Irreducible acute anterior dislocation of the shoulder caused by interposed fragment of the anterior glenoid rim

A Systematic Review of Acute Irreducible Shoulder Dislocations in the 21st Century

Background

Rarely, closed reduction cannot be achieved in patients with acute shoulder dislocation, necessitating open management. A paucity of literature exists regarding these cases.

Purpose

To perform a systematic review on the mechanism, management, and outcome data of acute irreducible shoulder dislocations.

Study Design

Systematic review; Level of evidence, 4.

Methods

A systematic review of the literature was performed using the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed, and MEDLINE between 2000 and 2020. Inclusion criteria were as follows: human participants, acute irreducible shoulder dislocation requiring open management, English language, and publication within the past 20 years. We excluded basic science articles, technique articles, reviews, editorials, and studies of chronic shoulder dislocations or dislocations with ipsilateral humeral shaft fractures.

Results

Twelve articles fit the inclusion criteria and were considered for review. All studies were single case reports (level 4 evidence). Ten of the 12 studies were of male patients. The direction of dislocation included 7 anterior/anteroinferior, 2 posterior, 1 inferior, 1 bilateral inferior, and 1 superolateral. Most dislocations were irreducible owing to a mechanical block to reduction. The most common type of block was an incarcerated long head of the biceps tendon, followed by interposition of 1 of the rotator cuff tendons. The axillary and musculocutaneous nerves, displaced fracture fragments, and Hill-Sachs and bony Bankart lesions were other causes of blocks to reduction. Eleven patients were treated with open surgery, while 1 patient was treated arthroscopically. Procedures performed were dependent on concurrent pathology. Final follow-up ranged from 6 weeks to 2 years, with no repeat dislocation episodes reported. Complications after open reduction included 1 case of brachial plexopathy (posterior cord) and 1 case of musculocutaneous nerve palsy.

Conclusion

There is a paucity of literature on the management of irreducible acute shoulder dislocations. The most common irreducible dislocation found in this systematic review was anterior with a mechanical block attributed to interposition of the long head of the biceps tendon. When patients were treated with an open or arthroscopic procedure, recurrence was low, with none reporting recurrent dislocation in limited follow-up.

[Initial management of traumatic ventral shoulder dislocation]

BACKGROUND

In the current literature a consensus on the specific management of primary anterior traumatic shoulder instability has not been reached. While the steps of the initial diagnostic and therapeutic procedures are mostly well-defined, a variety of factors need to be considered for the planning of further treatment.

OBJECTIVE

This article aims at giving an overview of the essential aspects of the initial management in the rescue center, clinical and radiological diagnostic procedures and the subsequent treatment options.

MATERIAL AND METHODS

The content of this article is based on our own clinical experiences in combination with a systematic literature search for relevant clinical and baseline studies.

RESULTS

Besides a detailed anamnesis and clinical examination, X‑rays in two planes are important for the diagnosis. Potential nerve injuries or fractures need to be borne in mind before and after reduction of the joint and documented accordingly. The Matsen's maneuver can be recommended as it enables a careful repositioning. In rare cases of an irreducible shoulder dislocation due to soft tissue or bony articular interpositions, an open reduction might be necessary. Further therapeutic concepts should be adapted to patient age, activity level and accompanying pathologies, which determine the risk of a recurrent dislocation. A surgical approach for stabilization of the shoulder is highly recommended in cases of concomitant bony defects as well as in young and physically active patients.

CONCLUSION

A well-structured treatment plan is essential for the initial management of primary anterior traumatic shoulder instability. A generally applicable algorithm for further management is not yet established. The treatment should therefore be individually planned based on patient-specific characteristics.

Treatment of Irreducible Traumatic Anterior Shoulder Dislocation Caused by Subscapularis Tendon Interposition

Irreducible shoulder dislocation is an uncommon event. When it does occur, blocks to reduction can include bone, labrum, rotator cuff musculature, or tendon. Concomitant rotator cuff tear at the time of initial dislocation is not an exclusive complication of anterior shoulder dislocation in the older population. Indeed, rotator cuff tear should not be excluded based solely on the patient's age. Rotator cuff interposition is not an uncommon complication after anterior dislocation of the shoulder. It should be suspected when there is incongruency of the joint and persistent subluxation on postreduction radiographs. If such incongruence or subluxation is seen, a computed tomographic (CT) or magnetic resonance imaging (MRI) scan must then be obtained to determine the nature of the interposed soft tissues. The key to treatment is early diagnosis and adequate imaging. Open reduction and repair of the rotator cuff should be performed. We present a technique for treating irreducible anterior shoulder dislocation caused by interposition of the subscapularis tendon. Both CT and MRI observations, along with intraoperative findings and surgical technique, are discussed.

Irreducible Anterior Shoulder Dislocation with Interposition of the Long Head of the Biceps and Greater Tuberosity Fracture: A Case Report and Review of the Literature

Background:

Failure of closed manipulative reduction of an acute anterior shoulder dislocation is seldom reported in the literature and is usually due to structural blocks such as soft tissue entrapment (biceps, subscapularis, labrum), bony fragments (glenoid, greater tuberosity) and severe head impaction (Hill-Sachs lesion).

Case report:

We present a case of an irreducible anterior shoulder dislocation in a 57-year-old male patient after a road-traffic accident. He had severe impaction of the head underneath glenoid rim and associated fracture of the greater tuberosity. Closed reduction performed in the emergency room under sedation and later at the theatre under general anaesthesia was unsuccessful. Open reduction using the dectopectoral approach revealed that the reason for obstruction was the posterolateral entrapment of the biceps tendon between the humeral head and the tuberosity fragment. Reduction was achieved after subscapularis tenotomy and opening of the joint; the tuberosity fragment was fixed with transosseous sutures and the long head of the biceps tendon was tenodesized. The patient had an uneventful postoperative recovery and at his last follow up, 12 months postoperatively, he had a stable joint, full range of motion and a Constant score of 90.

Conclusion:

A comprehensive literature review revealed 22 similar reports affecting a total of 30 patients. Interposition of the LHBT alone or in combination with greater tuberosity fracture was the most common obstacle to reduction, followed by subscapularis tendon interposition and other less common reasons. Early surgical intervention with open reduction and confrontation of associated injuries is mandatory for a successful outcome.

Locked bucket-handle type bony Bankart lesion resulting from manipulation

A patient who underwent manipulation for stiffness accompanying a rotator cuff tear experienced a complication consisting of a bony Bankart lesion connected to the superior and inferior labrum. This lesion was displaced posteriorly, locked behind the humeral head and blocking the reduction. Attachment of the labrum to this fragment made reduction and fixation easier. This bony Bankart lesion was fixed successfully by arthroscopic placement of knotless suture anchors. Level of evidence Case report, Level IV.

Glenohumeral interposition of rotator cuff stumps: a rare complication of traumatic rotator cuff tear

The present report describes a case where typical findings of traumatic glenohumeral interposition of rotator cuff stumps were surgically confirmed. This condition is a rare complication of shoulder trauma. Generally, it occurs in high-energy trauma, frequently in association with glenohumeral joint dislocation. Radiography demonstrated increased joint space, internal rotation of the humerus and coracoid process fracture. In addition to the mentioned findings, magnetic resonance imaging showed massive rotator cuff tear with interposition of the supraspinatus, infraspinatus and subscapularis stumps within the glenohumeral joint. Surgical treatment was performed confirming the injury and the rotator cuff stumps interposition. It is important that radiologists and orthopedic surgeons become familiar with this entity which, because of its rarity, might be neglected in cases of shoulder trauma.

Irreducible superolateral dislocation of the glenohumeral joint

The overwhelming majority of glenohumeral dislocations are anterior dislocations that either spontaneously reduce or are reduced at the point of care without significant complications. Posterior dislocations are uncommon, and superior and inferior dislocations are even rarer. We present a case of "superolateral" shoulder dislocation in which the entire rotator cuff was torn either off its insertion or at the musculotendinous junction in combination with a large longitudinal split tear of the deltoid muscle. This allowed the humeral head to dislocate both superiorly and laterally into a subcutaneous position through the tear of the anterolateral deltoid muscle with an associated de-gloving soft tissue lesion. Buttonholing of the humeral head through the deltoid and interposition of the dislocated long head of the biceps tendon and macerated rotator cuff prevented closed reduction of the glenohumeral joint. The resultant radiographic appearance and treatment of this dislocation is unique. To our knowledge, this is the first reported case of this dislocation in the literature.

Pseudoparalysis of shoulder caused by glenohumeral interposition of rotator cuff tendon stumps: a rare complication of posterior shoulder dislocation

Magnetic resonance imaging (MRI) findings of a rare complication of posterior glenohumeral dislocation are described in two patients which led to shoulder dysfunction caused by interposition of rotator cuff tendon(s) into the glenohumeral joint. Both patients underwent successful surgical fixation and now have returned to normal shoulder function.

Occult interpositional rotator cuff - an extremely rare case of traumatic rotator cuff tear

Traumatic interposition of a rotator cuff tendon in the glenohumeral joint without recognizable glenohumeral dislocation is an unusual complication after shoulder trauma. Here we report the clinical and imaging presentations of a 17-year-old man with trapped rotator cuff tendons in the glenohumeral joint after a bicycle accident. The possible trauma mechanism is also discussed.

Innovative use of computer-assisted tomography in the management of an irreducible anterior shoulder dislocation

Anterior dislocation of the shoulder is a common injury which is often reduced in the emergency department, without specialist orthopedic input. We report a case of an irreducible locked anterior glenohumeral dislocation with impaction of the humeral head onto the antero-inferior glenoid rim and subsequent generation of a Hill–Sachs lesion. To our knowledge, we describe the first reported case of using computer-assisted tomography to generate a sequence of movements to safely disimpact the locked dislocation without causing further iatrogenic injury or a fracture through the humeral articular surface. This novel image-assisted closed reduction technique spared the patient from the morbidity associated with performing open reduction surgery. At 6-month follow-up, the patient reported no re-dislocations, returned to work and had excellent range of motion.

Irreducible anterior and posterior dislocation of the shoulder due to incarceration of the biceps tendon

Mechanical obstacles may infrequently impede closed reduction of anterior shoulder dislocation. Imaging techniques such as arthrography, computed tomography (CT) and magnetic resonance imaging (MRI) complement conventional radiography by allowing identification of obstacles to reduction. We present a case of irreducible anterior glenohumeral dislocation resulting from an initial anterior dislocation, converted to a posterior dislocation with an attempt at reduction, then converted back to anterior dislocation with a second reduction attempt. Soft tissue obstacles to shoulder reduction should be suspected when plain films do not identify a bony fragment as the culprit. CT and MRI are useful for identifying the cause of irreducibility and for operative planning.

Irreducible anterior dislocation of the shoulder due to soft tissue interposition of subscapularis tendon

The shoulder joint is the most unstable joint in the body and is easily dislocated. Anterior shoulder dislocation is the commonest and can be associated with glenoid and humeral fractures. Anterior shoulder dislocations are not infrequently associated with cuff tendon tears; however, anterior shoulder dislocation is easily reducible. Irreducible anterior dislocation of the glenohumeral joint is uncommon, and this could be due to bony as well as soft tissue causes. Persistent anterior dislocation due to torn subscapularis interposition in the glenohumeral joint is very rare, and only a few operative cases have been reported in the literature. We present MR features of one such case and a literature review.