Shoulder impingement syndrome

Definition:Shoulder impingement has been

defined as compression and mechanical abrasion of the supraspinatus as they pass beneath the coracoacromial arch during elevation of the arm.

Rotator cuff tendinitis : It encompasses impingement, and result from acute rotator cuff overload, intrinsic rotator cuff degeneration, or chronic overuse.

Functional anatomy:The rotator cuff (Figure 21) comprises four

muscles The subscapularis, the supraspinatus, the infraspinatus and the teres minor and their musculotendinous attachments.

The subscapularis muscle is innervated by the subscapular nerve and originates on the scapula. It inserts on the lesser tuberosity of the humerus.

The supraspinatus and infraspinatus are both innervated by the suprascapular nerve, originate in the scapula and insert on the greater tuberosity.

The teres minor is innervated by the axillary nerve, originates on the scapula and inserts on the greater tuberosity.

A bursa in the subacromial space provides lubrication for the rotator cuff.

Etiology:1. Extrinsic causes:A- Bony factors: The type I acromion, which is flat, is the

"normal" acromion. The type II acromion is more curved and

downward dipping, The type III acromion is hooked and

downward dipping, obstructing the outlet for the supraspinatus tendon and therefore may impinge on the rotator cuff on elevation of the arm.

•Osteophytes under the acromioclavicular joint reduces the subacromial space and can also lead to cuff impingement and therefore failure" '

B- Soft tissue factors Examples include

• Subacromial bursitis • Thickened coracoacromial ligament.

2. Intrinsic causesa. Degenerative cuff failure :b. Traumatic cuff failure:

Neer divided impingement syndrome into three stages:

1. Stage I involves edema and/or hemorrhage. This stage generally occurs in patients less than 25 years of age and is frequently associated with an overuse injury. Generally, at this stage the syndrome is reversible.

2. Stage II is more advanced and tends to occur in patients 25 to 40 years of age. The pathologic changes that are now evident show fibrosis as well as irreversible tendon changes.

3. Stage III generally occurs in patients over 50 years of age and frequently involves a tendon rupture or tear.

Physical examination:1. Manual motor testing for the rotator cuff

muscles:Geber's lift-off test for subscapularisExternal rotation with adducted and elbow

flexed 90 degrees for test of the infraspinatus and teres minor. Arm abduction 90 degrees in the scapular plane (30 degrees anterior to the coronal plane of the body and internal rotation for test of the supraspinatus.

2. SPECIAL TESTS: a-Neer impingement sign: With the patient

seated or standing place one hand on the posterior aspect of the scapula to stabilize the shoulder girdle, and, with the other hand, take the patient's internally rotated arm by the wrist, and place it in full forward flexion. If there is impingement, the patient will report pain in the range of 70 degrees to 120 degrees of forward flexion as the rotator cuff comes into contact with the rigid coracoacromial arch.

b-Hawkins impingement sign:With the patient sitting or standing, the

examiner places the patient's arm in 90 degrees of forward flexion and forcefully internally rotates the arm, bringing the greater tuberosity in contact with the lateral acromion. A positive result is indicated if pain is reproduced during the forced internal rotation at the supraspinatus site.

C-AROM of shoulder : Forward flexion, abduction, external rotation and internal rotation.

Figure 26: AROM of shoulder flexion, abduction, ext. rotation with 90 abduction and neutral the last is Apleys scratch test for internal rotation.

Management:There are three ways of approaching

impingement syndrome: І-Physical therapy rehabilitation, ІІ-subacromial injections of cortisone,

and ІІІ-surgical intervention.

І -Physical therapy rehabilitation in :1- Pain control and inflammation reduction

by: Relative rest: A sling may be used but

it is crucial that the sling be removed several times daily to perform exercises.

Acute phase

Icing (20 min, 3-4 times per day): It decreases the size of blood vessels in the sore area.

Have the patient sleep with a pillow between the trunk and arm to decrease tension on the; upraspinatus tendon (that is the arm is littleabduction, flexion and internal rotation) and prevent blood flow comprise in its watershed region.

Patients are instructed to continue the pain control techniques at home, work, or vacation as part of their exercise program. The home exercise program builds on itself through each phase of the rehabilitation process, and carry-over should be monitored

The recovery phase from a rotator cuff injury must include several components to be successful. These include the following:

(1)Restoration of shoulder ROM,(2)Normalization of strength and dynamic

muscle control, and (3)Proprioception and dynamic joint

stabilization.

Recovery Phase

1-Restoration of shoulder range of motion

After the pain has been managed, restoration of motion can be initiated:

Codman pendulum exercises. Wall walking Stick or towel exercises Stretching of the posterior capsule. The

focus of treatment in this early stage should be on improving range, flexibility of the posterior capsular postural biomechanics, and restoring normal scapular motion. Each stretch should be held for a minimum of 30 seconds, although stretching for 1 minute is encouraged.

2-Normalization of strength and dynamic muscle controlPerform strengthening in a pain-free range only. Begin with the Scapulothroracic stabilizers to help return smooth motion allowing normal rhythm between scapula and GH joint. The scapular stabilizers include the rhomboids, levator scapulae, trapezius, and serratus anterior.:

Shoulder shrugs.push-ups.

Many ways to strengthen muscles are available. The rehabilitation program usually starts with isometric progresses to concentric contractions, and finally incorporates eccentric contractions as part of the preparation for return to sports. Additional strengthening techniques that can be used are progressive resistive exercises (PREs), Thera-Band.

Proprioceptive training is important to retrain neurologic control of the strengthened muscles, providing improved dynamic interaction and coupled execution of tasks for harmonious movement of the shoulder and arm. Begin tasks with closed kinetic chain exercises to provide joint stabilizing forces. Then as the muscles become reeducated, one can progress to open chain activities, In addition, proprioceptive neuromuscular facilitation (PNF) is designed to stimulate muscle/tendon stretch receptors for reeducation.

Return to task-specific or sport-specific activities is the last phase of rehabilitation. This phase is an advanced form of proprioceptive training for the muscles to relearn prior activities. It is an important phase of rehabilitation and should be supervised properly to minimize the possibility of re injury. At the conclusion of formal therapy sessions, patients should be independent in a ROM and strengthening program and should continue these exercises. Athletes are often tempted to return to their overhead throwing sport too soon after recovery of the acute phase.

Maintenance Phase

ІІ-Subacromial injections of cortisone:Although these injection do not cure

the underlying pathology, they decrease swelling of the inflamed bursa and rotator cuff tissue and allow for more room in the sudacromial space for the rotator cuff to move.

Corticosteroids delivered directly to the subacromial space via injection can be considered.

ІІІ -Surgical Intervention Indications for operative treatment of

rotator cuff disease include partial-thickness or full-thickness tears in an active individual who does not improve pain and/or function within 3-6 months with a supervised rehabilitation program. An acromioplasty is usually performed in the presence of a type II (curved) or type III (hooked) acromion with an associated rotator cuff tear.

In surgical candidates, early repair is useful to avoid fatty degeneration and retraction of the remnant rotator cuff musculature