiographs show an elevated distal clavicle and increased CC distance compared with the uninjured side (normal 11 to 13 mm) (image 6). The distal clavicle is positioned above the plane of the top of the acromion.

Type IV AC injuries occur with forceful shoulder trauma that causes disruption of the AC and CC ligaments, and displaces the distal clavicle into or through the trapezius (image 7). There is usually a palpable posterior fullness or deformity to the shoulder despite significant swelling. There may be tenting of the posterior skin. Sternoclavicular (SC) dislocations occur more often with Type IV injuries. SC joint injuries can compromise the airway in certain circumstances and careful assessment of the airway and neck along with the neurovascular function of the ipsilateral upper extremity is important if such an injury is suspected. (See "Initial evaluation and management of chest wall trauma in adults", section on 'Sternoclavicular dislocation'.)

Type V AC injuries represent significant disruption of the AC and CC ligaments, along with disruption of the muscular and fascial attachments of the distal clavicle (image 8). The shoulder appears to droop due to the inferior position of the scapula and glenohumeral joint. There is severe superior displacement of the clavicle, which may cause tenting, ischemia, or even disruption of the overlying skin. The clavicle is perched above the muscle and does not reduce when the patient attempts to shrug their shoulder or when the examiner gently pushes down on the distal clavicle. The clavicle is elevated above the acromion approximately one to three times the width of the clavicle, and the CC distance is increased two to three times the normal range (11 to 13 mm).

Type VI AC injuries are rare and involve severe dislocations of the AC joint in which the distal clavicle is forced into the subacromial or subcoracoid position. There is complete disruption of the AC and CC ligaments and muscular supports. Associated injuries are common and reduction is urgently needed to relieve pressure on the neurovascular bundle. An unusual deformity near the AC joint with a large amount of swelling is common with these injuries.

The mechanism of Type VI injuries generally involves a high-energy collision or direct blow to the shoulder. Examples include skateboard or snowboard accidents involving a collision with a fixed object such as a rail or a tree, motor vehicle collisions, and altercations such as with a baseball bat striking the distal clavicle. AP radiographs reveal a markedly abnormal, inferior position of the clavicle.

Multiple trauma may be present with Type VI AC injuries, including possible spine and thoracic injuries. A basic trauma assessment should be performed and appropriate management instituted. Thereafter, a careful neurologic and vascular examination is mandatory, followed by immediate reduction should a deficit be identified. If no neurovascular deficit is identified, the examination should be repeated frequently until reduction is performed. (See "Initial evaluation and management of blunt thoracic trauma in adults".)

DIAGNOSIS — In most cases, the diagnosis of an acute acromioclavicular (AC) joint injury is made without difficulty based upon the history, examination, and imaging studies. Typically, the history involves direct trauma to the superior or lateral aspect of the shoulder; examination reveals focal tenderness at the AC joint, pain with shoulder abduction and cross-body adduction, and deformity with more severe injury; and plain radiographs or ultrasound reveal elevation of the clavicle and abnormal joint spacing for all but the mildest (Type I) injuries. Focal tenderness is typically mild or absent at other structures at and around the shoulder.

DIFFERENTIAL DIAGNOSIS — It can be difficult to differentiate among the myriad causes of acute shoulder pain. However, the diagnosis of an acute acromioclavicular (AC) joint injury is often straightforward if the patient has a classic mechanism along with suggestive examination findings (eg, focal AC tenderness, deformity of the AC joint) and radiographs. Nevertheless, direct trauma to the shoulder may cause other injuries, which are briefly described below. The differential diagnosis for shoulder pain generally and a clinical approach to diagnosing such pain are provided separately. (See "Evaluation of the adult with shoulder complaints" and 'Epidemiology, mechanism, and classification' above.)

Acute exacerbations of chronic non-traumatic conditions of the AC joint may present with acute pain and an uncertain mechanism of injury. The presence of AC joint osteoarthritis, inflammatory arthritis, or distal clavicular osteolysis can usually be identified by a careful history (some degree of discomfort has been present for months or longer) and appropriate imaging studies. In most cases, no trauma immediately preceded the increase in pain and imaging studies reveal inflammatory or degenerative changes but no acute injury. Diagnostic imaging for these disorders is described in detail separately. (See "Acromioclavicular joint disorders", section on 'Diagnostic imaging' and "Acromioclavicular joint disorders", section on 'Diagnostic approach'.)

Acute injury of the brachial plexus (ie, "burner" or "stinger") may mimic or occur along with injury to the AC joint. Like an AC injury, a brachial plexus injury is caused by direct trauma to the neck and shoulder. However, unlike AC injury, it is characterized by pain radiating down one upper extremity. Immediately after contact, the patient with a brachial plexus injury typically feels burning pain in the supraclavicular area that radiates down the arm, generally in a circumferential, nondermatomal pattern. The patient may also experience numbness, paresthesias, or weakness in the extremity. Frequently the discomfort resolves spontaneously within one to two minutes, unlike AC injury where pain persists. Imaging studies with an isolated brachial plexus injury are unremarkable. (See "Burners (stingers): Acute brachial plexus injury in the athlete".)

Severe shoulder trauma that damages the AC joint may simultaneously cause other shoulder injuries, such as subluxation or instability of the glenohumeral joint or damage to the rotator cuff. The examiner should assess the glenohumeral joint during follow-up visits after acute swelling and pain have subsided to assess for anterior and posterior instability, and focal rotator cuff weakness. Rotator cuff contusions or tears following direct shoulder trauma are more common in masters athletes and older adults. As an example, a fall onto the shoulder that injures only the AC joint in a younger athlete may also cause a rotator cuff tear in an older adult. Isolated AC injuries do not cause glenohumeral instability or focal rotator cuff weakness; a careful examination, including ultrasound evaluation of the shoulder if possible, will identify most such non-AC joint injuries. (See "Multidirectional instability of the shoulder" and "Presentation and diagnosis of rotator cuff tears".)

AC joint trauma can occur concomitantly with blunt chest trauma or trauma to the head and neck. In this setting, clinicians must consider clavicle fractures, rib fractures, fractures of other shoulder bones (eg, scapula, acromion, coracoid), sternoclavicular joint injury, and other chest injuries as possible sources of pain in the general region of the AC joint. Focal tenderness on examination and the presence of injury on diagnostic imaging are usually sufficient to distinguish among these potential causes of shoulder and upper thoracic pain. (See "Initial evaluation and management of blunt thoracic trauma in adults" and "Initial evaluation and management of chest wall trauma in adults".)

MANAGEMENT

General issues — There is little high quality evidence to determine when surgical management of acromioclavicular (AC) injuries is necessary [10,11]. Nevertheless, with the exception of Type III injuries, the management of AC injuries is well established. Conservative management with minimal intervention yields excellent results for Type I and II injuries, and operative reduction is necessary for Type IV, V, and VI injuries [2,12]. The trend over the last several decades for the initial treatment of Type III injuries has moved from operative to nonoperative in the majority of cases [2].

There is no role for glucocorticoid (steroid) injections in the acute management of these injuries. Injection may be considered for persistent pain after the ligamentous injury has healed, or in the setting of repeated minor injury with no instability but persistent AC joint arthralgia. The management of chronic conditions affecting the acromioclavicular joint is discussed separately. (See "Acromioclavicular joint disorders".)

Rehabilitation during recovery from Type I and II injuries — Rehabilitation consists of basic motion and strengthening exercises for the shoulder and scapular stabilizers. For Type II and Type III injuries, the risk of reinjury is increased until the ligaments have fully remodeled, which may require 6 to 10 weeks. Therefore, any exercises performed prior to complete healing must be performed cautiously. Mechanical support of the joint (eg, taping (picture 5)) may be useful for some patients during rehabilitation and when resuming activity.  

A basic scheme for the rehabilitation of uncomplicated Type I and Type II injuries is provided below [13]. Many rehabilitation exercises for the shoulder are described in detail separately. (See "Rehabilitation principles and practice for shoulder impingement and related problems".)

Weeks 1 to 3: Patients perform only gentle range of motion (ROM) exercises (eg, pendulum swings without weight (picture 6)) to prevent a loss of shoulder mobility, while allowing inflammation and pain to subside. These exercises can be performed several times per day. No exercise that places strain on the healing ligaments is performed. Shoulder motions to be avoided include cross-body adduction, extreme internal rotation (ie, behind the back), and overhead movements.

Weeks 2 to 6: Patients begin a limited strength program designed to prevent muscle atrophy and maintain basic strength as soon as the exercises can be tolerated. Exercises that place undue strain on the AC joint and associated ligaments are avoided. Exercises may include scapular protraction and retraction against a wall, isolated internal (picture 7) and external (picture 8) shoulder rotation using light resistance performed in the neutral position (shoulder adducted), and limited forward shoulder flexion with arm adducted using light resistance. For all exercises, avoid extremes of motion. Note that these exercises are only introduced if the patient can perform them without significant pain. The exercises can be performed three times per day, two to three sets of 10 to 15 repetitions per exercise during each session is reasonable.

Weeks 6 to 8: Patients begin to perform more challenging strength exercises. Again, these exercises are only introduced if they do not provoke significant pain. Exercises often include controlled rowing (picture 9) and scapular stabilization (picture 10 and picture 11 and picture 12). The exercises can be performed three times per day, two to three sets of 10 to 15 repetitions per exercise during each session is reasonable.

Weeks 8 to 10: Full upper extremity strength training is resumed provided the patient does not experience significant pain when performing these exercises. The importance of increasing resistance gradually and avoiding exercises that cause pain must be emphasized to the patient [13]. If pain persists beyond this time, the clinician should evaluate the patient for AC degeneration and other shoulder pathology. (See "Acromioclavicular joint disorders" and "Evaluation of the adult with shoulder complaints".)

Note that the time frames provided here are approximations. Patients with mild Type I injuries, no other trauma, and good baseline strength in the shoulder and periscapular muscles may require only a few weeks of rehabilitation, while patients with Type II injuries and poor baseline strength may require longer for a complete recovery. The time frames described above are on the conservative side. A key concept during rehabilitation is to use pain as the guide to progression: if particular exercises cause pain, the patient should stop doing them.

Type I (mild injury) — Type I injuries are treated initially with rest, ice, and protection, sometimes with a sling (table 2). The patient begins range of motion (ROM) and strengthening exercises as soon as they can be tolerated [14]. Return to sport or work is limited only by pain. With special protection, non-throwing athletes can sometimes return to the very game in which they sustained the injury. As an example, for American football players padding can be placed over the injured area or a doughnut-shaped pad can be made to minimize pressure directly over the joint.

We recommend against injecting a local anaesthetic to help athletes return to play. There is no high quality evidence supporting this practice and more importantly clinicians on the sideline sometimes cannot be certain the injury is a Type I; returning to play with a higher grade injury can result in an even more severe injury requiring prolonged recuperation and possibly surgical repair.

Most patients return to full activities between three days and two weeks following injury, although throwing and overhead athletes (eg, baseball pitchers, tennis, and volleyball players) may require two to six weeks of progressive rehabilitation before they can return to high level overhead activity [7]. Complete healing and remodeling of the injured ligaments may take four to six weeks. Type I injuries generally heal without deformity and without significant risk of reinjury once completely healed.

Type II — Type II injuries usually cause greater pain and swelling than Type I. In addition to ice and analgesics, initial management often includes three to seven days of immobilization in a sling (table 2). Otherwise, management is comparable to that for Type I injuries. The patient begins range of motion (ROM) exercises as soon as they are tolerated, and may return to normal activity once full ROM and full strength are regained. This often takes two to four weeks. Complete healing of the ligaments generally requires several more weeks. As with Type I injuries, overhead and throwing athletes require additional time and rehabilitation before returning to full activity.

Type III (moderate injury) — For the large majority of Type III injuries, initial treatment is nonoperative, consisting of rest, ice, immobilization with a sling, and analgesics (table 2) [15-17]. A sling is helpful for two to three weeks, depending on patient symptoms, to aid healing and relieve pain [18-20]. The patient begins range of motion (ROM) and strengthening exercises as soon as the pain is tolerable. The intensity of these rehabilitation exercises is increased gradually and as tolerated based primarily on pain.

Patients may return to normal activity between 6 and 12 weeks following injury, depending on the demands of the activity. Athletes may return to competition once full ROM and strength is regained [15]. High level athletes and workers that place extreme loads on their shoulder should undergo early orthopedic evaluation. Otherwise, orthopedic consultation should be pursued if pain persists beyond 12 weeks, or returns when the patient increases activity.

This nonoperative approach to Type III AC injuries is supported by a review of 24 studies comparing operative and nonoperative treatment [17]. Studies included in the meta-analysis were of variable quality and included two randomized controlled trials [21,22]. This review, which included 1172 patients with Type III AC injuries, found no significant difference in functional outcome between the operative and nonoperative groups (88 versus 87 percent satisfactory outcome respectively), but found significantly higher complication rates among surgical patients. Operative care led to a greater need for further surgery (59 versus 6 percent) and a higher rate of infection (6 versus 1 percent). Greater cosmetic deformity (picture 13) was present among conservatively (ie, nonoperatively) treated patients (37 versus 3 percent). A subsequent review with more limited inclusion criteria reached similar conclusions [16]. Both reviews are limited by the lack of high quality studies on management of Type III AC injuries.

Types IV, V, and VI (severe injury) — These AC joint injuries are the most severe and require orthopedic evaluation. Emergency (ie, immediate) referral is needed if neurovascular compromise exists. Type IV injuries may initially be treated with open- or closed-reduction, and then treated conservatively, as with a Type III injury. Open repair of the deltotrapezial fascia may improve outcomes [15]. Type V injuries require open reduction and repair of the deltotrapezial fascia and reconstruction of the CC ligament [15], with two-thirds of patients achieving good or excellent results [7]. Type VI injuries can involve damage of the neurovascular bundle beneath the coracoid and require open reduction [15].

The long term outlook for these patients depends on the degree of injury and the procedure needed to correct the displaced clavicle. If the distal clavicle is easily reduced with a closed procedure, the injury is converted to a Type III with a comparable recovery. If a more extensive procedure is needed, recovery requires additional time and likely more intensive rehabilitation.

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Shoulder soft tissue injuries (including rotator cuff)".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5th to 6th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10th to 12th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

Basics topic (see "Patient education: Separated shoulder (The Basics)")

Beyond the Basics topics (see "Patient education: Shoulder impingement syndrome (Beyond the Basics)" and "Patient education: Acromioclavicular joint injury (shoulder separation) (Beyond the Basics)")

SUMMARY AND RECOMMENDATIONS

Anatomy and classification – The acromioclavicular (AC) joint complex is strong, but its position makes it vulnerable to injury from direct trauma. Injuries are classified based on the position of the clavicle with respect to the acromion and coracoid, and described by the injury type, not by the grade of ligament injury (table 1). (See 'Anatomy and biomechanics' above.)

Mechanism of injury and history – Injury to the AC joint usually occurs from direct trauma to the superior or lateral aspect of the shoulder (acromion) while the arm is adducted, such as a direct blow or falling onto the shoulder. The clinician should inquire about the mechanism of injury, any previous shoulder injuries or procedures, and associated neurovascular or cervical spine symptoms. The mechanism and classification of AC injuries are discussed in detail above. (See 'Epidemiology, mechanism, and classification' above.)

Physical examination – Typically, examination reveals tenderness directly over the AC joint and possible deformity; focal tenderness is generally mild or absent in other structures at and around the shoulder. A systematic approach to shoulder palpation helps to identify injuries. If injuries are not severe and the diagnosis unclear, passive cross-body adduction of the arm to compress the AC joint can be useful. Careful assessment of distal neurovascular function and the cervical spine should be performed in all cases. Each injury type is described in detail above. (See 'History and examination' above and 'Specific AC injuries: Description and radiograph appearance' above.)

Diagnostic imaging – Radiographic evaluation involves either of two approaches: a single anterior-posterior (AP) view including both AC joints or two AP radiographs, one of the involved shoulder and a comparison film of the uninvolved side. Stress or weighted views are obsolete. Skilled ultrasonographers use ultrasound to evaluate the shoulder complex and diagnose AC injury. Plain radiographs or ultrasound reveal elevation of the clavicle and abnormal joint spacing for all but the mildest (Type I) injuries. (See 'Diagnostic imaging' above.)

Diagnosis – In most cases, the diagnosis of an acute AC joint injury is made without difficulty based upon a history of direct shoulder trauma, examination findings consistent with AC injury, and imaging studies. (See 'Diagnosis' above and 'Differential diagnosis' above.)

Management – Initial management consists of rest, ice, and protection using a sling. Minor injuries (Type I (image 4) and Type II (figure 5 and image 5)) are managed nonoperatively. Severe injuries (Types IV, V, and VI) should be referred urgently to an orthopedic specialist for operative management. Injuries involving neurologic or vascular deficits require emergency (ie, immediate) orthopedic referral and intervention (see 'Management' above). If pain persists beyond 12 weeks, evaluation for AC degeneration or other shoulder pathology is indicated. (See "Acromioclavicular joint disorders" and "Evaluation of the adult with shoulder complaints".)

Operative management of intermediate injuries (Type III (figure 6 and image 6)) does not appear to improve functional outcome when compared with conservative management and increases the risk of complications. In general, we suggest nonoperative management of Type III injuries (Grade 2B). (See 'Management' above.)

  1. Renfree KJ, Wright TW. Anatomy and biomechanics of the acromioclavicular and sternoclavicular joints. Clin Sports Med 2003; 22:219.
  2. Lemos MJ. The evaluation and treatment of the injured acromioclavicular joint in athletes. Am J Sports Med 1998; 26:137.
  3. Rockwood, CA, Williams, et al. Disorders of the AC join. In: The Shoulder, WB Saunders, Philadelphia 1998. Vol Volume 1, p.483.
  4. Pallis M, Cameron KL, Svoboda SJ, Owens BD. Epidemiology of acromioclavicular joint injury in young athletes. Am J Sports Med 2012; 40:2072.
  5. Hibberd EE, Kerr ZY, Roos KG, et al. Epidemiology of Acromioclavicular Joint Sprains in 25 National Collegiate Athletic Association Sports: 2009-2010 to 2014-2015 Academic Years. Am J Sports Med 2016; 44:2667.
  6. Vanarthos WJ, Ekman EF, Bohrer SP. Radiographic diagnosis of acromioclavicular joint separation without weight bearing: importance of internal rotation of the arm. AJR Am J Roentgenol 1994; 162:120.
  7. Buss DD, Watts JD. Acromioclavicular injuries in the throwing athlete. Clin Sports Med 2003; 22:327.
  8. Bossart PJ, Joyce SM, Manaster BJ, Packer SM. Lack of efficacy of 'weighted' radiographs in diagnosing acute acromioclavicular separation. Ann Emerg Med 1988; 17:20.
  9. Peetrons P, Bédard JP. Acromioclavicular joint injury: enhanced technique of examination with dynamic maneuver. J Clin Ultrasound 2007; 35:262.
  10. Reid D, Polson K, Johnson L. Acromioclavicular joint separations grades I-III: a review of the literature and development of best practice guidelines. Sports Med 2012; 42:681.
  11. Tamaoki MJ, Lenza M, Matsunaga FT, et al. Surgical versus conservative interventions for treating acromioclavicular dislocation of the shoulder in adults. Cochrane Database Syst Rev 2019; 10:CD007429.
  12. Verstift DE, Kilsdonk ID, van Wier MF, et al. Long-term Outcome After Nonoperative Treatment for Rockwood I and II Acromioclavicular Joint Injuries. Am J Sports Med 2021; 49:757.
  13. Cote MP, Wojcik KE, Gomlinski G, Mazzocca AD. Rehabilitation of acromioclavicular joint separations: operative and nonoperative considerations. Clin Sports Med 2010; 29:213.
  14. Montellese P, Dancy T. The acromioclavicular joint. Prim Care 2004; 31:857.
  15. Bradley JP, Elkousy H. Decision making: operative versus nonoperative treatment of acromioclavicular joint injuries. Clin Sports Med 2003; 22:277.
  16. Spencer EE Jr. Treatment of grade III acromioclavicular joint injuries: a systematic review. Clin Orthop Relat Res 2007; 455:38.
  17. Phillips AM, Smart C, Groom AF. Acromioclavicular dislocation. Conservative or surgical therapy. Clin Orthop Relat Res 1998; :10.
  18. Wojtys EM, Nelson G. Conservative treatment of Grade III acromioclavicular dislocations. Clin Orthop Relat Res 1991; :112.
  19. Press J, Zuckerman JD, Gallagher M, Cuomo F. Treatment of grade III acromioclavicular separations. Operative versus nonoperative management. Bull Hosp Jt Dis 1997; 56:77.
  20. Schlegel TF, Burks RT, Marcus RL, Dunn HK. A prospective evaluation of untreated acute grade III acromioclavicular separations. Am J Sports Med 2001; 29:699.
  21. Bannister GC, Wallace WA, Stableforth PG, Hutson MA. The management of acute acromioclavicular dislocation. A randomised prospective controlled trial. J Bone Joint Surg Br 1989; 71:848.
  22. Larsen E, Bjerg-Nielsen A, Christensen P. Conservative or surgical treatment of acromioclavicular dislocation. A prospective, controlled, randomized study. J Bone Joint Surg Am 1986; 68:552.
Topic 254 Version 29.0

References

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