Acromioclavicular Joint Problems in Athletes and New Methods of Management

Acromioclavicular Joint Problems in Athletes and New Methods of Ma nagement Clifford G. Rios, MD, Augustus D. Mazzocca, MS, MD* KEYWORDS  Trauma  AC joint arthrosis  Distal clavicle osetolysis

The acromioclavicular (AC) complex consists of bony and ligamentous structures that stabilize the upper extremity through the scapula to the axial skeleton. The AC joint pathology in the athlete is generally caused by 1 of 3 processes: trauma (fracture, AC joint separation, or dislocation); AC joint arthrosis (posttraumatic or idiopathic); or distal clavicle osteolysis (DCO). This article presents systematically the relevant anatomy, classification, evaluation, and treatment of these disorders. Management of AC joint problems is dictated by the severity and chronicity of the injury, and the patient’s needs and expectations.

ANATOMY AND BIOMECHANICS

The AC complex is a diarthrodial joint between the distal clavicle and the medial aspect of the acromion. This is an inherently unstable articulation that is supported by the AC joint capsule and the robust coracoclavicular (CC) ligaments, which provide static stability. The dynamic stabilizers include the deltoid and trapezius muscles. Between the articular surfaces is a meniscal homolog, which has been shown to degenerate with age. In the intact state, the AC ligaments, in particular the superior and posterior ligaments, prevent excess motion in the horizontal plane.1 The CC ligaments prevent inferior migration of the scapulohumeral complex relative to the clavicle.2 However, when the AC ligaments are completely disrupted, the CC ligaments also become significant restraints to anteroposterior (AP) displacement. Using a cadaveric model, Debski and colleagues3 demonstrated that in the absence of the AC ligaments, the mean in situ force in the trapezoid ligament increases 66% in response to a posterior

Department of Orthopaedic Surgery, University of Connecticut Health Center, Medical Arts and Research Building, Room 4017, 263 Farmington Avenue, Farmington, CT 06030, USA * Corresponding author. E-mail address: [email protected] (A.D. Mazzocca). Clin Sports Med 27 (2008) 763–788 doi:10.1016/j.csm.2008.06.006 sportsmed.theclinics.com 0278-5919/08/$ – see front matter ª 2008 Elsevier Inc. All rights reserved.

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70 Newton (N) load. The mean force in the conoid ligament increases by over 225% in response to an anterior load. The clavicular origin of the CC ligaments has been defined as follows:4 the conoid ligament originates an average of 46 mm medial to the AC joint, and the trapezoid ligament originates 26 mm medial to the AC joint. The conoid is more posterior compared with the trapezoid origin on the mid-portion of the inferior surface of the clavicle.4 The superior, inferior, and posterior AC ligaments insert an average of 16 to 20 mm medial to the AC joint on the clavicle undersurface. The implication of this anatomic observation is that aggressive distal clavicle excision (DCE) can destabilize the AC joint and lead to symptomatic posterior impingement against the acromion. CLASSIFICATION OF ACROMIOCLAVICULAR JOINT PATHOLOGY

Pathology of the AC joint generally falls into 1 of 3 categories as follows: AC separations (ligament sprain, subluxation, or dislocation); AC joint arthrosis; and pain caused by DCO. Acromioclavicular Separations

The AC joint separation represents one of the most common shoulder injuries. The most common mechanism of this injury is a fall with a direct force to the superior aspect of the shoulder and with the arm in an adducted position. These injuries have been classified according to the degree of ligamentous and other soft-tissue injury. Cadenat5 originally described the process of acute AC joint disruption as a sequential injury, beginning with the AC ligaments, continuing to the CC ligaments, and ultimately violating the deltotrapezial fascia. Tossy and colleagues6,7 defined distinct stages of injury, labeled as types I (AC ligament sprain), II (AC ligaments torn and CC ligaments intact), and III (AC and CC ligaments torn), and this was modified to the system most commonly used today by Rockwood. This modification includes types IV (posterior dislocation of clavicle), V (AC and CC ligaments and deltotrapezial fascia torn), and VI (subcoracoid dislocation of clavicle) injuries. There are other injuries, albeit much less common, which may mimic type III AC joint dislocation.8 The first of these is an AC ligament rupture with a fracture through the base of the coracoid. Although the AC joint is dislocated, the CC ligaments remain intact. Another clinical entity which resembles a type III separation occurs in skeletally immature patients. Distal clavicular physeal closure occurs relatively late (18–22 years of age). The same mechanism that causes AC and CC joint rupture in older patients can cause separation of the distal clavicular metaphysis and proximal displacement from its periosteal shell in adolescent patients. A thick periosteal sleeve remains in its anatomic location owing to secure attachments to the AC and CC ligaments, whereas the distal clavicle displaces through a tear in this periosteal tube. Acromioclavicular Derangement/Arthrosis

The AC joint derangement, or more commonly, arthrosis, may be idiopathic or may result from injury and/or instability of this joint. Although radiographic evidence of primary osteoarthrosis of the AC joint is common particularly in older individuals, symptoms attributable solely to this joint are comparatively less frequent.9–11 Impingement, biceps pathology, and rotator cuff disease are just a few of many diagnoses that are more likely responsible for symptoms in this setting. Infrequently, acute pain in the AC joint may reflect an ‘‘internal derangement’’ in which there is a tear of the intra-articular meniscus. Although uncommon, recognition of this entity is important to distinguish it from idiopathic arthritis. Patients usually have

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abrupt onset of AC joint pain, accompanied by mechanical symptoms, such as clicking or popping. Posttraumatic osteoarthrosis is more common than primary osteoarthrosis and may occur after AC joint separation, distal clavicle fracture, or postoperatively.12 Studies on the natural history of the more innocuous type I and II AC joint injuries suggest that symptoms of posttraumatic arthritis occur in as few as 8% and as many as 42% of patients.13–15 Mouhsine and colleagues15 concluded that the severity of the consequences after grade I and II AC separations is underestimated. Distal Clavicle Osteolysis

Osteolysis of the distal clavicle is associated with heavy weight lifting.16,17 Scavenius and Iverson17 found that 28% of elite weight lifters in their series had pain of insidious onset, swelling, and AC joint tenderness consistent with distal osteolysis. The pain is aggravated by activity, in particular during flat bench pressing, and also with dips, flies, and pushups. Radiographic findings distinguish this condition from AC arthritis, and include rarefaction and subchondral cyst formation along the distal clavicle. Slawski and Cahill18 reported bilateral involvement in 79% of weight lifters at the time of presentation. PATIENT EVALUATION

The approach to the patient with shoulder pathology always begins with examination of the cervical spine. From there, the approach differs, depending on whether the patient has been injured acutely (AC joint strain, separation, or derangement), or has more insidious, chronic shoulder pain (arthrosis, osteolysis). History and Physical Examination Acute, Posttraumatic Pain

Direct trauma to the top of the shoulder with the arm adducted is the most frequently reported cause of acute AC joint injury. Much less commonly, a patient experiences an AC joint injury owing to a fall on the outstretched hand or elbow. In this latter case, CC ligament injury is uncommon. Instead, these patients are at risk for either fracture of the acromion or rotator cuff tear consequent to forceful superior humeral head displacement. Posttraumatic pain is typically localized over the anterosuperior aspect of the shoulder, and is attributed to cross-innervation of this region by the suprascapular and lateral pectoral nerves (Fig. 1). In the case of direct trauma to the top of the shoulder, a variable amount of deformity and tenderness may be present. No deformity will be present for type I injuries, although swelling is not uncommon and the joint is tender to palpation. In addition to tenderness and swelling, type II injuries also usually demonstrate mild prominence of the distal clavicle. With AC joint ligament disruption and injury to the conoid and trapezoid, the clavicle loses ligamentous connection with the scapulohumeral complex, and the weight of the upper extremity causes its downward displacement. This deformity is apparent in type III and V injuries. Distinguishing between type III and V injuries may be facilitated by having the patient shrug both shoulders, which in a type V injury exaggerates the degree of displacement. Another technique that may be helpful is closed manipulation of the joint; reduction of the deformity suggests an intact deltotrapezial fascia (type III), whereas failure to reduce indicates violation of this fascia with the distal clavicle buttonholed through it (type V). Acute joint derangement presents with acute onset of painful clicking in the AC joint. There is often a history of mild trauma and the patient will note discomfort over the

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Suprascapular n.

C5 C6 C7 C8 T1

Lateral pectoral n.

Fig.1. Innervation around the AC joint is provided by the suprascapular and lateral pectoral nerves. Pain is most often experienced directly over the AC joint, although patients may describe symptoms more anteriorly or posteriorly owing to this innervation pattern. This differs from pain caused by a SLAP lesion, which the patient may localize to the superior but not anterior shoulder (From Gerber CR, Galantay R, Hersche O. The pattern of pain produced by irritation of the acromioclavicular joint and the subacromial space. J Shoulder Elbow Surg 1998;7:71–7; with permission.)

superior aspect of the AC joint and mechanical catching or popping with shoulder movement. There is usually tenderness over the joint, along with palpable crepitus during circumduction of the arm or cross-body adduction. Chronic, Insidious Pain

Patients with a more insidious onset of pain may have AC joint arthrosis or DCO. AC joint pain can be fairly specific and localize to the AC joint, or refer into the trapezius or down the arm. There are several physical examination findings and maneuvers that help identify the AC joint as the source of a patient’s shoulder pain. However, similar to other causes of shoulder pain, none of these tests has established sensitivity and specificity. Tenderness over the AC joint is a very sensitive finding, and is easy to elicit owing to its subcutaneous location.19 A number of provocative tests are helpful in the subacute or chronic setting. Cross-arm adduction is thought to load and reproduce pain from the AC joint. A recent analysis of these maneuvers found cross-arm adduction to be sensitive (77%) and the active compression test of O’Brien to be 95% specific.20 Pain with active internal rotation with placement of the hand behind the back can also elicit discomfort directly over the AC joint. The Paxinos test examines the AC joint with the patient seated and with the arm resting along the chest.19 The examiner places his/her thumb over the posterolateral corner of the acromion and the index and long fingers of the ipsilateral or opposite hand superior to the mid-portion of the ipsilateral clavicle. The test is considered positive if compression of the clavicle and acromion causes pain localized to the AC joint. O’Brien’s active compression test helps the examiner differentiate pain attributable to a superior labral anterior to posterior (SLAP) lesion from pain owing to AC joint

AC Problems in Athletes

pathology. This test is performed with the patient’s arm in 90 of forward elevation, 10 to 15 of adduction, and maximal internal rotation. The examiner pushes down on the patient’s arm, and pain localized to the superior shoulder suggests AC joint pathology.21 This maneuver is then repeated with the forearm maximally supinated. Pain deep inside the shoulder, with or without a click, suggests a SLAP tear. O’Brien and colleagues21 report a 100% sensitivity and 96% specificity for AC joint pathology in patients who localized pain to the AC joint when the arm was in the internally rotated position. This distinction is important because missed SLAP lesions have been identified as an important cause of failed DCE for AC joint pathology, particularly in younger patients and those with a history of trauma.22 Whereas the cross-arm adduction and O’Brien’s tests rely on compression of the AC joint to diagnose AC joint pathology, the specificity is limited by the fact that forward elevation and adduction of the arm will cause pain in patients with other shoulder disorders, such as rotator cuff tears or tendinitis, labral pathology, or biceps pathology to name a few. Pain elicited by these tests should also be localized to the AC joint rather than being nonspecifically localized to the lateral or posterior shoulder. The Paxinos test has the advantage of compressing this joint while the arm rests at the patient’s side, potentially improving the specificity of this test. The authors preferred to perform this test on both of the patient’s shoulders to assess for subtle differences in horizontal translation. An attempt is made to discriminate between laxity and instability. A patient’s normal AC joint may permit some degree of horizontal plane motion (ie, laxity), but it is excess motion associated with pain which defines horizontal plane instability. This is analogous to the distinction between glenohumeral joint laxity and instability. Increased translation in the horizontal plane that is associated with pain may suggest a complete tear (type II injury) rather than a sprain (type I injury) of the AC ligaments, but this observation remains to be proven. Coronal plane instability is easier to detect. If the clavicle appears displaced superiorly, asking the patient to shrug his/her shoulder is a useful method to determine if the deltotrapezial fascia is intact (clavicle reduces, type III injury) or if it has been violated (clavicle remains dislocated, type V injury). Intra-articular injection of local anesthetic is an invaluable tool when evaluating the AC joint. Such an injection with or without corticosteroid can be both diagnostic and therapeutic in patients with AC joint pathology. Relief of pain postinjection implicates the AC joint as the pain generator. Preinjection radiograph can facilitate the ease with which the AC joint is injected because this joint’s obliquity varies considerably. Imaging

Evaluation of the patient with a suspected AC joint injury requires an AP, supraspinatus outlet, axillary, cross-arm adduction AP, and simultaneous bilateral Zanca radiograph. The authors do not use stress radiographs, because the diagnosis is usually obtained by the history, physical examination, and aforementioned radiographs. Because the AC joint is more subcutaneous than the glenohumeral joint, accurate visualization of the AC joint (ie, Zanca view) requires only a third to half of the radiographic penetration that is used for a standard AP shoulder projection. AP and axillary views define the amount and direction of displacement of the clavicle relative to the scapulohumeral complex: the axillary view helps assess posterior displacement of the clavicle through a torn trapezial fascia (type IV injury), and the AP view will show subacromial or subcoracoid displacement of the clavicle (type VI injury), which is rare and has not been seen in the authors’ practice. The supraspinatus outlet permits acromial morphology classification.

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Zanca23 originally described a specialized view for the AC joint whereby the x-ray beam is angled 10 cephalad to eliminate the overlap of the clavicle with the spine of the scapula. The normal appearance of the AC joint has been described in numerous reports. Zanca23 stated that the width of the AC joint is between 1 and 3 mm. Petersson and Redlund-Johnell24 reported an age-dependent decrease in AC joint width, such that a joint space of only 0.5 mm is normal in patients older than 60 years. The normal CC distance is between 1.1 and 1.3 cm, on average,25 and Bearden and colleagues26 reported that complete CC ligament disruption is indicated by an increase in the CC distance of 25% to 50% compared with the contralateral shoulder. The Zanca view helps identify the varying degree of superior displacement of the clavicle relative to the acromion in type I, II, III, and V AC joint injuries. The authors find that a source-to–image distance of 72 in with an x-ray tube voltage of 73 to 80 kV most reliably obtains a bilateral Zanca view. A simultaneous bilateral Zanca radiograph is an effective and reliable way to assess the degree of deformity compared with the patient’s contralateral, uninvolved shoulder (Fig. 2A). This allows direct comparison and eliminates inaccuracy attributable to slight changes in position if obtaining both shoulders independently. The distance from the superior aspect of the coracoid process to the inferior aspect of the clavicle on both sides is measured. An AC ligament sprain with intact CC ligaments (type I injury) will not alter the CC distance. In a cadaveric evaluation of simulated type II AC joint injuries, isolated sectioning of the conoid or trapezoid ligament permitted 4 to 6 mm more superior displacement on Zanca views compared with the intact state.27 The clinical implication is the subtle differences in side-to-side CC distance may represent complete injury to 1 of the CC ligaments, suggesting a more severe type II injury.

Fig. 2. (A) Example of simultaneous bilateral Zanca view in type III AC dislocation of the left shoulder. There is marked widening of the CC distance on the patient’s left shoulder. (B) Cross-arm adduction AP radiograph of the same patient demonstrates instability in the horizontal plane. (C) This overlap of the AC joint is not seen with the arm at the patient’s side in the standard AP view.

AC Problems in Athletes

The radiographic classification of Rockwood and colleagues7 is most often cited and is useful in distinguishing minor from the more severe AC joint injuries, but further delineation is necessary. Basmania defines AC joint injuries as either stable or unstable, and this is determined by the use of an AP radiograph of the affected shoulder with the arm adducted across the chest (Fig. 2B and C) (personal communication, AOSSM meeting Calgary, Canada 2007). The acromion will not overlap the clavicle in a normal or stable AC joint. Normal positioning may be prognostically positive and direct nonoperative treatment. Superimposition of the acromion and distal clavicle suggests instability and may indicate a role for surgery. Although the role of ultrasound in imaging AC joint injuries remains unclear, a recent study using this modality identified abnormal movements of the injured AC joint with cross-arm adduction which were not identified with plain resting or stress radiographs.28

NONOPERATIVE MANAGEMENT OF ACROMIOCLAVICULAR JOINT PATHOLOGY

Nonoperative treatment of the AC joint is dictated by the cause of the symptoms. The authors’ treatment algorithm is summarized in Fig. 3.

Fig. 3. Algorithm for management of AC joint pathology in athletes.

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Atraumatic Conditions: Acromioclavicular Joint Arthrosis and DCO

Injections play a major role in the treatment of pathology localized to the AC joint because of the immediate and potentially sustained relief experienced. The response to injection of local anesthetic with or without corticosteroid into the AC joint has important diagnostic and therapeutic implications. The degree to which the injection relieves symptoms is a prognostically useful indication that surgical intervention, if necessary, can be effective. Conversely, failure to reduce a patient’s level of pain substantially with an AC injection calls the diagnosis of pathology into question and suggests that surgical intervention may be ineffective. However, the reliability of these injections depends on accurate joint injection. The authors analyze the preinjection radiograph for AC joint morphology, observing the angle of the joint and the presence of osteophytes which may interfere with access to the joint. Subsequently, the authors feel for the softspot formed at the apex of the anterior portion of the scapular spine and the posterior border of the distal clavicle. Gentle pressure can elicit AC motion at the joint, which can confirm its position. One should feel an easy ‘‘pop’’ as the needle enters the joint, and should encounter little resistance when injecting. The joint typically will accommodate approximately 1 mL of medication, and overdistension can be painful. Occasionally, the surgeon may find it necessary to perform this injection under ultrasound or fluoroscopic guidance with or without the use of an interventional radiologist. A final helpful observation when injecting the AC joint is to examine pre- and postinjection. If symptoms can be created with cross-body adduction or doing a pushup immediately before the injection, and cannot be elicited later, one can then conclude that the AC joint is definitely the source of the pain, which hopefully will respond to the therapeutic injection. AC arthrosis may be idiopathic or may occur as a result of previous trauma, such as a fracture or AC ligament injury (sprain or separation). Pain caused by AC arthrosis is not likely to improve with physical therapy. However, comorbid shoulder disorders, such as rotator cuff tendinosis, proximal biceps tendinosis, and glenohumeral instability, are common, and may respond to rehabilitation exercises. Nonoperative management of DCO is the same as that of AC arthrosis; activity modification, rest, anti-inflammatory medications, and judicious use of injections are the mainstay of the treatment. Athletes may return to modified activity 48 to 72 hours postinjection. By this time, the local anesthetic effect wears off and the corticosteroid takes effect. Patients have protective sensation, and if a given activity reproduces their preinjection symptoms, they cease that activity. A second injection may be given 3 months after the first, provided the patient received considerable relief from the first. Generally, not more than 2 injections are given to the same AC joint. Traumatic Conditions of the Acromioclavicular Joint

A plethora of nonoperative treatment protocols have been described over the last century, ranging from supportive sling to cast or strap immobilization.29 No evidence strongly supports one method over another and, in fact, compliance with the more cumbersome methods has been poor in most reports.13,30–32 An athlete with AC joint injury can use a sling for comfort initially, and rehabilitation can be initiated as soon as the symptoms resolve. The goal is early return to function. Phase 1 treatment consists of ice, immobilization, oral analgesics, and active assisted range of motion (ROM) at low levels of shoulder abduction and elevation. Once pain and tenderness have nearly resolved, phase 2 begins with restoration of full ROM and initiation of strength training. Strengthening of the rotator cuff and periscapular

AC Problems in Athletes

muscles is encouraged. Phase 3 involves further strengthening of the entire shoulder girdle, including trapezius, latissimus, and pectoralis muscles. The goal in this phase is to achieve strength comparable with the contralateral arm. Once this is achieved, patients progress to sport-specific exercises. The authors do not use corticosteroid injections are in the conservative management of acute injuries. The authors have not treated any type III injuries with acute repair or reconstruction. Historically, the literature has not provided sufficient evidence to support surgical treatment of the acute type III AC separation.33 Patients with an acute type III AC separation are treated nonoperatively for up to 12 weeks. However, there is a subset of patients, who have persistent pain and dysfunction that prevents them from returning to work or sport. The authors offer surgical reconstruction to patients who have persistent symptoms despite a 12-week trial of rest and rehabilitation. Patients in the acute setting who have complete injuries (type IV or higher) owing to the significant morbidity attributable to the dislocated joint and soft tissue disruption will be operated on. Nonoperative treatment options for chronic AC joint injuries include activity modification or rest, anti-inflammatories and intra-articular corticosteroid injections. Considerable evidence indicates that type I and II injuries do well with nonoperative treatment, with most patients returning to their preinjury level of function.34–36 Highgrade injuries (types IV–VI) are treated surgically.25,28,30,37–44 Management of the patient with type III AC separation remains controversial, with success rates in this population ranging from 87% to 96% in both operative and nonoperative treatments. This injury is characterized by complete disruption of both the AC and CC ligaments, without much disruption of the deltoid or trapezial fascia. Clinically, the patient presents with a ‘‘high-riding’’ clavicle, which appears elevated owing to relative depression of the acromion and upper extremity. Nissen and Chatterjee45 surveyed nearly 600 American Orthopaedic Society for Sports Medicine members and found that 81% treated uncomplicated type III AC separations conservatively. Phillips and colleagues46 completed a meta-analysis of 1,172 patients with type III injuries and identified 88% and 87% satisfactory outcomes in patients treated operatively and nonoperatively, respectively. Spencer47 completed a systematic review of journals published in the English literature and concluded that nonoperative treatment is more appropriate for grade III injuries. Many of the studies on this topic are retrospective case series and lack assessment by way of validated outcome measures. Studies of elite throwing athletes suggest that anatomic reduction of the AC joint is not necessary.36,48 Most surgeons treat contact athletes nonoperatively owing to the high risk for re-injury. Finally, when comparing operative and nonoperative intervention, it has been shown that there is no difference in strength with either treatment regimen 2 years postinjury. Thus, it is difficult to predict which patients would benefit from surgical intervention in this setting. The management of AC joint injury during competition deserves mention. Periparticipation injection of local anesthetic (without cortisone) into the AC joint is an attractive option, as the joint is easily accessible, and proprioceptive feedback from this joint is probably less critical than that from the knee or ankle joint. Thus, it may reduce pain without compromising the athlete’s performance. Some physicians endorse such AC joint injection during competitive play as acceptable practice, such as Nelson, who stated ‘‘blocking an acromioclavicular joint or injecting a rib injury is reasonable at the professional level, not dangerous, and done routinely.’’49 However, opposition to this principle does exist, with some suggesting that injection into a painful joint in a young athlete may exacerbate the injury by inhibiting the perception of pain, which otherwise would serve to protect the patient by limiting use of the injured

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part.50 Orchard51 has published the only case series specifically evaluating the consequences of local anesthetic injection in professional football players, although these were not AC joint injections exclusively. In this series of 268 injuries, 27 AC joint injuries were managed with injection of local anesthetic, and complications were rare. Two cases of DCO occurred in this group compared with 1 case in 25 AC joint injuries managed without local anesthetic. This difference was not significant. Most evidence for local anesthetic injection during competitive play is anecdotal, and guidelines for such practice are largely lacking. In the acutely injured athlete, the benefits of immediate pain relief afforded by the anesthetic need to be calculated against the risk for a potentially greater injury or long-term (unreported) consequence.52 Thus, treatment should be evaluated on a case-by-case basis, taking into consideration the perceived risks and benefits by the player and treating physician.51 OPERATIVE MANAGEMENT OF ACROMIOCLAVICULAR JOINT PATHOLOGY

Most traumatic and atraumatic AC joint problems in athletes can be treated conservatively. However, some conditions are inappropriate to treat or fail to respond to nonoperative treatment. Surgical interventions include AC joint resection for arthrosis and DCO, and repair and/or reconstruction for select AC injuries. Atraumatic Conditions: Acromioclavicular Joint Arthrosis and DCO Distal Clavicle Excision

DCE has been described in the treatment of a painful AC joint in athletes, and many authorities have reported success with this technique.18,53–57 Indications include idiopathic AC joint arthrosis, DCO, and low-grade (grades I and II) AC joint separations that fail conservative treatment. Rabalais and McCarty53 completed a systematic review on this topic and concluded that the literature generally supports DCE for atraumatic AC joint arthrosis. The authors caution that the available literature consists of retrospective case series with low levels of evidence. Contraindications to DCE include chronic pain from severe (grade III or higher) AC joint separations or in grade II injuries associated with hypermobility.7,10,12,56,58 DCE may be performed either arthroscopically or as an open procedure. The advantages of the open technique include technical ease and the ability to reapproximate, imbricate, or repair the AC joint capsule, which may be of value in posttraumatic AC joint arthritis with possible occult instability. The arthroscopic technique allows examination of the rest of the shoulder and subacromial space and is less invasive, although it is technically more demanding.54 Alternatively, the surgeon may perform an arthroscopic shoulder evaluation followed by open distal clavicle resection. When performing an open DCE, a 3- to 5-cm transverse or saber incision is made and the deltotrapezial fascia is incised in line with the deltoid fibers. Subperiosteal elevation of the AC ligaments and capsule is performed, the joint is debrided of soft tissue and degenerative meniscal remnant, and an oscillating saw is used to resect 1 cm of the distal clavicle. Care is taken to ensure adequate resection and smoothing of resected edges. Meticulous wound closure in layers completes the procedure.55 Arthroscopic DCE can be performed directly through the AC joint, as described by Flatow and colleagues,56,57 or indirectly via the subacromial space. In the direct technique, small superior incisions are created anterior and posterior to the AC joint and a small arthroscope (2.7 mm) and mechanical burr are inserted first to initiate the resection. This creates enough space to insert the larger arthroscope (4.0 mm) and instruments which are then used to complete the resection. This technique is of value in patients who have isolated AC joint pathology, and in whom the AC joint space is

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sufficient to accommodate the small-diameter camera and instruments. The indirect approach is performed through the subacromial space and may be performed with concomitant glenohumeral or subacromial procedures (such as subacromial decompression). With the camera in the subacromial space, a mechanical burr is used to resect the distal clavicle.10,59 In a recent randomized trial comparing the direct and indirect arthroscopic DCE for osteolysis or posttraumatic arthritis in athletes, Charron and colleagues60 identified clinical improvement in both groups at a minimum 2-year follow-up. Of greater interest, the group treated with direct arthroscopic DCE had reported a faster return to sport (21 days vs. 42 days) and had earlier improvements in their American Shoulder and Elbow Society and American Shoulder Scoring System scores than the group treated with indirect DCE. Zawadsky and colleagues58 reported a high success rate following arthroscopic DCE for posttraumatic or stress-induced DCO. Whether the technique is performed as an open procedure or arthroscopically, the goal is to resect approximately 8 to 10 mm from the distal clavicle. More aggressive resection risks sacrificing the AC ligaments and destabilizing the joint. It is important to visualize the entire distal clavicle to ensure that a uniform resection has been achieved. Intraoperative fluoroscopy may be used if there is any question about the adequacy of the resection. Traumatic Conditions of the Acromioclavicular Joint

The AC joint may require surgical intervention following trauma, either acutely (which is arbitrarily defined as occurring within 4 weeks of presentation) or chronically. Historically, surgical management of AC joint dislocations emphasized open joint reduction and repair of the AC capsule ligaments under direct visualization, supplemented with temporary internal fixation.25,61,62 Sage and Salvatore61 reported 62% to 69% excellent results with this technique. Rigid internal fixation techniques failed to allow the physiologic motion of the AC complex, which led to hardware failure and migration in some patients. Most of the failures of these early surgical techniques were attributable to hardware complications, rather than a diseased distal clavicle. Nonetheless, failure to remove the distal clavicle was believed to lead to persistent symptoms in some patients and this was the impetus for distal clavicle resection as described by Mumford.63 In their classic article, Weaver and Dunn43 reported a technique which exploited the advantages of AC joint repair and DCE. This technique calls for removal of the distal clavicle, transfer of the coracoacromial (CA) ligament, and avoids the need for internal fixation. What ensued was an explosion in the literature of reconstructive techniques for the management of AC joint injuries. Current surgical options include, but are not limited to, open or arthroscopic DCE, acute stabilization with loop and button devices, AC joint reconstruction according to Weaver and Dunn43,64 and its modifications, or an anatomic CC reconstruction. A review of the primary operative techniques for AC joint dislocations published since 2000 is provided in Table 1. Acute AC Separations (Select Grades III and V)

Numerous surgical techniques have been advocated to achieve reduction and fixation of the AC joint, mostly using synthetic materials. These have been performed as isolated techniques or as augmentations to ligament or tendon transfers. They may be performed arthroscopically or arthroscopically assisted. The purported advantages of these more recently evolved techniques include less soft tissue dissection, ability to treat concomitant intra-articular pathology, and preservation of normal joint motion. The latter feature is thought to potentially reduce the complications that can occur after more rigid stabilization with screws or wires.80,81

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Table 1 Primary operative techniques forAC joint dislocations reported since 2000 Date

Description

Publication Details

2001

Arthroscopic stabilization with suture or allograft through single tunnels in clavicle and coracoid process.

Wolf et al. Athroscopy 17(5): 558–56365

2002

Distal clavicle resection and transfer of coracoid process to anteroinferior edge of distal clavicle.

Wang et al. Chin J Traumatol 5(5): 307–31066

2003

CA ligament transfer, AC joint fixation is accomplished with the use of absorbable, braided suture cord.

Tienen et al. AJSM 31(5):655–65941

2004

Modified Weaver–Dunn procedure whereby a loop of Mersilene tape or heavy nonabsorbable suture looped around the base of the coracoid and over the top of the clavicle augments the CA ligament transfer.

Rokito et al. Orhopedics 27(1):21–2867

2004

Closed reduction and stabilization with a cannulated screw through clavicle and coracoid process. The screw is removed at 12 wk.

Rolla et al. Arthroscopy 20(6): 662–66868

2004

Anatomic reconstruction of CC ligaments with allograft looped beneath coracoid process. Remaining graft used to reconstruct AC ligaments with suture anchors.

Mazzocca et al. OTSM 12(1):56–6164

2005

Anatomic reconstruction of CC ligaments with allograft passed through bone tunnel in coracoid. Remaining graft used to reconstruct AC ligaments with drill holes through acromion.

Grutter et al. AJSM 33(11): 1723–172869

2005

Stabilization of acute injury with Corkscrew (Arthrex Inc., Naples, FL) anchor in coracoid secured with nonabsorbable suture through 4 bone tunnels in clavicle.

Clavert et al. TSES 6(1):1–770

2006

Double loop with suture limbs tied AP to clavicle to minimize horizontal translation.

Dimakopoulos et al. AJSM 34(7): 1112–111971

2006

Arthroscopic AC joint reconstruction using suture anchors and small titanium plate.

Chernchujit et al. Arch Orthop Trauma Surg 126(7):575–58172

2007

Arthroscopic suture stabilization with double EndoButton.

Struhl et al. TSES 8(4):175–17973

2007

Transfer of portion of conjoined tendon into medullary canal of distal clavicle

Jiang et al. JBJS Am 89(11): 2408–241274 (continued on next page)

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Table 1 (continued) Date

Description

Publication Details

2007

Arthroscopically assisted stabilization using a gracilis tendon transclavicular– transcoracoid loop technique augmented with a TightRope.

Scheibel et al. Arch Orthop Trauma Surg. Epub75

2007

Double-flip button with loop of polydioxanone suture beneath coracoid and limbs of suture replicating orientation of CC ligaments.

Wellmann et al. Arthroscopy 23(10):1132e1–576

2007

Metallic anchor loaded with a braided polyfilament suture for fixation of the clavicle to the coracoid process.

Somers et al. Acta Orthop Belg 73(5): 566–57077

2007

Stabilization of coracoclavicular interval with low-profile double-metallic button technique (TightRrope).

Lim et al. TSES 8(4):213–22178

2008

Arthroscopically assisted reconstruction of CC ligaments with suture or tendon allograft.

Tomlinson et al. CORR 466(3):639–64579

TightRope System

Perhaps the newest technique to achieve anatomic reduction and secure fixation is an arthroscopically assisted approach using the TightRope system (Arthrex, Naples, FL). The TightRope system was designed originally to maintain the reduction of injuries to the ankle syndesmosis. Its application has been expanded to stabilization of an acute AC separation, thus permitting immediate return to sport or work because this method does not rely on biologic incorporation of auto- or allograft into clavicular bone tunnels. This device consists of a No. 5 FiberWire (Arthrex, Naples, FL) suture that has metallic buttons on each end between which the coracoid can be secured to the clavicle (Fig. 4A–E). The presumed advantage of this technique is that it maintains reduction of the CC distance and allows normal movement of the AC joint.78 A 1.5-cm incision is made and the deltotrapezial fascia is opened transversely. The surgeon must confirm that the joint can be reduced in a closed fashion before attempting this technique. The AC joint is not debrided and the distal clavicle is left intact. Caring to ensure anatomic reduction, the drill guide is positioned at the base of the coracoid. A 2.4-mm guide pin is passed through the drill guide starting at the region between the footprint of the conoid and trapezoid ligaments, in the AP center of the clavicle. Care must be taken to ensure the guide is set on the inferior coracoid so that the drill hole is centered within the coracoid. A 4.0-mm cannulated drill bit is then passed over this wire through the clavicle and coracoid, and the guide pin is removed (Fig. 4A). An 18-in Nitinol wire is then passed through the cannulated drill bit clavicle and coracoid tunnels and grasped from the arthroscopic portal (Fig. 4B). Using the Nitinol passing wire, the 2 white traction sutures of the oblong button of the TightRope system are passed through the clavicle, coracoid, and the anteroinferior portal (Fig. 4C). The cortical button is pulled until it emerges through the inferior coracoid (Fig. 4D). The cortical button is then deployed with the AC joint reduced (Fig. 4E). The ends are then tied over the clavicle button, securing fixation (Fig. 4F). Richards and Tennent82 reported their results in 10 patients treated with the TightRope system. At a mean 15 months, the mean Constant score was 93, and 7 of 10 AC joints

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had no change in reduction. The remaining 3 had a slight loss of reduction, and this was attributed to a larger cannulated drill which was used in this initial group. EndoButton Closed Loop

Struhl73 recently described the EndoButton Closed Loop (CL) (Smith & Nephew, Memphis, TN), which is similar to the TightRope in that it is a nonrigid fixation and reduces the AC joint while also permitting slight motion through the joint. An EndoButton rests on the inferior cortex of the coracoid and the EndoButton CL loop is passed through a single tunnel in the clavicle. A second EndoButton then traps the loop and is sutured on the superior aspect of the clavicle (Fig. 5). A second suture is passed through a separate bone tunnel in the clavicle to enhance stability in the AP plane. Clinical outcome data of acute AC joint injuries stabilized with the TightRope or EndoButton CL are lacking. Double-Loop Repair

Dimakopoulos and colleagues71 proposed another technique for acute AC joint injuries which does not require hardware and may better control AP translation of the AC joint. Four braided polyester Ethibond Excel No. 5 sutures (Ethicon, Johnson & Johnson, Somerville, NJ, USA) are passed around the base of the coracoid. The suture limbs are passed through a bone tunnel in the clavicle, and 1 limb from each is tied and passed anterior and posterior to the clavicle. The AC joint is reduced and the sutures are tied beneath or near the anterior and posterior edges of the clavicle. In their series, reduction of the AC joint was maintained in 32 of 34 patients at a mean follow-up period of 33 months. The other 2 patients had only mild loss of reduction and the mean Constant–Murley score was 93.5. Results of Surgical Treatment of Acute Acromioclavicular Joint Injuries Surgical Treatment of Chronic Acromioclavicular Joint Injuries

:

Dozens of techniques have been described to repair or reconstruct the more severely injured AC joint, mostly types III and V. In their classic article, Weaver and Dunn43 described an open technique to treat acute and chronic AC joint dislocations, which consists of distal clavicular resection followed by transfer of the CA ligament into the medullary cavity of the clavicle. In their original report, these authors recognized recurrence or incomplete reduction in as many as 24% of their patients.43 Moreover, subsequent studies have shown that the CA ligament possesses only 20% of the ultimate load of the intact CC ligaments, and is a biomechanically inferior graft.81,83 In addition, the vector of attachment from the tip of the coracoid to the distal clavicle does not anatomically recreate the normal line of pull of the CC ligaments, whose origin is at the base of the coracoid. More recent modifications of the Weaver–Dunn procedure have been described, whereby the CA ligament transfer is augmented with a loop of Mersilene tape,

Fig. 4. TightRope for acute AC joint injury. The procedure is arthroscopically assisted. (A) The joint is reduced and a 2.4-mm guide pin is advanced under guidance from the clavicle through the coracoid base. A 4.0-mm cannulated drill is passed over the wire, and the wire is removed. (B) A Nitinol wire is passed through the cannulated drill bit and grasped from a cannula in an anteroinferior portal. (C) The traction sutures of the oblong button are fed into the Nitinol wire. (D) The cortical button is pulled until it emerges through the inferior coracoid. (E) Arthroscopic image of inferior surface of coracoid with cortical button. (F) The construct is then cinched on the superior aspect of the clavicle, and the ends are then tied over the clavicle button, securing fixation. (Courtesy of Arthrex, Inc., Naples, FL; with permission.)

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Fig. 5. The sutures have now been tied locking the clavicular EndoButton CL in place. The second pair of sutures is passed through a more lateral hole in the clavicle, improving stability in the AP plane by recreating the course of the trapezoid portion of the CC ligament (From Struhl S. Double endobutton technique for repair of complete acromioclavicular joint dislocations. Tech Shoulder Elbow Surg 2007;8(4):175–9; permission pending).

heavy nonabsorbable suture, or biologic graft (auto- or allograft tissue) looped around the base of the coracoid and over the top of the clavicle (Fig. 6).67 Another modification involves stabilization of the AC joint with 2-mm absorbable suture cord after CA ligament transfer.41

Conjoint Tendon Transfer

Jiang and colleagues74 recently reported their results in a group of patients with grade III–V AC dislocations treated with conjoined tendon transfer. According to this technique, a strap incision is made and the deltotrapezial fascia is split longitudinally. Distal clavicle (5–8 mm) is excised. The lateral half of the conjoined tendon is isolated and sectioned 4 to 5 cm distal to the coracoid process. This is then secured within the medullary cavity of the clavicle similar to the way the CA ligament is used in the Weaver–Dunn procedure. To augment this reconstruction, the authors placed suture anchors in the base of the coracoid, passed the sutures through bone tunnels in the clavicle, and tied them over a bone bridge (Fig. 7). These authors reported 89% good or excellent results, with 92% returning to their preinjury level of function.

Fig. 6. Modified Weaver–Dunn procedure. The CA ligament has been transferred into the intramedullary cavity of the clavicle after distal clavicle resection. An allograft is looped around the coracoid and through the clavicle for augmentation.

AC Problems in Athletes

Fig. 7. Proximally based transfer of the lateral half of the conjoined tendon into the clavicle. Arrows show that the sutures from the suture anchors were tied over the top of the clavicle through the holes that were drilled in the anterior third of the clavicle. (From Jiang C, Wang M, Rong G. Proximally based conjoined tendon transfer for coracoclavicular reconstruction in the treatment of acromioclavicular dislocation. J Bone Joint Surg Am 2007;89(11):2408–12; with permission.)

Arthroscopic Reconstruction

Wolf and Pennington65 described an arthroscopically assisted method of stabilizing the AC joint with suture between the clavicle and coracoid. The coracoid is visualized with the arthroscope in the glenohumeral joint, and the distal clavicle from the subacromial space. Suture or semitendinosus allograft is looped beneath the coracoid and secured through a single small bone tunnel in the clavicle (Fig. 8A and B). In this technique, resection of the distal clavicle facilitated reduction of the joint. A similar arthroscopically assisted technique uses a suture anchor in the coracoid with 2 limbs of suture which are passed through bone tunnels in the clavicle to reconstruct the conoid and trapezoid ligaments.65 Anatomic Coracoclavicular Reconstruction

Anatomic reconstruction is the preferred method, in which the ligaments of the AC joint and CC ligaments are re-established.64 From a biomechanical perspective, the importance of the CC and AC ligaments in controlling superior and horizontal translations has been elucidated.1,3,84,85 In fact, failure to surgically reproduce the conoid, trapezoid, and AC ligament function with current techniques may explain the observed incidence of recurrent instability and pain.84,85 This has been the impetus to reconstruct the conoid and trapezoid ligaments anatomically. The distal clavicle is not excised as part of this reconstruction because the authors believe that the congruous bony surfaces impart stability to the reduced AC joint. Semitendinosus, anterior tibialis, allo- or autograft are suitable grafts for this procedure.86 Lee and colleagues86 found no difference in peak load-to-failure between semitendinosus, toe extensors, and gracilis tendons for reconstruction of the AC joint. In this technique, there are 2 options for handling the fixation to the coracoid process: The graft may either be looped around the base of the coracoid, or it can be secured within a bone tunnel with interference screw–type fixation. In the authors’

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Fig. 8. Arthroscopic stabilization with suture or allograft through coracoid and single clavicular bone tunnel. (A) A guide pin confirms adequate orientation before creating the tunnels. (B) Once the tunnels are created, an interference screw is inserted through the clavicular tunnel into the coracoid. (C) A second screw is inserted after the graft or suture is placed (Adapted from Wolf EM, Fragomen AT. Arthroscopic reconstruction for acromioclavicular dislocations. Oper Tech Sports Med 2004;12:149–55; with permission.)

biomechanical testing, the graft within a bone tunnel in the coracoid process was secured. The authors’ current practice is to loop the graft under the base of the coracoid as the conjoint tendon is present to prevent anterior migration of the graft in vivo. Passage of the graft is facilitated by the use of a curved aortic cross-clamp (Stanitsky clamp) and a suture-passing device. At the same time that the graft is passed, a No. 2 FiberWire is also passed around the base of the coracoid. A TightRope device may be used to augment this reconstruction, but it is not done because it requires another bone tunnel in the clavicle. It is important to place the clavicular bone tunnels in an anatomic position to recreate the CC ligaments. Two cannulated reamer guide pins are used for placement of the tunnels. The first tunnel is for the conoid ligament and is roughly 45 mm away from the distal end of the clavicle, in the posterior one half of the clavicle. The footprint of the conoid ligament is extremely posterior, along the entire posterior edge of the clavicle. Therefore, making this bone tunnel as posterior as possible is important. The guide pin is also angled approximately 45 from the direct perpendicular of the clavicle to

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recreate the oblique nature of the ligament. The authors start with a 5-mm reamer and increase in 0.5-mm increments until the graft passes through the tunnel. Before reaming, the surgeon inspects the posterior clavicle to ensure that the reamer does not ‘‘blow out’’ the posterior cortex (Fig. 9A). The graft diameter may be measured, but the smallest tunnel that allows graft passage is chosen. With the guide pin in place, the same procedure is repeated for the trapezoid ligament. This is a more anterior structure than the conoid and its origin is approximately 15 mm lateral to the first tunnel, in the mid-portion of the superior surface of the clavicle. The tunnels are reamed completely through the entire depth of the clavicle.

Fig. 9. Anatomic CC reconstruction. (A) Once the guide pins are placed, the surgeon inspects the posterior clavicle to ensure the reamer will not ‘‘blow out’’ the posterior cortex. The tunnels are reamed completely through the entire width of the clavicle. (B) The graft has been passed through both tunnels and secured with No. 2 FiberWire. The remaining portions of the tendon graft are laid longitudinally in the direction of the AC joint and sutured to the acromion to reconstruct the superior and posterior AC ligaments.

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One of the limbs of the graft is placed through each tunnel, thus reconstructing the conoid and trapezoid ligaments. Upper displacement of the scapulohumeral complex by the assistant reduces the AC joint. A large pointed-reduction forceps placed on the coracoid process and the clavicle can assist while securing the tendon grafts. The AC joint should be reduced anatomically during initial fixation. With complete upper displacement on the graft ensuring its tautness, a 5.5  8 mm polyetherether-ketone (Arthrex, Naples, FL) screw is placed in either the posterior or the midline bone tunnel. For both of these, the screw is placed anteriorly so that the graft would be posterior within the tunnels. The No. 2 FiberWire is brought up through the cannulated screw. Another bioabsorbable screw is then placed into the second bone tunnel. Once both grafts have been secured, the No. 2 FiberWire is tied over the top, becoming a nonbiologic fixation for the anatomically reduced AC joint (Fig. 9B). The remaining portions of the tendon graft are laid longitudinally in the direction of the AC joint and sewn to the acromion to reconstruct the superior and posterior AC ligaments. POSTOPERATIVE MANAGEMENT

Radiographs, including Zanca and axillary view, are taken immediately postoperatively and repeated for comparison at 6 weeks. Pendulum exercises 3 times a day are started immediately. The patient is told that he/she will be in a platform brace (Lerman Shoulder Orthosis, DonJoy, Inc, Vista, CA.) for 6 weeks, and can come out of it only during supervised therapy, which involves active assisted ROM in all planes. However, the use of brace support is critical. With this platform brace, the weight of the shoulder (70 N, on average) is supported on the hip, rather than through the newly reconstructed AC joint (Fig. 10A and B). The sling is generally discontinued between 6 to 12 weeks; however, no strengthening or lifting can be done as the graft is still maturing. Light jogging is allowed at 12 weeks. From 12 to 24 weeks, isometric exercises are begun. Contact athletics, throwing, and swimming are allowed at 6 months postoperatively. COMPLICATIONS

Repair or reconstruction of the dislocated AC joint has been associated with several intra- and postoperative complications. Fortunately, reports of such problems have diminished as understanding of the normal AC joint anatomy and mechanics has improved. Specific complications include wound breakdown and infection, hardware migration and failure, clavicle and coracoid fracture, loss of reduction, and neurovascular injury. Owing to the normal motion of the AC joint, stabilizing AC relationship with pins or screws has been associated with high rates of complications. These include screws missing the coracoid, late screw failure, wound drainage, and subluxation after screw removal.42 Smooth Kirschner wires, threaded pins, and Steinmann pins have all been reported to migrate.87 Hardware removal is necessary, and loss of reduction following removal has been described frequently. The newer techniques described in the current account may have lower complication rates, although this remains to be proven in follow-up studies. Complications with anatomic CC reconstruction have been infrequent at the authors’ institution. Superficial wound problems can be minimized with gentle, meticulous soft tissue handling and layered wound closure. The possibility of clavicle fracture exists owing to placement of 2 fairly large bone tunnels, failure to support the arm postoperatively, and premature return to activity or contact. This complication has not happened in the

AC Problems in Athletes

Fig.10. (A) Lerman Shoulder Orthosis for AC joint reconstruction supports the weight of the upper extremity on the patient’s hip rather than the reconstructed AC joint. (B) Height of arm support can be raised or lowered as needed.

authors’ clinical series, but there are anecdotal cases of clavicle fracture, all of which were managed conservatively. Extreme care must be taken when preparing the conoid bone tunnel so that posterior wall ‘‘blow out’’ is avoided. The tendon graft can be looped around the coracoid, rather than securing it within a bone tunnel in the coracoid. If the surgeon chooses to create a bone tunnel in the coracoid process, this tunnel needs to be as close to the base as possible for 2 reasons. First, this represents the anatomic origin of the conoid and trapezoid. Second, this will help decrease the risk for coracoid fracture. Heterotopic ossification and tunnel widening are rare findings and their clinical significance is unclear.

DISCUSSION

Most problems that affect the athlete’s AC joint are attributed to arthrosis (idiopathic, iatrogenic, or posttraumatic), osteolysis, or ligament injury. Fortunately, nonoperative management is usually successful. Open or arthroscopic DCE alleviates AC joint symptoms in properly selected athletes with idiopathic osteoarthritis or repetitive stress-induced osteolysis. Positive response to preoperative lidocaine injection into the AC joint is prognostically favorable for a good outcome. Although there is controversy over the exact amount of clavicular resection necessary, most authors advocate

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a resection distance of approximately 1 cm. Care must be taken to avoid resection in cases of posttraumatic arthritis with occult instability. Although traditional treatment for AC separations has been nonoperative, a growing trend has been recognized that not all of these patients have favorable outcomes. The current challenge is to identify the subtly unstable type II injuries and clinically at-risk type III injuries in selected athletes, who merit surgical intervention acutely. It is hoped that prospective studies will help confirm the validity of some of the newer diagnostic maneuvers, such as that described by Paxinos and Basmania in helping identify subtle, yet clinically significant, instability. For example, cross-arm adduction AP radiographs may predict instability, although this remains unproven. The exact indications for early intervention of type III AC separation remains unclear, although in the context of recent advances in surgical techniques, there seems to be a growing enthusiasm for earlier reconstruction, particularly in the elite overhead athlete.

REFERENCES

1. Fukuda K, Craig EV, An KN, et al. Biomechanical study of the ligamentous system of the acromioclavicular joint. J Bone Joint Surg Am 1986;68(3):434–40. 2. Urist MR. Complete dislocation of the acromioclavicular joint. Follow-up notes on articles previously published in the Journal. J Bone Joint Surg Am 1963;45: 1750–3. 3. Debski RE, Parsons IM, Woo SL, et al. Effect of capsular injury on acromioclavicular mechanics. J Bone Joint Surg Am 2001;83(9):1344–51. 4. Rios CG, Arciero RA, Mazzocca AD. Anatomy of the clavicle and coracoid process for reconstruction of the coracoclavicular ligaments. Am J Sports Med 2007;35(5):811–7. 5. Cadenat F. The treatment of dislocations and fractures of the outer end of the clavicle. Int Clin 1917;1:145–69. 6. Tossy JD, Mead NC, Sigmond HM. Acromioclavicular separations: useful and practical classification for treatment. Clin Orthop 1963;28:111–9. 7. Rockwood CA Jr, Williams GR, Young DC. Injuries to the acromioclavicular joint. In: Rockwood CA Jr, Bucholz RW, Green DP, editors. Fractures in Adults. Philadelphia: Lippincott-Raven; 1996. p. 1341–413. 8. Garretson RB III, Williams GR Jr. Clinical evaluation of injuries to the acromioclavicular and sternoclavicular joints. Clin Sports Med 2003;22:239–54. 9. DePalma AF, Callery G, Bennett GA. Variational anatomy and degenerative lesions of the shoulder joint. Instr Course Lect 1949;6:255–81. 10. Gartsman GM. Arthroscopic resection of the acromioclavicular joint. Am J Sports Med 1993;21(1):71–7. 11. Needell SD, Zlatkin MB, Sher JS, et al. MR imaging of the rotator cuff: peritendinous and bone abnormalities in an asymptomatic population. Am J Roentgenol 1996;166(4):863–7. 12. Shaffer BS. Painful conditions of the acromioclavicular joint. J Am Acad Orthop Surg 1999;7(3):176–88. 13. Taft TN, Wilson FC, Oglesby W. Dislocation of the acromioclavicular joint. J Bone Joint Surg Am 1987;69(7):1045–51. 14. Bergfeld JA, Andrish JT, Clancy WG. Evaluation of the acromioclavicular joint following first- and second-degree sprains. Am J Sports Med 1978;6: 153–9.

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15. Mouhsine E, Garofalo R, Crevoisier X, et al. Grade I and II acromioclavicular dislocations: results of conservative treatment. J Shoulder Elbow Surg 2003; 12(6):599–602. 16. Cahill BR. Osteolysis of the distal part of the clavicle in male athletes. J Bone Joint Surg Am 1982;64(7):1053–8. 17. Scavenius M, Iverson BG. Nontraumatic clavicular osteolysis in weight lifters. Am J Sports Med 1992;20(4):463–7. 18. Slawski DP, Cahill BR. Atraumatic osteolysis of the distal clavicle: results of open surgical excision. Am J Sports Med 1994;22(2):267–71. 19. Walton J, Mahajan S, Paxinos A, et al. Diagnostic value of tests for acromioclavicular joint pain. J Bone Joint Surg Am 2004;86(4):807–12. 20. Chronopoulos E, Kim TK, Park HB, et al. Diagnostic value of physical tests for isolated chronic acromioclavicular lesions. Am J Sports Med 2004;32(3): 655–61. 21. O’Brien SJ, Pagnani MJ, Fealy S, et al. The active compression test: a new and effective for diagnosing labral tears and acromioclavicular joint abnormality. Am J Sports Med 1998;26(5):610–3. 22. Berg EE, Ciullo JV. The SLAP lesion: a cause of failure after distal clavicle excision. Arthroscopy 1997;13(1):85–9. 23. Zanca P. Shoulder pain: involvement of the acromioclavicular joint. Analysis of 1000 cases. Am J Roentenol Radium Ther Nucl Med 1971;112(3):493–506. 24. Petersson CJ, Redlund-Johnell I. Radiographic joint space in normal acromioclavicular joints. Acta Orthop Scand 1983;54(3):431–3. 25. Bosworth BM. Acromioclavicular separation: new method of repair. Surg Gynecol Obstet 1941;73:866–71. 26. Bearden JM, Hughston JC, Whatley GS. Acromioclavicular dislocation: method of treatment. Am J Sports Med 1973;1:5–17. 27. Mazzocca AD, Spang JT, Rodriguez R, et al. Biomechanical and radiographic significance of isolated trapezoid or conoid injury in the setting of a simulated type II acromioclavicular join injury. Am J Sports Med 2008; 36(7):1397–402. 28. Peetrons P, Bedard JP. Acromioclavicular joint injury: enhanced technique of examination with dynamic maneuver. J Clin Ultrasound 2007;35(5):262–7. 29. Urist MR. The treatment of dislocations of the acromioclavicular joint: a survey of the past decade. Am J Surg 1959;98:423–31. 30. Kennedy JC, Cameron H. Complete dislocation of the acromion-clavicular joint. J Bone Joint Surg Br 1954;36(2):202–8. 31. Powers JA, Bach PJ. Acromioclavicular separations: closed or open treatment? Clin Orthop 1974;104:213–23. 32. Wojtys EM, Nelson G. Conservative treatment of grade III acromioclavicular dislocations. Clin Orthop 1991;268:112–9. 33. Mazzocca AD, Arciero RA, Bicos J. Evaluation and treatment of acromioclavicular joint injuries. Am J Sports Med 2007;35(2):316–29. 34. Cox JS. The fate of the acromioclavicular joint in athletic injuries. Am J Sports Med 1981;9(1):50–3. 35. Dias JJ. The conservative treatment of acromioclavicular dislocation: review after five years. J Bone Joint Surg Br 1987;69(5):719–22. 36. Galpin RD. A comparative analysis of operative versus non-operative treatment of grade III acromioclavicular separations. Clin Orthop 1985;193:150–5. 37. Lemos MJ. The evaluation and treatment of the injured acromioclavicular joint in athletes. Am J Sports Med 1998;26(1):137–44.

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Rios & Mazzocca

38. Ahstrom JP Jr. Surgical repair of complete acromioclavicular separation. J Am Med Assoc 1971;215:785–9. 39. Bunnell S. Facial graft for dislocation of the acromioclavicular joint. Surg Gynecol Obstet 1928;46:563–4. 40. Larsen E. Conservative or surgical treatment of acromioclavicular dislocation: a prospective, controlled, randomized study. J Bone Joint Surg Am 1986;68(4): 552–5. 41. Tienen TG, Oyen JF, Eggen P. A modified technique for complete acromioclavicular dislocation: a prospective study. Am J Sports Med 2003;31(5):655–9. 42. Tsou PM. Percutaneous cannulated screw coracoclavicular fixation for acute acromioclavicular dislocations. Clin Orthop 1989;243:112–21. 43. Weaver JK, Dunn HK. Treatment of acromioclavicular injuries, especially complete acromioclavicular separation. J Bone Joint Surg Am 1972;54(6):1187–94. 44. Weinstein DM, McCann PD, McIlveen SJ, et al. Surgical treatment of complete acromioclavicular dislocations. Am J Sports Med 1995;23(3):324–31. 45. Nissen CW, Chatterjee A. Type III acromioclavicular joint separation: results of a recent survey on its management. Am J Orthop 2007;36(2):89–93. 46. Phillips A, Smart C, Groom A. Acromioclavicular dislocation. Clin Orthop 1998; 353:10–7. 47. Spencer EE Jr. Treatment of grade III acromioclavicular joint injuries: a systematic review. Clin Orthop 2006;455:38–44. 48. Glick JM, Milburn LJ, Haggerty JF, et al. Dislocated acromioclavicular joint: follow-up study of 35 unreduced acromioclavicular dislocations. Am J Sports Med 1977;5(6):264–70. 49. Nelson C. Anesthetic injections in football: an ethical dilemma. Sports Med Digest 2001;23:133. 50. Snibbe JC, Gamgardella RA. Use of injections for osteoarthritis in joints and sports activity. Clin Sports Med 2005;24:83–91. 51. Orchard JW. Benefits and risks of using local anesthetic for pain relief to allow early return to play in professional football. Br J Sports Med 2002;36(3): 209–13. 52. Genuario J, Carr C. The role of shared decision making in sports medicine. Journal of Musculoskeletal Medicine 2008;25:63–9. 53. Rabalais DR, McCarty E. Surgical treatment of symptomatic acromioclavicular problems: a systematic review. Clin Orthop 2007;455:30–7. 54. Nuber GW, Bowen MK. Arthroscopic treatment of acromioclavicular joint injuries and results. Clin Sports Med 2003;22(2):301–17. 55. Alford W, Bach BR. Open distal clavicle resection. Operative Techniques in Sports Medicine 2004;12:9–17. 56. Flatow EL, Duralde XA, Nicholson GP, et al. Arthroscopic resection of the distal clavicle with a superior approach. J Shoulder Elbow Surg 1995;4(1 Pt 1):41–50. 57. Esch JC, Ozerkis LR, Helgager JA, et al. Arthroscopic subacromial decompression: results according to the degree of rotator cuff tear. Arthroscopy 1988;4(4): 241–9. 58. Zawadsky M, Marra G, Wiater JM, et al. Osteolysis of the distal clavicle: long-term results of arthroscopic resection. Arthroscopy 2000;16(6):600–5. 59. Kay SP, Ellman H, Harris E. Arthroscopic distal clavicle excision: technique and early results. Clin Orthop 1994;301:181–4. 60. Charron KM, Schepsis AA, Voloshin I. Arthroscopic distal clavicle resection in athletes: a prospective comparison of the direct and indirect approach. Am J Sports Med 2007;35(1):53–8.

AC Problems in Athletes

61. Sage FP, Salvatore JE. Injuries of the acromioclavicular joint: a study of results in 96 patients. South Med J 1963;56:486–95. 62. Horn JS. The traumatic anatomy and treatment of acute acromioclavicular dislocation. J Bone Joint Surg Br 1954;36(2):194–201. 63. Mumford E. Acromioclavicular dislocation: a new operative treatment. J Bone Joint Surg 1941;23:799–802. 64. Mazzocca AD, Conway JE, Johnson SJ, et al. The anatomic coracoclavicular reconstruction. Oper Tech Sports Med 2004;12(1):56–61. 65. Wolf EM, Pennington WT. Arthroscopic reconstruction for acromioclavicular joint dislocation. Arthroscopy 2001;17(5):558–63. 66. Wang S, Du D, Zhang P, et al. A modified method of coracoid transposition for the treatment of complete dislocation of acromioclavicular joint. Chin J Traumatol 2002;5(5):307–10. 67. Rokito AS, Oh YH, Zuckerman JD. Modified Weaver-Dunn procedure or acromioclavicular joint dislocations. Orthopedics 2004;27(1):21–8. 68. Rolla PR, Surace MF, Murena L. Arthroscopic treatment of acute acromioclavicular joint dislocation. Arthroscopy 2004;20(6):662–8. 69. Grutter PW, Petersen SA. Anatomical acromioclavicular ligament reconstruction: a biomechanical comparison of reconstructive techniques of the acromioclavicular joint. Am J Sports Med 2005;33(11):1723–8. 70. Clavert P, Moulinoux P, Kempf J-F. Technique of stabilization in acromioclavicular joint dislocation. Techniques in Shoulder and Elbow Surgery 2005;6(1):1–7. 71. Dimakopoulos P, Panagopoulos A, Syggelos SA, et al. Double-loop repair for acute acromioclavicular joint disruption. Am J Sports Med 2006;34(7): 1112–9. 72. Chernchujit B, Tischer T, Imhoff AB. Arthroscopic reconstruction of the acromioclavicular joint disruption: surgical technique and preliminary results. Arch Orthop Trauma Surg 2006;126(9):575–81. 73. Struhl S. Double endobutton technique for repair of complete acromioclavicular joint dislocations. Tech Shoulder Elbow Surg 2007;8(4):175–9. 74. Jiang C, Wang M, Rong G. Proximally based conjoined tendon transfer for coracoclavicular reconstruction in the treatment of acromioclavicular dislocation. J Bone Joint Surg Am 2007;89(11):2408–12. 75. Scheibel M, Ifesanya A, Pauly S, et al. Arthroscopically assisted coracoclavicular ligament reconstruction for chronic acromioclavicular joint instability. Arch Orthop Trauma Surg 2007 [Epub]. 76. Wellmann M, Zantop T, Petersen W. Minimally invasive coracoclavicular ligament augmentation with a flip button/polydioxanone repair for treatment of total acromioclavicular joint dislocation. Arthroscopy 2007;23(10):1132. 77. Somers JF, Van der Linden D. Arthroscopic fixation of type III acromioclavicular dislocations. Acta Orthop Belg 2007;73(5):566–70. 78. Lim YW, Sood A, van Riet RP, et al. Acromioclavicular joint reduction, repair and reconstruction using metallic buttons—early results and complications. Tech Shoulder Elbow Surg 2007;8(4):213–21. 79. Tomlinson DP, Altchek DW, Davila J, et al. A modified technique of arthroscopically assisted AC joint reconstruction and preliminary results. Clin Orthop Relat Res 2008;466(3):639–45. 80. Lindsey RW, Gutowski WT. The migration of a broken pin following fixation of the acromioclavicular joint. Orthopedics 1986;9(3):413–6. 81. Nuber GW, Bowen MK. Acromioclavicular joint injuries and distal clavicle fractures. J Am Acad Orthop Surg 1997;5(1):11–8.

787

788

Rios & Mazzocca

82. Richards A, Tennent TD. Arthroscopic stabilization of acute acromioclavicular joint dislocation using the tightrope system. Tech Shoulder Elbow Surg 2008; 9(2):51–4. 83. Motamedi AR, Blevins FT, Willis MC, et al. Biomechanics of the coracoclavicular ligament complex and augmentations used in its repair and reconstruction. Am J Sports Med 2000;28(3):380–4. 84. Jari R, Costic RS, Rodosky MW, et al. Biomechanical function of surgical procedures for acromioclavicular joint dislocation. Arthroscopy 2004;20(3):237–45. 85. Klimkiewicz JJ, Williams GR, Sher JS, et al. The acromioclavicular capsule as a restraint to posterior translation of the clavicle: a biomechanical analysis. J Shoulder Elbow Surg 1999;8(2):119–24. 86. Lee SJ, Nicholas SJ, Akizuki KH, et al. Reconstruction of the coracoclavicular ligaments with tendon grafts: a comparative biomechanical study. Am J Sports Med 2003;31(5):648–55. 87. Guttmann D, Paksima NE, Zuckerman JD. Complications of treatment of complete acromioclavicular joint dislocations. Instr Course Lect 2000;49:407–13.