© Springer-Verlag France 2015
Cyril Mauffrey and David J. Hak (eds.)Passport for the Orthopedic Boards and FRCS Examination10.1007/978-2-8178-0475-0_1Upper Limb Anatomy and Surgical Approaches
(1)
Department of Orthopaedics, Lincoln Medical Center, Bronx, USA
(2)
Department of Orthopaedics, University of Louisville Hospital, Louisville, KY, USA
1 Shoulder
Anterior (deltopectoral) Approach
Indications
Access to anterior glenohumeral joint, anterior glenoid, and proximal humerus
Superficial dissection
Internervous plane.
Deltoid (axillary nerve) and pectoralis major (medial and lateral pectoral nerves).
The cephalic vein can serve as a guide to delineate where the deltoid and pectoralis major meet.
Dangers
Cephalic vein is found in deltopectoral groove.
Multiple branches are found medially and laterally and need to be ligated or cauterized for hemostasis.
Deep dissection
Short head of biceps and coracobrachialis are retracted medially.
Both supplied by musculocutaneous nerve.
Both attach to the coracoid process as the conjoint tendon.
The subscapularis tendon is exposed deep to the deltoid (laterally) and the conjoint tendon (medially).
The subscapularis tendon can be elevated after incision through the lateral aspect of the tendon or an osteotomy of the lesser tuberosity of the proximal humerus.
The joint capsule is located just deep to the subscapularis.
Dangers
Musculocutaneous nerve.
Inserts into coracobrachialis and short head of biceps medially to each muscle.
Over-retraction of the conjoint tendon can put the nerve on stretch and cause injury.
Axillary nerve
Passes just below the subscapularis and wraps around the posterior proximal humerus, innervating the deltoid and teres minor.
Adducting the shoulder will help prevent injury to nerve by decreasing tension on nerve and keeping it more inferior to subscapularis.
Axillary sheath
Contains brachial plexus and axillary vessels.
Travels under the clavicle, medial to coracoid, deep to pectoralis minor, the short head of the biceps, and the coracobrachialis.
Extensive medial dissection or retraction can cause injury.
Lateral Approach
Indications
Access to greater tuberosity and proximal humerus
Access to subacromial pathology
Repair of lateral rotator cuff tears
Superficial dissection
Internervous plane
No true internervous plane
Split the fibers of the deltoid longitudinally at the junction of the anterior 1/3 and posterior 2/3 of the muscle
Deep dissection
Subacromial bursa is directly under the deltoid proximally.
Can be excised for better visualization of proximal humerus.
Insertion of supraspinatus to the greater tuberosity can be visualized.
Access to the supraspinatus tendon can be difficult as the tendon is significantly retracted medially.
Dangers
Axillary nerve
The nerve travels through the quadrilateral space (medial, long head of triceps; lateral, humerus; superior, teres minor; inferior, teres major) and then wraps around humerus with posterior circumflex arteries.
The axillary nerve enters the deltoid slightly posteriorly, approximately 7 cm inferior to the acromion.
Placing a stay suture at the inferior apex of the deltoid split to prevent unintentional distal dissection and axillary nerve damage.
Posterior (Judet) Approach
Indications
Access to posterior glenohumeral joint
Access to scapula
Superficial dissection
Internervous plane
Deltoid (axillary nerve) and the infraspinatus (suprascapular nerve)
Detach origin of deltoid off the scapular spine
The plane between the deltoid and the infraspinatus is easier to appreciate more laterally.
Deep dissection
Internervous plane
Infraspinatus (suprascapular nerve) and the teres minor (axillary nerve).
The infraspinatus should be retracted superiorly and the teres minor should be retracted inferiorly.
The posteroinferior aspect of the glenohumeral joint capsule is then exposed.
Joint capsule should be incised longitudinally.
Dangers
Axillary nerve
The nerve courses through the quadrilateral space under the teres minor, so it is important to stay superior to teres minor and exploit the interval between the infraspinatus and teres minor.
Suprascapular nerve
The nerve courses under the suprascapular ligament as it passes through the suprascapular notch, then around the base of the scapular spine as it descends from the supraspinatus fossa to the infraspinatus fossa.
Innervates both the supraspinatus and the infraspinatus.
Aggressive medial retraction should be avoided to prevent stretching of the nerve.
2 Arm
Anterior Approach
Indications
Access to humerus and anterior structures of the arm
Superficial dissection
Essentially this is a distal extension of the deltopectoral approach.
Internervous plane
Proximally
Deltoid (axillary nerve) and pectoralis major (medial and lateral pectoral nerves)
Distally
Lateral fibers of brachialis muscle (radial nerve) and medial fibers of brachialis muscle (musculocutaneous nerve)
The deltoid inserts into the deltoid tuberosity distally and laterally to the insertion of the pectoralis major.
The belly of the brachialis is distal and medial to the insertion of the deltoid.
The brachialis is exposed by developing the interval between it and the biceps brachii, then retracting the biceps medially.
Deep dissection
The pectoralis major tendon covers the bicipital groove and inserts into the humerus lateral to groove.
This insertion may need to be partially elevated subperiosteally to gain access to proximal third of humeral shaft.
The brachialis fibers should be split longitudinally along the midline to preserve the innervation medially and laterally.
Flexing the elbow will relieve some tension of the fibers to assist with retraction and exposure of the anterior humerus.
Dangers
Anterior circumflex humeral vessels
Encountered deep between the deltoid and pectoralis major in the proximal humerus.
Vessels need to be either ligated or cauterized.
Radial nerve
Proximally
Primarily a posterior structure in the proximal two thirds of the humerus.
Courses along the spiral groove and exits the groove 10–14 cm proximal to the lateral epicondyle
Despite being located posteriorly, the nerve can be damaged during an anterior approach by retractors, drill bits, and depth gauges.
To minimize risk, stay subperiosteal during dissection and retractor placement.
Distally
The nerve courses anterior as it pierces the lateral intermuscular septum between the triceps and the brachialis.
It enters the anterior compartment of the arm between the brachioradialis and the brachialis muscles (approximately 7.5–10 cm proximal to distal articular surface of humerus).
If the brachialis is split along the midline, the lateral portion will protect the radial nerve during retraction.
Axillary nerve
Courses deep to deltoid and wraps around posterior and lateral to proximal humerus
At risk during vigorous retraction of deltoid
Anterolateral Approach
Indications
Provides better exposure to distal humerus than direct anterior approach
Superficial dissection
Internervous plane
No true internervous plane.
The brachioradialis and the lateral half of the brachialis are both innervated by the radial nerve.
Retracting the biceps medially will expose the brachialis medially and the brachioradialis laterally.
The radial nerve is found between the brachialis and the brachioradialis.
Bluntly dissect this interval.
Identify and protect the radial nerve.
The nerve can be traced proximally to where it pierces the lateral intermuscular septum.
Deep dissection
Internervous plane
There is no internervous plane at this level.
Carry out dissection medial to radial nerve.
The lateral aspect of the brachialis is incised, and bony anatomy of the distal anterior humeral shaft is revealed.
Dangers
Superficially
Lateral cutaneous nerve of the forearm
Branches off the musculocutaneous nerve and surfaces from between the brachialis and the biceps brachii
Strictly sensory in function and innervates the radial aspect of the forearm
Deep
The radial nerve must be identified and protected in the lateral aspect of the dissection.
Lateral Approach
Indications
Access to lateral condyle of distal humerus
Superficial
Internervous plane
There is no true internervous plane.
Both the triceps brachii and the brachioradialis muscle are innervated by the radial nerve.
Dissection can be carried down straight to bone after identifying the plane between the brachioradialis and the triceps.
Deep dissection
Internervous plane
Proximally there is no internervous plane as described above.
If the exposure needs to extend distally to reveal the radiocapitellar joint, then the anconeus (radial nerve) can be retracted posteriorly, while the extensor carpi ulnaris (posterior interosseous nerve) can be retracted anteriorly.
This is essentially extending the lateral humerus approach into the posterolateral elbow approach.
The brachioradialis is retracted anteriorly and the triceps posteriorly.
The common extensor origin is found on the lateral epicondyle and can be taken down as needed for exposure.
Dangers
The distal exposure is free of significant neurovascular structures.
The radial nerve must be identified and protected if proximal extension of this approach is to be performed.
Posterior Approach
Indications
Provides access to the distal three fourths of the humerus
Ideal approach for exploring radial nerve in spiral groove
Superficial dissection
Internervous plane
There is no internervous plane.
The dissection goes directly through the triceps brachii.
Innervation of the triceps is by the radial nerve, and the nerve enters the muscle proximally at its origin.
The medial head of the triceps receives contributing innervation from the ulnar nerve as well.
Splitting the muscle longitudinally does not cause denervation from either source.
The triceps brachii has two layers.
The outer layer has two heads.
Lateral head originates from lateral lip of spiral groove.
Long head originates off the infraglenoid tubercle of the scapula.
The inner layer
Medial (deep) head originates over the entire width of the posterior humerus distal to the spiral groove.
Dissection of the outer layer is best done starting proximal to where they form a confluent tendon.
Interval can be developed with blunt dissection.
Several smaller vessels cross the muscle more distally and need to cauterized.
Deep dissection
The deep (medial) head of the triceps lies deep to the outer two heads.
The radial nerve passes around the posterolateral aspect of the humerus just proximal to the origin of the deep head.
Dissection through the medial head should be midline and down to the periosteum, and any further dissection medial or lateral should be done subperiosteal to prevent injury of the radial nerve proximally and the ulnar nerve medially.
The ulnar nerve pierces the medial intermuscular septum as it passes from anterior to posterior.
Dangers
Radial nerve
Dissection to bone in the proximal two thirds of the humerus should not be performed until the nerve has been identified and protected.
Ulnar nerve
Courses deep to the medial head of the triceps in distal third of arm.
Dissection must be done subperiosteally in this region to prevent injury.
3 Elbow
Posterolateral (Kocher) Approach
Indications
Access to the radiocapitellar joint
Superficial dissection
Internervous plane
Anconeus (radial nerve) and the extensor carpi ulnaris (posterior interosseous nerve).
The interval between the anconeus and the extensor carpi ulnaris is easier to appreciate more distally as the two muscles share a common aponeurosis proximally.
A fat stripe sometimes helps define the interval.
Releasing the proximal aspect of the anconeus where it attaches to the lateral epicondyle of the humerus will aid in exposure.Related posts:
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