Shoulder Instability

DR MANDEEP SINGH

ModeratorsDr. A PathakDr. A Ganvir

WHAT IS INSTABILITY?

During the use of normal shoulder,humeral head is centered within the glenoid and coracoacromial arch

When the shoulder cannot maintain this centered position it is said to be unstable

It is not the same as joint laxity allows the shoulder to attain its full range of functional positions while an unstable shoulder prevents normal function of that upper extremity

Factors contributing to shoulder stability

1. STATIC FACTORS2. DYNAMIC FACTORS

Normal glenoid is about 7 degrees retroverted

If the retroversion is excessive, it leads to posterior instability of shoulder

STATIC FACTORS

The labrum increases the superoinferior diameter of the glenoid by 75% and the anteroposterior (AP) diameter by 50%

The bony conformity of the glenoid and humeral head articular surfaces provides some of the stability of the shoulder.

Frequently, patients with recurrent dislocations have bony deficits in one or both of these surfaces.

LIGAMENTS

• Superior Glenohumeral ligament : Most important check at zero degrees of abduction

• Middle Glenohumeral Ligament : Most important check at middle ranges of abduction

•Inferior Glenohumeral ligament : Most important check at more than 45 degrees of abduction

1. The movement of rotator cuff muscles help to contribute to the negative intra - articular pressure.

2. The rotator cuff muscles themselves make a protective cuff all around the shoulder except inferiorly where shoulder capsule is the weakest.

DYNAMIC FACTORS

Other factors :

1.Muscles around the shoulder

- Levator scapulae- Rhomboids-Trapezius

2. Biceps Brachii

3. Proprioceptors

LABRAL LESIONS : 1.Bankart lesion

2.Reverse Bankart lesion

3.SLAP Lesion

PATHOLOGICAL ANATOMY

BANKART LESION-labral tear at anterior half of glenoid rim

Reverse Bankart lesion

SLAP Lesion

CAPSULAR LESIONS:

1. Intra Substance Tear

2. HAGL Lesion

3. Repetitive Micro Trauma

4. Excessive capsular laxity

HAGL Lesion(Humeral avulsion of the inferior glenohumeral ligament)

Repetitive Micro trauma

Glenoid Bone loss

Hill Sach Lesion

Classification of instability

T Traumatic U Unilateral B Bankart lesion S Surgery is often necessary

A Atraumatic M Multidirectional B Bilateral R Rehabilitation is the treatment I If surgery is needed inferior capsular shift is performed

MATSEN’S CLASSIFICATION

History

Define mechanism

Position of arm

Point of force

Amount of force

Electric Shock /Seizure

CLINICAL EXAMINATION

LOOK

FEEL

MOVE

SPECIAL TESTS

LOOK - Generalized joint laxity - Muscle wasting - Asymmetry - Previous operative scars - Ecchymosis

FEEL

Local temperatureTendernessAny palpable massBony defectMuscular weaknessNerve injury

The sulcus test.

CLINICAL TESTS

Shift and Load Test

The anterior apprehension test

The anterior drawer test

RADIOGRAPHIC EVALUATION

A routine AP shoulder radiograph shows overlap of the anterior and the posterior glenoid rims. A true AP radiograph demonstrates superimposition of the anterior and the posterior glenoid rims, producing an excellent view of the glenohumeral joint.

Normal Shoulder AP view

Transcapular Y-view of the glenohumeral joint allows assessment of humeral headlocation in relation to the Glenoid cavity

Axillary view represents the “gold standard” in radiographic assessment of location of the humeral head relative to the glenoid cavity.

The stryker notch view

The west point view

QUESTIONS TO BE ANSWERED WHILE EVALUATING A PATIENT

Is the problem in the glenohumeral joint ?

Is the problem one of failure to maintain the humeral head in its centered position ?

What mechanical factors are contributing to the instability ?

Are these factors amenable to surgical repair or reconstruction ?

McLaughlin & Cavallaro

After acute dislocations, development of recurrence

Rowe and Sakellarides

Frequent dislocations in young athletes

Duration of immobilization does not affect recurrence rates

Burkhart and Debeer; Sugaya et al; Itoi et al

Glenoid bone loss more than 20% leads to shoulder instability

RATIONALE FOR TREATMENT

2 important factors favoring surgical treatment

YOUNG AGE

HIGH ACTIVITY LEVEL

EMERGENT MANAGEMENT OF ACUTE DISLOCATIONS

NON-OPEREATIVE TREATMENT

A trial of non-operative treatment is recommended for the following group of patients-

a) All patients who sustained a traumatic first time dislocation regardless of age

b) Patients > 40 yrs with recurrent instability

c) All patients with atraumatic instability

NON-OPERATIVE TREATMENT PROTOCOL

All patients< 30 yrs shoulder immobilized for 3 wks Patients 30-40yrs shoulder immobilized for 1-2 wks Patients >40 yrs the shoulder immobilized for 1

wks Atraumatic instability- immobilization not

required Patients with anterior instability-limit ext. rotation

to 30 deg. and abd. to < 60 deg.

Patients with posterior instability- avoid flex.>60 deg. and int. rotation > 30 deg.

INDICATIONS FOR OPERATIVE TREATMENT IN INSTABILITY

Failure of non operative therapy

Young adult with high functional demands

Irreducible dislocation

Open dislocation

TREATMENT OPTIONSTYPE OF INSTABILITY PREFERRED SURGERY

Traumatic anterior, with Bankart Lesion Open / arthroscopic Bankart repair

Traumatic anterior , with no labral lesion, just capsular laxity

Open / arthroscopic capsular imbrication

AMBRI lesions Lateral capsular shift( modified Neer and Foster ) with closure of rotator interval

Recurrent posterior dislocation in association with a reverse Hill-Sachs lesion

modified McLaughlin procedure

Head defect > 30 – 45 % > 45 %

Acute disimpaction / Weber osteotomyProsthetic replacement

Glenoid defect Bristow – Latarjet coracoid transferStructural bone graft

OPEN SOFT TISSUE PROCEDURES FOR ANTERIOR INSTABILITY

Open Bankart procedure

Arthroscopic Bankart procedure

Arthroscopic Thermal capsulorraphy

Arthroscopic capsular imbrication

Putti-Platt procedure

Only 3 – 10 % failure rate by various studies

Long term follow up shows high incidence of OA, about 30 %

10 – 15 % failure rate by various studies

Anchor used for repair

Modified bankart repair

OPEN BONY PROCEDURES FOR ANTERIOR INSTABILITY

Bristow procedure

Latarjet procedure

Latarjet procedure

AMBRII Lesions-Idea of management Primary treatment nonoperative

Operative management recommended for patients who have continued pain or disability despite an adequate rehabilitation

The gold standard is open stabilization

Capsular shift( modified Neer and Foster )

POSTERIOR INSTABILITY-A general overview

Rare Often missed Often has a component of muscle

imbalance Indication for operative treatment is

generally continued problems despite rehab.

ProceduresProcedure Description Results

Neer’s Capsulorrraphy Posterior capsular tightening

Generally unsatisfactory, upto 50 % recurrence

Staple capsulorraphy Tightening done with staples

Small study group

Tieborne and bradley procedure

Capsular Imbrication with a horizontal T approach

Upto 20 % recurrence

Hawkins and Janda procedure

Subscapularis advancement and shortening

0 – 5 % recurrence

Rockwood Glenloid Plasty with Biceps Tenodesis to the posterior capsule

Combined bony and soft tissue procedure

Not often done

ARTHROSCOPIC PROCEDURES FOR POSTERIOR INSTABILITY

Posterior capsulolabral reattachment with the help of suture anchors

Arthroscopic posterior capsulorrhaphy

OPEN ANTERIOR PROCEDURES FOR POSTERIOR INSTABILITY

McLaughlin procedure

Neers modification of McLaughlin procedure

McLaughlin technique

subscapularis

Neer’s modification

Some procedures of historic interest

Weber osteotomy

Putty Platt OperationSurgical procedure for stabilizing the glenohumeral joint after recurrent anterior shoulder dislocations. The subscapularis tendon is detached near its insertion on the humerus, the joint opened, and the stump of the tendon on the lesser tuberosity is sutured to the glenoid labrum.

Sometimes the procedure is combined with reattachment of the glenoid labrum.

Technically an easy procedure

Disadvantages:

The Putti-Platt procedure is not to be performed on throwers because it can reduce the range of movement in the shoulder.

30 – 35 % incidence of late OA

Magnuson Stack procedure

ADVANTAGES AND DISADVANTAGES OF ARTHROSCOPIC STABILIZATION

ADVANTAGES DISADVANTAGES

-Improved cosmesis -Technically demanding

-Shorter operative time -Difficult in revision case

-Short hospital stay -Difficult in altered anatomy

-Decreased morbidity -Cannot address bony defect

-Decreased complication

-Lower cost

PHASES OF REHABILITATION

Phase I Rest and immobilization. Pain control with nonsteroidal anti-inflammatory drugs and ice applied to the shoulder

Phase II Isometric strengthening Isotonic strengthening. Begin exercises with shoulder in adducted, forward- flexed position, progressing to abducted position

Phase III Endurance building along with strengthening exercises. Goal: the patient reaches 90% strength in the injured shoulder compared with the uninjured shoulder

Phase IV Increase activity to sport- or job-specific activities

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