Persistent anterior shoulder instability following surgical stabilization

Persistent anterior shoulder instability following surgical stabilization

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D. Trofa, A.C. Hsu, W.N. Levine Columbia University, New York, NY, USA

13.1 Introduction As the joint in the body with the greatest range of motion and least amount of support, the shoulder is particularly susceptible to instability. Proper glenohumeral joint stability necessitates an appropriate interplay between a highly complex combination of dynamic and static stabilizers as well as a less well-understood mechanism of neuromuscular proprioception. A traumatic anterior glenohumeral dislocation often results in recurrent instability due to disruption of the anteroinferior labral ligamentous complex as first described by Bankart almost a century ago (Bankart, 1923, 1938). However, in addition to damaging the soft tissue surrounding the glenohumeral joint, traumatic dislocations can injure the osseous anatomy of the shoulder, which could lead to persistent instability even after soft-tissue repair. Studies have shown that up to 56% of patients experience recurrent instability following a first dislocation (Robinson et al., 2006). Given the high risk for recurrent instability in patients who sustain a single shoulder dislocation, as well as the high failure rate of nonoperative treatment (Handoll et al., 2004), the current recommendations emphasize surgical glenohumeral stabilization (Handoll et al., 2004; Arciero et al., 1994; Bottoni et al., 2002; Kirkley et al., 1999, 2005). While modern techniques of shoulder stabilization have acceptable failure rates, persistent instability following an attempt at surgical stabilization can be a highly frustrating and complex problem for both the patient and surgeon. Complicating this topic further is that success and failure of stabilization procedures have been defined in different ways and investigated among heterogeneous populations of patients. In general, failure is any persistent postoperative instability as defined by recurrent dislocation, subluxation, or apprehension with the shoulder in the vulnerable abducted externally rotated position (i.e., a positive apprehension test). Failure can also be a complication from a surgical procedure such as stiffness, glenohumeral arthritis, neurological injury, or infection (Levine et al., 2000). Successful surgical outcomes should be defined as return to full function with preservation of range of motion and strength without instability. Instability treatment starts with a thorough and complete history, focusing on the mechanism of injury, including the position of the arm at the time of trauma, as well as the circumstances of any recurrent dislocations or subluxations. One should also focus on the number of events, the force required to dislocate, and the mode of ­reduction Shoulder and Elbow Trauma and its Complications. http://dx.doi.org/10.1016/B978-1-78242-449-9.00013-3 © 2015 Elsevier Ltd. All rights reserved.

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(self-reduction versus formal reduction by a medical professional). A detailed physical exam is necessary to appropriately diagnose anterior instability and identify subgroups of patients who may not be appropriate candidates for a standard anterior stabilization procedure. This includes patients with posterior instability, multidirectional instability (MDI), voluntary dislocators, or subscapularis tendon ruptures (especially in patients previously treated for instability via an open technique). Findings may include decreased glenohumeral range of motion secondary to pain or apprehension and should incorporate a number of special tests, including the Jobe relocation test, anterior apprehension test, and the load and shift test. The examination should be followed by orthogonal view radiographs and appropriate advanced imaging, including magnetic resonance imaging (MRI) (with or without intra-articular gadolinium enhancement) and/or a computed tomography (CT) scan to identify the deficiencies in the glenohumeral osseous anatomy and guide operative planning. Finally, all efforts should be undertaken to obtain previous operative reports. This is particularly important for persistent instability following an open repair to determine if an anatomic or nonanatomic technique was used and how the subscapularis was approached to access the labrum and capsule. Failure to adequately understand the pathology can lead to incorrect diagnoses, inappropriate procedure selection, treatment failure, re-operation, and increased patient morbidity. Treatment for persistent instability following a failed stabilization procedure follows a similar diagnostic algorithm; however, one should also elicit if the patient’s preoperative symptoms were ever treated. If there was never a period of postsurgical stability, then either the procedure was poorly performed or performed for an incorrect diagnosis. There are numerous shoulder stabilization procedures. Anatomic or intracapsular repairs attempt to repair the original anatomy by reinserting the labrum into its native position and restoring the ligamentous and capsular tension (i.e., Bankart procedure). The Bankart procedure can be performed via both open and arthroscopic methods with a recurrence rate, as discussed below, of about 10% (Brophy and Marx, 2009). Nonanatomic or extracapsular repairs stabilize the glenohumeral joint with a bone block (Bristow–Latarjet or Eden–Hybinette procedures) or soft-tissue block (Magnuson–Stack or Putti–Platt procedures) (Levine et al., 2000). As reported by Lopiz-Morales et al. (2013), nonanatomic bone block procedures have varying outcomes with reported recurrence rates of 20% with the Eden–Hybinette technique (Rahme et al., 2003), 15% with the Bristow–Latarjet technique (Schroder et al., 2006), and less than 5% with the Latarjet technique (Schroder et al., 2006). Previously, the ideal soft-tissue stabilization technique—arthroscopic versus open—was debated with early data favoring open stabilization (Hobby et al., 2007; Lenters et al., 2007). For instance, a 2004 meta-analysis found arthroscopic failure rates of 23% with transglenoid sutures and 18% with bioabsorbable tacks, compared to 10% for open stabilization (Freedman et al., 2004). When gross dislocation was investigated as the final outcome, the study found that arthroscopic recurrence was 12.6% compared to 3.4% for open procedures. Despite early reports of inferior outcomes, certain limitations of open stabilization procedures made arthroscopic stabilization an attractive alternative. These include violation of the subscapularis muscle, limitations in postoperative external rotation, increased

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postoperative pain, and secondary osteoarthritis (Youssef et al., 1995; Grana et al., 1993). As a result, arthroscopic techniques for repairing the labrum to the glenoid underwent a rapid evolution, including staple capsulorrhaphy, transglenoid sutures, arthroscopic tacks, and suture anchors with improved results (Fritsch et al., 2010). Repair with suture anchors has been shown to decrease failure rates compared to other arthroscopic techniques and demonstrates similar success rates as open stabilization procedures (Guanche et al., 1996; Kim et al., 2008). A 2007 meta-analysis by Hobby et al. compared all arthroscopic procedures to an open technique for chronic anterior shoulder instability and confirmed that the rate of persistent instability using staples or transglenoid suture was unacceptable, but that the use of arthroscopic suture anchors, with an average 9.1% failure rate among 20 studies, was equivalent to open surgery (Hobby et al., 2007). Finally, two prospective randomized studies compared open versus arthroscopic suture anchor anterior stabilization outcomes (total of 121 patients in both studies) and found no difference in persistent instability between treatment groups (Fabbriciani et al., 2004; Bottoni et al., 2006). Other significant findings included decreased range of motion in patients who underwent open stabilization (Fabbriciani et al., 2004; Bottoni et al., 2006), and a 90-min decrease in operative time for arthroscopic surgery (Bottoni et al., 2006). As such, modern arthroscopic stabilization has become the primary surgical option in anterior shoulder instability management with multiple studies confirming equivalent success rates as open stabilization (Hobby et al., 2007; Kim et al., 2003, 2008; Fabbriciani et al., 2004; Bottoni et al., 2006; Cole and Warner, 2000; Jorgensen et al., 1999; Karlsson et al., 2001). This has led to a paradigm shift in instability treatment focus from open versus arthroscopic to soft tissue versus bony procedures. Recent research and discussion on instability highlights the need to select an operative technique based upon the underlying pathology; a tenet that holds true for both primary and revision cases.

13.2 Risk factors for persistent instability The importance of success for primary shoulder stabilization cannot be underscored given that revision stabilization surgery has a higher failure rate than primary surgery. As such, it is imperative to diagnose and treat persistent shoulder instability appropriately the first time to avoid repeated insult to the subscapularis tendon and glenohumeral capsule, prevent excessive scar tissue formation, decrease patient morbidity, and provide patients with the best chance to return to their preinjury function. This requires a comprehensive knowledge of instability risk factors and instability etiology. A number of risk factors for primary instability treatment failure have been elucidated in retrospective and prospective studies. The three most significantly cited causes for persistent instability include trauma (often in patients participating in collision or contact athletics), diagnostic errors leading to improper surgical selection based upon the etiology of instability, and technical errors, which include, but are not limited to, uncorrected excessive capsular redundancy, incorrect anchor placement, and the learning curve associated with modern arthroscopic techniques (Levine et al., 2000; Mauro et al., 2011). Studies provide conflicting findings as to the most common cause of persistent instability (Table 13.1).

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Table 13.1 

Shoulder and Elbow Trauma and its Complications

Risk factors for persistent instability

Trauma Younger age Male gender Participation in contact/collision sports Time from first dislocation to primary surgery Number of dislocations before primary surgery

13.2.1 Trauma and other patient-specific risk factors Trauma is commonly cited in the literature as a cause for persistent instability and can disrupt an adequately performed Bankart repair or cause a new injury following stabilization. In a study from 1997, Koss et al. retrospectively reviewed 27 patients who underwent arthroscopic Bankart reconstruction and found an unacceptable 30% failure rate over an average 40 months of follow-up. The authors reported that 87.5% of failures were secondary to a repeat traumatic event, which led to their recommendation for alternative treatment in individuals planning to return to contact sports (Koss et al., 1997). Cho et al. reported that 96.2% of 26 patients with persistent instability following arthroscopic repair had a new episode of moderate or severe trauma similar to their initial injury (Cho et al., 2009). Other case series confirm that trauma remains a significant risk factor for recurrence but found that the majority of persistent instability in their series occurred atraumatically. For instance, in 1 series of 83 patients who underwent arthroscopic Bankart repair with suture anchors, there were 13 (15.6%) failures—only 6 (46.2%) of whom experienced repeat trauma (Voos et al., 2010). Additionally, in 2000, Levine et al. retrospectively analyzed 50 patients who underwent open revision anterior stabilization surgery citing trauma as a cause for primary failure in 34% of patients (Levine et al., 2000). Several patient-specific factors increase the risk of postoperative trauma, including younger age (Voos et al., 2010; Balg and Boileau, 2007; Porcellini et al., 2009; Flinkkila et al., 2010; Sperber et al., 2001), male gender (Porcellini et al., 2009), and participation in contact or collision sports (Rhee et al., 2006). While these risk factors may not be interchangeable, there is obviously a great deal of overlap given that most at-risk athletes are young males with high physical activity levels (Balg and Boileau, 2007). For instance, Porcellini et al. investigated 385 patients who underwent an arthroscopic Bankart repair with an average follow-up of 36 months (Porcellini et al., 2009). The authors found an overall 8.1% persistent instability rate that was higher in patients younger than 22 years—13.3% versus 6.3%—and in males—10.1% versus 2.8%. Similar results were reported by Imhoff et al. where the mean age of 190 patients undergoing primary arthroscopic shoulder stabilization was 28.0 years, but the average age of patients who failed treatment was 23.8 years (Imhoff et al., 2010). Further, Voos et al. found a 37.5% failure rate in patients under 20 years old (Voos et al., 2010), and Flinkkila et al. identified young age as the most important risk factor for persistent instability, with a recurrence rate of 44% for patients aged 20 or less compared to 12% for older patients in their retrospective review of 174

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arthroscopically treated shoulders (Flinkkila et al., 2010). The latter also found that of 33 cases of persistent instability, 22 (66.7%) patients experienced a repeat traumatic event. Finally, Ahmed et al. analyzed the risk factors for recurrent instability in their database of 302 patients who had undergone arthroscopic Bankart repair and found a persistent instability rate of 13.2%, 14% in males versus 8.1% in females (Ahmed et al., 2012). In addition to glenoid and humeral bony pathology, as discussed below, the authors found that young age at the time of surgery independently predicted the risk of recurrence in their patient population. Collision and contact athletes represent a subgroup of patients that has been independently studied given its high risk for traumatic shoulder dislocation and subsequent recurrence. In fact, some authors have advocated for the open treatment of such patients given their risk of persistent instability. For instance, in 2006 Rhee et al. examined shoulder instability in 48 shoulders of 46 collision athletes, defined as patients involved in judo, wrestling, hockey, and American football, hypothesizing that this population might best be served with an open procedure (Rhee et al., 2006). Of 16 patients who underwent arthroscopic stabilization, 4 (25%) suffered from persistent instability compared to 4 (12.5%) of 32 patients in the open group, confirming the author’s hypothesis. On the other hand, Cho et al. compared arthroscopic outcomes in collision versus noncollision athletes finding similar results to open stabilization (Bacilla et al., 1997; Ide et al., 2004; Mazzocca et al., 2005). Furthermore, despite the multitude of studies looking at recurrence rates and patient-specific risk factors, there are many patients who are at a higher predicted risk of persistent instability but do not fail arthroscopic stabilization. Therefore, some authors are hesitant to apply an arbitrary threshold age or activity level to determine a patient’s treatment (Ahmed et al., 2012). Another patient-specific risk factor for persistent instability includes the time from first dislocation to primary surgery and the number of dislocations in that timeframe. Repeated dislocations and/or subluxations can lead to destruction of the glenoid or increased laxity of the capsule, which are both independent risk factors for persistent instability following surgical management if not appropriately addressed. Koss et al. found higher rates of persistent instability in patients with greater than five dislocations before surgical intervention (Koss et al., 1997), while other authors found that any number of dislocations or subluxation events greater than one significantly increased the risk of operative failure (Imhoff et al., 2010). In regard to the average time to surgery, Porcellini et al. found that greater than 6 months from the first dislocation until the time of surgery was a significant risk factor for persistent instability in a study of 385 patients (Porcellini et al., 2009). Interestingly, a 2010 systematic review of Levels I and II cohort studies found no differences in complications or recurrent rates in patients undergoing arthroscopic treatment for a first-time dislocation versus multiple dislocations (Grumet et al., 2010). Concomitant shoulder injuries such as rotator cuff tears, superior labral anterior posterior (SLAP) lesions, and osteoarthritis have also been investigated as possible risk factors for persistent instability. However, none of these conditions have been shown to increase postoperative instability (Flinkkila et al., 2010; Imhoff et al., 2010).

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13.2.2 Diagnostic and technical errors in treating soft tissue and bony pathology Diagnostic and technical errors are avoidable causes of recurrent instability. Diagnostic errors encompass failure to recognize bony defects (present in up to 89% of primary surgery failures), posterior instability, multidirectional instability, or a humeral avulsion of the glenohumeral ligaments (HAGL; Lopiz-Morales et al., 2013; Mauro et al., 2011; Burkhart and De Beer, 2000; see Figure 13.1). It is important to remember that not all cases of shoulder instability are due to anterior pathology, and not all anterior instability cases are secondary to Bankart lesions, which can be present in 65–90% of unstable shoulders (Gill and Zarins, 2006; Zarins et al., 1993; Bigliani et al., 1998; Rowe et al., 1984; Sugaya et al., 2003). As discussed earlier, failure etiology is elucidated through a complete history, physical exam, and appropriate imagining studies to determine the anatomic reason for instability. Further confirmation of the pathology can be obtained during an intraoperative diagnostic arthroscopy, which can confirm a failed labral repair, rule out a posterior labral tear, or dynamically assess a Hill–Sachs lesion. Investigations that have included intraoperative findings at the time of revision surgery have helped elucidate the etiology of persistent instability and recognize the technical errors that contributed to failure after a soft-tissue repair. These include failure to adequately tension the capsule, nonanatomical repairs of the glenoid labrum, and incorrect placement of suture anchors (Lopiz-Morales et al., 2013; Kim et al., 2003; Cho et al., 2009; Creighton et al., 2007; Neri et al., 2007; Sisto, 2007; Meehan and Petersen, 2005). Levine et al. found that the most important technical error identified at the time of open revision surgery was failure to address excessive capsular redundancy as seen in 43 (86%) of 50 revision patients (Rowe et al., 1984; Norris, 1993;

Figure 13.1  Coronal MRI demonstrating humeral avulsion of the glenohumeral ligament— arrow (HAGL lesion). Figure courtesy of Columbia University Center for Shoulder, Elbow and Sports Medicine.

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Norris and Bigliani, 1984). Interestingly, 11 of these shoulders were also asymmetrically tight in the anterosuperior structures, such as the superior and middle glenohumeral ligaments, coracohumeral ligament, rotator interval, and the upper portion of the subscapularis tendon. This technical error would limit external rotation with the arm at the side but permit instability with the arm in abduction and external rotation. Rowe et al. had also previously identified excessive laxity of the capsule in 83% of assessed shoulders that had failed primary instability surgery (Rowe et al., 1984), while Zabinski et al. identified capsular laxity in 91% of 44 patients who required revision stabilization (Zabinski et al., 1999). Meehan et al. also found that the most common findings during open revision surgery were capsular redundancy and Bankart lesions (Meehan and Petersen, 2005). A second technical error that may contribute to persistently unstable shoulders is an uncorrected Bankart lesion, as seen in 46% of revision cases by Levine et al., 83% of revision cases by Zabinski et al., and 100% of cases by Marquardt et al. (Levine et al., 2000; Zabinski et al., 1999; Marquardt et al., 2007). Nine of the 23 patients identified by Levine et al. had no history of new trauma, indicating that the original lesion was likely never adequately treated. In a study by Cho et al., nonanatomical reconstruction of the glenoid labrum was also identified in three (11.5%) revision patients who failed primary stabilization (Cho et al., 2009). Kim et al. summarized the technical errors they identified at the time of revision surgery as nonanatomical repair of the capsulolabral tissue, failure to restore the concentric capsulolabral bump, and proximal fixation of suture anchors (Kim et al., 2002). Finally, in regard to the proper number of suture anchors necessary for a typical Bankart repair, Boileau et al. found that patients in whom only three anchors were placed were at a high risk for persistent instability, a finding shared by Savoie et al. (Boileau et al., 2006; Savoie et al., 1997). However, in a similar study, Voss et al. found that the number of suture anchors used did not affect outcomes (Voos et al., 2010). In addition to capsular-labral pathology, osseous injury can occur during glenohumeral dislocations. The osseous anatomy of the shoulder plays a central role in the passive stabilization of the shoulder along with the glenoid labrum, glenohumeral ligaments, capsule, and rotator interval (Anakwenze et al., 2011). Pathologic osseous injuries include glenoid deficiency due to acute fracture (see Figure 13.2) or erosion and posterolateral humeral head impaction defects, or Hill–Sachs lesions. These fractures distort the glenohumeral anatomy resulting in loss of the natural convexity or concavity of the respective bones such that there is decreased articular conformity and surface area within the joint (Mauro et al., 2011). It is also speculated that bony defects disrupt the pathway between the central nervous system and neuromuscular elements for joint proprioception, thus increasing patient susceptibility to dislocation (Anakwenze et al., 2011). Acute fracture—a bony Bankart—or erosion of the anteroinferior glenoid rim after multiple dislocations or subluxations has been reported in anywhere from 8% to 95% of shoulders with recurrent glenohumeral instability (Itoi et al., 2003; Saito et al., 2005). To illustrate the significance of glenoid destruction, 11 of 53 patients who underwent arthroscopic treatment for anterior instability had an inverted-pear glenoid with an average 36% loss of glenoid bone (Lo et al., 2004). Thus, one of every five patients with a diagnosis of anterior instability may have enough bone loss where an

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Figure 13.2  44-year-old male s/p acute fall with dislocation. 3D CT reconstruction (sagittal) demonstrating acute anteroinferior glenoid fracture (bony Bankart). Figure courtesy of Columbia University Center for Shoulder, Elbow and Sports Medicine.

alternative to soft-tissue stabilization should be considered. Itoi et al. stated that the critical size of an effect requiring a graft was 21% as determined by a cadaveric model, while Bigliani et al. recommended a coracoid transfer in any case with a defect greater that 25% of the anterior–posterior width to prevent instability (Bigliani et al., 1998; Saito et al., 2005; Itoi et al., 2000). On the other hand, Hill–Sachs lesions may occur in 25% of patients with anterior shoulder subluxation, in 65–71% of patients with a first anterior dislocation, and in 100% of patients with recurrent anterior instability (Anakwenze et al., 2011; Chen et al., 2005; Taylor and Arciero, 1997). Hill–Sachs lesions decrease the rotational arc length of the humeral head on the glenoid and may engage the anterior glenoid rim with the arm in abduction and external rotation (Burkhart and De Beer, 2000; Burkhart and Danaceau, 2000). Soft-tissue repairs are inadequate in restoring stability in the setting of significant osseous pathology. There should be a high index of suspicion for bony defects in any patient presenting with anterior shoulder instability in the context of a high-­ energy injury with subsequent dislocation or subluxations requiring minimal force (Piasecki et al., 2009). As in all cases of instability, orthogonal view radiographs are necessary; however, additional views are more accurate in diagnosing bony lesions. These include the Stryker notch and internal rotation anteroposterior view for Hill– Sachs lesions as well as the West Point and Bernageau glenoid profile views for glenoid deficiency (Mauro et al., 2011; Anakwenze et al., 2011; Rozing et al., 1986). While specialized radiographic views may be helpful in diagnosing bony lesions,

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CT ­imaging is the ­premier imaging modality to quantify glenoid bone loss and assess candidates for nonanatomical reconstructive repairs (Itoi et al., 2003; Piasecki et al., 2009; Provencher et al., 2010). For instance, a preoperative CT scan was able to accurately predict 96% of patients who qualified for a Latarjet procedure as determined by arthroscopic assessment of ≥25% of glenoid bone loss (Chuang et al., 2008). CT scans also provide the best quantification of bone loss in humeral head lesions, although the gold standard diagnostic test for an engaging Hill–Sachs lesion is dynamic arthroscopic visualization. A high percentage of patients with persistent instability after stabilization procedures has recognized bony defects postoperatively. For example, Burkhart et al. reported a 67% recurrence rate for 194 arthroscopic Bankart repairs in the presence of an ­inverted-pear glenoid compared to a 4% recurrence rate in patients without a glenoid defect (Burkhart and De Beer, 2000). In total, 45% of the patients who failed had ≥25% bone loss, and 100% of patients had Hill–Sachs lesions (Burkhart and De Beer, 2000). The same study further analyzed contact athletes in whom there was a recurrence rate of 6.5% in patients without bony defects compared to 89% for those patients with defects, suggesting that these patients were highly susceptible to persistent traumatic instability. In 2006, Boileau et al. prospectively reviewed the outcomes of 91 consecutive patients who underwent arthroscopic stabilization for recurrent anterior traumatic shoulder instability with suture anchors (Boileau et al., 2006). At a mean of 36 months, 15.3% of patients experienced persistent instability, and the authors found that the rate of recurrence was significantly increased in patients with the presence of a glenoid bone defect involving more than 25% of the glenoid as well as a large Hill–Sachs lesion. In 2010, Voss et al. found that the presence of a large Hill–Sachs lesion, defined as >250 mm, was a significant risk factor for instability (Voos et al., 2010), and Flinkkila et al. retrospectively found that a Hill–Sachs lesion had a statistically significant odds-ratio of 3.3 for persistent instability following surgical stabilization (Flinkkila et al., 2010). Ahmed et al. found that of the 40 patients who failed arthroscopic stabilization in a retrospective analysis of 302 patients treated with arthroscopic stabilization for anterior instability, 26 (65%) patients had an engaging Hill–Sachs lesion, and 18 (45%) of patients had ≥25% glenoid destruction (Ahmed et al., 2012). There was a 5.5% failure rate in patients with <25% glenoid bone loss, and no Hill–Sachs lesion compared to a 51.5% failure rate in patients with both lesions. Finally, several studies have noted that the most common reason for revision surgery is glenoid bone loss (Kirkley et al., 1999; Levine et al., 2000; Brophy and Marx, 2009; Youssef et al., 1995).

13.3 Revision treatment options and associated outcomes Treatment options for persistent instability following primary anterior shoulder stabilization begin with nonoperative management, including immobilization, a graduated physical therapy program focused on rotator cuff, deltoid and periscapular strengthening, and patient education to avoid at-risk shoulder positions (Shah et al.,

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2011). However, as is the case with primary instability, it is unlikely that any new poststabilization instability would cease without surgical intervention. As such, the literature provides a paucity of reports comparing outcomes of operative versus non operative management for failed instability stabilization cases, and the majority of research in this field is dedicated to investigating surgical management and outcomes. Furthermore, while nonoperative management alone would be appropriate for elderly or low-demand patients, the majority of reported cases of shoulder instability are in young, healthy athletic patients who wish to return to their preinjury level of activities, thus presenting a great challenge to the treating orthopedic surgeon. The principles of treatment for patients with recurrence after anterior stabilization are identical to primary stabilization in that treatment is carefully selected after considering the cause of failure, risk factors, and etiology. Capsular laxity and the degree of any bone loss, humeral and/or glenoid, play essential roles to determining the optimal treatment for patients with recurrent instability. In the absence of any bony pathology, a revision open or arthroscopic soft-tissue repair, usually involving a Bankart repair and capsular tightening, can be performed. If any uncertainty arises preoperatively as to the etiology of persistent instability, a diagnostic arthroscopy can be of value, even if an open procedure is planned (Shah et al., 2011). Shah et al. recommends performing a diagnostic arthroscopy prior to any open procedure as it allows better visualization of the posterior aspect of the shoulder and aids in identifying secondary intra-articular lesions more commonly associated with chronic shoulder instability, such as SLAP tears, loose bodies, rotator cuff tears, and chondromalacia (Shah et al., 2011). Unfortunately, despite the number of studies in recent years analyzing revision surgeries, very few have investigated homogenous patient populations in regard to the type of primary operation, etiology of persistent instability, and final treatment.

13.3.1 Soft-tissue revision repairs Open revisions for failed surgery have reported failure rates of 0–26% (Mauro et al., 2011; Cho et al., 2009; Rowe et al., 1984; Sisto, 2007; Zabinski et al., 1999). Zabinski et al. reported their results on open revision in 23 shoulders with persistent anterior shoulder instability after a primary open stabilization surgery with a failure in 4 (17%) patients—two due to repeat trauma and one due to >33% of glenoid deficiency (Zabinski et al., 1999). Revision surgery included an open Bankart repair in 19 patients, with a capsular shift in 15 for capsular redundancy and a capsular shift alone in four patients. Open revision Bankart repairs were analyzed in a study by Levine et al. in which a laterally based anterior–inferior capsular shift procedure was used in a heterogeneous population of 49 shoulders, with concurrent repair of a Bankart lesion in 23 shoulders (Levine et al., 2000). At an average follow-up of 4.7 years, 78% of the patients had satisfactory results with recurrent subluxation in two shoulders (4%) and recurrent dislocation in nine shoulders (18%). However, 7 of the 11 patients who failed revision were later found to be voluntary dislocators. Interestingly, Levine et al. found that 100% of patients who suffered a repeat traumatic event after their initial stabilization leading to instability had satisfactory outcomes with open revision shoulder stabilization compared to only 67% of the patients with atraumatic failure. Meehan et al. similarly performed an open

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Bankart, capsular shift, or both on 25 patients who had failed open or arthroscopic anterior stabilization with satisfactory results in 21 (84%) patients (Meehan and Petersen, 2005). These investigations demonstrated that open Bankart with anteroinferior capsular shift procedure was an effective treatment for the two most common soft-tissue pathologies encountered in persistent instability. Despite these results, not all reports on open Bankart repairs have been as encouraging. Marquardt et al. investigated a heterogeneous population of 16 primary open and arthroscopic persistent instability patients requiring revision (Marquardt et al., 2007). All 16 patients underwent an open Bankart repair with only four requiring a concomitant capsulorrhaphy for capsular redundancy. There was a 50% failure rate, with five of eight patients experiencing new trauma, two patients with >30% loss of glenoid bone stock, and three patients with redundant capsules. Two more recent investigations evaluated open Bankart repairs in homogenous populations of patients who had failed arthroscopic Bankart repair. Cho et al. evaluated the efficacy of open revision Bankart surgery for failed arthroscopic Bankart repair in 26 shoulders with mean age of 24 years old and average follow-up time of 42 months (Cho et al., 2009). Up to 88.5% of the patients had good or excellent Rowe score postoperatively despite a decrease in average external rotation from 65° to 55°. Redislocation occurred in three (11%) patients, all of whom had an engaging Hill–Sachs lesion and associated hyperlaxity (Cho et al., 2009). A few factors may have contributed to Cho et al.’s low recurrence rate. First, while eight (30.8%) patients had glenoid defects, only one was of sufficient size, 21–30%, to necessitate performing a bone block procedure and was treated appropriately. Second, the large majority of patients, 96.2%, experienced recurrent instability as a result of trauma, which Levine et al. previously showed was a predictive factor for successful revision treatment (Levine et al., 2000; Cho et al., 2009). As such, a careful diagnostic approach to identify a homogenous patient population without associated risk factors for failure contributed to their low recurrence. In a similar study, Sisto et al. also evaluated the efficacy of open Bankart revision repair for a homogenous population of arthroscopic Bankart repair failures in 30 patients with average age of 24 years and 46 months of follow-up (Sisto, 2007). The authors reported no recurrences, significantly improved Rowe and UCLA scores, and an 8° loss of external rotation. Arthroscopic revision surgery approaches have been gaining in popularity given advances in instrumentation and surgeon comfort tackling difficult pathologies (Cho et al., 2009). Minimally invasive techniques are desirable due to the ability to accurately identify pathology, preserve anatomy and subscapularis function, minimize iatrogenic damage, increase postoperative range of motion, provide better cosmesis, and decrease postoperative pain (Mauro et al., 2011; Abouali et al., 2013). Currently, there have been no randomized controlled trials comparing long-term outcomes of arthroscopic and open revision repairs; however, a number of studies provide encouraging results for arthroscopic repairs in patients without glenoid bone or humeral head defects (Creighton et al., 2007; Abouali et al., 2013). Furthermore, lesions that were once considered amenable to open surgery alone can now be treated efficiently and simply via arthroscopic techniques, such as capsular plication (Creighton et al., 2007; Shah et al., 2011; Patel et al., 2008; Boileau et al., 2009). The majority of studies investigating outcomes of arthroscopic revisions have been limited by heterogeneous groups of patients who have failed both open and ­arthroscopic

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primary surgeries, small patient populations, short follow-up time, and inclusion of patients with glenoid and humeral head defects. The first was published in 2002 by Kim et al. whose series of 23 patents demonstrated five (21.7%) failures (Kim et al., 2002). This was followed by a smaller study by Neri et al. who followed 11 patients for an average of 8 months after arthroscopic revision in which three (27%) patients experienced a subluxation or dislocation (Neri et al., 2007). Creighton et al. found more satisfactory outcomes in his evaluation of 18 patients with failed traumatic instability repair who were treated with arthroscopic labral fixation, capsular plication, and rotator interval closure when indicated (Creighton et al., 2007). With a mean follow-up time of 29.7 months, three (16.7%) patients experienced recurrent instability. Four (10.0%) of 40 patients were found to have persistent instability at an average 36 months in an investigation by Patel et al. among a patient population in which no clinically significant glenoid or humeral head bone lesions were identified (Patel et al., 2008). Further studies have continued to find recurrence rates equivalent to open revision surgery with instability rates of 11% in 56 patients (Bartl et al., 2011) and 0% in 20 patients (Krueger et al., 2011). Franceschi et al. evaluated the surgical outcomes of arthroscopic revision involving capsular plication, labral repair, and rotator interval closure when indicated in a homogenous population of failed arthroscopic Bankart repairs with an average ­follow-up of 68 months. All patients were found to have a postoperative range of motion equal to preoperative range of motion and only one (10.0%) of 10 patients experienced a recurrent dislocation. All remaining patients returned to their pre-injury level of sport. Abouali et al. reported a systematic review comprised of 16 studies to illustrate excellent outcomes for revision arthroscopic Bankart repairs (Abouali et al., 2013). The authors selected studies of patients failing both open and arthroscopic primary procedures but only included patients with minimal bone loss such that 1% of patients had glenoid bone loss, and none had an engaging Hill–Sachs lesion. Taken collectively, the rate of recurrent instability was 14.6% among 349 patients with an 85% return to sports rate over a mean 35.4 months. These results show that open surgery does not necessarily provide an advantage over arthroscopic treatment if the etiology of persistent instability is due to a soft-tissue lesion, such as a recurrent or inadequately addressed Bankart lesion and/or capsular laxity (Shah et al., 2011). Nevertheless, some authors still advocate for open treatment in a selected group of patients. In Mauro et al.’s algorithm for revision anterior stabilization, in the absence of significant bone loss, defined as <20%, open stabilization was advocated for patients under 20 years old, contact athletes, and the presence of poor tissue quality as determined by arthroscopy (Mauro et al., 2011). As can be seen, despite the advances made in arthroscopy, there remains controversy over the appropriate soft-tissue technique. Furthermore, it should be noted that among the arthroscopic studies with the highest success rates, there were strict exclusion criteria such as excluding patients with nonanatomic index procedures, with rotator cuff tears, MDI or voluntary instability, glenoid bone loss >20%, and any engaging Hill–Sachs lesions (Bartl et al., 2011). Arthroscopic procedures are typically recommended for repairs in the setting of bone loss involving less than 20% of the glenoid since open and arthroscopic revision repairs have equivocal outcomes. However, due to the technical demands of arthroscopic repairs, selection of approach should be made accordingly based on the surgeon’s experience.

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13.3.2 Bony deficiency repairs A clinician’s index of suspicion for glenoid or humeral head pathology should be high in the setting of persistent instability following prior stabilization. A number of authors have recently published algorithms to aid physicians to manage patients with anterior recurrent shoulder instability associated with bony defects (Anakwenze et al., 2011; Taylor and Arciero, 1997). It should be noted that although bony lesions may be more common in patients failing prior stabilization, the treatment approach is identical for primary cases. Minimally invasive arthroscopic techniques have a limited role in the treatment of significant glenoid defects, usually defined by >20%. In the presence of small glenoid defects, <15%, an isolated arthroscopic soft-tissue stabilization may be performed without addressing the bony defect (Anakwenze et al., 2011; Piasecki et al., 2009). Arthroscopic approaches to larger lesions, 15–30%, have also been investigated and involve arthroscopic stabilization with incorporation of the glenoid bone fragment (Anakwenze et al., 2011; Porcellini et al., 2002, 2007; Sugaya et al., 2005). For instance, Porcellini et al. found a 2.4% and 4.2% traumatic redislocation rate in 25 acute (<3 months) and subacute (>3 months), respectively, bony Bankart lesions of <25% treated with arthroscopic fragment mobilization and reduction with suture anchor fixation at the labral interface (Porcellini et al., 2002). Sugaya performed a similar series on 42 shoulders with an average glenoid loss of 24.5% treated arthroscopically with fragment reduction and suture anchor fixation with a 5% failure rate, both due to trauma during athletic activities, at a mean 34 months of follow-up (Sugaya et al., 2005). Interestingly, 12 patients received postoperative CT scans that showed 100% viability of the bone fragments, even those repaired 6 months after injury. According to Piasecki et al. there are anecdotal examples of arthroscopically treated glenoid rim fractures >25%, however, in most cases, these larger lesions lack an adequate fracture fragment for reconstruction (Burkhart and De Beer, 2000; Piasecki et al., 2009). Piasecki et al. advises against arthroscopic repair in most cases of glenoid bone loss of >25%, while others, such as Anakwenze et al., recommend open treatment for any glenoid defect >20%. In general, chronic bone loss greater than 20–30% requires reconstruction using a bone block procedure as a means of glenoid augmentation (Balg and Boileau, 2007; Burkhart and De Beer, 2000; Boileau et al., 2009; Auffarth et al., 2008; Burkhart et al., 2007; Tauber et al., 2004). Among the options available, the Latarjet procedure is among the most successful with recurrence rates as low as 4.9% in patients with extensive bone loss (Burkhart et al., 2007; see Figure 13.3). Various surgical techniques such as remplissage, disimpaction, bone grafting, humeral head allograft, humeral osteotomy, and prosthetic reconstruction may be employed to address humeral head bone loss (Burkhart and De Beer, 2000; Chen et al., 2005; Kaar et al., 2010; Sekiya et al., 2009). Multiple studies have tried to classify Hill–Sachs lesions based on the size and whether the lesion engages the glenoid to determine which are clinically significant and may lead to persistent instability. While it has not yet been fully elucidated which Hill–Sachs lesions must be treated, Chen et al. published an algorithm for humeral head defects suggesting that lesions less than 20% of humeral head could be treated with standard shoulder stabilization while

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Figure 13.3  Intraoperative photo demonstrating coracoid transfer (Latarjet procedure) affixed to the anteroinferior glenoid in a 23-year-old RHD male who had failed two prior soft-tissue instability repairs. Figure courtesy of Columbia University Center for Shoulder, Elbow and Sports Medicine.

d­ efects with 20–30% may require tendon transfer or disimpaction with bone graft (Chen et al., 2005). Arthroscopic remplissage is ideal for these patients with glenoid bone loss and a large Hill–Sachs lesion because the procedure entails arthroscopic capsulotenodesis of the posterior capsule and infraspinatus tendon to fill the Hill– Sachs lesions (Abouali et al., 2013; Purchase et al., 2008; see Figure 13.4). Hill–Sachs defects that are 30–45% should be repaired with bone graft or humeral osteotomy whereas ­prosthetic reconstruction should be employed for defects greater than 45% (Lopiz-Morales et al., 2013; Chen et al., 2005).

Figure 13.4  Arthroscopic view of a remplissage procedure in a 21-year-old male with a labral tear and medium Hill–Sachs deformity (arrow points to infraspinatus/capsule repaired into bony defect in posterolateral humeral head). Figure courtesy of Columbia University Center for Shoulder, Elbow and Sports Medicine.

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13.4 Risk factors for revision failures Unfortunately, the results of revision stabilization surgery, both open and arthroscopic, have been shown to be inferior to primary stabilization with highly variable failure rates that are directly proportional to the number of revisions performed (Lopiz-Morales et al., 2013; Meehan and Petersen, 2005; Marquardt et al., 2007). For instance, Levine et al. found that persistent instability after one attempted revision was 17% compared to 44% in shoulders with multiple prior surgeries (Levine et al., 2000). Several other risk factors have been identified that contribute to negative outcomes in revision shoulder stabilization. In a study by Meehan et al., factors that adversely affected the outcome after revision surgery were the presence of arthritis, age greater than 30 years, multiple prior instability surgeries, the presence of a bony Bankart lesion, the diagnosis of MDI, and surgery of the nondominant arm (Meehan and Petersen, 2005). Revision shoulder stabilization is unpredictable in patients with MDI and often suffers from repeat surgical failures, as was previously shown by Zabinski et al. in which only 39% of 20 patients with MDI had satisfactory outcomes after revision surgery (Zabinski et al., 1999). Additionally, patients with atraumatic causes of failure, as well as voluntary dislocators have a higher incidence of revision failure (Levine et al., 2000). Bartl et al. demonstrated a significant correlation between younger age and recurrent instability following revision arthroscopic Bankart repair, presumably due to higher activity level as 66.7% of the failures occurred traumatically (Bartl et al., 2011). The study found an 11% failure rate, with 100% of failures having poor capsulolabral quality and 83% of failures having a thinned or absent labrum. Only one of the failures was found to have a 20% glenoid defect. According to Abouali et al.’s systematic review, up to 88% of persistent instability cases were related to postoperative trauma (Table 13.2; Abouali et al., 2013). Table 13.2 

Risk factors for revision failures

Multiple prior surgeries Diagnostic error   Improper surgical selection   Failure to recognize bony defect   Failure to recognize posterior instability/multidirectional instability   Failure to recognize HAGL Technical errors   Lack of adequate tension of capsule   Nonanatomical repairs of the glenoid labrum   Incorrect anchor placement   Operator curve associated with arthroscopy techniques Presence of arthritis Age greater than 30 Presence of bony Bankart lesion Patients with MDI Surgery of nondominant arm Patients with atraumatic causes of failure Voluntary dislocators

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13.5 Future directions Over the last decade, numerous studies attempted to assess the efficacy of surgical revision and even attempted to formulate a treatment algorithm for surgical revision of recurrent anterior instability. However, with a limited follow-up period ranging from 16 to 68 months, the true efficacy of these revisions remains to be determined. Due to the large variety of surgical treatment techniques and heterogeneous populations of patients treated, the current literature lacks comprehensive comparative studies. Surgical revision of instability is extremely complex due to the difficulty in recognizing the problem as well as the high technical demand with increasing variety of surgical techniques (LopizMorales et al., 2013). However, with improving technology and newer arthroscopic soft-tissue techniques, such as remplissage procedure and closure of deficient rotator cuff interval, results of instability revision may continue to improve (Ahmed et al., 2012; Purchase et al., 2008). Furthermore, increased emphasis of modern repairs to restore the true anatomic structures, such as the footprint of the anterior capsulolabral complex with double row technique, may also affect the long-term efficacy of surgical revision for recurrent anterior instability (Ahmad et al., 2009; Lafosse et al., 2006). The combination of improving surgical techniques and skill in conjunction with more effective long-term studies will likely overcome the challenges of establishing an effective algorithm for the treatment of recurrent shoulder instability in the future.

References Abouali, J.A., et al., 2013. Revision arthroscopic Bankart repair. Arthroscopy 29 (9), 1572–1578. Ahmad, C.S., et al., 2009. Evaluation of glenoid capsulolabral complex insertional anatomy and restoration with single- and double-row capsulolabral repairs. J. Shoulder Elbow Surg. 18 (6), 948–954. Ahmed, I., Ashton, F., Robinson, C.M., 2012. Arthroscopic Bankart repair and capsular shift for recurrent anterior shoulder instability: functional outcomes and identification of risk factors for recurrence. J. Bone Joint Surg. Am. 94 (14), 1308–1315. Anakwenze, O.A., et al., 2011. Recurrent anterior shoulder instability associated with bony defects. Orthopedics 34 (7), 538–544, quiz 545–546. Arciero, R.A., et al., 1994. Arthroscopic Bankart repair versus nonoperative treatment for acute, initial anterior shoulder dislocations. Am. J. Sports Med. 22 (5), 589–594. Auffarth, A., et al., 2008. The J-bone graft for anatomical glenoid reconstruction in recurrent posttraumatic anterior shoulder dislocation. Am. J. Sports Med. 36 (4), 638–647. Bacilla, P., Field, L.D., Savoie 3rd, F.H., 1997. Arthroscopic Bankart repair in a high demand patient population. Arthroscopy 13 (1), 51–60. Balg, F., Boileau, P., 2007. The instability severity index score. A simple pre-operative score to select patients for arthroscopic or open shoulder stabilisation. J. Bone Joint Surg. (Br.) 89 (11), 1470–1477. Bankart, A.S., 1923. Recurrent or habitual dislocation of the shoulder-joint. Br. Med. J. 2 (3285), 1132–1133. Bankart, A.S.B., 1938. The pathology and treatment of recurrent dislocation of the shoulder joint. Br. J. Surg. 26, 23–29.

Persistent anterior shoulder instability

287

Bartl, C., et al., 2011. Arthroscopic capsulolabral revision repair for recurrent anterior shoulder instability. Am. J. Sports Med. 39 (3), 511–518. Bigliani, L.U., et al., 1998. Glenoid rim lesions associated with recurrent anterior dislocation of the shoulder. Am. J. Sports Med. 26 (1), 41–45. Boileau, P., et al., 2006. Risk factors for recurrence of shoulder instability after arthroscopic Bankart repair. J. Bone Joint Surg. Am. 88 (8), 1755–1763. Boileau, P., et al., 2009. The role of arthroscopy in revision of failed open anterior stabilization of the shoulder. Arthroscopy 25 (10), 1075–1084. Bottoni, C.R., et al., 2002. A prospective, randomized evaluation of arthroscopic stabilization versus nonoperative treatment in patients with acute, traumatic, first-time shoulder dislocations. Am. J. Sports Med. 30 (4), 576–580. Bottoni, C.R., et al., 2006. Arthroscopic versus open shoulder stabilization for recurrent anterior instability: a prospective randomized clinical trial. Am. J. Sports Med. 34 (11), 1730–1737. Brophy, R.H., Marx, R.G., 2009. The treatment of traumatic anterior instability of the shoulder: nonoperative and surgical treatment. Arthroscopy 25 (3), 298–304. Burkhart, S.S., Danaceau, S.M., 2000. Articular arc length mismatch as a cause of failed Bankart repair. Arthroscopy 16 (7), 740–744. Burkhart, S.S., De Beer, J.F., 2000. Traumatic glenohumeral bone defects and their relationship to failure of arthroscopic Bankart repairs: significance of the inverted-pear glenoid and the humeral engaging Hill–Sachs lesion. Arthroscopy 16 (7), 677–694. Burkhart, S.S., et al., 2007. Results of modified Latarjet reconstruction in patients with anteroinferior instability and significant bone loss. Arthroscopy 23 (10), 1033–1041. Chen, A.L., et al., 2005. Management of bone loss associated with recurrent anterior glenohumeral instability. Am. J. Sports Med. 33 (6), 912–925. Cho, N.S., et al., 2009. Revision open Bankart surgery after arthroscopic repair for traumatic anterior shoulder instability. Am. J. Sports Med. 37 (11), 2158–2164. Chuang, T.Y., Adams, C.R., Burkhart, S.S., 2008. Use of preoperative three-dimensional computed tomography to quantify glenoid bone loss in shoulder instability. Arthroscopy 24 (4), 376–382. Cole, B.J., Warner, J.J., 2000. Arthroscopic versus open Bankart repair for traumatic anterior shoulder instability. Clin. Sports Med. 19 (1), 19–48. Creighton, R.A., et al., 2007. Revision arthroscopic shoulder instability repair. Arthroscopy 23 (7), 703–709. Fabbriciani, C., et al., 2004. Arthroscopic versus open treatment of Bankart lesion of the shoulder: a prospective randomized study. Arthroscopy 20 (5), 456–462. Flinkkila, T., et al., 2010. Arthroscopic Bankart repair: results and risk factors of recurrence of instability. Knee Surg. Sports Traumatol. Arthrosc. 18 (12), 1752–1758. Freedman, K.B., et al., 2004. Open Bankart repair versus arthroscopic repair with transglenoid sutures or bioabsorbable tacks for Recurrent Anterior instability of the shoulder: a ­meta-analysis. Am. J. Sports Med. 32 (6), 1520–1527. Fritsch, B.A., Arciero, R.A., Taylor, D.C., 2010. Glenoid rim fracture after anchor repair: a report of 4 cases. Am. J. Sports Med. 38 (8), 1682–1686. Gill, T.J., Zarins, B., 2006. Complications of surgery for anterior shoulder instability. In: Gill, T.J., Hawkins, R.J. (Eds.), Complications of Shoulder Surgery, Treatment and Prevention. Lippincott Williams & Wilkins, Philadelphia, pp. 3–14. Grana, W.A., Buckley, P.D., Yates, C.K., 1993. Arthroscopic Bankart suture repair. Am. J. Sports Med. 21 (3), 348–353. Grumet, R.C., Bach Jr., B.R., Provencher, M.T., 2010. Arthroscopic stabilization for first-time versus recurrent shoulder instability. Arthroscopy 26 (2), 239–248.

288

Shoulder and Elbow Trauma and its Complications

Guanche, C.A., et al., 1996. Arthroscopic versus open reconstruction of the shoulder in patients with isolated Bankart lesions. Am. J. Sports Med. 24 (2), 144–148. Handoll, H.H., Almaiyah, M.A., Rangan, A., 2004. Surgical versus non-surgical treatment for acute anterior shoulder dislocation. Cochrane Database Syst. Rev. (1), CD004325. Hobby, J., et al., 2007. Is arthroscopic surgery for stabilisation of chronic shoulder instability as effective as open surgery? A systematic review and meta-analysis of 62 studies including 3044 arthroscopic operations. J. Bone Joint Surg. (Br.) 89 (9), 1188–1196. Ide, J., Maeda, S., Takagi, K., 2004. Arthroscopic Bankart repair using suture anchors in athletes: patient selection and postoperative sports activity. Am. J. Sports Med. 32 (8), 1899–1905. Imhoff, A.B., et al., 2010. Arthroscopic repair of anterior–inferior glenohumeral instability using a portal at the 5:30-o'clock position: analysis of the effects of age, fixation method, and concomitant shoulder injury on surgical outcomes. Am. J. Sports Med. 38 (9), 1795–1803. Itoi, E., et al., 2000. The effect of a glenoid defect on anteroinferior stability of the shoulder after Bankart repair: a cadaveric study. J. Bone Joint Surg. Am. 82 (1), 35–46. Itoi, E., et al., 2003. Quantitative assessment of classic anteroinferior bony Bankart lesions by radiography and computed tomography. Am. J. Sports Med. 31 (1), 112–118. Jorgensen, U., et al., 1999. Recurrent post-traumatic anterior shoulder dislocation—open versus arthroscopic repair. Knee Surg. Sports Traumatol. Arthrosc. 7 (2), 118–124. Kaar, S.G., et al., 2010. Effect of humeral head defect size on glenohumeral stability: a cadaveric study of simulated Hill–Sachs defects. Am. J. Sports Med. 38 (3), 594–599. Karlsson, J., et al., 2001. Comparison of open and arthroscopic stabilization for recurrent shoulder dislocation in patients with a Bankart lesion. Am. J. Sports Med. 29 (5), 538–542. Kim, S.H., Ha, K.I., Kim, Y.M., 2002. Arthroscopic revision Bankart repair: a prospective outcome study. Arthroscopy 18 (5), 469–482. Kim, S.H., et al., 2003. Arthroscopic anterior stabilization of the shoulder: two to six-year ­follow-up. J. Bone Joint Surg. Am. 85-A (8), 1511–1518. Kim, J.M., et al., 2008. Arthroscopic stabilization for traumatic anterior dislocation of the shoulder: suture anchor fixation versus transglenoid technique. J. Orthop. Sci. 13 (4), 318–323. Kirkley, A., et al., 1999. Prospective randomized clinical trial comparing the effectiveness of immediate arthroscopic stabilization versus immobilization and rehabilitation in first traumatic anterior dislocations of the shoulder. Arthroscopy 15 (5), 507–514. Kirkley, A., et al., 2005. Prospective randomized clinical trial comparing the effectiveness of immediate arthroscopic stabilization versus immobilization and rehabilitation in first traumatic anterior dislocations of the shoulder: long-term evaluation. Arthroscopy 21 (1), 55–63. Koss, S., Richmond, J.C., Woodward Jr., J.S., 1997. Two- to five-year followup of arthroscopic Bankart reconstruction using a suture anchor technique. Am. J. Sports Med. 25 (6), 809–812. Krueger, D., et al., 2011. Subjective and objective outcome after revision arthroscopic stabilization for recurrent anterior instability versus initial shoulder stabilization. Am. J. Sports Med. 39 (1), 71–77. Lafosse, L., Baier, G.P., Jost, B., 2006. Footprint fixation for arthroscopic reconstruction in anterior shoulder instability: the Cassiopeia double-row technique. Arthroscopy 22 (2), 231 e1–231 e6. Lenters, T.R., et al., 2007. Arthroscopic compared with open repairs for recurrent anterior shoulder instability. A systematic review and meta-analysis of the literature. J. Bone Joint Surg. Am. 89 (2), 244–254. Levine, W.N., et al., 2000. Open revision stabilization surgery for recurrent anterior glenohumeral instability. Am. J. Sports Med. 28 (2), 156–160.

Persistent anterior shoulder instability

289

Lo, I.K., Parten, P.M., Burkhart, S.S., 2004. The inverted pear glenoid: an indicator of significant glenoid bone loss. Arthroscopy 20 (2), 169–174. Lopiz-Morales, Y., et al., 2013. Results of revision after failed surgical treatment for traumatic anterior shoulder instability. Rev. Esp. Cir. Ortop. Traumatol. 57 (3), 208–216. Marquardt, B., et al., 2007. Outcome after failed traumatic anterior shoulder instability repair with and without surgical revision. J. Shoulder Elbow Surg. 16 (6), 742–747. Mauro, C.S., et al., 2011. Failed anterior shoulder stabilization. J. Shoulder Elbow Surg. 20 (8), 1340–1350. Mazzocca, A.D., et al., 2005. Arthroscopic anterior shoulder stabilization of collision and contact athletes. Am. J. Sports Med. 33 (1), 52–60. Meehan, R.E., Petersen, S.A., 2005. Results and factors affecting outcome of revision surgery for shoulder instability. J. Shoulder Elbow Surg. 14 (1), 31–37. Neri, B.R., et al., 2007. Arthroscopic revision of Bankart repair. J. Shoulder Elbow Surg. 16 (4), 419–424. Norris, T.R., 1993. Complications following anterior instability repairs. In: Bigliani, L.U. (Ed.), Complications of Shoulder Surgery. Williams & Wilkins, Baltimore, pp. 98–116. Norris, T.R., Bigliani, L., 1984. Analysis of failed repair for shoulder instability: a preliminary report. In: Bateman, J.E., Welsh, R.P. (Eds.), Surgery of the Shoulder. BC Decker, Philadelphia, pp. 111–116. Patel, R.V., et al., 2008. Revision arthroscopic capsulolabral reconstruction for recurrent instability of the shoulder. J. Bone Joint Surg. (Br.) 90 (11), 1462–1467. Piasecki, D.P., et al., 2009. Glenoid bone deficiency in recurrent anterior shoulder instability: diagnosis and management. J. Am. Acad. Orthop. Surg. 17 (8), 482–493. Porcellini, G., Campi, F., Paladini, P., 2002. Arthroscopic approach to acute bony Bankart ­lesion. Arthroscopy 18 (7), 764–769. Porcellini, G., et al., 2007. Long-term outcome of acute versus chronic bony Bankart lesions managed arthroscopically. Am. J. Sports Med. 35 (12), 2067–2072. Porcellini, G., et al., 2009. Predisposing factors for recurrent shoulder dislocation after arthroscopic treatment. J. Bone Joint Surg. Am. 91 (11), 2537–2542. Provencher, M.T., et al., 2010. Recurrent shoulder instability: current concepts for evaluation and management of glenoid bone loss. J. Bone Joint Surg. Am. 92 (Suppl. 2), 133–151. Purchase, R.J., et al., 2008. Hill–Sachs “remplissage”: an arthroscopic solution for the engaging Hill–Sachs lesion. Arthroscopy 24 (6), 723–726. Rahme, H., et al., 2003. Long-term clinical and radiologic results after Eden–Hybbinette operation for anterior instability of the shoulder. J. Shoulder Elbow Surg. 12 (1), 15–19. Rhee, Y.G., Ha, J.H., Cho, N.S., 2006. Anterior shoulder stabilization in collision athletes: ­arthroscopic versus open Bankart repair. Am. J. Sports Med. 34 (6), 979–985. Robinson, C.M., et al., 2006. Functional outcome and risk of recurrent instability after primary traumatic anterior shoulder dislocation in young patients. J. Bone Joint Surg. Am. 88 (11), 2326–2336. Rowe, C.R., Zarins, B., Ciullo, J.V., 1984. Recurrent anterior dislocation of the shoulder after surgical repair. Apparent causes of failure and treatment. J. Bone Joint Surg. Am. 66 (2), 159–168. Rozing, P.M., de Bakker, H.M., Obermann, W.R., 1986. Radiographic views in recurrent anterior shoulder dislocation. Comparison of six methods for identification of typical lesions. Acta Orthop. Scand. 57 (4), 328–330. Saito, H., et al., 2005. Location of the glenoid defect in shoulders with recurrent anterior dislocation. Am. J. Sports Med. 33 (6), 889–893.

290

Shoulder and Elbow Trauma and its Complications

Savoie 3rd., F.H., Miller, C.D., Field, L.D., 1997. Arthroscopic reconstruction of traumatic anterior instability of the shoulder: the Caspari technique. Arthroscopy 13 (2), 201–209. Schroder, D.T., et al., 2006. The modified Bristow procedure for anterior shoulder instability: 26-year outcomes in Naval Academy midshipmen. Am. J. Sports Med. 34 (5), 778–786. Sekiya, J.K., et al., 2009. Hill–Sachs defects and repair using osteoarticular allograft transplantation: biomechanical analysis using a joint compression model. Am. J. Sports Med. 37 (12), 2459–2466. Shah, A.S., Karadsheh, M.S., Sekiya, J.K., 2011. Failure of operative treatment for glenohumeral instability: etiology and management. Arthroscopy 27 (5), 681–694. Sisto, D.J., 2007. Revision of failed arthroscopic Bankart repairs. Am. J. Sports Med. 35 (4), 537–541. Sperber, A., et al., 2001. Comparison of an arthroscopic and an open procedure for posttraumatic instability of the shoulder: a prospective, randomized multicenter study. J. Shoulder Elbow Surg. 10 (2), 105–108. Sugaya, H., et al., 2003. Glenoid rim morphology in recurrent anterior glenohumeral instability. J. Bone Joint Surg. Am. 85-A (5), 878–884. Sugaya, H., et al., 2005. Arthroscopic osseous Bankart repair for chronic recurrent traumatic anterior glenohumeral instability. J. Bone Joint Surg. Am. 87 (8), 1752–1760. Tauber, M., et al., 2004. Reasons for failure after surgical repair of anterior shoulder instability. J. Shoulder Elbow Surg. 13 (3), 279–285. Taylor, D.C., Arciero, R.A., 1997. Pathologic changes associated with shoulder dislocations. Arthroscopic and physical examination findings in first-time, traumatic anterior dislocations. Am. J. Sports Med. 25 (3), 306–311. Voos, J.E., et al., 2010. Prospective evaluation of arthroscopic Bankart repairs for anterior instability. Am. J. Sports Med. 38 (2), 302–307. Youssef, J.A., et al., 1995. Arthroscopic Bankart suture repair for recurrent traumatic unidirectional anterior shoulder dislocations. Arthroscopy 11 (5), 561–563. Zabinski, S.J., et al., 1999. Revision shoulder stabilization: 2- to 10-year results. J. Shoulder Elbow Surg. 8 (1), 58–65. Zarins, B., McMahon, M.S., Rowe, C.R., 1993. Diagnosis and treatment of traumatic anterior instability of the shoulder. Clin. Orthop. Relat. Res. 291, 75–84.