Anterior instability: Arthroscopic surgery and outcomes





Introduction


The management of anterior shoulder instability includes a menu of operations that have been used to treat patients with this problem. These procedures include arthroscopic stabilization, open stabilization, and bone augmentation procedures. Chapter 30 reviewed the epidemiology, history, clinical and imaging findings, and the nonoperative treatment of anterior instability. This chapter focuses on the indications and techniques for arthroscopic treatment, while subsequent chapters in this section cover the open and bone augmentation procedures used to manage anterior instability.


Arthroscopic treatment of shoulder instability has continued to gain wide acceptance as advanced techniques have improved clinical outcomes. The early literature regarding arthroscopic techniques demonstrated distinct advantages in the treatment of glenohumeral instability; these include improved visualization and examination of pathoanatomy, , confirmation of preoperative imaging findings, and minimally invasive treatment to avoid significant compromise of the subscapularis. Although open stabilization continues to have a role in the surgical management of glenohumeral instability (particularly in the presence of bone loss, poor quality tissue, hypermobility, or in the revision setting), advanced arthroscopic techniques continue to offer expanded indications for arthroscopic stabilization.


Arthroscopic stabilization provides maximal surgical visualization achieved with minimal surgical dissection and is associated with significant reduction in operative time, length of hospitalization, and perioperative complications. In recent years, shoulder surgeons have reported results that are comparable with those of traditional open techniques in patients with traumatic anterior glenohumeral instability.


This chapter reviews the indications for arthroscopic management of unidirectional anterior shoulder instability within the menu of operations noted earlier. The indications, techniques, and outcomes are emphasized, particularly focusing upon recurrence, revision, and return-to-sport (RTS) rates. Recent evidence pertaining to the arthroscopic treatment of first-time anterior shoulder dislocation in high-risk athletes is presented, including a review of the American Shoulder and Elbow Surgeons (ASES) Neer Circle Consensus Statements on this topic. The chapter concludes with our preferred techniques for arthroscopic stabilization of anterior instability.


Historical background


Historically, surgical treatment of shoulder instability focused on extra-articular nonanatomic procedures to address anterior instability rather than restoring the intra-articular capsulolabral avulsion. This was frequently achieved through procedures that limited external rotation (Putti-Platt, Magnusson-Stack) or provided a bony block to anterior instability (Bristow, Latarjet). , Although often effective in preventing further dislocations, these procedures may limit shoulder mobility, especially in external rotation, which is relevant for the overhead athlete, and may in turn result in what has been termed capsulorraphy arthropathy, dislocation arthropathy, or arthritis of dislocation. Rowe refocused attention on what he termed the “essential lesion,” the capsulolabral avulsion or Bankart tear. Although bone augmentation procedures such as the Bristow and Latarjet and open soft tissue stabilization have continued to play a significant role in anterior shoulder stabilization, the anatomy altering soft tissue procedures such as the Putti-Platt and Magnusen-Stack are, for the most part, of historical interest only.


Although open anterior stabilization has yielded excellent outcomes in patients with and without bone loss and in patients with traumatic anterior instability and in American football players, , the trend in recent years among many shoulder specialists has been to repair uncomplicated Bankart lesions arthroscopically, and arthroscopic stabilization is the most commonly used stabilization technique in the United States. Studies that have evaluated the early outcomes of arthroscopic stabilization have largely involved use of first-generation techniques and implants, which do not perform as well as current instrumentation. These studies are further perpetuated in the orthopedic literature through meta-analyses that combine results from heterogeneous cohorts, , thus leading to open repair being described as the gold standard for shoulder stabilization. This should be interpreted with caution because there is significant noncomparability between first-generation arthroscopic techniques and those performed nowadays.


More recent studies have shown that outcomes of arthroscopic stabilization using modern techniques and fixation methods for recurrent traumatic anterior shoulder instability are comparable with those of open stabilization and involve minimal bone loss. , , , This has resulted in a relative increase in the use of arthroscopic stabilization techniques and a decline in open stabilization techniques on the whole. , Although there is a paucity of adequately powered randomized controlled trials comparing current arthroscopic stabilization techniques versus open stabilization, a large study of a cohort of 3854 active duty military personnel who underwent Bankart repair revealed a 4.5% rate of recurrence after arthroscopic stabilization compared with a 7.7% recurrence rate associated with open stabilization. Yet, there remains controversy in the literature as noted by a randomized controlled trial demonstrating a higher failure rate in the arthroscopic stabilization group (23% vs. 11% in the open stabilization group).


Arthroscopy has provided improved visualization and understanding of the pathoanatomy of shoulder instability and has enabled surgeons to focus on arthroscopic or open restoration of anatomy, reserving open stabilization and bone augmentation procedures for the appropriate indications. The orthopedic surgeon who provides treatment for patients and athletes with anterior shoulder instability must be facile with all components within the menu of operations (arthroscopic, open, and bone augmentation procedures) available to manage them.


Indications


Although history and physical examination are covered in Chapter 30 , it is important to revisit this topic here as it pertains to anterior shoulder instability and arthroscopic stabilization. Failure of an arthroscopic stabilization procedure often starts not in the operating room but with the failure to identify red flags in the patient’s history and physical examination that might preclude a successful arthroscopic repair. The risk factors associated with arthroscopic stabilization failure (recurrent instability or functional deficits) include age, sex, anterior apprehension below the level of the shoulder, the presence of a bony Bankart lesion, bone loss that includes anterior glenoid attritional deficiency, the presence of a medially located Hill-Sachs lesion, bipolar bone loss, the participation in competitive collision or forced overhead sports, hypermobility, and a significant interval between dislocation and reduction. Regarding the Hill-Sachs lesion, it is not necessarily the depth of the Hill-Sachs lesion, but rather the location. Lesions located closer to the footprint of the rotator cuff (lateral) are less worrisome than lesions located further away from the footprint (medially) because they have a greater Hill-Sachs interval. This concept is discussed further in Chapter 33 .


The Instability Severity Index (ISI) score originally described by Balg and Boileau is a 10-point scale that identified six risk factors. Age younger than 20 years is worth 2 points, participation in competitive or contact sports accounts for 2 points, forced overhead sports is credited with 1 point, shoulder hyperlaxity is worth 1 point, and glenoid and/or humeral head bone loss accounts for 2 points each. In the original paper, patients scoring more than 6 points had an unacceptable risk of recurrence greater than 70% with an arthroscopic Bankart repair. The authors concluded that an arthroscopic anterior stabilization is contraindicated in this population and that the Bristow-Latarjet procedure is preferred. Loppini et al. subsequently validated the ISI score, and they and other authors have recommended that patients with an ISI score greater than 3 should be managed with a Bristow-Latarjet procedure because of unacceptably high failure rates following arthroscopic stabilization in their experience. ,


The majority of high school and college athletes younger than 21 years who present after their first dislocation will have an ISI score of 5 based only on age, sport, and level of competition. Predicated upon the recommendations from these published papers from Europe, , , all of the competitive athletes in this high school and college cohort would be indicated for a bone augmentation procedure. The North American approach generally does not favor bone augmentation procedures for all athletes in this population. We favor a thoughtful selection, from the menu of options available, based upon objective data. Chan et al. reported a series of 42 higher-demand military personnel and concluded that the composite ISI score and its individual risk factors were not predictive of subsequent surgical failure after primary arthroscopic Bankart repair in this cohort of patients.


The ISI score does not directly assign points for the number of preoperative instability episodes, yet this may be the most important risk factor associated with recurrent anterior instability following arthroscopic stabilization. We believe the number of preoperative instability episodes is causally associated with further soft tissue damage, sequentially increasing bone loss and the attendant higher recurrence rate following arthroscopic stabilization. The number of preoperative instability episodes is generally readily apparent from the athlete’s history.


We believe the most important risk factor for recurrent instability after arthroscopic stabilization is the number of preoperative instability episodes, particularly in young athletes. , , A brief summary of our approach in diagnosing shoulder instability is presented in Box 31.1 .



BOX 31.1

History and Physical Examination for Shoulder Instability


History taking





  • Age



  • Handedness



  • Sport or recreational activity



  • Unilateral or bilateral complaint



  • Family history of shoulder dislocation



  • Initial traumatic event



  • Position of arm during subluxation or dislocation



  • Number of previous episodes of dislocations or subluxations



  • Was this dislocation reduced in the emergency department?



  • Interval of time between dislocation and reduction



  • Degree of trauma required for recurrence



  • Voluntary dislocation



  • Dislocation during sleep



  • Presence of and location of pain



  • Presence or absence of mechanical symptoms



  • Sensory disturbance or motor weakness



  • Previous shoulder surgery



Physical examination





  • Inspection



  • Constitutional ligamentous laxity (e.g., Marshall test, Beighton score)



  • Neck range of motion and Spurling maneuver



  • Shoulder range of motion and scapular symmetry



  • Strength testing of shoulder girdle muscles



  • Lift-off and belly press tests



  • Sulcus sign



  • Anterior apprehension test and position of arm (include evaluation for midrange instability)



  • Relocation test



  • Load and shift (anterior and posterior)



  • Jerk test



  • O’Brien’s active compression test



  • Hawkin’s and Neer’s impingement tests



  • Cross-body adduction




A thorough history and physical examination should allow the examiner to understand the etiology, direction, degree, and frequency of a patient’s shoulder instability. Radiographs and magnetic resonance imaging (MRI) are used as adjuncts to diagnosis, to determine whether a patient is a candidate for arthroscopic stabilization, and for preoperative planning. MRI has proven to be useful in identifying capsulolabral avulsions, anterior labroligamentous periosteal sleeve avulsion (ALPSA) lesions, humeral avulsion of the glenohumeral ligament (HAGL) lesions, and rotator cuff pathology. , The latter is more common in patients older than 40 years with glenohumeral dislocations and at times may coexist with capsulolabral lesions. Unless such lesions are actively sought, correctly identified, and appropriately addressed, the treatment may likely fail. Although plain radiography is able to assess significant bone loss of the glenoid and humerus, advanced imaging modalities such as standard and three-dimensional (3D) computed tomography (CT) or recent advances with 3D MRI allow for a more precise quantification of bone loss in patients with anterior instability. , We advocate advanced imaging (generally 3D CT) in high-risk young athletes with a history of more than two or three instability events and in patients with evidence of a medial Hill-Sachs or anteroinferior glenoid bone loss on radiographs and in the revision setting. Using CT, the best views to evaluate the glenoid are sagittal cuts and 3D reconstructions with an en face glenoid view and the humerus subtracted. The inferior two-thirds of the glenoid forms a circle; any bone loss is likely to result in circumferential asymmetry. A 1.5-mm osseous lesion corresponds to 5% glenoid bone loss. Glenoid bone loss greater than 18% to 25% of the glenoid surface area has been shown to increase the risk of failure of nonoperative and operative management that does not address the bone loss. , , Recent analysis of the combined effects of glenoid and humeral head bone loss in the so-called bipolar lesions suggests 18% glenoid bone loss may be too large to serve as the threshold for concern in these cases. This threshold may be even lower as reported in a series of high-demand military personnel following arthroscopic Bankart repair who had unacceptably low Western Ontario Shoulder Instability scores, when the anteroinferior glenoid bone loss was greater than 13.5%. Dickens et al. reported that the amount of glenoid bone loss in patients after a first-time instability event averaged 6.8%, several athletes had greater than 13.5%, and none had greater than 20% bone loss after a first-time instability event. They also reported the mean total calculated bone loss in patients with recurrent instability was 22.8%, which had progressed from a baseline of 10.8%. This demonstrates that even after the first dislocation, there are some patients with significant (>13.5%) bone loss. Nevertheless, the critical limits of glenoid and humeral head bone loss are yet to be reproducibly defined. , The ASES Neer Circle defined glenoid side meaningful bone loss to be greater than 13.5% based upon this and other recently published data.


Traumatic anterior instability can occasionally result in avulsion of the glenohumeral ligament complex at the humeral insertion. This pathology was first described by Nicola but was first reported arthroscopically by Bach et al. in 1988. Like Bankart lesions at the glenoid, the HAGL lesion may involve soft tissue or bony avulsion. In a published series, the incidence of HAGL lesions was between 7.5% and 9.3% ; the lesion occurs in the setting of high-velocity sports injury or violent traumatic injury and generally in an older patient population. It is important for the surgeon to identify this lesion on MRI or during diagnostic arthroscopy for shoulder instability, because these lesions may occur in conjunction with Bankart lesions, a condition termed a bipolar or floating anterior-inferior glenohumeral ligament (IGHL). If a floating capsule is addressed only on the glenoid side, the Bankart repair will fail because the procedure will advance but not repair the capsule. In the case of a bipolar or floating IGHL, the Bankart or capsulolabral avulsion may be repaired arthroscopically and the HAGL may be repaired through an arthrotomy with a subscapularis split.


The HAGL lesion has received more attention in recent years because the advent of arthroscopy has allowed direct visualization of lesions that may otherwise have been overlooked during open stabilization procedures. In their retrospective review of 547 shoulders treated for instability, Bokor et al. reported a 39% incidence of HAGL as the cause of anterior instability in the subset of patients who had a posttraumatic primary dislocation without a discrete Bankart lesion and a purely unidirectional instability. In addition, HAGL has been reported as a cause of recurrent instability after arthroscopic Bankart repair. Although repair of HAGL lesions arthroscopically has been reported by several authors, , there are no large case series to suggest that the arthroscopic repair of HAGL is routinely reliable, unlike the reverse HAGL, due in part to the angle of approach required to place suture anchors. Therefore many surgeons continue to treat HAGL lesions via an open approach.


The indications for arthroscopic anterior stabilization have evolved during the past 20 years. Initial enthusiasm for the procedure has been tempered, in particular, by the increased failure rates in young male athletes. , , , ,


Advanced arthroscopic techniques have improved the ability to address more significant pathology in association with arthroscopic anterior stabilization, thereby increasing the indications. , Posteroinferior labral pathology consistent with Warren’s “full-circle” concept can be managed effectively and has become an important associated treatment modality during arthroscopic anterior stabilization. , , Double-row labral repair is useful in high-risk athletes to provide a more extensive surface area for healing. , Osseous Bankart lesions can be effectively managed using arthroscopic techniques as well. , , Some investigators have used remplissage as an advanced technique to expand the indications for arthroscopic anterior stabilization in select patients. , , The senior author (F.A.C.) rarely indicates the use of remplissage in young athletes and overhead athletes and prefers to treat posterior humeral bone loss from an anterior approach with either open stabilization or with bone augmentation procedures. In the event of large humeral head defects, humeral head osteochondral allograft or arthroplasty procedures are sometimes indicated. This discussion is beyond the scope of this chapter and will be further elucidated in Chapter 33 .


At this time, it is clear that the use of arthroscopic anterior stabilization can yield low recurrence rates and high RTS rates when patients are appropriately selected by excluding those with greater numbers of preoperative instability episodes and meaningful bone loss. , We reserve open stabilization for individuals with greater numbers of preoperative instability episodes, bone loss that is present but does not reach the meaningful level, athletes who are otherwise at high risk given their sport or position within a sport, and in the revision setting. We perform bone augmentation procedures for patients with meaningful bone loss, off-track and engaging lesions, and significant bipolar bone deficiencies.


Arthroscopic techniques


All anterior stabilization techniques should begin with an examination under anesthesia (EUA). EUA is critical to the success of arthroscopic stabilization and is more sensitive for determining both the degree and direction of instability in the anesthetized patient. Warren described the axial load test or load-and-shift test. This is performed and the translation noted in the anterior, inferior, and posterior directions. Grading reflects the degree of humeral head translation anterior and posterior to the glenoid rim. Grade 1+ corresponds to the translation of the humeral head to the edge of the glenoid, 2+ if the humeral head can be subluxated over the glenoid rim but reduces spontaneously, and 3+ if a frank dislocation of the humeral head over the glenoid rim does not reduce spontaneously. We use combined general and regional anesthesia that facilitates the performance of a contralateral EUA, which is important to provide patient-specific data (assuming the contralateral side has not been injured or treated surgically in the past).


After EUA, diagnostic arthroscopy is performed. Arthroscopic anterior shoulder stabilization can be successfully performed in either the beach chair or lateral decubitus position but varies primarily depending on surgeon preference, as either position confers specific advantages and disadvantages ( Table 31.1 ). Advantages of the beach chair position include unimpeded mobility of the operative arm during arthroscopy, and easy conversion to an open stabilization procedure if necessary. Advantages of the lateral decubitus position include unimpeded use of the posterior and superior portals, purported easier access to the inferior aspect of the glenoid for suture anchor placement due to arm positioning and traction, and lower risk of impaired visualization due to arthroscopic bubbles. This issue is discussed later in the chapter.



TABLE 31.1

Advantages and Disadvantages of the Beach Chair and Lateral Decubitus Positions

From Frank RM, Saccomanno MF, McDonald LS, et al. Outcomes of arthroscopic anterior shoulder instability in the beach chair versus lateral decubitus position: a systematic review and meta-regression analysis. Arthroscopy . 2014;30(10):1349–1365.
















Advantages Disadvantages
Beach chair


  • Ease of anatomic orientation



  • Ease of setup



  • Ease of conversion to open procedures



  • No additional equipment required , although specific beach chair attachments are often used



  • Excellent visualization of subacromial space



  • Arm is not in the way of the anterior portal



  • Optimal rotational control of shoulder; especially helpful for positioning during rotator interval closure



  • Can use regional anesthesia




  • Surgeon’s arms abducted at glenohumeral joint for most of procedure; can lead to fatigue



  • Less visualization of posterior and posteroinferior aspects of joint



  • Difficult to provide balanced suspension without an assistant



  • Requires assistant (or well-positioned drapes)



  • Setup may create physical barrier to the posterior or superior portals



  • Increased risk of cerebral hypoperfusion



  • Arthroscopic bubbles obscure subacromial space visualization

Lateral decubitus


  • Efficient setup



  • Surgeon’s arms work at the side for most of procedure; less fatigue



  • Provides better access to anterior, inferior, and posterior glenoid



  • Traction increases joint space



  • Traction better accentuates labral tears



  • Ease of performing instability repairs, SLAP repairs, and LHBT procedures



  • Excellent visualization of subacromial space



  • Arthroscopic bubbles float laterally (subdeltoid space) out of field



  • Decreased risk for cerebral hypoperfusion




  • Difficult (nonanatomic) orientation



  • Requires repositioning and redraping for conversion to open procedures



  • More difficult to train residents



  • Less ability to rotate shoulder



  • Difficult anesthesia airway management



  • Requires arm-holding device and balanced suspension device



  • Risk of traction-related injury



  • Increased risk to axillary and musculocutaneous nerves during anteroinferior portal placement



  • Typically requires general anesthesia because regional anesthesia is not well tolerated


LHBT , long head of the biceps tendon; SLAP, superior labrum anterior and posterior.


A thorough diagnostic arthroscopy is critical for finalizing the surgical plan and includes evaluation of the circumferential glenoid labrum (including the posteroinferior aspect), the humeral attachment of the glenohumeral ligaments, the capsular redundancy and tissue quality, size and location of the humeral Hill-Sachs defect, anterior-inferior bony defects of the glenoid, and the presence of osteochondral loose bodies and articular cartilage defects.


Arthroscopic inspection of the intra-articular and bursal surfaces of the rotator cuff should also be performed, particularly in older patients who tend to have a higher prevalence of concomitant rotator cuff pathology. Snyder and Strafford noted that 20% to 25% of patients with instability undergoing arthroscopy have associated loose bodies, rotator cuff tears, biceps tendon pathology, or superior labrum anterior and posterior lesions. In a study by Mok et al., arthroscopic examination altered the diagnosis in 40% of patients with atraumatic instability and in 8% of those with traumatic anterior instability. Adolfsson and Lysholm found concurrent pathology at the time of diagnostic arthroscopy that could have influenced the outcome of surgery in 44% of 39 dislocating shoulders. These lesions, if unrecognized or untreated, may compromise surgical outcomes. Although advanced imaging modalities in the form of CT and MRI have improved significantly over the past 2 decades, arthroscopic examination remains an important tool to clarify the diagnosis in ambiguous cases and identify associated pathology that may require altering the surgical management and converting to an open stabilization or bone augmentation procedure. Diagnostic arthroscopic examination can be useful even in the setting of planned open or bone augmentation procedures as well.


Once the pathology has been comprehensively documented and the decision to perform an arthroscopic stabilization is confirmed, the repair is initiated. Standard current arthroscopic capsulolabral repair technique choices that are available to the surgeon include the type of suture, the suture technique, repair with traditional (using knots) and knotless techniques, the fixation technique, the anchor type, and the use of advanced arthroscopic techniques. In addition, the options include using one or more anterior cannulas versus supplementing with percutaneous shuttling and/or anchor placement devices. Suture types will include multifilament, partially absorbable sutures or tapes. In general, completely absorbable sutures such as PDS are not indicated for the bulk of the repair. Some suture types are partially rigid, which may allow for a simplified mattress construct. The suture technique may include simple, mattress, or “luggage tag” constructs. The state of the art for fixation to bone will include some type of anchor; in general, suture to labrum without including bone fixation has fallen into disfavor due to the less satisfactory outcomes. Of the anchor types, the choices include metal, nonmetallic inert materials such as polyetheretherketone (PEEK), bioabsorbable anchors, which are generally proprietary, and all-suture anchors (also known as all-soft suture anchors) which are fixed to bone with a prominent suture construct that is buried in bone. Although metallic anchors remain commercially available, we do not advocate their use given the alternatives, the significant risk of metallic hardware complication, and the potential for the development of arthropathy. Suture configurations and recent-generation fixation options have been tested in time zero cadaver studies as well as clinical follow-up studies and, in general, there do not appear to be any significant biomechanical or clinical outcome differences among several types. , Nonetheless, it is incumbent upon the surgeon to be familiar with the biomechanical and biologic resorption characteristics specific to the implant and/or suture options because adverse effects and suboptimal results have been reported.


Aforementioned advanced arthroscopic techniques include the use of a posteroinferior capsulolabral repair, a double-row labral repair, a bony Bankart repair, and a remplissage. These techniques are included in the armamentarium based upon intraoperative findings and surgeon preference. ,


Outcomes


Historically, the initial experience with arthroscopic repairs reported higher failure rates than open techniques. Staples or transglenoid sutures were used, with a high incidence of recurrence and hardware migration. , Transglenoid suturing of the Bankart lesion showed some success but fell out of favor due to variable recurrence rates, technical difficulty, and the risk of injuring the suprascapular nerve by tying sutures over the posterior fascia. Warren developed a bioabsorbable polyglycolic acid tack which improved the ease with which arthroscopic techniques could be performed; however, these devices were unable to adequately treat capsular redundancy , and resulted in synovitis as the device loosened with time. ,


Early clinical outcomes of suture anchor repair were promising and realized similar results to open stabilization even in high-demand athletes, with low redislocation rates and low revision surgery rates. ,


Investigators reporting results using modern state-of-the-art techniques have generally reported significantly improved clinical outcomes and RTS following arthroscopic anterior stabilization compared with the historical data. , , , , , Ozturk et al. reported on a series of 58 patients, noting a revision rate of 8.6% and an RTS rate of 87%. A greater number of preoperative instability episodes was associated with revision. Rhee and colleagues reviewed a series of 48 patients undergoing panlabral repair and noted a low recurrence rate of 1 out of 48 (2%). Trinh et al. reported the clinical outcomes following arthroscopic anterior stabilization in overhead athletes as part of the Multicenter Orthopaedic Outcomes Network Shoulder Instability Consortium. The study included 49 athletes with 2-year follow-up. Two patients (4.1%) required revision, although 14 (26.8%) reported subjective apprehension of looseness and 31 (63%) RTS but only 22 (45%) were able to RTS at their previous level of participation. Two recent papers reviewed results in a group of athletes and evaluated the impact the number of preoperative instability episodes had on revision rates. , Nakagawa and colleagues compared arthroscopic stabilization performed in 45 patients after a first-time dislocation to a control group of 95 patients with recurrent instability. The postoperative recurrence rate was 6.7% in shoulders following the first instability episode compared with 23.2% in the recurrent instability group. Bone loss was significantly greater in the recurrent instability group as well. The senior author reported on a series of 67 athletes between the ages of 13 and 21 years (mean, 17.5 years) following an arthroscopic stabilization with minimum 2-year follow-up. There were 48 males (72%) and 19 females. The exclusion criteria included athletes with more than three preoperative instability episodes and those with meaningful bone loss. The average number of preoperative instability episodes was 1.4 (range, 1 to 3). Forty-two athletes (63%) had only one preoperative instability episode. All athletes were involved in high levels of competition that included school, travel, and/or club teams. All athletes were managed with an anterior stabilization with an average of 3.6 anchors. A posteroinferior capsulolabral repair was also performed in 42 of 67 athletes (63%). The revision rate was 6% (4 of 67), and all four athletes requiring a revision were male and had more than one preoperative instability episode. The four recurrences occurred in collision sports. There were no recurrences and no revisions in the 42 athletes who sustained only one preoperative instability episode. Regarding RTS, 59 of 67 (88%) returned to their previous sport and 50 of 67 (75%) returned at the same level or higher. Average time to RTS was 7.1 months. The eight athletes who did not RTS and 15 of 17 who did not RTS at the same level cited reasons other than apprehension or reinjury as the cause in that they were transitioning to the workforce or graduating from high school or college.


The outcomes following anterior stabilization with the addition of a concomitant remplissage for the management of an engaging Hill-Sachs lesion have yielded satisfactory outcomes as well. Park and colleagues reported a total of 193 patients, 23 with off-track lesions and 170 with on-track lesions. Arthroscopic Bankart repair was performed with the additional use of a remplissage in the off-track group. There was no significant difference in recurrence rates between the two groups. Brilakis et al. reviewed 65 patients following an arthroscopic Bankart repair and remplissage for an engaging Hill-Sachs lesion. They reported a 5.6% recurrence rate (3 of 65) and a 71% RTS rate. No significant ROM limitations were noted. Lazarides et al. performed a systematic review of arthroscopic remplissage for anterior instability in patients with engaging Hill-Sachs lesions. The authors reported a 5.8% recurrence rate (33 of 570) with some deficits in external rotation with the arm in neutral compared with the contralateral shoulder ranging from 9 to 14 degrees.


Several investigators have reviewed RTS rates. , , , , , It is important to define RTS particularly as it relates to RTS at the previous level of competition within the same sport as well as defining a minimum time of participation, which we believe should be a minimum of one complete season. Robins et al. reported on a series of NCAA Division I football athletes and noted an 85.4% RTS. The percentage of games played before the injury was 49.9% and rose to 71.5% after surgery ( P = .001). Athletes who were starters before the injury returned at a 91% rate after surgery. Abdul-Rassoul et al. performed a systematic review evaluating arthroscopic, open, and bone augmentation procedures and reported a 97.5% RTS following arthroscopic Bankart repair and a 95.5% RTS following arthroscopic Bankart with remplissage. Of the athletes who did RTS, arthroscopic Bankart had the highest number of athletes who returned to sport at preinjury levels (91.5%). Kasik and colleagues performed a systematic review of adolescent athletes (ages 10 to 19 years) following anterior shoulder stabilization; 400 shoulders were treated arthroscopically, and 69 underwent open stabilization. Overall, there was an 81.5% RTS at preinjury level at an average of 5 months postoperatively; however, the recurrence rates were high (18.5%) and with a 12.1% revision rate. Although timing before RTS following shoulder stabilization has not received as much attention as RTS following acromioclavicular ligament reconstruction, this systematic review might be interpreted to suggest that a longer delay should be considered in the contact athlete in this youth cohort.


Regarding outcomes as related to patient positioning, systematic reviews found overall excellent clinical outcomes and low rates of recurrence following arthroscopic anterior shoulder stabilization performed in either the beach chair or lateral decubitus position but noted significantly lower rates of recurrent instability in the lateral decubitus group. , Nevertheless, the results of these systematic reviews could be due to surgeon variables other than positioning alone and is likely the result of multifactorial components. Rhee et al. compared two groups of patients undergoing panlabral repair (270-degree repairs) divided equally between the beach chair and lateral decubitus positions. No significant differences were noted in clinical outcomes between groups. As we are all aware, high-volume surgeons performing surgery in high-volume institutions generally achieve the best outcomes, and the use of the beach chair position does not appear to be a significant risk factor for failure in our experience.


Insurance status may also play a role in surgical wait time and overall clinical outcomes following traumatic anterior shoulder dislocations. A study by Williams et al. demonstrated that the average wait time from initial injury to surgery was 1640 days (95% confidence interval [CI], 1155 to 2125 days) for Medicaid patients compared with 1237 days (95% CI, 834 to 1639 days) for patients with other types of insurance ( P = .005). In addition, Medicaid patients were found to be more likely to sustain five or more instability events, have a higher risk of significant (>15%) glenoid bone loss, and have a higher risk of requiring a Latarjet or open stabilization procedure compared with other patients.


Treatment of the first-time dislocation


The surgical management of young collision athletes following a first-time dislocation is not a new concept and was initially reported through the experience in the US Military Academy at West Point. The findings from the medical staff at West Point demonstrated the unacceptably high failure rate (92%) with nonoperative treatment of West Point cadets following their first anterior shoulder dislocation compared with preliminary findings of 78% success with arthroscopic repair. The follow-up studies from this center confirmed the success of the approach to proceed with surgical repair in this cohort of athletes. ,


Research on the treatment of first-time glenohumeral dislocation in youth athletes has provided insight into differences between the youngest patients and older adolescents. Leroux et al. performed an administrative database analysis on a cohort of 1937 patients aged 10 to 16 years who underwent closed reduction of a first-time anterior glenohumeral dislocation. They found that patients age 14 to 16 years had a similar risk profile for subsequent dislocation as that reported for 17- to 20-year-olds and, for treatment decision purposes, may be considered as young adults. Conversely, they noted that patients 13 years old and younger had a lower risk of recurrent dislocation, therefore making them more amenable to a nonoperative treatment strategy. This is likely due in part to the fact that collagen composition changes from predominantly elastic type III collagen at birth to inelastic type I collagen as development progresses through adolescence and into adulthood. Taken together with the aforementioned young adult data from West Point, we advocate for strong consideration of surgical treatment of patients age 14 to 21 years at the time of the first dislocation event but consider nonoperative management for the first-time dislocator 13 years old and younger or with an open proximal humerus physis in the absence of a bony Bankart lesion, ALPSA, or glenolabral articular disruption lesion.


As noted earlier, there is a direct relationship between the number of instability episodes and the development of meaningful bone loss. Di Giacomo and colleagues reported on 102 patients following a first-time anterior dislocation. All patients were found to have humeral-sided bone loss upon 3D CT reconstructions. Dickens et al. followed 714 military academy athletes through 4 years of collegiate sports. Athletes sustaining a first-time dislocation resulted in an average of 6.8% glenoid bone loss. Athletes sustaining a recurrent instability episode were found to have progressed from a baseline of 10.8% glenoid bone loss to 22.8% glenoid bone loss following the recurrence.


In addition, multiple clinical studies have documented the worsening outcomes when arthroscopic anterior stabilization is performed after even the second instability episode. , , , , Gasparini et al. reported a mean odds ratio for failure of 3.8 (95% CI, 1.2 to 11.6; P = .044) when arthroscopic anterior stabilization was performed after the second or further dislocation compared with those treated after one dislocation. Shin and colleagues reported significantly decreased recurrence rates following arthroscopic management for first-time dislocators (3%) compared with a recurrent group (7%; P = .039). In addition, 10 of 89 (11%) patients in the recurrent group had significant apprehension and lower patient satisfaction scores, and six of those 10 patients had ALPSA lesions. As noted earlier, the senior author reviewed a series of 67 athletes and reported no revisions in the 42 athletes treated arthroscopically after a first-time dislocation at minimum 2-year follow-up with a mean of 3.56 years. Nakagawa and colleagues reported a 6.7% recurrence rate for first-time dislocators and a 23.2% recurrence rate in the recurrent instability group. Although recurrence and revision are concerning outcomes, investigators have also reported diminished patient satisfaction and functional outcomes scores in athletes treated with arthroscopic anterior stabilization with higher numbers of preoperative instability episodes, even in the absence of recurrence or revision. Park and colleagues reported that in a cohort of 180 patients who did not sustain a recurrence or require a revision following arthroscopic stabilization, lower patient satisfaction scores were correlated with increasing numbers of preoperative instability events. Shaha et al. reported that glenoid bone loss greater than 13.5% led to a significant decrease in Western Ontario Shoulder Instability scores consistent with an unacceptable outcome even in the absence of recurrence or revision. In addition, Aboalata et al. followed a series of 143 patients at 10-year follow-up after arthroscopic anterior stabilization and found a 12% incidence of dislocation arthropathy, which was correlated with increasing numbers of preoperative instability episodes.


A paper authored by Buss et al. is often cited in which 30 athletes, 19 who sustained a dislocation and 11 who sustained a subluxation during a 2-year period, were managed in season with bracing. Twenty-six of 30 completed the season, 37% sustained a recurrence during the season, and 16 of 30 patients (53%) underwent stabilization in the off-season. The information that is not reported is the 2-year follow-up of the entire cohort. Also unavailable are the recurrence, revision, and RTS rates of those treated surgically. Although in-season bracing is often the standard of care in professional sports, given the substantial data reviewed earlier, it may not represent the best treatment for the high school athlete.


For all of these reasons, we believe the data are compelling that the young male athlete involved in competitive contact sports who sustains a first-time dislocation is in a high-risk cohort. They have unacceptably high failure rates with nonoperative treatment and diminished outcomes following arthroscopic anterior stabilization with each recurrent preoperative instability episode. The athlete and family must be educated and counseled regarding the natural history of anterior shoulder instability in this setting. If they plan to continue competitive sports, they must understand that the best outcomes (low recurrence rates and high RTS rates) following arthroscopic anterior stabilization will occur after the first dislocation and before the second. Beyond the second or third dislocation, open stabilization or bone augmentation procedures will likely yield better outcomes in this cohort of young high-risk athletes.


ASES neer circle 2019 consensus statements


The ASES established the Neer Circle, which is a service recognition group whose membership is composed of an international group of ASES members who have provided leadership and service to the society. One of the purposes of the Neer Circle is to provide a forum for thought leaders to develop consensus statements on a difficult or controversial clinical and/or academic topic. The Inaugural Meeting of the Neer Circle took place during the ASES Annual Meeting in October 2019. There are more than 1000 ASES members, and the Neer Circle at the time of the Inaugural meeting was composed of 112 members. The Neer Circle selected the first consensus question “The Management of the First Time Dislocator” for this Inaugural Meeting. It began with a 15-month Delphi process in which Neer Circle members were surveyed multiple times. The group was presented with 162 clinical scenarios as the final component of the survey. They voted yes or no for operative intervention and ranked the responses on a 5-point Likert scale. The final questionnaire was completed by 89% of Neer Circle members.


The Conclusions of this Neer Circle Consensus are as follows :



  • 1.

    ASES Neer Circle members do not believe surgery should be the standard of care for all patients sustaining a first-time dislocation.


  • 2.

    Contact athletes, at the end of their season, aged 14 to 22 years, with anterior apprehension and meaningful bone loss had very high levels of recommending surgery (>96%) with very strong Likert recommendations (>4) to do so.


  • 3.

    Conversely, noncontact athletes younger than 14 years, without apprehension and without meaningful bone loss, had extremely low levels of surgical recommendation (<3%), with very strong Likert recommendations (>4) against surgery.


  • 4.

    Patient features that strongly influenced a recommendation to proceed to surgery were apprehension and meaningful bone loss.


  • 5.

    Age followed a distribution such that those younger than 14 and older than 30 years were less likely to have a recommendation for surgery.



Summary of indications


We routinely perform arthroscopic anterior stabilization for the following conditions:



  • 1.

    Young athletes (14 to 21 years) who have sustained a first-time anterior dislocation


  • 2.

    Young athletes (<21 years) with one or two recurrences of anterior instability


  • 3.

    Older adults with recurrent anterior instability


  • 4.

    Anterior instability with an acute bony Bankart


  • 5.

    Select revision cases in which there is identifiable pathology that can be addressed arthroscopically


  • 6.

    Revision anterior instability in older adults with a lower activity profile.



We do counsel young contact athletes and their families that they represent a high-risk cohort and that postoperative rehabilitation and compliance is of paramount importance. We also educate them preoperatively regarding clearance and the RTS process.


In general, we have been satisfied with our arthroscopic results when the following conditions are met :




  • The patient has unidirectional instability of traumatic origin that consists of anterior or anteroinferior instability



  • Arthroscopic examination shows a discrete anterior or anteroinferior capsulolabral lesion that may include a panlabral component (posterior, posterosuperior, or biceps-labral complex injury).



  • The capsule is robust, and the IGHL complex does not exhibit signs of attrition.



  • No HAGL is present.



  • Absence of meaningful glenoid bone loss (<13.5%)



  • Absence of off-track or engaging bony Bankart, Hill-Sachs, or significant bipolar lesion



It is important to be prepared to convert to open surgery when intraoperative findings of the EUA and/or diagnostic arthroscopy reveal any of the aforementioned risk factors that are not amenable to successful arthroscopic reconstruction.


Complications


The primary complications of recurrence, revision, and functional deficits as they relate to RTS have been thoroughly covered in the preceding sections of this chapter. In general, the complications of arthroscopic stabilization are less significant than those for open and bone augmentation procedures. The remaining complications are typical of most arthroscopic joint stabilization procedures and include infection, neurovascular injuries, fracture, hardware complications, , , postoperative stiffness, anchor arthropathy (secondary osteoarthritis from prominent suture anchors), the progression to postsurgical arthritis (in this setting referred to as capsulorrhaphy arthropathy, arthritis of dislocation and dislocation arthropathy), and chondrolysis. The complication of chondrolysis was devastating and iatrogenic, related to thermal capsulorrhaphy or postsurgical infusion of local anesthetic, both of which are thankfully at this time, for the most part, of historic relevance only. One must nevertheless be mindful of the excessive use of a radiofrequency probe within the joint to avoid insult to chondrocytes. A systematic review reported by Williams et al. demonstrated overall complications as follows: arthroscopic soft tissue repair (1.6%, N = 2805), arthroscopic soft tissue repair with remplissage (0.5%, N = 219), open stabilization (6.2%, N = 219), open bone augmentation (7.2%, N = 573), and arthroscopic bone augmentation (13.6%, N = 163).


Preferred technique


We prefer regional anesthesia with an interscalene block combined with general endotracheal anesthesia so that paralysis may be used if necessary in the well-muscled large athlete. The patient is placed in the beach chair (modified Fowler) position. Arthroscopic landmarks are palpated and marked on the skin of the shoulder, including acromion, acromioclavicular joint, clavicle, and coracoid ( Fig. 31.1 ).


Aug 21, 2021 | Posted by in ORTHOPEDIC | Comments Off on Anterior instability: Arthroscopic surgery and outcomes

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