summary Traumatic Anterior Shoulder Instability, also referred to as TUBS (Traumatic Unilateral dislocations with a Bankart lesion requiring Surgery), are traumatic shoulder injuries that generally occur as a result of an anterior force to the shoulder while its abducted and externally rotated and may lead to recurrent anterior shoulder instability. Diagnosis is made clinically with the presence of positive anterior instability provocative tests and confirmed with MRI studies that may reveal labral and/or bony injuries of the glenoid and proximal humerus (Hill-Sachs lesion). Treatment may be nonoperative or operative depending on the chronicity of symptoms, the presence of risk factors for recurrence, and the severity of labral and/or glenoid defects. In high-risk populations, surgery is often offered after a single dislocation event. Epidemiology Incidence one of most common shoulder injuries 1.7% annual rate in general population Demographics have a high recurrence rate that correlates with age at dislocation up to 80-90% in teenagers (90% chance for recurrence in age <20) Risk factors markedly higher incidence in military patients contact athlete patients Etiology Pathophysiology mechanism of injury anteriorly directed force on the arm when the shoulder is abducted and externally rotated pathoanatomy "on-track" versus "off-track" concept of Hill-Sachs lesion (instability as a bipolar concept) login to view 7 more bullets Associated injuries orthopaedic labrum & cartilage Injuries login to view 16 more bullets fractures & bone Defects login to view 20 more bullets nerve injuries login to view 3 more bullets rotator cuff tears login to view 2 more bullets medical global hyperlaxity (i.e. Ehlers-Danlos Syndrome, collagen disorders) login to view 3 more bullets patients with global hyperlaxity are less likely to develop capsulolabral lesions Anatomy Glenohumeral anatomy Static restraints bony anatomy capsule glenohumeral ligaments labrum labrum contributes 50% of additional glenoid depth Dynamic restraints rotator cuff muscles long head of biceps tendon Anterior static shoulder stability is provided by Anterior band of IGHL (main restraint) provides static restraint with arm in 90° of abduction and external rotation MGHL provides static restraint with arm in 45° of abduction and external rotation SGHL provides static restraint with arm at the side Classification Anteroposterior Translation Grading Scheme Grade 0 Normal glenohumeral translation Grade 1+ Humeral head translation up to glenoid rim Grade 2+ Humeral head translation over glenoid rim with spontaneous reduction once force withdrawn Grade 3+ Humeral head translation over glenoid rim without spontaneous reduction Sulcus Test Grading Scheme Grade 1 Acromiohumeral interval < 1cm Grade 2 Acromiohumeral interval 1-2 cm Grade 3 Acromiohumeral interval > 2cm Instability Severity Score Variable Parameter Score Age < 20 years > 20 years 2 0 Degree of sports participation Competitive Recreational/none 2 0 Type of sport participation Contact/forced overhead Other 1 0 Shoulder Hyperlaxity Hyperlaxity (anterior/inferior) Normal 1 0 Hill sachs on AP x-ray Visible on external rotation Not visible on external rotation 2 0 Glenoid contour loss on AP x-ray Loss of contour No lesions 2 0 Clinical Implications Total Possible = 10 An acceptable recurrence risk of 10% with arthroscopic stabilization. < 6 points A score of > 6 points has an unacceptable recurrence risk of 70% and should be advised to undergo open surgery (i.e. Laterjet procedure). > 6 points Presentation History patients often recount a traumatic event leading to a dislocation important to clarify whether patient needed a formal reduction, or if they spontaneously reduced Symptoms traumatic event causing dislocation feeling of instability shoulder pain complaints caused by subluxation and excessive translation of the humeral head on the glenoid Physical exam load and shift Grade 0 - normal glenohumeral translation Grade I - translation to the glenoid rim, without dislocation Grade II - shifts over glenoid rim, spontaneously reduces Grade III - shifts over glenoid rim, does not spontaneously reduce apprehension sign patient supine with arm 90 degrees abducted and 90 degrees externally rotated positive when patients experiences apprehension positive sign in mid-ranges of abduction is highly suggestive of concomitant glenoid bone loss relocation sign decrease in apprehension with anterior force applied on shoulder during apprehension testing sulcus sign tested with patient's arm at side generalized ligamentous laxity increased risk of recurrent instability in patients with hyperlaxity assess via Beighton's criteria (score > 4) shoulder specific laxity defined as login to view 3 more bullets Imaging Radiographs see imaging of shoulder recommended views a complete trauma series needed for evaluation login to view 3 more bullets optional views West Point view login to view 1 more bullet Stryker view login to view 1 more bullet CT scan +/- arthrogram indications helpful for evaluation of bony injuries and calculation of glenoid bone loss arthrogram usually reserved for patients who are unable to undergo MRI i.e. patients with pacemakers and/or cochlear implants due to limited soft-tissue contrast, CT arthrogram not as effective at visualizing internal soft-tissue derangements as MR arthrogram MRI indications best for visualization of labral tear has been validated as an imaging modality through which to assess bone loss abduction and external rotation (ABER) sequences can be utilized to better visualize the antero-inferior glenoid labrum MR Arthrogram increases sensitivity and specificity (86-91% and 86-96%) for detecting soft-tissue injuries when compared to conventional MRI (44-100% and 66-95%) Treatment Nonoperative acute reduction, ± immobilization, followed by therapy indications login to view 2 more bullets reduction login to view 5 more bullets immobilization login to view 4 more bullets physical therapy login to view 1 more bullet outcomes login to view 9 more bullets Operative Arthroscopic Bankart repair +/- capsular plication indications login to view 6 more bullets techniques login to view 2 more bullets outcomes login to view 3 more bullets Open Bankart repair +/- capsular shift indications login to view 5 more bullets technique login to view 2 more bullets outcomes login to view 2 more bullets Latarjet (coracoid transfer) or Bristow Procedure indications login to view 5 more bullets technique login to view 2 more bullets outcomes login to view 2 more bullets Autograft (tricortical iliac crest or distal clavicle) or allograft (iliac crest or distal tibia) indications login to view 2 more bullets technique login to view 2 more bullets outcomes login to view 1 more bullet Remplissage + Bankart Repair indication login to view 2 more bullets technique login to view 3 more bullets outcomes login to view 2 more bullets Bone graft reconstruction for Hill Sachs defects indication login to view 1 more bullet technique login to view 3 more bullets outcomes login to view 3 more bullets Tendon transfers indication login to view 2 more bullets technique login to view 6 more bullets outcomes login to view 4 more bullets Historical procedures: Putti-Platt / Magnuson-Stack / Boyd-Sisk indications login to view 1 more bullet technique login to view 4 more bullets outcomes login to view 3 more bullets Techniques Acute Reduction +/- Immobilization followed by physical therapy indications acute dislocations presenting to the emergency departments techniques relaxation of patient with sedation or intraarticular lidocaine is essential various methods for reduction exist login to view 3 more bullets pros/cons timely reduction can help to style the development of further bone loss or joint contractures complications unsuccessful in 5-10% of cases login to view 1 more bullet nerve injury login to view 1 more bullet recurrent instability login to view 1 more bullet Arthroscopic Bankart Repair + Capsular plication indications recurrent anterior instability anterior instability in young athletes current trend is towards surgical management after first-time dislocation event, as recurrent instability is associated with greater degrees of glenoid bone loss, which may preclude arthroscopic stabilization approach shoulder arthroscopic approach technique drive through sign might be present prior to labral repair and capsulorraphy studies support use of > 3 anchors (< 4 anchors is a risk factor for failure) complications recurrence, most often due to unrecognized glenoid bone loss or lack of concomitantly addressing "off-track" HS lesion stiffness, especially in external rotation, further loss of ER may occur with the addition of remplissage login to view 1 more bullet axillary nerve injury login to view 1 more bullet chondrolysis (from use of thermal capsulorraphy which is no longer used) Open Bankart repair +/- capsular shift indications often employed in the setting of failed arthroscopic stabilization some surgeons prefer an open procedure if the patient is found to have a HAGL lesion approach shoulder anterior (deltopectoral) approach technique subscapularis transverse split or tenotomy open labral repair and capsulorraphy capsular shift login to view 1 more bullet complications recurrence login to view 1 more bullet subscapularis injury or failed repair login to view 1 more bullet stiffness login to view 3 more bullets axillary nerve injury login to view 2 more bullets arthritis login to view 3 more bullets Latarjet or Bristow Procedure indications indications vary based on geographic region login to view 1 more bullet young, high-demand contact athletes or athletes of consequence (mountain climbers, big wave surfers) anterior instability with critical (>20-25%) or subcritical (>13.5%) bone loss patients at high-risk of failure with soft-tissue procedures alone (ISIS > 4-6 points) approach shoulder anterior (deltopectoral) approach can be performed arthroscopically technique coracoid transfer to anterior inferior glenoid bone defect traditional or congruent arc technique for coracoid graft placement after harvest, coracoid is passed through a split in the distal 1/3 or middle 1/2 subscapularis traditional versus congruent arc technique login to view 3 more bullets graft can be placed intraarticularly (capsular repaired to CA ligament stump) or extraarticularly (capsule repaired to native glenoid rim) login to view 1 more bullet no difference in outcomes between open and arthroscopic procedures, although literature has identified a profound learning curve for the arthroscopic latarjet complications generally higher than arthroscopic or open Bankart, some studies report up to 25% incidence of complications nonunion graft lysis login to view 1 more bullet hardware problems stiffness, particularly in external rotation glenohumeral osteoarthritis login to view 2 more bullets nerve injury login to view 8 more bullets vascular injury login to view 3 more bullets Autograft (tricortical iliac crest or distal clavicle) or allograft (iliac crest or distal tibia) indications area of research ideal patient for latarjet versus bone block is yet to be identified indications similar to those of latarjet login to view 5 more bullets approach shoulder anterior (deltopectoral) approach arthroscopic technique can use autograft of allograft iliac crest, allograft glenoid or allograft distal tibia can secure with screws or buttons complications hardware failure subscapularis repair failure Remplissage + Bankart Repair indications medium to large engaging/off-track Hill-Sachs lesion some surgeons have begun using remplissage in the setting of subcritical bone loss, as in these patients rates of recurrent instability following arthroscopic management alone approaches 20% approach arthroscopic login to view 2 more bullets technique goal is to fill Hill-Sachs with capsule and infraspinatus tendon can use knotted or knotless configurations most surgeons recommend passing sutures prior to anterior labral repair, and then tying once anterior labral repair is complete new knotless anchors allow for passage and construction of a "double-pulley" configuration, with final tensioning completed after additional intraarticular work complications stiffness, specifically loss of external rotation login to view 1 more bullet recurrence login to view 1 more bullet Bone graft reconstruction for Hill-Sachs defects indications large Hill-Sachs (>40% of articular surface) approach open login to view 2 more bullets arthroscopic technique autograft iliac crest allograft (humeral head, talus, femoral head) fresh-frozen osteochondral allograft complications graft lysis disease transmission from allograft osteoarthritis Historical procedures: Putti-Platt / Magnuson-Stack / Boyd-Sisk indications historically indicated for recurrent instability rarely indicated now approach open anterior (deltopectoral) approach technique Putti-Platt is performed by lateral advancement of subscapularis and medial advancement of the shoulder capsule Magnuson-Stack is performed with lateral advancement of subscapularis (lateral to bicipital groove and at times to greater tuberosity) Boyd-Sisk transfer of biceps laterally and posteriorly outcomes Putti-Platt and Magnuson-Stack both lead to decreased external rotation and increased loading on the posterior glenoid, which can lead to post-capsulorraphy arthropathy Complications Recurrence often due to unrecognized glenoid bone loss treated with a soft tissue only procedure (especially with glenoid bone loss >20-25%) can be due to poor surgical technique (ie, < 4 suture anchors) increased risk with preoperative risk factors including age < 20, male sex, contact/collision sport, ligamentous laxity, and unrecognized glenoid and/or humeral head bone loss (critical bone loss or "off-track" lesion) medical management should be exhausted prior to surgery in patients with seizures, as there is a high recurrence risk even when bony augmentation techniques are used unrecognized pan-labral tear high incidence of posterior and/or combined front-to-back tears in the military population Shoulder pain overtightening during labral repair can lead to post-capsulorrhaphy arthropathy Nerve injury (Latarjet) musculocutaneous (most common) axillary Stiffness especially in external rotation (particularly with Latarjet and additional remplissage) Infection Graft lysis (Latarjet) present in up to 90% of patients at six-months Hardware complications anchor pull-out (Bankart repair) screw pull-out (Latarjet) Chondrolysis historically due to use of thermal capsulorraphy (now contraindicated) or intra-articular pain pumps (now contraindicated)