SEMINAR ON APPLIED ANATOMY AND SURGICAL

APPROACHES TO SHOULDER

Moderator :- Dr.B.B.Dayanand

Presentor :- Dr. Hari krishna Bachu

Surgical anatomy of shoulderAnatomy

Shoulder

• It is a ball and socket joint that moves in all three planes and has.

• Most mobile and least stable joint.

• Humeral head

• Tuberosities:– Greater (lateral)

– Lesser (medial)

– Bicipital Groove

• Glenohumeral Joint– Instability/laxity

– Labrum

– Capsule

Muscles of the Shoulder Joint

• The four rotator cuff muscles cover the humeral head and hold the head against the glenoid fossa.

1 2

3

4

1. Subscapularis

2. Supraspinatus

3. Infraspinatus

4. Teres Minor

• Glenoid labrum-fibrocartilage ring attached to the rim of the glenoid fossa, which deepens the cavity.

Shoulder Landmarks

• Greater Tubercle/Tuberosity- large projection lateral to the head. Supraspinatus, infraspinatus and teres minor attach here.

• Lesser Tubercle/Tuberosity- smaller projection on the anterior surface, subscapularis attaches here.

Deltoid.•Origin. Anterior border of lateral third of clavicle. Outer border of acromion and inferior lip of crest of scapular spine.

•Insertion. Deltoid tubercle of humerus.

•Action. Abduction of shoulder. Anterior fibers act as flexors of shoulder; posterior fibers act as extensors of shoulder.

•Nerve supply. Axillary nerve.

Pectoralis Major.•Origin. From two heads• Clavicular head: from medial half of clavicle.Sternocostal head: from manubrium and body ofsternum, upper 6 costal cartilages, andaponeurosis of external oblique.• Insertion. Lateral lip of bicipital groove ofhumerus.•Action. Adduction of arm.•Nerve supply. Medial and lateral pectoral nerves.(A separate branch of the lateral pectoral groovesupplies the clavicular fibers.)

Coracobrachialis.• Origin. Tip of coracoid process.• Insertion. Middle of medial border of humerus. •Action. Weak flexor of arm and weak adductor of arm.• Nerve supply. Musculocutaneous nerve.

Biceps Brachii.• Origin. Short head from tip of coracoid process. Long head from supraglenoid tubercle of scapula. •Insertion. Bicipital tuberosity of radius. •Action. Flexor of elbow. Supinator of forearm. Weak flexor of shoulder.• Nerve supply. Musculocutaneous nerve.

•Pectoralis Minor.• Origin. Outer borders of third, fourth, fifth, and sixth ribs.•

•Insertion. Coracoid process of scapula.

• Action. Lowers lateral angle of scapula. Protracts scapula.

•Nerve supply. Medial pectoral nerve

• Articulations

– Sternoclavicular

– Acromioclavicular

– Scapulothoracic

– Glenohumeral

Coracoacromial Ligament• coracoacromial ligament is

triangular and connects the horizontal portion of the coracoidprocess to the tip of the acromion.

•

The coracoid process, the acromion, and the coracoacromialligament form the coracoacromialarch

Conoid and Trapezoid LigamentsThe conoid ligament:resembles an inverted cone,extends upward from the upper surface of the knuckle of thecoracoid process to the undersurface of the clavicle.

The trapezoid ligament:runs from the upper surface of the coracoid process and

extends superiorly and laterally to the trapezoid ridge on theundersurface of the clavicle.

These two structures are the main accessory ligaments of theacromioclavicular joint.They are extremely difficult to repair in cases ofacromioclavicular dislocation.

Vasuclar supply

Lymphatic drainage

Surgical approaches to shoulder

Six surgical approaches 1. anterior,2. anterolateral,3. lateral,4. minimal access approach to the proximal

humerus,5. posterior, and 6. Anterior arthroscopic

Anterior Approach

The anterior surgical approach offers good wide exposure of the shoulder joint, allowing repairs to be made of its anterior, inferior, and superior coverings.

the anterior approach permits the following:

•Reconstruction of recurrent dislocations,

•Drainage of sepsis ,biopsy and excision of tumors

•Repair or stabilization of the tendon of the long head of the biceps

•Shoulder arthroplasties, which usually are inserted through modified anterior incisions

Position of the Patient

• supine position on the operating table.

• Wedge a sandbag under the spine and medial border of the scapula to push the affected side forward while allowing the arm to fall backward, opening up the front of the joint.

Applied Surgical Anatomy of the Anterior ApproachLandmarks and Incision

Landmarks

•The coracoid process of the scapula is an accessible bony protuberance that lies at the upper end of the deltopectoral groove and is the landmark for incisions based on that groove.

• critical landmark for injections and arthroscopic examinations of the shoulder joint. Hook shaped.

• The tip of the coracoid process projects forward, laterally, and inferiorly toward the glenoid cavity.

• it is palpated best by posterior and medial pressure.

• tenderness over this site is not diagnostic of local pathology.

•Ligaments attached to the coracoid process

Deltopectoral Groove

The cephalic vein, runs in the groove, sometimed is visible

Incisions

The anterior aspect of the shoulder can be approachedthrough either of two skin incisions

Anterior and axillary

Anterior IncisionMake a 10- to 15-cm straight incision, following the lineof the deltopectoral groove. The incision should beginjust above the coracoid

Axillary Incision

• the patient supine,abduct the shoulder 90° and rotate it externally.• Mark the anterior axillary skin fold with a sterile pen.•Make a vertical incision 8 to 10 cm long, starting at themidpoint of the anterior axillary fold and extendingposteriorly into the axilla.•The skin flaps should be undermined extensively with afinger, especially superiorly in the area of the deltopectoralgroove, using the cephalic vein as a guide to ensure correctposition in the vertical plane.•Retract the skin flaps upward and laterally so that theincision comes to lie over the deltopectoral groove

the groove between the fascia overlying the pectoralis major and the fascia overlying the deltoid. The cephalic vein will be of help in locating the groove

•Superficial Surgical Dissection

•superficial surgical dissection of the anterior approach to the shoulder joint: the deltoid muscle laterally, •the pectoralis major muscle medially, and •the cephalic vein.

•Deltoid Muscle•The anterior fibers of the deltoid muscle run parallel to each other, without fibrous septa between them.• Sutures must be placed through the full thickness of the muscle, including its fascialcoverings, to effect a strong reattachment.•The attachment should be protected from active stress for 4 weeks to heaiadequately•The anterior portion of the deltoid can be denervated only if the entire anterior part of the muscle is stripped and retracted vigorously in a lateral direction.

•Pectoralis Major Muscle•Cephalic Vein•The cephalic vein drains into the axillary vein after passing through the clavipectoralfascia.

Surgical Dissection•The short head of the biceps and the coracobrachialis (which is supplied by the musculocutaneous nerve) must be displaced medially before access can be gained to the anterior aspect of the shoulder joint.

•the two muscles can be detached with the tip of the coracoidprocess. To release them, detach the tip of the coracoid process with an osteotome. The bone can be replaced later either with a screw or with sutures

•If a screw is used, the coracoid process must be drilled and tapped before the osteotomy is carried out.

•Otherwise, the small piece of coracoid may split during drilling, and anatomic reduction can be obtained only with extreme difficulty

The axillary artery is surrounded by the cords of the brachial plexus, which lie behind the pectoralis minor muscle. Abduction of the arm causes these neurovascular structures to become tight and brings them close to the tip of the coracoid and the operative site. Retract the coracoid mediallyDivide the fascia that fans out from the conjoined tendons of the coracobrachialis and the short head of the biceps on the lateral side of the coracobrachialis—because the musculocutaneous nerve enters the coracobrachialis on its medial side. downward retraction can cause a neurapraxia of the musculocutaneous nerve. If the coracoid process is left intact, the attached coracoid muscles protect the nerve from traction injury.

Beneath the conjoined tendons of the coracobrachialis and the short head of the biceps lie the transversely running fibers of the subscapularis muscle, which forms anterior covering of the shoulder joint capsule

As the muscle crosses the glenoid cavity, abursa separates it from the joint capsule;that bursa communicate with the shoulderjoint.

A) The subscapularis muscle lies in the deep part of the wound. It is to be incised perpendicular to its

fibers, close to its tendon. The axillary nerve passes anteroposteriorly through the quadrangular space.

B) External rotation of the arm during incision into the subscapularis tendon will draw the point of incision

away from the axillary nerve.

multiple anterior dislocations, adhesions often exist between the muscle and the joint capsule, making it difficult, to find the layer between the two. .

• Apply external rotation to the arm to stretch the subscapularis, increases the distance between the subscapularis and the axillary nerve as it disappears below the lower border of the muscle

• landmarks on the inferior border of the subscapularis are a series of small vessels that run transversely The vessels run as a triad: a small artery with its two surrounding venae comitantes,

• The superior border of the subscapularis muscle is indistinct and blends in with the fibers of the supraspinatus muscle

•Deep Surgical Dissection•The coracobrachialis and the short head of the biceps brachii share a common origin from the tip of the coracoid process. common nerve supply, the musculocutaneous nerve. These muscles form an intermediate layer during the surgical approach

•Coracobrachialis Muscle•The coracobrachialis muscle is largely vestigial and has little function. •The coracobrachialis used to have three heads of origin. The musculocutaneous nerve passes between two of the original heads, which now are fused during development.

•Biceps Brachii Muscle•The joint capsule of the shoulder is incomplete inferiorly, so the tendon can escape under the transverse ligament. •it runs in the bicipital groove of the humerus.

Pectoralis Minor Muscle•second part of the axillary artery and the cords of the brachialplexus lie directly behind the muscle and below the coracoidprocess

Subscapularis Muscle•Forms the deep layer of the dissectio•inserts partly into the capsule of the joint.•The subscapularis limits external rotation, helping to preventanterior dislocations Because the two subscapular nerves enterthe subscapularis medially, incising it 2.5 cm from its insertiondoes not denervate the muscle•Superiorly, the muscle is connected to the supraspinatus.•The plane of cleavage between the two muscles, whichrepresents a true internervous plane between the suprascapularand subscapular nervesThe tendon of the long head of thebiceps corresponds to the interval between the muscles and canbe used as a surgical guideline to that interval.

Shoulder Joint CapsuleAnteriorly, attached to scapula via the border of the glenoid labrum

Posteriorly and inferiorly, attached to the border of the labrum.

The fibrous capsule inserts into the humerus around the articular margins of the neck, except inferiorly, where the insertion is 1 cm below the articular margin.

The capsule bridges the gap across the bicipital groove, forming a structure known as the transverse ligament. The long head of the biceps enters the joint beneath this ligament

Synovial Lining of the Shoulder Joint•The synovial membrane, which is attached around theglenoid labrum, lines the capsule of the joint.

• The membrane usually communicates with the subscapularis bursa and with the infraspinatus bursa.

•It envelopes the tendon of the long head of the biceps within the shoulder joint.

•The synovium forms a tubular sleeve that permits thetendon to glide back and forth during abduction andadduction of the arm.•Therefore, the tendon is anatomically intracapsular, butextrasynovial

Glenoid LabrumThe glenoid labrum is a triangular, fibrocartilaginous structure that rings the glenoidcavity .The joint capsule attaches to it superiorly, inferiorly, and posteriorly.

To Enlarge the ApproachLocal MeasuresThe exposure can be enlarged in the following four ways:1. extend the skin incision superiorly by curving it laterally along the

lower border of the clavicle. Detach the deltoid from its origin on the outer surface of the clavicle for 2 to 4 cm to permit better lateral retraction of the muscle (Fig. 1-15).

2. Lengthen the skin incision inferiorly along the deltopectoralgroove to separate the pectoralis major from the deltoid further inferiorly and to improve the exposure without having to detach the deltoid origin.

3. Use a suitable retractor (such as the Bankart skid) for the humeral head. A humeral head retractor is the key to excellent exposure of the inside of the glenoid fossa

4. Rotate the shoulder internally and externally to bring different elements of the anterior shoulder coverings into view.

Extensile Measures•Proximal Extension

•extend the skin incision superomedially, crossing the middle third ofthe clavicle.• dissect the middle third of the clavicle subperiosteally and performosteotomy of the bone,•Cut the subclavius muscle, which runs transversely under theclavicle. Retract the trapezius superiorly and the pectoralis majorand pectoralis minor inferiorly to reveal the underlying axillaryartery and the surrounding brachial plexus .

•Distal Extension•The approach can be extended into an anterolateral approachto the humerus.•Extend the skin incision down the deltopectoral groove, thencurve it inferiorly, following the lateral border of the biceps.Deep dissection consists of moving the biceps brachii medially toreveal the underlying brachialis

Dangers•Nerves

•The musculocutaneous nerve enters the body of the coracobrachialis about 5 to 8 cm distal to the muscle's origin at the coracoid process. Because the nerve enters the muscle from its medial side, all dissection must remain on the lateral side of the muscle.great care should be taken not to retract the muscle inferiorly, to avoid stretching the nerve and causing paralysis of the elbow flexors.

•Vessels• The cephalic vein should be preserved• A traumatized cephalic vein should be ligated to prevent the slight danger of thromboembolism

Anterolateral Approach

The anterolateral approach to the shoulder offers excellent exposure of the acromioclavicular joint and the underlying coracoacromial ligament and supraspinatus tendon.

•Anterior decompression of the shoulder

•Repair of the rotator cuff

•Repair or stabilization of the long head of a biceps tendon

•Excision of osteophytes from the acromioclavicular joint

•extensive degenerative disease of the rotator cuff.

Position of the Patient•Place the patient in the supine position on the operating table, with a sandbag under the spine and medial border of the scapula to push the affected side forward.•Elevate the head of the table 45°.

Superficial Surgical DissectionSuperficial surgical dissection involves splitting the fibers of the deltoid muscle. Proximal extension of the approach to expose the supraspinatusinvolves splitting the fibers of the trapezius muscle

•Deltoid Muscle•The lateral deltoid consists of oblique fibers arising in a multipennatefashion from tough tendinous bands that originate from the acromion.

•This multipennate arrangement provides the deltoid muscle with maximum strength, although it limits the degree to which it can contract. •it is relatively easy to split the muscle in a longitudinal fashion. The tough tendinous bands also prevent excessive damage to the muscle when it is split during surgery

Landmarks and IncisionLandmarks:

Coracoid ProcessPalpate the coracoid process 1 in. from the anterior end of the clavicle just inferior to the deepest point of the clavicular concavity.

AcromionPalpate the acromion at the shoulder summit.

Incision:Make a transverse incision that begins at the anterolateral corner of the acromion and ends just lateral to the coracoid process

Internervous PlaneNo internervous plane is available for use. The deltoid muscle is detached at a point well proximal to its nerve supply, which, therefore, is not in danger.

Supraspinatus Muscle•multipennate muscle, •passes laterally beneath the coracoacromial ligament.• The muscle is the frequent site of degenerative changes and frank tears. •Degeneration in its tendon invokes an inflammatory response in the overlying subacromial bursa, and most cases of subacromial bursitis probably reflect pathology in the muscle.

Superficial Surgical Dissection

Split the deltoid muscle in the line of its fibers from the acromiondownward for 5 cm. Insert a suture at the inferior apex of the split to help prevent it from extending accidentally, with consequent axillarynerve damage.

Deep Surgical Dissection•The lateral aspect of the upper humerus and its attached rotator cuff lie directly under the deltoid muscle and the subacromial bursa •In fractures of the neck of the humerus, the bare ends of bone usually appear at this point without further dissection.•Small tears of the supraspinatus muscle also can be reached through this approach.

•Dangers•Nerves•The axillary nerve leaves the posterior wall of the axilla by penetrating the quadrangular space. Then it winds around the humerus with the posterior circumflex humeral arteries .•The nerve enters the deltoid muscle posteriorly from its deep surface, about 7 cm below the tip of the acromion. From that point, its fibers spread anteriorly.

•the dissection cannot be extended farther in an inferior direction without denervating that portion of the deltoid muscle that is located anterior to the muscle split.

Extensile MeasuresProximal Extension•Extend the incision superiorly and medially across the acromion and parallel to the upper margin of the spine of the scapula, about 1 cm above it along the lateral two thirds of the scapular spine

• Incise the trapezius muscle parallel to the spine of the scapula and about 1 cm above it. Retract the muscle superiorly to reveal the supraspinatus and its fascial covering

To expose the entire supraspinatus muscle, cut the acromionand split the trapezius muscle to reveal the underlyingsupraspinatus muscle belly and tendon

Posterior ApproachThe posterior approach offers access to the posterior and inferior aspects of the shoulder joint.It rarely is needed, but can be used in the following instances:

•Repairs in cases of recurrent posterior dislocation or subluxationof the shoulder.

•Glenoid osteotomy.

•Biopsy and excision of tumors•Removal of loose bodies in the posterior recess of the shoulder•Drainage of sepsis (the approach allows dependent drainage with the patient in the normal position in bed)•Treatment of fractures of the scapula neck, particularly those in association with fractured clavicles (floating shoulder)•Treatment of posterior fracture dislocations of the proximal humerus.

Applied Surgical Anatomy of the Posterior Approach

LandmarkThe spine of the scapula

Superficial Surgical Dissection•In the posterior approach, only those fibers of the deltoid muscle that arise from the spine of the scapula are detached.

Deep Surgical Dissection•The deep dissection in this approach lies between the infraspinatus and teres minor muscles

•Infraspinatus Muscle•The fibers of the infraspinatus muscle are multipennate; •numerous fibrous intramuscular septa give attachment to them.•The infraspinatus forms its tendon just before crossing the back of the shoulder joint; a small bursa lies between the muscle and the posterior aspect of the scapular neck to help the tendon glide freely over the bone.

•Teres Minor Muscle•The teres minor runs side by side with the infraspinatus. Its fibers run parallel with one another, in contrast to the multipennate fibers of the infraspinatus; this difference may help in identification of the interval between the two muscles.

DangersAxillary NerveThe axillary nerve is a branch of the posterior cord of the brachial plexus. It runs down along the posterior wall of the axilla on the surface of the subscapularis, far from the incision made in that muscle during the anterior approach to the shoulder

Radial Nervebranch of the posterior cord of the brachial plexus, leaves the axilla by passing backward through a triangular space that is defined superiorly by the lower border of the teres major, laterally by the shaft of the humerus, and medially by the long head of the triceps

Circumflex Scapular VesselsYet another triangular space exists when the inner sleeve of shoulder muscles is viewed from the back. Its boundaries are as follows: superiorly, the lower border of the teres minor.

Arthroscopic Approaches to the ShoulderGeneral Principles of Arthroscopy

•The most commonly used arthroscope is angulated 30° at its tip so that the view obtained shows the structures that are 30° from the long axis of the arthroscope and not the structures that are directly in front of the scope

•The use of an angled scope allows the surgeon tosee “around the corner” and thereby greatlyincreases the view obtained within any joint.

Visualization of structures using an arthroscope

Rotating the scope will provide a series of views at angles of 30°

•Because the scope is angled 30° from its axis, it is not possible to zoom in on an object merely by advancing the scope.•Rotating the arthroscope will reveal a series of views angled at 30° from the axis of the scope

•Angling the scope will change the direction of the view.one will not be able to visualize those structures directly in front of the arthroscope unless you angle it.

•It is possible to change the view by moving the joint while leaving the arthroscope in the same position. This maneuver is vital for full inspection of any joint

Arthroscopy of the shoulder is indicated in

•Arthroscopic subacromial decompression for chronic rotator cuff tendonitis•Treatment of partial thickness tears of the rotator cuff•Treatment of tears of the glenoid labrum•Treatment of degenerative disease of the acromioclavicular joint•Removal of loose bodies •Treatment of osteochondritis dissecans•Synovectomy

“beach chair” position

Position of the patient

IncisionsPosteriorMake an 8-mm stab incision 2 cm inferior and 1 cm medial to the posterolateral tip of the acromion

AnteriorMake an 8-mm stab incision halfway between the tip of the coracoid process and the anterior aspect of the acromion

Internervous PlanePosteriorThe internervous plane lies between the teres minor muscle (supplied by the axillary nerve) and the infraspinatusmuscle (supplied by the suprascapularnerve)

AnteriorThe internervous plane lies between the pectoralis major muscle (supplied by the medial and lateral pectoral nerves) and the deltoid (supplied by the axillarynerve).

Posterior insertion of the arthroscope. Place your finger on the coracoid process. Insert the trochar and arthroscopic sheath through the posterior skin incision, aiming the tip of the arthroscope toward your finger.

Anterior insertion of the arthroscope. Insert an arthroscopethrough the posterior portal to allow you to visualize the anterior capsule of the shoulder joint. Next, insert a long hypodermic needle through the anterior skin incision and enter the joint under direct vision of the scope

Order of ScopingInsert a 30° arthroscope through the posterior incision.

•Identify the biceps tendon and its origin as it runs from superior to inferior.•Next, rotate the arthroscope superiorly to allow visualization of the supraspinatus .The supraspinatus lies posterior to the biceps tendon. •To visualize infraspinatus and teres minor you will need to rotate not only the arthroscope but also the humeral head .•Next, note the anterior triangle of the shoulder, formed by the biceps tendon, the superior edge of the subscapularis, and the glenoid .This triangle marks the safe spot for entry through the anterior portal.

•Pass the arthroscope to the upper anterior margin of the glenoid and rotate the scope inferiorly to allow examination of the anterior glenohumeral complex. You may need to apply a distraction force to the shoulder at that time, or alternatively use a 70° rather than a 30°

telescope.•Pass the arthroscope anteriorly into the anterior triangle and rotate the scope so as to allow you to look inferiorly into a space underlying the subscapularis. This space is a frequent site for loose bodies. •Next, redirect the arthroscope inferiorly and rotate the telescope posteriorly to allow access to the posterior recess of the shoulder . Visualization of the humeral head and glenoid are easily accomplished through the posterior portal. Careful manipulation of the shoulder is required to visualize the whole of the articular surface.

DangersNervesPosterior

•The axillary nerve leaves the posterior wall of the axilla by penetrating the quadrangular space. It winds around the humerus running on the deep surface of the deltoid muscle, about 7 cm below the tip of the acromion.If the posterior portal is correctly located with regard to the posterolateral tip of the acromion, this portal should lie about 3 cm superior to the nerve. •The suprascapular nerve,runs around the base of the spine of the scapula as it runs from the supraspinatusfossa to the infraspinatus fossa .• The correctly positioned portal is approximately 2 cm lateral to the nerve.

Anterior•The axillary nerve may be in danger as it traverses along the deep surface of the deltoid from superiorly placed incisions.•The musculocutaneous nerve, the nerve supply of the flexor muscles of the upper arm, enters those muscles some 2 cm to 8 cm distal to the tip of the coracoidprocess. The nerve, therefore, is unlikely to be damaged by a portal made superior and lateral to the level of the coracoid process

•Vessels• The cephalic vein runs superficially between the deltoid and pectoralis major muscle. It can only be damaged from incisions made too laterally.

Thank you