Shoulder:Glenohumeral Instability/Posterior Instability - Revision history

Alexandre.laedermann: /* B2: Structural dynamic posterior instability */

2022-04-14T16:08:03Z

B2: Structural dynamic posterior instability

Alexandre.laedermann: /* B2: Structural dynamic posterior instability */

2022-04-14T14:55:21Z

B2: Structural dynamic posterior instability

Alexandre.laedermann at 07:03, 15 August 2021

2021-08-15T07:03:58Z

Alexandre.laedermann at 07:03, 15 August 2021

2021-08-15T07:03:05Z

Alexandre.laedermann: /* Sequelae of brachial plexus birth palsy */

2021-07-29T15:30:22Z

Sequelae of brachial plexus birth palsy

Alexandre.laedermann: /* Bullet Points */

2021-07-29T15:25:53Z

Bullet Points

Alexandre.laedermann at 11:11, 3 June 2021

2021-06-03T11:11:09Z

Show changes

Alexandre.laedermann at 10:55, 3 June 2021

2021-06-03T10:55:51Z

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Alexandre.laedermann at 10:35, 3 June 2021

2021-06-03T10:35:43Z

Alexandre.laedermann at 10:22, 3 June 2021

2021-06-03T10:22:00Z

@@ Line 115: / Line 115: @@
 ===B2: Structural dynamic posterior instability===
-The B2 includes involuntary and reproducible dislocators.
+The B2 includes unstable painful shoulder, involuntary and reproducible dislocators.
 ====Unstable Painful Shoulder====

@@ Line 115: / Line 115: @@
 ===B2: Structural dynamic posterior instability===
-The B2 includes unstable painful shoulders, involuntary and reproducible dislocators.
+The B2 includes involuntary and reproducible dislocators.
 ====Unstable Painful Shoulder====

@@ Line 282: / Line 282: @@
 =Treatment=
 ==Clinical Practice Guideline==
 The goal of this section is to provide clinicians with recommendations based on the best available evidence; to inform clinicians of when there is no evidence; and finally, to help clinicians deliver the best health care possible.

@@ Line 282: / Line 282: @@
 =Treatment=
 ==Conservative (Non Operative) Treatment==
@@ Line 301: / Line 306: @@
 Shoulder braces or posture correctors and supports that can center the arm in the socket through improved proprioception and reafferentation. Depending of their design, they can provide secure stability during movement. This type of support could help athletes to return to sport.
-==Operative (Surgical) Treatment==
+==Surgical (Operative) Treatment==
 ===Acute dislocation===

@@ Line 41: / Line 41: @@
-Consequently, a subchondral cleft (labrum and capsule attached but no tear) may be a normal finding.<ref>Campbell SE, Dewitt RM, Cameron KL, Thompson AK, Owens BD. Posterior chondrolabral cleft: clinical significance and associations with shoulder instability. HSS J. 2014;10:208-212.</ref> Surgeons should be aware that while anterior capsule anatomy is quite variable, the posterior capsular insertion tends to be more homogenous in appearance among patients (Figure 1).
+Consequently, a subchondral cleft (labrum and capsule attached but no tear) may be a normal finding.<ref>Campbell SE, Dewitt RM, Cameron KL, Thompson AK, Owens BD. Posterior chondrolabral cleft: clinical significance and associations with shoulder instability. HSS J. 2014;10:208-212.</ref> Surgeons should be aware that while anterior capsule anatomy is quite variable, the posterior capsular insertion tends to be more homogenous in appearance among patients (Figure).
-[[File:Abnormal insertion of the capsule.jpg|thumb|Figure 1. A) Normal insertion of the posterior capsule. B) Posterior disinsertion of the capsule.|alt=|center]]
+[[File:Abnormal insertion of the capsule.jpg|thumb|A) Normal insertion of the posterior capsule. B) Posterior disinsertion of the capsule.|alt=|center]]
 <br />
 ===Reverse humeral avulsion of the glenohumeral ligaments (rHAGL)===
-[[File:Reverse humeral avulsion of the glenohumeral ligaments (rHAGL).jpg|thumb|alt=|Figure 2. Posterior arthroscopic view of a left shoulder. Observe the humeral avulsion of the capsule.|center]]
+[[File:Reverse humeral avulsion of the glenohumeral ligaments (rHAGL).jpg|thumb|alt=|Posterior arthroscopic view of a left shoulder. Observe the humeral avulsion of the capsule.|center]]
 ===Kim lesion===
@@ Line 54: / Line 54: @@
 ==Bony lesion==
-[[File:Bony lesion.png|thumb|Figure 3. Reverse bony Bankart|alt=|center]]
+[[File:Bony lesion.png|thumb|Reverse bony Bankart|alt=|center]]
-[[File:Humeral head fracture.png|thumb|Figure 4. Humeral head fracture|alt=|center]]
+[[File:Humeral head fracture.png|thumb|Humeral head fracture|alt=|center]]
 ===Reverse Malgaigne (Hill-Sachs)===
@@ Line 62: / Line 62: @@
 ==Associated lesions==
-Associated intra-articular pathology such as superior labrum anterior posterior (SLAP) lesion, rotator cuff lesions or a paralabral cyst should be also assessed (Figure 5). Unlike spinoglenoid cysts, posterior or posterior-inferior labral cysts rarely results in impingement of the suprascapular nerve and suprascapular neuropathy.
+Associated intra-articular pathology such as superior labrum anterior posterior (SLAP) lesion, rotator cuff lesions or a paralabral cyst should be also assessed (Figure). Unlike spinoglenoid cysts, posterior or posterior-inferior labral cysts rarely results in impingement of the suprascapular nerve and suprascapular neuropathy.
-[[File:Image7-29.jpg|thumb|Figure 5. A) 3D maximum intensity projection reconstruction showing a remarkably voluminous cyst dissecting 9 cm from the glenoidal labrum through the long head of the triceps muscle. B) The patient complains from a lump in his axillary fold.]]
+[[File:Image7-29.jpg|thumb|A) 3D maximum intensity projection reconstruction showing a remarkably voluminous cyst dissecting 9 cm from the glenoidal labrum through the long head of the triceps muscle. B) The patient complains from a lump in his axillary fold.]]
 =Definitions=
-Dislocation is defined by a complete displacement of the humeral head from its articulation with the glenoid, whereas subluxation represents an incomplete or partial dislocation of the joint. Laxity is a physiologic and an asymptomatic finding, that corresponds to translation of the humeral head in any direction to the glenoid. Hyperlaxity is constitutional, multidirectional, bilateral and also asymptomatic. Hyperlaxity of the shoulder is probably best defined as external rotation elbow at the side equal or greater than 85 degrees (Figure 6).<ref>Walch G, Agostini JY, Levigne C, Nove-Josserand L. [Recurrent anterior and multidirectional instability of the shoulder]. Rev Chir Orthop Reparatrice Appar Mot 1995;81:682-90.</ref>
+Dislocation is defined by a complete displacement of the humeral head from its articulation with the glenoid, whereas subluxation represents an incomplete or partial dislocation of the joint. Laxity is a physiologic and an asymptomatic finding, that corresponds to translation of the humeral head in any direction to the glenoid. Hyperlaxity is constitutional, multidirectional, bilateral and also asymptomatic. Hyperlaxity of the shoulder is probably best defined as external rotation elbow at the side equal or greater than 85 degrees (Figure).<ref>Walch G, Agostini JY, Levigne C, Nove-Josserand L. [Recurrent anterior and multidirectional instability of the shoulder]. Rev Chir Orthop Reparatrice Appar Mot 1995;81:682-90.</ref>
-[[File:Hyperlaxity of the shoulder.jpg|thumb|Figure 6. Hyperlaxity of the shoulder is defined as external rotation elbow at the side equal or greater than 85 degrees.]]
+[[File:Hyperlaxity of the shoulder.jpg|thumb|Hyperlaxity of the shoulder is defined as external rotation elbow at the side equal or greater than 85 degrees.]]
-This finding is most of the time non-pathological (except in soft tissue pathologies like Ehler-Danlos syndrome), is a risk factor for instability but does not by itself demand treatment.<ref>Nourissat G, Vigan M, Hamonet C, Doursounian L, Deranlot J. Diagnosis of Ehlers-Danlos syndrome after a first shoulder dislocation. J Shoulder Elbow Surg 2018;27:65-9.</ref> Hyperlaxity is multidirectional but instability is almost exclusively unidirectional (Figure 7). From an etiological point of view, the posterior dislocation is typically differentiated into acute traumatic dislocation that becomes locked after 6 weeks if neglected, and recurrent instability.
+This finding is most of the time non-pathological (except in soft tissue pathologies like Ehler-Danlos syndrome), is a risk factor for instability but does not by itself demand treatment.<ref>Nourissat G, Vigan M, Hamonet C, Doursounian L, Deranlot J. Diagnosis of Ehlers-Danlos syndrome after a first shoulder dislocation. J Shoulder Elbow Surg 2018;27:65-9.</ref> Hyperlaxity is multidirectional but instability is almost exclusively unidirectional (Figure). From an etiological point of view, the posterior dislocation is typically differentiated into acute traumatic dislocation that becomes locked after 6 weeks if neglected, and recurrent instability.
-[[File:Anterior and Posterior Instability.jpg|thumb|center|Figure 7. Observe the anterior and posterior humeral bone loss in case of anteroinferior and posterior instability. Such case is exceptional.]]
+[[File:Anterior and Posterior Instability.jpg|thumb|center|Observe the anterior and posterior humeral bone loss in case of anteroinferior and posterior instability. Such case is exceptional.]]
@@ Line 100: / Line 100: @@
-[[File:Instabilité postérieure.png|thumb|center|Figure 7. First-time posterior subluxation (A1). Magnetic resonance image of a young male patient who sustained an acute posterior shoulder subluxation with small reverse Hill–Sachs lesion and minor posterior capsulolabral damage during sports participation without major trauma]]
+[[File:Instabilité postérieure.png|thumb|center|First-time posterior subluxation (A1). Magnetic resonance image of a young male patient who sustained an acute posterior shoulder subluxation with small reverse Hill–Sachs lesion and minor posterior capsulolabral damage during sports participation without major trauma]]
 ===A2===
-[[File:Post dislocation.png|thumb|Figure 8. Axial A) and saggital B-C) views of a reduced acute posterior glenohumeral dislocation. A) Observe the posterior labral lesion and the reverse Malgaigne (Hill-Sachs) lesion. B and C demonstrate important post-traumatic muscular edema of the posterior rotator cuff.]]
+[[File:Post dislocation.png|thumb|Axial A) and saggital B-C) views of a reduced acute posterior glenohumeral dislocation. A) Observe the posterior labral lesion and the reverse Malgaigne (Hill-Sachs) lesion. B and C demonstrate important post-traumatic muscular edema of the posterior rotator cuff.]]
 ==Group B==
@@ Line 110: / Line 110: @@
 ===B1: Functional dynamic posterior instability===
-In many cases, the instability is voluntary but positional that is, the patient’s shoulder is dislocated/subluxed in the position of forward flexion, pronation, and internal rotation but relocates with the arm brought into abduction and extension. A voluntary dislocation is associated to a normal laxity or hyperlaxity. In voluntary dislocation, an aberrant muscle activation pattern is observed, the patient is able to demonstrate the phenomena and to repeat it with (Video 1), often, an amused mimic. There is no imaging finding.
+In many cases, the instability is voluntary but positional that is, the patient’s shoulder is dislocated/subluxed in the position of forward flexion, pronation, and internal rotation but relocates with the arm brought into abduction and extension. A voluntary dislocation is associated to a normal laxity or hyperlaxity. In voluntary dislocation, an aberrant muscle activation pattern is observed, the patient is able to demonstrate the phenomena and to repeat it with (Video), often, an amused mimic. There is no imaging finding.
-[[File:Media3-54.mov|thumb|center|Video 1. Voluntary dislocation]]
+[[File:Media3-54.mov|thumb|center|Voluntary dislocation]]
 ===B2: Structural dynamic posterior instability===
@@ Line 120: / Line 120: @@
 This condition (micro-instability) is characterized by pain that appears without trauma, without macro-instability (subluxation or dislocation) in a patient that usually does not suffer from hyperlaxity.<ref>Boileau P, Zumstein M, Balg F, Penington S, Bicknell RT. The unstable painful shoulder (UPS) as a cause of pain from unrecognized anteroinferior instability in the young athlete. J Shoulder Elbow Surg 2011;20:98-106</ref><ref>Patte D, Bernageau J, Rodineau J, Gardes JC. [Unstable painful shoulders (author's transl)]. Rev Chir Orthop Reparatrice Appar Mot 1980;66:157-65</ref>
-Diagnosis is difficult and should not be confused with posterior static subluxation (B0 glenoid according to Walch)<ref name=":1">Domos P, Checchia CS, Walch G. Walch B0 glenoid: pre-osteoarthritic posterior subluxation of the humeral head. J Shoulder Elbow Surg 2018;27:181-8</ref> that belong to the type C2. Images are often relevant with 52% of reverse Bankart, glenoid or humeral cartilage lesions (28% and 8%, respectively) reported (Video 2).
+Diagnosis is difficult and should not be confused with posterior static subluxation (B0 glenoid according to Walch)<ref name=":1">Domos P, Checchia CS, Walch G. Walch B0 glenoid: pre-osteoarthritic posterior subluxation of the humeral head. J Shoulder Elbow Surg 2018;27:181-8</ref> that belong to the type C2. Images are often relevant with 52% of reverse Bankart, glenoid or humeral cartilage lesions (28% and 8%, respectively) reported (Video).
-[[File:Media11-94.mov|thumb|Video 2. Posterior labral lesion in a patient suffering from unstable painful shoulder]]
+[[File:Media11-94.mov|thumb|Posterior labral lesion in a patient suffering from unstable painful shoulder]]
 ====Involontary====
@@ Line 128: / Line 128: @@
 ====Reproducible====
-Reproducible (B2) are voluntary dislocators (B1) that become involuntary after decompensation by a trauma or after losing control of stability. If asked, the patient can reproduce the movement even if the excessive glenohumeral translation leads to symptoms which are sudden, painful and disagreeable (Video 3). A radiological substrate can be found.
+Reproducible (B2) are voluntary dislocators (B1) that become involuntary after decompensation by a trauma or after losing control of stability. If asked, the patient can reproduce the movement even if the excessive glenohumeral translation leads to symptoms which are sudden, painful and disagreeable (Video). A radiological substrate can be found.
-[[File:Reproducible.mov|thumb|Video 3. Reproducible  dislocators. The patient reproduce the movement even if the excessive glenohumeral translation leads to symptoms which are sudden, painful and disagreeable. ]]
+[[File:Reproducible.mov|thumb|Reproducible  dislocators. The patient reproduce the movement even if the excessive glenohumeral translation leads to symptoms which are sudden, painful and disagreeable. ]]
 ==Group C==
@@ Line 146: / Line 146: @@
-[[File:B0.jpg|thumb|Figure 10. Anteroposterior, Neer and axial view of a right shoulder with static posterior subluxation (B0 glenoid)]]
+[[File:B0.jpg|thumb|Anteroposterior, Neer and axial view of a right shoulder with static posterior subluxation (B0 glenoid)]]
 ====Locked Dislocation====
-[[File:Locked dislocation.png|thumb|Figure 11. Locked dislocation of a left shoulder. Observe the important reverse Malgaigne (Hill-Sachs) lesion.]]
+[[File:Locked dislocation.png|thumb|Locked dislocation of a left shoulder. Observe the important reverse Malgaigne (Hill-Sachs) lesion.]]
 ====Sequelae of brachial plexus birth palsy====
-Obstetric brachial plexus palsy (OBPP) frequently leads to secondary glenohumeral dysplasia (Video 4).
+Obstetric brachial plexus palsy (OBPP) frequently leads to secondary glenohumeral dysplasia (Video).
-[[File:OBPP.mov|thumb|Video 4. Acquired glenoid dysplasia secondary to obstetric brachial plexus palsy]]
+[[File:OBPP.mov|thumb|Acquired glenoid dysplasia secondary to obstetric brachial plexus palsy]]
 =Etiology=

@@ Line 2: / Line 2: @@
 *Posterior shoulder instability is not as rare as previously thought.
 *Diagnosing posterior instability may be difficult because patients often report vague symptoms not linked to a clear history of traumatic shoulder dislocation.
 *This condition is consequently often misdiagnosed or patients experience a delay in diagnosis.
 *It that encompasses different acute and chronic pathologies involving the labrum, the cartilage, the capsule, bony lesions.
 *A tear between the posterior labrum and the glenoid cartilage without complete detachment of the labrum is described as a Kim lesion. It is postulated that this lesion is due to posterior force acting on the posterior-inferior glenohumeral ligament as it attaches to the posterior labrum.
 *Numerous classifications exist, none having unanimity.
 *Risk factors for recurrent instability are: (1) age below 40 at time of first instability; (2) dislocation during a seizure; (3) a large reverse Malgaigne (Hill-Sachs) lesion; (4) glenoid retroversion, and (5) a high and horizontally oriented acromion in the sagittal plan.
 *Hyperlaxity is multidirectional but instability is almost exclusively unidirectional.
 *Physical examination comprises the articular range of motion, the rotator cuff, and jerk, Kim and O’Brien tests.
 *Three views plain radiographs, including true anteroposterior of the glenohumeral joint, scapular Y (scapular lateral), and Bernageau views are the mainstay of imaging in the setting of shoulder instability.
 *An internally rotated humeral head gives a rounded appearance on anteroposterior view, which is called the lightbulb sign.
 *In case of a suspicion about posterior dislocation of the shoulder, additional imaging including, depending of the type of instability, magnetic resonance arthrography (MRA) or computed tomography (CT) is required.
 *Acute or recurrent posterior dislocations can be treated conservatively, by soft tissue or bony procedures.
 *Surgical options include anatomic reconstruction as well as non-anatomic procedures such as subscapularis tendon transfer, allo-/autograft reconstruction, derotation osteotomy or shoulder arthroplasty.
 *Treatment of locked dislocation depends on the extent of the articular defect size of the humeral head, duration of the dislocation and patient-specific conditions such as age and activity levels.

@@ Line 316: / Line 316: @@
 ===Recurrent===
-Patients with A1-C1 type of instability tend to have a more favorable result with conservative measures.<ref>Clavert P, Furioli E, Andieu K, et al. Clinical outcomes of posterior bone block procedures for posterior shoulder instability: Multicenter retrospective study of 66 cases. Orthop Traumatol Surg Res 2017;103:S193-S7</ref><ref name=":0" /><ref>Aydin N, Enes Kayaalp M, Asansu M, Karaismailoglu B. Treatment options for locked posterior shoulder dislocations and clinical outcomes. EFORT Open Rev. 2019;4:194-200.</ref> Voluntary posterior dislocators should not be operated on. Management begins with activity modification to prevent further injury, medications as needed and physiotherapy.
+Patients with A1-C1 type of instability tend to have a more favorable result with conservative measures.<ref>Clavert P, Furioli E, Andieu K, Sirveaux F, Hardy MB, Nourissat G, Bouju Y, Garret J, Godenèche A, Mansatet P. Clinical outcomes of posterior bone block procedures for posterior shoulder instability: Multicenter retrospective study of 66 cases. Orthop Traumatol Surg Res 2017;103:S193-S7.</ref><ref name=":0" /><ref>Aydin N, Enes Kayaalp M, Asansu M, Karaismailoglu B. Treatment options for locked posterior shoulder dislocations and clinical outcomes. EFORT Open Rev. 2019;4:194-200.</ref> Voluntary posterior dislocators should not be operated on. Management begins with activity modification to prevent further injury, medications as needed and physiotherapy.
 ===Physiotherapy===
-Physical therapy is focused on strengthening of the subscapularis that will maintain the humeral head anteriorly, posterior deltoid, and the periscapular stabilizers through resisted external rotation exercises.<ref>McIntyre K, Bèlanger A, Dhir J, et al. Evidence-based conservative rehabilitation for posterior glenohumeral instability: a systematic review. Phys Ther Sport. 2016;22:94–100</ref> The aim is to improve the neuromuscular control of the shoulder joint and to regain dynamic muscular stability.
+Physical therapy is focused on strengthening of the subscapularis that will maintain the humeral head anteriorly, posterior deltoid, and the periscapular stabilizers through resisted external rotation exercises.<ref name=":3">McIntyre K, Bèlanger A, Dhir J, Somerville L, Watson L, Willis M, Sadi J. Evidence-based conservative rehabilitation for posterior glenohumeral instability: a systematic review. Phys Ther Sport. 2016;22:94–100.</ref> The aim is to improve the neuromuscular control of the shoulder joint and to regain dynamic muscular stability.
 Isokinetic muscle performance testing can assess muscle strength and neuromuscular control ability using time to peak torque and acceleration time in patients with traumatic shoulder instability. The injured shoulder usually shows delayed neuromuscular control in rotations. This information helps clinicians and therapists to implement exercises that aim to restore neuromuscular control in patients' rehabilitation.<ref>Lee JH, Park JS, Hwang HJ, Jeong WK. Time to peak torque and acceleration time are altered in male patients following traumatic shoulder instability. J Shoulder Elbow Surg. 2018 Aug;27(8):1505-1511</ref><ref>Jan J, Benkalfate T, Rochcongar P. The impact of recurrent dislocation on shoulder rotator muscle balance (a prospective study of 102 male patients). Ann Phys Rehabil Med. 2012 Sep;55(6):404-14</ref>
@@ Line 335: / Line 335: @@
 Open reduction is indicated in dislocations in which closed reduction cannot or should not be achieved. Several conditions are contraindications (i.e. if fracture dislocation). Reverse Malgaigne (Hill-Sachs) lesions > 25% of the humeral head articular surface in size are often unstable after closed reduction and they also require surgical intervention. Open reduction and surgical stabilization are indicated in such cases with defects 25% to 45% of the humeral head articular surface.
-The deltopectoral approach is used to reconstruct the humeral head bony defect by the transfer of the subscapularis tendon with transosseous sutures described by McLaughlin<ref>McLaughlin HL. Posterior dislocation of the shoulder (follow-up note). J Bone Joint Surg [Am]1962;44-A:1477</ref> or by suture anchors described by Spencer and Brems.<ref>Spencer EE, Jr, Brems JJ. A simple technique for management of locked posterior shoulder dislocations: report of two cases. J Shoulder Elbow Surg 2005;14:650–652.</ref> The posterior subdeltoid approach can also be used and this approach lets the surgeon to fill the defect with autograft and perform a Bankart type capsulorrhaphy.<ref>Dubousset J. Posterior dislocations of the shoulder. Rev Chir Orthop Reparatrice Appar Mot 1967;53:65–85.</ref> If the injury is < 3 weeks old, disimpaction and bone grafting of the defect can be performed. For any glenoid bone loss, an iliac crest bone graft can be used as a block and both approaches can be preferred.<ref>Augereau B, Leyder P, Apoil A. Treatment of inveterate posterior shoulder dislocation by the double approach and retroglenoid bone support. Rev Chir Orthop Reparatrice Appar Mot 1983;69(Suppl. 2):89–90</ref>
+The deltopectoral approach is used to reconstruct the humeral head bony defect by the transfer of the subscapularis tendon with transosseous sutures described by McLaughlin<ref>McLaughlin HL. Posterior dislocation of the shoulder (follow-up note). J Bone Joint Surg [Am]1962;44-A:1477</ref> or by suture anchors described by Spencer and Brems.<ref name=":4">Spencer EE, Jr, Brems JJ. A simple technique for management of locked posterior shoulder dislocations: report of two cases. J Shoulder Elbow Surg 2005;14:650–652.</ref> The posterior subdeltoid approach can also be used and this approach lets the surgeon to fill the defect with autograft and perform a Bankart type capsulorrhaphy.<ref>Dubousset J. Posterior dislocations of the shoulder. Rev Chir Orthop Reparatrice Appar Mot 1967;53:65–85.</ref> If the injury is < 3 weeks old, disimpaction and bone grafting of the defect can be performed. For any glenoid bone loss, an iliac crest bone graft can be used as a block and both approaches can be preferred.<ref>Augereau B, Leyder P, Apoil A. Treatment of inveterate posterior shoulder dislocation by the double approach and retroglenoid bone support. Rev Chir Orthop Reparatrice Appar Mot 1983;69(Suppl. 2):89–90</ref>
 [[File:1562915201982-lg.jpg|center|thumb|700x700px|Figure 25. Coronal (A) and axial (B) CT sections of a left-side type IV cephalotubercular fracture. In this situation, the head should not be reduced via the deltopectoral approach, but simply make a small posterior approach through which a tamp is passed (green arrow) which will push the head backwards (C). Anteroposterior and Lamy lateral postoperative radiographs (D and E, respectively).]]
@@ Line 380: / Line 380: @@
 =====McLaughlin Procedure (Open Transfer of the Subscapularis Tendon)=====
-One of the earliest described techniques involves transferring the tenotomized subscapularis tendon to the humeral defect (from 25% to 45% of the humeral head articular surface) and is known as the McLaughlin procedure.<ref>McLaughlin HL. Locked posterior subluxation of the shoulder: diagnosis and treatment. Surg Clin North Am 1963;43:1621–1622</ref> Hawkins et al reported that if the period of delay is > 6 months, the articular cartilage of humeral head gets non-viable; therefore, the McLaughlin procedure should not be preferred.<ref name=":2" /><ref>Delcogliano A, Caporaso A, Chiossi S, et al. Surgical management of chronic, unreduced posterior dislocation of the shoulder. Knee Surg Sports Traumatol Arthrosc 2005;13:151–155.</ref>
+One of the earliest described techniques involves transferring the tenotomized subscapularis tendon to the humeral defect (from 25% to 45% of the humeral head articular surface) and is known as the McLaughlin procedure.<ref>McLaughlin HL. Locked posterior subluxation of the shoulder: diagnosis and treatment. Surg Clin North Am 1963;43:1621–1622</ref> Hawkins et al reported that if the period of delay is > 6 months, the articular cartilage of humeral head gets non-viable; therefore, the McLaughlin procedure should not be preferred.<ref name=":2" /><ref name=":5">Delcogliano A, Caporaso A, Chiossi S, Menghi A, Cillo M, Delcogliano M. Surgical management of chronic, unreduced posterior dislocation of the shoulder. Knee Surg Sports Traumatol Arthrosc 2005;13:151–155.</ref>
@@ Line 390: / Line 390: @@
 =====Osteotomy of the Lesser Tuberosity With the Attached Subscapularis (Hughes and Neer method)=====
-Several authors modified McLaughlin’s method and described osteotomizing the lesser tuberosity with the attached subscapularis tendon and fixing it to the defective area.<ref>Delcogliano A, Caporaso A, Chiossi S, et al. Surgical management of chronic, unreduced posterior dislocation of the shoulder. Knee Surg Sports Traumatol Arthrosc 2005;13(2):151–155</ref><ref>Spencer EE, Jr, Brems JJ. A simple technique for management of locked posterior shoulder dislocations: report of two cases. J Shoulder Elbow Surg 2005;14(6):650–652</ref> The modified McLaughlin method provides additional bony support for the defective area and is preferred for patients when the injury is older than three weeks.<ref>Castagna A, Delle Rose G, Borroni M, et al. Modified MacLaughlin procedure in the treatment of neglected posterior dislocation of the shoulder. Chir Organi Mov 2009;93:1–5.</ref> Depending on the importance of the bone loss, simultaneous iliac crest autograft, dry morselized allograft, fresh-frozen femoral head bone allograft can be perform.<ref>Khira YM, Salama AM. Treatment of locked posterior shoulder dislocation with bone defect. Orthopedics 2017;40:501–5.</ref><ref>Kokkalis ZT, Mavrogenis AF, Ballas EG, Papanastasiou J, Papagelopoulos PJ. Modified McLaughlin technique for neglected locked posterior dislocation of the shoulder. Orthopedics 2013;36:912–6.</ref>
+Several authors modified McLaughlin’s method and described osteotomizing the lesser tuberosity with the attached subscapularis tendon and fixing it to the defective area.<ref name=":5" /><ref name=":4" /> The modified McLaughlin method provides additional bony support for the defective area and is preferred for patients when the injury is older than three weeks.<ref name=":6">Castagna A, Delle Rose G, Borroni M, Markopoulos N, Conti M, Maradei L, Garofalo R. Modified MacLaughlin procedure in the treatment of neglected posterior dislocation of the shoulder. Chir Organi Mov 2009;93:1–5.</ref> Depending on the importance of the bone loss, simultaneous iliac crest autograft, dry morselized allograft, fresh-frozen femoral head bone allograft can be perform.<ref>Khira YM, Salama AM. Treatment of locked posterior shoulder dislocation with bone defect. Orthopedics 2017;40:501–5.</ref><ref>Kokkalis ZT, Mavrogenis AF, Ballas EG, Papanastasiou J, Papagelopoulos PJ. Modified McLaughlin technique for neglected locked posterior dislocation of the shoulder. Orthopedics 2013;36:912–6.</ref>
-The surgery is performed in a beach chair position. The deltopectoral approach is used. First, the biceps tendon is identified as a landmark for the bicipital groove. The lower edge of the subscapularis tendon is detected in order to mark lesser tuberosity. Osteotomy of the lesser tuberosity is performed from lateral to medial, starting from the bicipital groove to the defect of the humeral head.<ref>Castagna A, Delle Rose G, Borroni M, et al. Modified MacLaughlin procedure in the treatment of neglected posterior dislocation of the shoulder. Chir Organi Mov 2009;93(1):1–5</ref> The lesser tuberosity with the attached subscapularis tendon is elevated in order to demonstrate the head and the glenoid. Reduction is performed and when achieved, the lesser tuberosity with the attached subscapularis tendon is fixed into the humeral head defect using ether screws, anchors or sutures.<ref>Shams A, El-Sayed M, Gamal O, ElSawy M, Azzam W. Modified technique for reconstructing reverse Hill-Sachs lesion in locked chronic posterior shoulder dislocation. Eur J Orthop Surg Traumatol 2016;26:843–9.</ref><ref>Kokkalis ZT, Mavrogenis AF, Ballas EG, Papanastasiou J, Papagelopoulos PJ. Modified McLaughlin technique for neglected locked posterior dislocation of the shoulder. Orthopedics 2013;36:912–6.</ref> Reported results are usually excellent.<ref>Banerjee M, Balke M, Bouillon B, Wafaisade A, Helm P, Akoto R, Shafizadeh S. Excellent results of lesser tuberosity transfer in acute locked posterior shoulder dislocation. Knee Surg Sports Traumatol Arthrosc 2013;21:2884–8.</ref><ref>Kokkalis ZT, Mavrogenis AF, Ballas EG, Papanastasiou J, Papagelopoulos PJ. Modified McLaughlin technique for neglected locked posterior dislocation of the shoulder. Orthopedics 2013;36:912–6.</ref>
+The surgery is performed in a beach chair position. The deltopectoral approach is used. First, the biceps tendon is identified as a landmark for the bicipital groove. The lower edge of the subscapularis tendon is detected in order to mark lesser tuberosity. Osteotomy of the lesser tuberosity is performed from lateral to medial, starting from the bicipital groove to the defect of the humeral head.<ref name=":6" /> The lesser tuberosity with the attached subscapularis tendon is elevated in order to demonstrate the head and the glenoid. Reduction is performed and when achieved, the lesser tuberosity with the attached subscapularis tendon is fixed into the humeral head defect using ether screws, anchors or sutures.<ref>Shams A, El-Sayed M, Gamal O, ElSawy M, Azzam W. Modified technique for reconstructing reverse Hill-Sachs lesion in locked chronic posterior shoulder dislocation. Eur J Orthop Surg Traumatol 2016;26:843–9.</ref><ref>Kokkalis ZT, Mavrogenis AF, Ballas EG, Papanastasiou J, Papagelopoulos PJ. Modified McLaughlin technique for neglected locked posterior dislocation of the shoulder. Orthopedics 2013;36:912–6.</ref> Reported results are usually excellent.<ref>Banerjee M, Balke M, Bouillon B, Wafaisade A, Helm P, Akoto R, Shafizadeh S. Excellent results of lesser tuberosity transfer in acute locked posterior shoulder dislocation. Knee Surg Sports Traumatol Arthrosc 2013;21:2884–8.</ref><ref>Kokkalis ZT, Mavrogenis AF, Ballas EG, Papanastasiou J, Papagelopoulos PJ. Modified McLaughlin technique for neglected locked posterior dislocation of the shoulder. Orthopedics 2013;36:912–6.</ref>
 ====Humeral Reconstruction with Autograft or Allograft====
@@ Line 448: / Line 448: @@
 =Postoperative Rehabilitation=
-Postoperatively patients are placed into a neutral rotation splint, position that decreases stress on the posterior capsule (Figure 30). Immobilization is carried out for 6 to 8 weeks after surgery. Passive range of motion and active assist range of motion can then begin under the supervision of a physical therapist. Physiotherapy is focused on strengthening of the subscapularis that will maintain the humeral head anteriorly, posterior deltoid, and the periscapular stabilizers through resisted external rotation exercises.<ref>McIntyre K, Bèlanger A, Dhir J, et al. Evidence-based conservative rehabilitation for posterior glenohumeral instability: a systematic review. Phys Ther Sport. 2016;22:94–100</ref> The aim is to improve the neuromuscular control of the shoulder joint and to regain dynamic muscular stability. Strengthening typically begins during the third postoperative month. Return to sports should be decided on a case-by-case basis but usually return is restricted until 6 months out from surgery.
+Postoperatively patients are placed into a neutral rotation splint, position that decreases stress on the posterior capsule (Figure 30). Immobilization is carried out for 6 to 8 weeks after surgery. Passive range of motion and active assist range of motion can then begin under the supervision of a physical therapist. Physiotherapy is focused on strengthening of the subscapularis that will maintain the humeral head anteriorly, posterior deltoid, and the periscapular stabilizers through resisted external rotation exercises.<ref name=":3" /> The aim is to improve the neuromuscular control of the shoulder joint and to regain dynamic muscular stability. Strengthening typically begins during the third postoperative month. Return to sports should be decided on a case-by-case basis but usually return is restricted until 6 months out from surgery.
 [[File:Image51-119.jpg|thumb|Figure 30. Post-traumatic or postoperative immobilization into a neutral rotation splint.]]
 =Complications=
-Complications are specific to patient subsets and the technique of stabilization used. Chronic shoulder pain, allograft collapse, avascular necrosis, non-union, stiffness, omarthrosis and recurrent instability can be seen.<ref>Sperling JW, Pring M, Antuna SA, Cofield RH. Shoulder arthroplasty for locked posterior dislocation of the shoulder. J Shoulder Elbow Surg 2004;13(5):522–527</ref><ref>Castagna A, Delle Rose G, Borroni M, et al. Modified MacLaughlin procedure in the treatment of neglected posterior dislocation of the shoulder. Chir Organi Mov 2009;93(1):1–5</ref> Patients with recalcitrant epileptic seizures are more prone to redislocation.
+Complications are specific to patient subsets and the technique of stabilization used. Chronic shoulder pain, allograft collapse, avascular necrosis, non-union, stiffness, omarthrosis and recurrent instability can be seen.<ref>Sperling JW, Pring M, Antuna SA, Cofield RH. Shoulder arthroplasty for locked posterior dislocation of the shoulder. J Shoulder Elbow Surg 2004;13(5):522–527</ref><ref name=":6" /> Patients with recalcitrant epileptic seizures are more prone to redislocation.

@@ Line 109: / Line 109: @@
 Posterior instability includes a wide spectrum of pathological conditions, which are sometimes difficult to classify homogeneously.
-Classifications of posterior instability have been confusing and most attempt of classification failed. The ABC classification has the merit to be correlated to the presence or not of lesion(s), indication for surgery and results.<ref>Moroder P, Scheibel M. ABC classification of posterior shoulder instability. Obere Extrem 2017;12:66-74</ref>
+Classifications of posterior instability have been confusing and most attempt of classification failed. The ABC classification has the merit to be correlated to the presence or not of lesion(s), indication for surgery and results.<ref name=":0">Moroder P, Scheibel M. ABC classification of posterior shoulder instability. Obere Extrem 2017;12:66-74</ref>
 Table 1: The ABC classification of posterior shoulder instability
@@ Line 148: / Line 148: @@
 This condition (micro-instability) is characterized by pain that appears without trauma, without macro-instability (subluxation or dislocation) in a patient that usually does not suffer from hyperlaxity.<ref>Boileau P, Zumstein M, Balg F, Penington S, Bicknell RT. The unstable painful shoulder (UPS) as a cause of pain from unrecognized anteroinferior instability in the young athlete. J Shoulder Elbow Surg 2011;20:98-106</ref><ref>Patte D, Bernageau J, Rodineau J, Gardes JC. [Unstable painful shoulders (author's transl)]. Rev Chir Orthop Reparatrice Appar Mot 1980;66:157-65</ref>
-Diagnosis is difficult and should not be confused with posterior static subluxation (B0 glenoid according to Walch)<ref>Domos P, Checchia CS, Walch G. Walch B0 glenoid: pre-osteoarthritic posterior subluxation of the humeral head. J Shoulder Elbow Surg 2018;27:181-8</ref> that belong to the type C2. Images are often relevant with 52% of reverse Bankart, glenoid or humeral cartilage lesions (28% and 8%, respectively) reported (Video 2).
+Diagnosis is difficult and should not be confused with posterior static subluxation (B0 glenoid according to Walch)<ref name=":1">Domos P, Checchia CS, Walch G. Walch B0 glenoid: pre-osteoarthritic posterior subluxation of the humeral head. J Shoulder Elbow Surg 2018;27:181-8</ref> that belong to the type C2. Images are often relevant with 52% of reverse Bankart, glenoid or humeral cartilage lesions (28% and 8%, respectively) reported (Video 2).
 [[File:Media11-94.mov|thumb|Video 2. Posterior labral lesion in a patient suffering from unstable painful shoulder]]
@@ Line 171: / Line 171: @@
 ====Static Posterior Subluxation====
-The finding of static posterior subluxation of the humeral head before the development of posterior bone erosion of the glenoid in young men with radiographic findings of primary osteoarthritis has been described as arthrogenic (pre-osteoarthritic) posterior subluxation of the humeral head,<ref>Walch G, Ascani C, Boulahia A, Nove-Josserand L, Edwards TB. Static posterior subluxation of the humeral head: an unrecognized entity responsible for glenohumeral osteoarthritis in the young adult. J Shoulder Elbow Surg 2002;11:309-14</ref> or Walch B0 glenoid.<ref>Domos P, Checchia CS, Walch G. Walch B0 glenoid: pre-osteoarthritic posterior subluxation of the humeral head. J Shoulder Elbow Surg 2018;27:181-8</ref> This condition could be initially dynamic, eventually evolving into a static condition and may lead to posterior erosion of the glenoid, taking place once there is asymmetrically increased posterior glenohumeral contact forces and possibly associated with increased glenoid retroversion (Figure 9).
+The finding of static posterior subluxation of the humeral head before the development of posterior bone erosion of the glenoid in young men with radiographic findings of primary osteoarthritis has been described as arthrogenic (pre-osteoarthritic) posterior subluxation of the humeral head,<ref>Walch G, Ascani C, Boulahia A, Nove-Josserand L, Edwards TB. Static posterior subluxation of the humeral head: an unrecognized entity responsible for glenohumeral osteoarthritis in the young adult. J Shoulder Elbow Surg 2002;11:309-14</ref> or Walch B0 glenoid.<ref name=":1" /> This condition could be initially dynamic, eventually evolving into a static condition and may lead to posterior erosion of the glenoid, taking place once there is asymmetrically increased posterior glenohumeral contact forces and possibly associated with increased glenoid retroversion (Figure 9).
@@ Line 254: / Line 254: @@
 =Imaging=
-The diagnosis of this injury is often missed at initial examination, despite highly suggestive injury circumstances, notable clinical signs and radiographic evidence.<ref>Hawkins RJ, Neer CS, II, Pianta RM, Mendoza FX. Locked posterior dislocation of the shoulder. J Bone Joint Surg [Am] 1987;69-A(1):9–18</ref>
+The diagnosis of this injury is often missed at initial examination, despite highly suggestive injury circumstances, notable clinical signs and radiographic evidence.<ref name=":2">Hawkins RJ, Neer CS, II, Pianta RM, Mendoza FX. Locked posterior dislocation of the shoulder. J Bone Joint Surg [Am] 1987;69-A:9–18.</ref>
 ==Plain Radiographs==
@@ Line 316: / Line 316: @@
 ===Recurrent===
-Patients with A1-C1 type of instability tend to have a more favorable result with conservative measures.<ref>Clavert P, Furioli E, Andieu K, et al. Clinical outcomes of posterior bone block procedures for posterior shoulder instability: Multicenter retrospective study of 66 cases. Orthop Traumatol Surg Res 2017;103:S193-S7</ref><ref>Moroder P, Scheibel M. ABC classification of posterior shoulder instability. Obere Extrem 2017;12:66-74</ref><ref>Aydin N, Enes Kayaalp M, Asansu M, Karaismailoglu B. Treatment options for locked posterior shoulder dislocations and clinical outcomes. EFORT Open Rev. 2019;4:194-200.</ref> Voluntary posterior dislocators should not be operated on. Management begins with activity modification to prevent further injury, medications as needed and physiotherapy.
+Patients with A1-C1 type of instability tend to have a more favorable result with conservative measures.<ref>Clavert P, Furioli E, Andieu K, et al. Clinical outcomes of posterior bone block procedures for posterior shoulder instability: Multicenter retrospective study of 66 cases. Orthop Traumatol Surg Res 2017;103:S193-S7</ref><ref name=":0" /><ref>Aydin N, Enes Kayaalp M, Asansu M, Karaismailoglu B. Treatment options for locked posterior shoulder dislocations and clinical outcomes. EFORT Open Rev. 2019;4:194-200.</ref> Voluntary posterior dislocators should not be operated on. Management begins with activity modification to prevent further injury, medications as needed and physiotherapy.
 ===Physiotherapy===
@@ Line 380: / Line 380: @@
 =====McLaughlin Procedure (Open Transfer of the Subscapularis Tendon)=====
-One of the earliest described techniques involves transferring the tenotomized subscapularis tendon to the humeral defect (from 25% to 45% of the humeral head articular surface) and is known as the McLaughlin procedure.<ref>McLaughlin HL. Locked posterior subluxation of the shoulder: diagnosis and treatment. Surg Clin North Am 1963;43:1621–1622</ref> Hawkins et al reported that if the period of delay is > 6 months, the articular cartilage of humeral head gets non-viable; therefore, the McLaughlin procedure should not be preferred.<ref>Hawkins RJ, Neer CS, II, Pianta RM, Mendoza FX. Locked posterior dislocation of the shoulder. J Bone Joint Surg [Am] 1987;69-A(1):9–18</ref><ref>Delcogliano A, Caporaso A, Chiossi S, et al. Surgical management of chronic, unreduced posterior dislocation of the shoulder. Knee Surg Sports Traumatol Arthrosc 2005;13:151–155.</ref>
+One of the earliest described techniques involves transferring the tenotomized subscapularis tendon to the humeral defect (from 25% to 45% of the humeral head articular surface) and is known as the McLaughlin procedure.<ref>McLaughlin HL. Locked posterior subluxation of the shoulder: diagnosis and treatment. Surg Clin North Am 1963;43:1621–1622</ref> Hawkins et al reported that if the period of delay is > 6 months, the articular cartilage of humeral head gets non-viable; therefore, the McLaughlin procedure should not be preferred.<ref name=":2" /><ref>Delcogliano A, Caporaso A, Chiossi S, et al. Surgical management of chronic, unreduced posterior dislocation of the shoulder. Knee Surg Sports Traumatol Arthrosc 2005;13:151–155.</ref>