PART 2 – THE ELBOW

Section   – General Principles

CHAPTER 31 – Patient Positioning and Portal Placement

As advances in technology and technique allow better visualization and navigation of the elbow joint, indications for elbow arthroscopy are expanding. Descriptions of new portals, instrumentation, and techniques are frequent in the literature and continue to increase the use of the arthroscope for diagnosis and treatment of a number of elbow injuries and disorders. A thorough understanding of portal placement and normal arthroscopic anatomy is essential for use of the arthroscope in the elbow joint to be mastered and for complications to be avoided.

Preoperative Considerations

History

A comprehensive history discerns whether a single traumatic event or repetitive traumatic episodes occurred before the onset of symptoms. The circumstances under which symptoms occur and whether they are related to activities of daily living, occupational activities, or athletic activities are noted.

Typical History

	•	Loss of velocity and control in a throwing athlete
	•	Repetitive episodes versus traumatic event
	•	Acute versus chronic pain
	•	Mechanical symptoms: popping, locking, catching
	•	Instability
	•	Neurovascular symptoms

Physical Examination

All three elbow compartments (medial, lateral, posterior) are carefully examined. Elbow stability, range of motion, and neurovascular status are evaluated.

Medial Compartment

	•	Check for valgus instability. With the elbow flexed to 30 degrees to relax the anterior capsule and to free the olecranon from its bony articulation in the olecranon fossa, apply valgus stress with the arm in full supination. Discomfort along the medial aspect of the elbow may indicate ulnar collateral ligament injury.
	•	Palpate the proximal flexor-pronator mass and medial epicondyle.
	•	Test resisted wrist flexion and forearm pronation; pain with these maneuvers may indicate medial epicondylitis or flexor-pronator tendon disease.
	•	Palpate the ulnar nerve in the cubital tunnel; flex and extend the elbow as the nerve is palpated to detect nerve subluxation.
	•	Assess the Tinel sign over the ulnar nerve.

Posterior Compartment

	•	Palpate the triceps muscle insertion and the posterolateral and posteromedial joint to check for bone spurs or impingement.
	•	“Clunk” test for posterior olecranon impingement: Grasp the patient’s upper arm to stabilize the arm as the elbow is brought into full extension. Pain with this maneuver may indicate compression of the olecranon into the fossa (valgus extension overload).

Lateral Compartment

	•	Palpate the lateral epicondyle and extensor origin to identify lateral epicondylitis or tendon disease.
	•	Pain with resisted wrist dorsiflexion and forearm supination is indicative of lateral epicondylitis.
	•	Palpate the radiocapitellar joint while the forearm is pronated and supinated to check for crepitus or catching, which may indicate chondromalacia.
	•	Inspect the “soft spot” to check for synovitis or effusion.

Stability

•

The O’Driscoll posterolateral instability test can be performed to evaluate posterolateral rotatory instability. However, because of the patient’s apprehension, the test result is usually negative. This test is best done under general anesthesia.

Range of Motion

•

Flexion, extension, pronation, and supination are determined and compared with the opposite extremity.

Imaging

Radiography

Review carefully for fractures, subluxation, dislocation, degenerative changes, osteophytes, and loose bodies.

	•	Anteroposterior view with elbow in full extension
	•	Lateral view with elbow flexed 90 degrees
	•	Axial view (best for identifying posteromedial osteophytes)
	•	Gravity stress test view (detects valgus laxity)

Magnetic Resonance Imaging

	•	Evaluation of osteochondral lesions in radiocapitellar joint
	•	Detection of early vascular changes
	•	Assessment of extent of lesion and displacement of fragments
	•	Evaluation of soft tissue structures
	•	Detection of partial-thickness undersurface tears or full-thickness tears of the ulnar collateral ligament (magnetic resonance arthrography with saline contrast or gadolinium)
	•	Detection of loose bodies

Indications and Contraindications

Common indications include removal of loose bodies, resection of symptomatic plicae, capsular release in patients with contracture, removal of osteophytes, synovectomy in patients with inflammatory arthritis, treatment of osteochondritis dissecans, débridement for lateral epicondylitis, and treatment of some elbow fractures (Steinmann et al). The primary contraindication to elbow arthroscopy is any severe distortion of normal bone or soft tissue anatomy that jeopardizes safe entry of the arthroscope into the joint. Local soft tissue infection in the area of portal sites also is a contraindication.

Surgical Technique

Anesthesia and Positioning

We prefer to use a general anesthetic because it is reliable, provides muscle relaxation, allows positioning without discomfort to the patient, and permits the use of a tourniquet when it is needed. Local and intravenous blocks have the disadvantage of making neurovascular evaluation unreliable postoperatively.

Supine Position (
Fig. 31-1

; authors’ preference)

The patient is placed supine on the operating table with the scapula at the edge of the table and the shoulder abducted 90 degrees. The operative extremity is placed in a prefabricated wrist gauntlet, stockinette, or finger traps. Enough traction is applied to suspend the elbow away from the table at 90 degrees of flexion (10 pounds is the standard amount). A well-padded tourniquet is placed high on the operative arm to allow proper portal placement and instrument manipulation. Use of a traction setup allows access for medial and lateral approaches and eliminates the need for an assistant to hold the extremity. Flexing the elbow 90 degrees relaxes the neurovascular structures, making portal placement safer, and the forearm can be supinated and pronated during the procedure.

If a suspension device is not available, two arm boards can be used to support the operative extremity. This requires an assistant to hold the arm at 90 degrees of elbow flexion at all times. This setup is more stable but does require more operative personnel.

Prone Position (
Fig. 31-2

)

After intubation, the patient is placed prone, with care taken to place chest bolsters to assist in torso and airway care. The patient is then positioned near the edge of the table; with a rolled towel or arm holder, the operative extremity is positioned with the shoulder abducted 90 degrees, the elbow flexed 90 degrees, and the hand pointed toward the floor. Before the extremity is prepared, a well-padded tourniquet is placed high on the arm, and the elbow is moved through a full range of motion to ensure that complete flexion and extension can be obtained and the shoulder is not hyperextended. Baker noted several advantages of the prone position. First, because of the weight of the arm over a bolster, no traction is needed because gravity assists in joint distraction. Second, the arm is stable during the procedure, unlike in the supine position, in which the arm may tend to swing during portal placement and instrument introduction. Third, the neurovascular structures are protected by being farther away from the capsule as a result of gravity and fluid distention of the joint. Next, if it is needed, conversion to an open procedure can be done through a medial or lateral exposure. Finally, the elbow can be fully extended during the procedure if necessary.

Lateral Decubitus Position (
Fig. 31-3

)

This position is similar to the prone position but allows access to the posterior compartment and also provides easy maintenance of anesthesia during the procedure. Again, a tourniquet is applied high on the arm, and the arm is positioned with a bump or bolster attached to the bed.

Surgical Landmarks, Incisions, and Portals

General Principles of Portal Placement

	•	Mark all portal sites before surgery, when the elbow is not distended or edematous.
	•	Mark all surface landmarks with a pen (lateral epicondyle, medial epicondyle, radial head, capitellum, and olecranon).
	•	Palpate the ulnar nerve and mark its location; check that it does not subluxate from the cubital tunnel.
	•	Identify the location and course of any visible superficial cutaneous nerves and mark them; when necessary, use a retractor to expose and protect these nerves.
	•	Distend the joint by an 18-gauge needle through the direct lateral portal site (soft spot) with 20 to 40 mL of lactated Ringer solution.
	•	Initiate an anterolateral portal (authors’ preference) or anteromedial portal after placing a second 18-gauge needle in the anticipated portal site.
	•	A blunt or conical trocar and cannula are used to trap the capsule over the radial head for anterolateral portal placement.
	•	The 18-gauge needle is left in the soft spot to be used as an outflow.
	•	Once the initial portal is made, all subsequent portals should be made under direct vision with use of an 18-gauge needle.
	•	When making portals, avoid “stab” incisions. Instead, lay the tip of the blade against the skin and pull the skin across the blade; this allows subcutaneous tissue and sensory nerves to fall away to a safe distance and reduces the risk of nerve injury. Spread the subcutaneous tissues with a mosquito hemostat to prevent damage to the superficial cutaneous nerves.
	•	A switching stick is a helpful alternative to establishing the anteromedial from the anterolateral portal or the anterolateral from the anteromedial portal by driving the arthroscope directly to the second portal site from inside and then cutting down on the switching stick from outside and placing a cannula over the exposed tip.
	•	Pump pressures should be maintained at 35 to 45 mm Hg to prevent fluid extravasation and possible compartment syndrome. The use of nonvented cannulas decreases fluid extravasation into the soft tissues.

After general anesthesia has been administered, bone anatomy and landmarks are palpated and marked (
Fig. 31-4

). The radial head, found by supination and pronation of the forearm, is outlined, as are the medial and lateral epicondyles and the olecranon. The course of the ulnar nerve through the cubital tunnel also should be outlined.

Specific Portal Placement

Lateral Portals (
Fig. 31-5

)

The direct lateral portal lies in the center of a triangle formed by the lateral epicondyle, radial head, and olecranon. This soft spot is easily palpated before distention. This approach passes through the anconeus muscle; it is used for initial joint distention and for lateral portal viewing. Watch for the posterior antebrachial cutaneous nerve, which passes within 7 mm.

The anterolateral portal lies 2 to 3 cm distal and 1 to 2 cm anterior to the lateral humeral epicondyle, within the sulcus between radial head and capitellum anteriorly. These measurements may vary, depending on the size of the patient, and portal placement depends on locating the radiocapitellar articulation. The anterolateral portal passes through the extensor carpi radialis brevis and the supinator muscle before reaching the capsule. This portal provides an excellent view of the medial capsule, medial plica, coronoid process, trochlea, and coronoid fossa. Watch for the posterior antebrachial cutaneous nerve, an average of 2 mm from the sheath; the radial nerve, which is usually 7 to 11 mm anteromedial to the portal but may be as close as 2 or 3 mm; and the posterior interosseous nerve, 1 to 13 mm from the portal, depending on the degree of forearm pronation.

The middle anterolateral portal, located 1 cm directly anterior to the lateral epicondyle, provides access to the radiocapitellar joint and lateral compartment and is a good working portal for instrumentation. It also functions as a good viewing portal for the anterior ulnohumeral joint.

The proximal anterolateral portal is made 1 to 2 cm proximal and 1 cm anterior to the lateral epicondyle. Stothers et al described this portal as being safer than the middle anterolateral portal, which was safer than the standard distal anterolateral portal.

Medial Portals (
Fig. 31-6

)

The anteromedial portal is placed 2 cm anterior and 2 cm distal to the medial epicondyle. It is usually placed under direct visualization with the use of an 18-gauge needle. The anteromedial portal passes between the radial aspect of the flexor digitorum sublimis and the tendinous portion of the pronator teres before entering the joint capsule. It allows examination of the radiocapitellar and humeroulnar joints, the coronoid fossa, the capitellum, and the superior capsule. Watch for the medial antebrachial cutaneous nerve, which is an average of 6 mm from the portal but may be as close as 1 mm; the median nerve, which is 19 mm anterolateral to the portal with the joint distended and 12 mm without distention; and the ulnar nerve, located an average of 21 mm from the portal. The portal lies 17 mm posteromedial to the brachial artery.

The proximal medial (superomedial) portal is placed 1 cm anterior and 1 to 2 cm proximal to the medial epicondyle and passes through a tendinous portion of the flexor-pronator group. This portal provides excellent viewing of the anterior compartment of the elbow, particularly the radiocapitellar joint. Watch for the median nerve, which is 22.3 mm from the portal.

Posterior Portals (
Fig. 31-7

)

The posterolateral portal is placed 2 to 3 cm proximal to the olecranon tip and just lateral to the lateral border of the triceps muscle. This portal allows examination of the olecranon tip, olecranon fossa, and posterior trochlea.

The straight posterior portal is located over the center of the triceps tendon, 2 cm medial to the posterolateral portal and 3 cm proximal to the tip of the olecranon. This portal is helpful for removal of impinging olecranon osteophytes and loose bodies from the posterior elbow joint. Watch for the posterior and medial antebrachial cutaneous nerves, which lie on the lateral and medial aspects of the upper arm 23 to 25 mm medial to the straight posterior portal, and the ulnar nerve, located within 25 mm of the straight posterior portal.

Normal Arthroscopic Anatomy

Anterior Compartment

Through the anterolateral portal (
Fig. 31-8

), the coronoid and its articulation with the trochlea can be viewed. Flexion and extension of the elbow bring the anterior trochlea into view. The brachialis tendon insertion can be evaluated on the coronoid process. The coronoid fossa can be seen proximal in the compartment. With the arthroscope directed medially, the medial portion of the capsule can be examined, including the anterior third of the anterior bundle of the ulnar collateral ligament. With proper orientation of the scope, the proximal ulna and medial gutter can be viewed. The sublime tubercle, with the intersection of the anteromedial capsule and the proximal medial ulna, can be evaluated.

Through the anteromedial portal (
Fig. 31-9

), established under direct vision by initial placement of an 18-gauge needle, the radial head and the radiocapitellar articulation can be identified. Supination and pronation of the forearm allow viewing of 75% of the surface of the radial head. The annular ligament can be noted crossing the radial neck, and the radial fossa can be evaluated with proximal viewing of the scope. The attachment of the capsule to the humerus can be seen superiorly. The scope can then be advanced to examine the lateral gutter, the undersurface of the capsule, and the origin of the extensor muscles to the lateral epicondyle. The articulations of the radius, ulna, and distal humerus can be viewed by placing the scope between the trochlear and capitellar ridges up to the medial border of the radial head.

Lateral Compartment

Through the direct lateral portal (
Fig. 31-10

), the articulation of the olecranon, radial head, and capitellum can be seen. Again, supination and pronation of the forearm allow viewing of 75% of the radial head articular surface. The capitellum can be seen and most of the smooth convex surface can be examined through this portal. The olecranon fossa can also be evaluated at this position. The scope can then be positioned posterior into the groove formed by the olecranon and trochlea. The entire olecranon can be seen from this vantage. The apophyseal scar can be viewed at the midpoint as a bare area of roughened articular cartilage. The undersurface of the trochlea should be visible when the scope is turned anteriorly. The posterolateral corner and capsule are viewed by looking posteriorly from the olecranon-trochlear groove. The posterior compartment can then be viewed for establishment of the posterior portals. If the 4-mm arthroscope is too large for this portal, a 2.7-mm arthroscope can be used.

Posterior Compartment

The olecranon tip will be the first landmark seen through the posterolateral portal (
Fig. 31-11

). The triceps tendon insertion will be seen at the olecranon tip, where osteophyte formation may be noted posteromedially in patients with posterior impingement due to valgus extension overload. The olecranon fossa and posterior trochlear surface also can be seen from this position. Normally 50% to 60% of the ulnar collateral ligament can be seen when the scope is pushed medially and the posteromedial corner of the elbow is seen. The ulnar nerve is superficial to this area of the elbow and must be identified and protected.

Postoperative Considerations

Complications

	•	Neurovascular: superficial or deep
	•	Infection
	•	Articular cartilage damage
	•	Fluid extravasation and compartment syndrome
	•	Synovial-cutaneous fistula
	•	Arthrofibrosis
	•	Complex regional pain syndrome

The most common complication related to portal placement is nerve damage, which occurs in about 3% of procedures. Most of these injuries are to cutaneous nerves and are transient, although there have been isolated reports of major neurovascular injuries. These include irreparable damage to the ulnar nerve; transection of the ulnar, radial, and posterior interosseous nerves; and compression neuropathy of the radial nerve.

Drainage from a portal site occurs in approximately 2.5% of patients, but deep infection is less frequent (∼1%).