RECURRENT ANTERIOR DISLOCATION OF THE SHOULDER

This is very common complication of anterior dislocation of shoulder and accounts for the greater then 80% of dislocation of the upper extremity. Age at the time of initial dislocation is an important prognostic factor, recurrence rate being 55% in patient 12-22 year old, 37% in 23-29 year old and 12% in 30-40 year old.

CAUSES

• Failure to immobilize the shoulder for 3 to 4 weeks after initial dislocation
• Size and nature of damage at the time of initial dislocation
• Greater the trauma, lower the incidence
• Younger the patient less is the recurrence

MECHANISM OF DISLOCATION

In some individual the dislocation can be predictable and can be avoided. In others the mechanism is unpredictable and thus makes it a very disabling problem. The usual mechanism of dislocation is external rotation in abducted position.

PATHOLOGICAL ANATOMY

No single deformity is responsible for the recurrent dislocation of shoulder. Three important reasons have been cited and they have been called the essential lesions

TRIAD OF ESSENTIAL LESION

1. 1.     Hill-sach lesion: is a posterlateral defect in the head of the humerus.This is produced due to the impact of the posterolateral part of the head of the humerus against the sharp anterior margin of the glenoid.
2. 2.     Bankart's lesion: THIS was described by Perthes as a defect in the anterior part of the glenoid labrum and also the anterior capsules. If the defect does not heal properly or heals in elongated position it results in RDS.
3. 3.     Erosion of the anterior rim of glenoid cavity

How does RDS occur?

External rotation of the shoulder in abducted position pops out the head of the humerus from the glenoid cavity due to the lax anterior capsular structure. The posterlateral defect now comes in contact with glenoid rim and is levered out of the socket producing dislocation

Since no single factor is responsible for the every recurrent dislocation no single operative procedure can be applied to every patient.

CLINICAL FEATURE OF RECURRENT DISLOCATIONS

Usually patient gives history of a previous episode of traumatic dislocation. After that there could be one or two instances of repeated dislocation during abduction. There could be wasting of deltoid, supraspinatus and infraspinatus muscle there tests help to indentify instability of the shoulder prone to develop RDS.

THE SULCUS TEST: with arm hanging at the side stabilize the scapula from behind and pull the humerus down. A large gap appears beneath the acromian. This suggests interior laxity and is for superior glenohumeral and coracohumeral ligaments.

THE APPREHENSION TEST: THIS is a provocative test where if the arm is placed in abduction, extension and external rotation and if a force is applied, patient, becomes apprehensive and resists the provocation.

RELOCATION TEST: The joint can be dislocated and relocated back into position by manual pressure.

 TREATMENT

There is no role of conservative treatment in recurrent dislocation of the shoulder. Patient is advised to avoid abduction and external rotation rotation of the shoulder. However surgery is the treatment of choice and is indicated if the patient has more than three episodes of RDS

More than 150 operations are devised. Few important ones are mentioned here. All the surgeries aim at correction of the essential lesions and prevent external rotation of the arm.

 

SURGERIES IN RDS

 

 

NAME OF THE SURGERIES

 

 

WHAT IS DONE

Bankart's operation

Detached anterior structures are attached to the rim of the glenoid cavity with sutures

Staple capsulorraphy of Destot and Roux

 

Bankart's lesion attached to labrum with staples

Putti-Platt's operation

Subscapularis tendon and capsule is overlapped and tightened.

Magnuson and Stack

Subscapularis tendon and capsule is advanced laterally on the humerus

Bristow's

Transplantation of coracoids process with its attachment to the anterior rim of glenoid

 

PHYSIOTHERAPY IN RDS

RDS is a disconcerting problem which keeps coming again and again at frequent intervals providing the patient with a harrowing experience of the dismay and discomfort. What makes the situation of the patient more pathetic is that sometimes due to the slightest provocation the shoulder pops out throwing the life out of gear. This problem makes its unwelcome entry when it is least expected and keeps the victim always on tenterhooks.

POINTS TO PONDER

Certain common history given by a victim of RDS (mechanism of occurrence)

• While commuting in a bus catching the upper railing, due to sudden jerk, my shoulder gave way
• While trying to catch a failing object ( may be book,ball,pen etc.) my shoulder popped out
• While jostling through crowded train, market, etc,there was an unexpected push from someone behind and even before I could realize lo and behold my shoulder was in a quandary

It is here that the physiotherapy makes its welcome entry to rein in this problem aiming at preventive rather than the curative part.

A simple three prolonged approach by a physiotherapist is enough to combat this otherwise tricky problem

APPROACH NO 1 (HEALTH EDUCATION)

Educate the patient about the proper and careful use of his shoulder. Extreme degree of shoulder elevation, abduction and external rotation is a strict taboo as it jeopardizes the shoulder into popping out. Hence instruct the patient to avoid all, such movements.

 

 APPROACH NO 2 (MUSCLES EDUCATION OR STRENGTHENING)

Laxity in shoulder muscles, ligaments and capsules due to improper and in adequate healing following the initial injury is the prime reason for RDS. Hence training these structures to regain their strength and vitality is a very logical inevitability to prevent RDS.

Since frequent, repetitive exercises are required to retrain this structure, the most sensible option would be to train the patient himself to carry out the exercises with self resistance either in sitting or standing positions. If properly formed these self resistive exercises is very effective and are popularly called reversal technique.

APPROACH NO 3 (MOVEMENT TRAINING)

Help the patient to achieve full range of passive shoulder movements. This can be done by two steps:

1. This involves the role of a physiotherapist. In a very gentle, gradual and restrained manner he is required to put shoulder into entire range of movements like shoulder elevation , abduction and external rotation
2. Once the complete range of passive movements are attained the physiotherapist now teaches and encourages the patient to himself carry out all these movements at home after carefully training him

Physiotherapy for surgically managed patients is less demanding as the joint is made patients is less demanding as the joint is made stable by repairing the defect and overlapping the subscapularies muscle. Due to this it may be difficult to achieve painless terminal range of movements but however passive sustained stretching is recommended as it is a considered to be harmless and effective.

 


POINTS OF CAUTION

• Both the physiotherapist and the patient should guard against aggression approach and should be especially careful during the terminal range of movements.
• Perseverance and patience should be the watchwords it may take 3-6 months of sustained and prolonged effort to be successful.