Uncommon dislocations

March 25, 2020 0 By FM

The shoulder joint has the greatest range of motion when compared to hip joint even though both of them are ball and socket joints. The stability of shoulder joint depends on static stabilisers and dynamic stabilisers.

The static stabilisers are the joint, glenoid labrum, capsule and superior, middle and inferior gleno-humeral ligaments.

The dynamic stabilisers are:

1. The rotator cuff

It is made up of four muscles, the supraspinatus, the infraspinatus, the teres minor and subscapularis which is located anteriorly. These muscles are inserted into the greater tuberocity of the humerus. The rotator cuff is clinically important because the supraspinatus is the most commonly ruptured muscle near its insertion. 

2. Muscles

Long head of biceps and scapular muscles. 

The sternocleidomastoid muscle is palpated on the side opposite to which the head is turned and is mainly important for hematomas in the muscle. Hematoma along with other causes of wryneck, swollen lymph nodes due to infection, and trauma particularly injuries of the neck or whiplash injury sternocleidomastoid place an important role in stabilisation of neck.

The pectoralis major muscle sometimes may be absent congenitally, most frequently either in whole or in part. The costochondral junctions which lie just next to the sternum are the frequent site of costochondritis and tenderness at the site is the most common sign on palpation.

The biceps muscle is palpated with the elbow in resisted flexion and can be seen curled up in the mid arm when the long head of the biceps is torn. The long head of the biceps may be involved in tenosynovitis when it is tender or may be dislocated in the bicipital groove which is well palpated when the shoulder is laterally rotated.

The deltoid may be atrophied in cases of axillary nerve damage usually because of shoulder dislocations. The deltoid muscle converges down to the midpoint of the lateral aspect of the arm to a bony prominence known as the deltoid tuberocity.

The trapezius is a fan-shaped muscle which extends from the occiput along the spinous processes of the cervical spine into the clavicle, acromion, and the spine of the scapula where it merges into the origin of the deltoid.

The shoulder dislocations are classified as:

1. Acute and chronic.

2. Voluntary and involuntary.

3. Traumatic and atraumatic. 

4. Anterior, posterior, inferior or superior.

5. Recurrent dislocations: Anterior or posterior. 

The most common acute and recurrent dislocation of shoulder are anterior dislocation. Posterior dislocations are rare. 

The shoulder girdle consists of three joints and one articulation: 

1. The sterno-clavicular joint

2.The acromion-clavicular joint and the subacromial bursa which has two main components, the subacromial and the sub deltoid parts. Bursitis is a frequent pathology causing tenderness and limitation of shoulder movements. The most common conditions which causes pain in the sub acromial region are sub acromion bursitis, shoulder impingement syndrome, rotator cuff tendinitis and partial tear of rotator cuff. 

3. The gleno-humeral or shoulder joint and

4. The scapula-thoracic articulation.

Range of movements 

The Apley’s scratch test evaluates all ranges of movements of the shoulder girdle. Firstly, ask the patient to touch the superomedial angle of the opposite scapula behind the head. This tests abduction and lateral rotation. Then ask the patient to touch the opposite acromion in front of the head, which tests internal rotation and adduction. Finally, further test adduction and internal rotation by asking the patient to touch the opposite scapula at its inferior angle, from behind.

Anterior dislocations

Anterior dislocations of the shoulder are the most common among acute as well as recurrent dislocations of the shoulder. It is caused by direct blow or due to fall on outstretched hand. Usually the limb is kept in externally rotated and abducted position. 

Two typical lesions described are: 

1. The Hill Sachs lesion which is nothing but an impaction of humeral head by glenoid rim. 30 to 40% of anterior dislocations may have this.

2. Bankart lesion which is a disruption of glenoid, may be associated with an avulsion bony injury.

Complications following anterior dislocations are: 

1. Axillary artery injury: The axilla is a pyramidal space through which nerves and vessels pass into the upper arm. The axilla is formed anteriorly by the pectoralis major muscle and posteriorly by the latissimus dorsi muscle, medial border is formed by the second to sixth ribs with its overlying serratus anterior muscle, and the lateral wall is by bicipital groove of the humerus. The shoulder joint is the apex of the pyramid, and the axilla is supplied by the brachial plexus and the axillary arteries.

2. Axillary nerve injury: The incidence is 37%. It causes deltoid muscle weakness, clinically characterized by loss of contour of the shoulder joint.

3. Supra-scapular nerve injury: Incidence is 29%.

4. Radial nerve injury: Incidence is 22%.

Posterior dislocations are rather uncommon, and it occurs typically due to violent muscle contractions in electrocution and epilepsy. Very often this may go unrecognized particularly in elder patients. Clinically flattening of anterior shoulder, absent glenoid sign and limitation of external rotation and they hold the arm adducted and internally rotated. 

A case report of posterior dislocation shoulder in 55 year old man was presented to us after 5 days which was neglected. We have reduced the dislocation under general anaesthesia. The X-ray is shown in Fig 1.

Inferior dislocation otherwise called luxatio in erecta, is a rare entity often less than 1% of occurrence when compared to other types of dislocations. It is caused by hyper abduction of arm that forces the humeral head against the acromion. Inferior dislocations have more vascular and neurological complications than the others.

Operative procedures of recurrent anterior dislocation of shoulder:

The surgical procedures for recurrent anterior dislocation of shoulder are based on two principles: either passive control of humeral head with capsular repair, like in the Bankart procedure, or active control, in which the muscle power prevents re-dislocation, as in the Bristow procedure / Boytchev procedure. More than 150 operations and many other modifications of some have devised to treat recurrent anterior dislocation of the shoulder. The needs and demands of the patients may vary and also the pathologic conditions of the glenoid and head of the humerus.  

Bankart Operation

In Bankart operation the detached glenoid labrum and anterior part of the capsule are reattached to the rim of the glenoid cavity with sutures passed through holes in the glenoid rim. The subscapularis muscle is separated from the anterior capsule by blunt dissection. It is then divided near its musculo- tendinous junction. Expose the joint by making an incision in the capsule about 5 cm long, 6mm lateral to the rim of the glenoid. With an osteotome roughen rim of the glenoid. Four drill holes are made over the glenoid rim. Suture the free margin of the lateral part of the capsule to the roughened glenoid rim with shoulder in internal rotation. This brings the edge of the capsule to the raw bone of the glenoid rim. The medial part of the capsule may be overlapped and sutured in place. Then suture the subscapularis tendon (Helfet, 1958).

Gallie-le mesurier procedure: It is based on the construction of a ‘‘new ligament” using fascia lata to reinforce the anterior capsule and gleno-humeral ligament.

Hybbinette-Eden procedure: Tibial auto grafts or iliac crest are used to fill the defects. It is fixed to the glenoid defects with the help of screws. The same technique can also be used for recurrent posterior dislocations of the shoulder.

Magnuson-Stack repair: The repair was designed to form a “cup of muscle or tendon around the lower and anterior part of the head of the humerus” and to eliminate the imbalance of the subscapularis muscle when the arm is elevated at the shoulder. Stability of the shoulder after this procedure may depend on limitation of external rotation.

Nicola procedure: Here a suspension is produced by transplanting the long head of the biceps through the humeral head.

Mosely’s vitallium prosthesis: Mosely devised a vitallium rim usually fixed with 2 screws to reconstruct the damaged anterior glenoid rim. The prosthesis is extra articular in position and in no way should impinge on the humeral head.

The Boytchev Procedure: It is based on active muscular control. A musculo-tendinous flap obtained by rerouting the origin of short head of biceps, pectoralis minor and coracobrachialis from the coracoid process, is passed under the subscapularis muscle. Here we have limited the re-routing to the coracobrachialis and short head of biceps, so that muscle fibers with a single direction only are used (Fig. 2) and then reinserted with a screw to the original site of coracoid process. (Fig. 3 and 4)

Theoretically, the net result of Boytchev technique is “an active belt” which prevents anterior displacement of the head of humerus. By splitting the subscapularis longitudinally, the conjoint tendon is re-routed through the upper two third and lower one-third junctions. This avoids pulling the joint capsule anteriorly and less chance of injury to the axillary nerve. To reattach the conjoined tendon, we used two techniques, either osteotomising the coracoid process and reattaching it with a 4mm cancellous screw or resecting the conjoined tendon and reattaching with OS Vicryl.

Bristow Procedure: Helfet (1958) described the Bristow procedure. May (1970) modified the Bristow operation. In this procedure, the coracoid process is transplanted with the attached conjoined tendons of the short head of biceps and coracobrachialis to the anterior rim of glenoid and fixed with a screw. It is also utilized to reinforce the anterior capsule muscular wall in combination with other procedures, usually stapling of the detached anterior capsule and labrum. (Inman, 1944 and Ivar, 1940).

A case report on failed Bristow procedure

A failed Bristow’s procedure due to development of epileptiform attack is described here. The person fell unconscious for 2 days. The posterio-lateral defect can be seen in Fig 6 a and b.

We have treated it by doing PuttiPlatt Surgery:

Putti-Platt repair

This repair leaves the patient with less external rotation, which if forced, may damage the repair. In the Bankart procedure, the subscapularis muscle and tendon are separated from the underlying joint capsule. In the Putti-Platt procedure, the incision is carried down directly
through the subscapularis muscle and capsule into the joint. Overlapping and double breasting are then carried out by internally rotating the arm and attaching the lateral stump of the subscapularis muscle and capsule to the anterior rim of the glenoid and the periosteal tissue of the scapular neck. The medial stump of the subscapularis muscle is then double-breasted over this repair and attached to the lesser tuberocity or bicipital groove (Campbell’s.). We have drilled 4 holes to the anterior rim of glenoid and suturing done with no.5 ethibond.

A second case admitted with fracture dislocation of right shoulder following a road traffic accident. (Fig. 7)

Open reduction and internal fixation of the shoulder done. Philos plate and screw system is used to fix the fracture.  

Dr VinodKumar BP is Additional Professor in Orthopaedics and Dr CS Vikraman is Professor and HOD Orthopaedics at Govt. Medical College, Kollam, Kerala