The Elbow

 

 

 

Posterior Approach to the Elbow with Olecranon Osteotomy Posterior Approach to the Elbow without Olecranon Osteotomy Anteromedial Approach to the Elbow

Posteromedial Approach to the Coronoid Process of Ulna Anterolateral Approach to the Elbow

Anterior Approach to the Cubital Fossa Posterolateral Approach to the Radial Head Applied Surgical Anatomy

Applied Surgical Anatomy of the Medial Approaches

Applied Surgical Anatomy of the Anterolateral Approach to the Elbow

Applied Surgical Anatomy of the Anterior Approach to the Cubital Fossa

Applied Surgical Anatomy of the Posterior Approaches to the Elbow The elbow is a hinged joint supported by strong collateral ligaments. The

key neurovascular structures running down the arm pass anterior and posterior to the joint. The medial and lateral approaches, therefore, avoid the obvious neurovascular dangers, but provide limited access to the elbow because of its bony configuration. Anterior and posterior approaches provide better access to the joint, but may endanger the key neurovascular structures.

Of the seven surgical approaches that are described in this chapter, the posterior approach with osteotomy provides the best possible exposure to all surfaces of the elbow and is the approach used most often for the internal fixation of complex fractures of this joint. The posterior approach without osteotomy also provides good exposure of the elbow and the approach is widely used for total elbow replacement where an intact olecranon is required for the fixation of the distal component of the prosthesis. The anteromedial approach provides good access to the medial side of the joint, but requires an osteotomy of the medial epicondyle for best exposure. This osteotomy does not involve any part of the articular surface, however. Although the approach is extensile to the distal humerus, it is most useful in dealing with local pathologies of the medial side of the joint. The posteromedial approach is used mainly for fixation of the coronoid process and the medial collateral ligament of the elbow. The anterolateral approach exposes the lateral side of the joint; in addition, it can be extended both proximally and distally to expose both the humerus and the radius from the shoulder to the wrist. The anterior approach to the cubital fossa is designed primarily for exploration of the critical neurovascular structures that pass in front of the elbow joint. The posterolateral approach to the radial head is designed exclusively for surgery on that structure.

The applied anatomy of the elbow is discussed in a single section of this chapter after the various surgical approaches are described, mainly because the keys to the surgical anatomy are the neurovascular bundles that pass across the elbow joint; their positions are important in all the approaches. Separate subsections outline the anatomy that applies to each particular approach.

 

Posterior Approach to the Elbow with Olecranon Osteotomy

 

 

The posterior approach provides the best possible view of the bones that

comprise the elbow joint.1,2 Although it is basically a safe and reliable operative technique, it does have one major drawback: It requires an osteotomy of the olecranon on its articular surface, creating another “fracture” that must be internally fixed. The uses of the posterior approach include the following:

1. Open reduction and internal fixation of fractures of the distal humerus3,4

2. Removal of loose bodies within the elbow joint

3. Treatment of nonunions of the distal humerus

Extension contractures of the elbow can be treated by using some portions of this approach to lengthen the triceps muscle, without performing an olecranon osteotomy.

 

Position of the Patient

 

Exsanguinate the limb by elevating it for 3 to 5 minutes and then apply a tourniquet as high up on the arm as possible. Place the intubated patient prone on the operating table, ensuring adequate padding for the chest and pelvis to allow free movement of the abdomen during respiration. Abduct the arm about 90 degrees and place a small sandbag underneath the tourniquet, elevating the upper arm from the operating table. Allow the elbow to flex and the forearm to hang over the side of the table (Fig. 3-1).

 

 

Figure 3-1 Position of the patient on the operating table.

 

Landmarks and Incision

Landmark

Palpate the large, bony olecranon process at the upper end of the ulna. It is conical and has a relatively sharp apex.

Incision

Make a longitudinal incision on the posterior aspect of the elbow. Begin 5 cm above the olecranon in the midline of the posterior aspect of the arm. Just above the tip of the olecranon, curve the incision laterally so that it runs down the lateral side of the process. To complete the incision, curve it medially again so that it overlies the middle of the subcutaneous surface of the ulna. Running the incision around the tip of the olecranon moves the suture line away from devices that are used to fix the olecranon osteotomy and away from the weight-bearing tip of the elbow (Fig. 3-2).

Internervous Plane

 

There is no true internervous plane, because the approach involves little more than detaching the extensor mechanism of the elbow. The nerve supply of the triceps muscle (the radial nerve) enters the muscle well proximal to the dissection.

 

Superficial Surgical Dissection

 

Incise the deep fascia in the midline. Palpate the ulnar nerve as it lies in the bony groove on the back of the medial epicondyle and incise the fascia overlying the nerve to expose it. Fully dissect out the ulnar nerve and pass tapes around it so that it can be identified at all times (Fig. 3-3). Do not use these tapes for retraction as this can create a traction lesion to the nerve.

If a screw is going to be used to fix the olecranon osteotomy, drill and tap the olecranon before the osteotomy is performed.5

Score the bone longitudinally with an osteotome so that the pieces can be aligned correctly when the osteotomy is repaired (see Fig. 3-3, inset).

Make a V-shaped osteotomy of the olecranon about 2 cm from its tip using an oscillating saw. The apex of the V is directed distally. A V-shaped osteotomy gives greater stability than a transverse osteotomy after fixation. Divide the bone until it is cut through almost entirely. Snap the remaining cortex by wedging the two cut surfaces apart with an osteotome. This will cause an irregularity in the osteotomy, allowing it to key together better during reconstruction (see Fig. 3-3, inset).

 

 

Figure 3-2 Incision for the posterior approach to the elbow.

 

 

Figure 3-3 Dissect the ulnar nerve from its bed and hold it free with tape. Predrill the olecranon before performing an osteotomy for easy reattachment. A V-shaped osteotomy is inherently more stable than a transverse osteotomy.

 

 

 

Figure 3-4 Perform a V-shaped osteotomy of the olecranon and retract it proximally, with the triceps muscle attached. Strip a portion of the joint capsule with an osteotome.

 

Deep Surgical Dissection

 

Strip the soft tissue attachments off the medial and lateral sides of the portion of the olecranon that has been subjected to osteotomy and retract it proximally, elevating the triceps from the back of the humerus (Fig. 3-4). The posterior aspect of the distal end of the humerus is directly underneath; subperiosteal dissection around the medial and lateral borders of the bone allows exposure of all surfaces of the distal fourth of the humerus (Fig. 3-5). Note that full exposure seldom will be needed. Preserve as many of the soft tissue attachments to bone as possible when the approach is used for open reduction and internal fixation of fractures. Stripping excessive soft tissue attachments off the bone leaves the bone

fragments without a vascular supply and jeopardizes healing.

Be careful not to extend the dissection proximally above the distal fourth of the humerus, because the radial nerve, which passes from the posterior to the anterior compartment of the arm through the lateral intermuscular septum, may be damaged. Flex the elbow to relax the anterior structures if they need to be elevated off the front of the humerus (see Fig. 2-41).

The ulnar nerve must be kept clear of the operative field during all stages of the dissection. Some surgeons advise routine anterior transposition of the nerve during closure, especially if implant removal is anticipated in the future.

 

 

Dang

 

 

Nerves

The ulnar nerve is in no danger as long as it is identified early and protected, and excessive traction is not placed on it. It is at most risk when transverse K wires are inserted from the lateral side that may overpenetrate the medial cortex.

 

 

 

Figure 3-5 Dissect around the medial and lateral borders of the bone to expose all

the surfaces of the distal fourth of the humerus.

 

The median nerve lies anterior to the distal humerus. It may be endangered if the anterior structures are not stripped off the distal humerus in an epiperiosteal plane. In cases of fracture, this dissection has usually been done for you. In the treatment of nonunions or when the approach is used for osteotomies, a strictly subperiosteal plane must be used to avoid damage to the nerve (see Fig. 3-5, inset).

The radial nerve is at risk if the dissection ventures farther proximally than the distal third of the humerus, one handbreadth above the lateral epicondyle (see Fig. 2-43).

Vessels

The brachial artery lies with the median nerve in front of the elbow. It should be afforded the same protection as the nerve (see Fig. 3-5, inset).

 

Special Points

 

Great care must be taken to realign the olecranon correctly during closure. Alignment after fractures is easy, because the uneven ends of the bone usually fit snugly, like a jigsaw puzzle. Osteotomies may result in flat surfaces, however, and can make accurate reattachment difficult (see Fig. 3-3). Also the oscillating saw will remove approximately 1 mm of bone making true anatomical reduction of the fracture impossible.

 

How to Enlarge the Approach

Extensile Measures

 

Proximal Extension. The posterior approach cannot be extended more proximally than the distal third of the humerus because of the danger to the radial nerve (see Figs. 2-43 and 2-47).

 

Distal Extension. The incision can be continued along the subcutaneous border of the ulna, exposing the entire length of that bone (see Applied Surgical Anatomy of the Approach to the Ulna in Chapter 4).

 

Posterior Approach to the Elbow without Olecranon Osteotomy

 

The posterior approach to the elbow without osteotomy provides excellent exposure of the elbow while preserving bony anatomy.6 A variety of techniques have been described for this approach but all of them have the same end point—the creation of a flap consisting of the triceps muscle, its insertion into the olecranon, and the fascia covering the flexor carpi ulnaris muscle based laterally on the anconeus muscle.7

The uses for the posterior approach include the following:

1. Open reduction and internal fixation of fractures of the distal humerus.3,4

2. Total joint arthroplasty

3. Excision of tumors

 

Position of the Patient

 

Place the patient lateral on the operating table ensuring adequate protection for the chest, pelvis, and arm using a padded table. Exsanguinate the limb by elevating it and apply a tourniquet as high up on the arm as possible. Allow the elbow to flex and the forearm and hand to lie over the side of the table (Fig. 3-6)

 

Landmarks and Incision

Landmark

Palpate the large, bony olecranon process at the upper end of the ulna. It is conical and has a relatively sharp apex. Palpate the medial and lateral epicondyles and mark them to be sure during surgery which side is medial and which side is lateral.

Incision

Make a longitudinal incision on the posterior aspect of the elbow. Begin 12 cm above the olecranon in the midline of the posterior aspect of the arm. Just above the elbow curve the incision laterally so that it runs down the lateral side of the olecranon process. Distally continue the incision along the subcutaneous surface of the ulna for 8 to 10 cm. Running the incision around the tip of the olecranon moves the suture line and resultant surgical scar away from the prominent olecranon (Fig. 3-7).

 

Internervous Plane

 

There is no true internervous plane because the approach involves little

more than detaching the extensor mechanism of the elbow from its insertion into the ulna. The nerve supply of the triceps muscle (radial nerve) enters the muscle well proximal to the dissection.

 

Superficial Surgical Dissection

 

Incise the deep fascia in the midline. Palpate the ulnar nerve as it lies in the bony groove at the back of the medial epicondyle and incise the fascia overlying the nerve to expose it. Fully dissect out the ulnar nerve and pass tapes around it so that it can be identified at all times (see Fig. 3-3). Do not use these tapes for retraction as this can create a traction lesion to the nerve. Incise the fascia overlying the flexor carpi ulnaris muscle at the border of the ulna.

 

 

 

Figure 3-6 Place the patient in the lateral position on the operating table.

 

 

Figure 3-7 Make a 12-cm longitudinal incision on the posterior aspect of the elbow. Gently curve the incision to run on the lateral side of the olecranon process.

 

 

 

Figure 3-8 With the elbow flexed about 30 degrees reflect the triceps mechanism

from medial to lateral in continuity with the forearm fascia and the olecranon and ulnar periosteum.

 

 

 

Figure 3-9 Incise the fascia on the medial border of the triceps. Reflect the entire extensor mechanism laterally flexing the elbow to 100 degrees to improve visualization of the joint surface.

 

Deep Surgical Dissection

 

The key to this approach is keeping a large thick fascial insertion of triceps for reinsertion onto the olecranon when the approach is complete. With the elbow flexed about 30 degrees reflect the triceps mechanism from medial to lateral in continuity with the forearm fascia and the olecranon and ulnar periosteum. Strip the forearm fascia and triceps insertion off the ulna by sharp dissection. At the level of the olecranon detach these structures together with a sliver of bone using a sharp osteotome (Fig. 3-8). Proximal to the olecranon of the elbow incise the fascia on the medial border of the triceps (Fig. 3-9). Incise the posterior capsule of the joint and reflect the entire extensor mechanism laterally flexing the elbow to 100 degrees to improve visualization of the joint surface (Fig. 3-10). Always be aware of the ulnar nerve on the medial side of the elbow.

 

 

Dang

 

Nerves

The ulnar nerve is always at risk, and must be protected throughout from a traction injury.

 

Special Points

 

Great care must be taken when the triceps tendon is detached from the olecranon to ensure that the full thickness of the triceps tendon is detached. To ensure this removing a small sliver of bone is advised.

 

 

 

Figure 3-10 Proximal to the olecranon incise the posterior capsule of the elbow.

 

How to Enlarge the Approach

Extensile Measures

 

Proximal Extension. The posterior approach can be easily extended proximally by freeing the medial aspect of the triceps muscle from the medial intermuscular septum preserving the ulna nerve.

 

Distal Extension. The incision can be continued along the subcutaneous border of the ulna exposing the entire length of that bone between the extensors of the elbow and wrist and the flexors of the wrist.

(See Exposure of the Shaft of the Ulna in Chapter 4.)

 

Anteromedial Approach to the Elbow

 

 

The anteromedial approach gives good exposure of the medial compartment of the joint.8,9 It also can be enlarged to expose the anterior surface of the distal fourth of the humerus. The ulnar nerve (which runs across the operative field), median nerve, and brachial artery may be at risk in this exposure. The uses of the medial approach include the following:

1. Removal of loose bodies (now more commonly removed arthroscopically).

2. Open reduction and internal fixation of fractures of the coronoid process of the ulna especially if associated with repair of the medial supporting structures of the elbow.

3. Open reduction and internal fixation of fractures of the medial humeral condyle and epicondyle.

4. The medial approach provides poor access to the lateral side of the joint and should not be used for routine exploration of the elbow. The joint may be dislocated during the procedure, however, to gain access to the lateral side of the elbow, if necessary.

 

Position of the Patient

 

Place the patient supine on the operating table, with the arm supported on an arm board or table. Abduct the arm and rotate the shoulder fully externally so that the medial epicondyle of the humerus faces anteriorly. Flex the elbow to 90 degrees. Alternatively, flex the patient’s shoulder and elbow such that the forearm comes to lie over the front of the face. This allows easier exposure of the medial side of the elbow, but requires an assistant to hold the forearm to provide adequate exposure (Fig. 3-11).

Exsanguinate the limb either by elevating it for 5 minutes or by applying a soft rubber bandage (or exsanguinator). Then, inflate a tourniquet.

 

Landmarks and Incision

Landmarks

Palpate the medial epicondyle of the humerus, the large subcutaneous bony mass that stands out on the medial side of the distal end of the humerus.

 

 

Figure 3-11 Position of the patient on the operating table.

 

 

 

Figure 3-12 Incision for the medial approach to the elbow, centered on the medial epicondyle.

 

Incision

Make a curved incision 8 to 10 cm long on the medial aspect of the elbow, centering the incision on the medial epicondyle (Fig. 3-12).

 

Internervous Plane

 

Proximally, the internervous plane lies between the brachialis muscle (which is supplied by the musculocutaneous nerve) and the triceps muscle (which is supplied by the radial nerve) (Fig. 3-13).

Distally, the plane lies between the brachialis muscle (which is

supplied by the musculocutaneous nerve) and the pronator teres muscle (which is supplied by the median nerve; see Fig. 3-13).

 

Superficial Surgical Dissection

 

Palpate the ulnar nerve as it runs in its groove behind the medial condyle of the humerus. Incise the fascia over the nerve, starting proximal to the medial epicondyle; then, isolate the nerve along the length of the incision (Fig. 3-14).

 

 

 

Figure 3-13 Internervous plane. Proximally, the plane is between the brachialis (musculocutaneous nerve) and the triceps (radial nerve); distally, it is between the brachialis and the pronator teres (median nerve).

 

 

Figure 3-14 Superficial surgical dissection. Isolate the ulnar nerve along the length of the incision.

 

Retract the anterior skin flap, together with the fascia overlying the pronator teres. The superficial flexor muscles of the forearm now are visible as they pass directly from their common origin on the medial epicondyle of the humerus (Fig. 3-15).

Define the interval between the pronator teres and brachialis muscles, taking care not to damage the median nerve, which enters the pronator teres near the midline. Gently retract the pronator teres medially, lifting it off the brachialis (Fig. 3-16). Make sure that the ulnar nerve is retracted inferiorly; then, perform an osteotomy of the medial epicondyle. Place a periosteal elevator beneath the medial collateral ligament in order to be certain that when the medial epicondyle is osteotomized the ligament remains attached to the medial epicondyle. Reflect the epicondyle with its attached flexors distally, avoiding traction that might damage the median or anterior interosseous nerves. Superiorly, continue the dissection between the brachialis, retracting it anteriorly, and the triceps, retracting it posteriorly (Fig. 3-17). The medial collateral ligaments must be preserved during osteotomy of the medial epicondyle. Division of this ligament will result in valgus instability of the elbow.

 

 

Figure 3-15 Retract the skin anteriorly with the fascia to uncover the common origin of the superficial flexor muscles from the medial epicondyle.

 

 

 

Figure 3-16 Enter the interval between the pronator teres and the brachialis. Retract the pronator teres medially.

 

Deep Surgical Dissection

The medial side of the joint now can be seen. Incise the capsule and the medial collateral ligament to expose the joint (Fig. 3-18).

 

 

 

Figure 3-17 Subject the medial epicondyle to osteotomy and retract it (gently) with its attached flexors. Vigorous retraction of the epicondyle and its attached muscles may stretch the branch of the median nerve to the flexors.

 

 

 

Figure 3-18 Incise the joint capsule and the medial collateral ligament to expose the joint.

 

 

Dang

 

 

Nerves

The ulnar nerve must be dissected out and isolated before the medial epicondyle undergoes osteotomy (see Fig. 3-16).

The median nerve can suffer a traction lesion, with special damage to its multiple branches to the pronator teres muscle, if the medial epicondyle and its superficial flexor muscles are retracted too vigorously in a distal direction. Its major branch, the anterior interosseous nerve, also may suffer a traction lesion (see Fig. 3-17).

 

How to Enlarge the Approach

Local Measures

If a better view of the joint is required, the forearm can be abducted to open its medial side. To dislocate the elbow, the joint capsule and periosteum should be stripped off the distal humerus, working from within the joint. By this means, the mobility of the proximal ulna will be increased significantly. This increased mobility then will allow dislocation of the joint laterally, thereby opening all the surfaces of the joint to inspection.

Extensile Measures

 

Proximal Extension. Enlarge the exposure proximally by developing the plane between the triceps and brachialis muscles. Subperiosteal dissection and elevation of the brachialis expose the anterior surface of the distal fourth of the humerus (see Figs. 3-18 and 3-48).

 

Distal Extension. The medial epicondyle of the humerus, with its attached flexor muscles, can be retracted only as far as the branches from the median nerve allow. Thus, although the exposure provides an adequate view of the brachialis inserting into the coronoid, it cannot offer a more distal exposure of the ulna.

 

Posteromedial Approach to the Coronoid

 

Process of the Ulna

This approach provides excellent exposure of the coronoid process and the medial aspect of the proximal ulna.10,11

Because the approach is through the bed of the ulnar nerve this structure is at risk in this exposure. The approach does not utilize an internervous plane exposure and therefore cannot be extended but it does provide excellent exposure of the anteromedial aspect of the coronoid process of the ulna, medial collateral ligament of the elbow, and the sublime tubercle. The uses of the posteromedial approach include the following:

1. Open reduction and internal fixation of fractures of the coronoid process of the ulna. A lateral approach may be preferred if the fracture is associated with a fracture of the radial head and/or rupture of the lateral collateral ligament of the elbow.

2. Repair of the medial collateral ligament of the elbow—usually in conjunction with fixation of the coronoid process.

3. Exposure of the sublime tubercle of the ulna for stabilization of fractures.

 

Position of the Patient

 

Place the patient lateral on the operating table with the arm supported by a padded arm board or table. Exsanguinate the limb by elevating it and then apply a tourniquet as high up on the arm as possible. Allow the elbow to flex and the forearm to hang over this padded table (see Fig. 3-6). This position is ideal for open reduction and internal fixation of a coronoid fracture because flexion relaxes the pull of the brachialis muscle. In addition this position allows the limb to be pulled by gravity which assists in the reduction of fractures of the proximal ulna.

 

Landmarks and Incision

Landmarks

Palpate the large, bony olecranon process at the upper end of the ulna and identify the medial epicondyle and the lateral epicondyle of the distal humerus.

Incision

Make a curved incision 8 cm long on the medial aspect of the elbow. Begin the incision proximally just posterior to the medial epicondyle and extend it distally to run along the medial aspect of the forearm (Fig. 3-19).

 

Internervous Plane

 

Superficially this exposure does not utilize a true internervous plane. The approach is made between the humeral head of the flexor carpi ulnaris and the ulnar head of the flexor carpi ulnaris which are both innervated by the ulnar nerve (see Fig. 3-45). The deep dissection lies between the ulnar innervated flexors of the wrist and the deep head of the pronator teres (innervated by the median nerve) (see Fig. 3-45).

 

Superficial Surgical Dissection

 

Palpate the ulnar nerve as it runs in the groove behind the medial condyle of the humerus. Incise the fascia over the nerve, starting proximally at the level of the medial epicondyle. Isolate the nerve lifting it out of its groove on the back of the medial epicondyle (Fig. 3-20). Define the interval between the two heads of the flexor carpi ulnaris, and develop this plane. Try to preserve branches of the ulnar nerve going to the flexor carpi ulnaris. Identify the sublime tubercle of the ulna. This is a prominent smooth elevation on the medial aspect of the lip of the coronoid process. The ulna nerve is actually in contact with this tubercle and when the nerve is mobilized from its canal the bone is exposed (see Fig. 3-21).

 

Deep Surgical Dissection

 

Identify the medial collateral ligament of the elbow just below the sublime tubercle. If needed strip off the soft tissue from the medial aspect of the coronoid process (Fig. 3-22). In cases of fracture this dissection had often been done for you. Complete exposure of the medial aspect of the proximal ulna involves detachment of the origins of the ulna heads of the pronator teres and the flexor carpi ulnaris. These heads are very small.

 

 

Figure 3-19 Make a 8-cm curvilinear incision on the medial aspect of the elbow beginning at the posterior aspect of the medial epicondyle and ending on the medial aspect of the forearm.

 

 

 

Figure 3-20 Isolate the ulnar nerve from the posterior aspect of the medial epicondyle to the interval between the two heads of flexor carpi ulnaris.

Dang

 

 

Nerves

The ulnar nerve must be dissected out and isolated so as to protect it (see Fig. 3-20). Small branches of the ulnar nerve enter the ulnar and humeral head of the flexor carpi ulnaris and should be preserved if possible. Often many small vessels run with the ulnar nerve in its cubital tunnel and require ligation.

 

 

 

Figure 3-21 Develop a plane between the two heads of flexor carpi ulnaris. Lift the ulna nerve away from the ulna to reveal the sublime tubercle.

 

 

Figure 3-22 Detach the ulna heads of flexor carpi ulnaris and pronator teres from the ulna to reveal the proximal ulna and coronoid process.

 

How to Enlarge the Approach

Extensile Measures

Enlarge the exposure proximally by developing the plane between the triceps and the brachialis muscles. An osteotomy of the medial epicondyle can be performed for viewing the medial side of the elbow joint (see Fig. 3-18). Distally this approach is not extensile because it does not utilize an internervous plane and the many small nerves going to the humeral and ulnar heads of the flexor carpi ulnaris would be at risk if the dissection was carried out more distally. This is a very specific exposure designed to expose the medial side of the coronoid.

 

Anterolateral Approach to the Elbow

The anterolateral approach exposes the lateral half of the elbow joint, especially the capitulum and the proximal third of the anterior aspect of the

radius. Its uses include the following:

1. Open reduction and internal fixation of fractures of the capitulum

2. Excision of tumors of the proximal radius

3. Treatment of aseptic necrosis of the capitulum

4. Drainage of infection from the elbow joint

5. Treatment of neural compression lesions of the proximal half of the posterior interosseous nerve and of the proximal part of the superficial radial nerve—access to the arcade of Frohse, as well as treatment of radial head fractures with paralysis of this nerve

6. Treatment of biceps avulsion from the radial tuberosity

7. Total elbow replacements

This approach is a distal extension of the anterolateral approach to the humerus and a proximal extension of the anterior approach to the radius. Theoretically, the approach can link the two together to expose the entire upper extremity from shoulder to wrist.

 

Position of the Patient

 

Place the patient supine on the operating table, with the arm on an arm board. Exsanguinate the limb either by elevating it for 3 to 5 minutes or by applying a soft rubber bandage or exsanguinator. Then, inflate a tourniquet (Fig. 3-23).

 

 

 

Figure 3-23 Position of the patient on the operating table.

 

Landmarks and Incision

Landmarks

The brachioradialis is palpable as part of a thick wad of muscle on the anterolateral aspect of the forearm. This “mobile wad” consists of muscles; the brachioradialis forms the medial border of the wad.

The biceps tendon is a taut band that is palpable on the anterior aspect of the elbow.

Incision

Make a curved incision along the anterior aspect of the elbow joint. Begin 5 cm above the flexion crease of the elbow, over the lateral border of the biceps muscle. Follow the lateral border of the biceps distally, but curve the incision laterally at the level of the elbow joint to avoid crossing a flexion crease at 90 degrees. Then, continue the incision inferiorly, curving medially and following the medial border of the brachioradialis muscle. The lower limit of the extension depends on the amount of the radius that must be exposed (Fig. 3-24).

 

 

 

Figure 3-24 Incision for the anterolateral approach to the elbow. The upper portion of the incision follows the lateral border of the biceps muscle. The lower portion follows the medial border of the brachioradialis muscle.

 

 

 

Figure 3-25 Internervous plane. Proximally, the plane is between the brachialis (musculocutaneous nerve) and the brachioradialis (radial nerve); distally, it is between the brachioradialis and the pronator teres (median nerve).

 

Internervous Plane

 

Proximally, the plane lies between the brachialis muscle (which is supplied by the musculocutaneous nerve) and the brachioradialis muscle (which is supplied by the radial nerve).

Distally, the plane lies between the brachioradialis muscle (which is supplied by the radial nerve) and the pronator teres muscle (which is supplied by the median nerve) (Fig. 3-25).

 

Superficial Surgical Dissection

 

Identify the lateral cutaneous nerve of the forearm (the sensory branch of the musculocutaneous nerve) as it becomes superficial to the deep fascia in the distal 5 cm of the arm lateral to the biceps tendon in the interval between it and the brachialis muscle. Retract it with the lateral skin flap

(Fig. 3-26). It is more superficial than the superficial radial nerve, lying outside the fascial compartment of the brachioradialis; the superficial radial nerve still lies within the compartment at this level.

 

 

 

Figure 3-26 Superficial surgical dissection. Incise the deep fascia along the medial border of the brachioradialis. Be careful to identify the lateral antebrachial cutaneous nerve and retract it.

 

Incise the deep fascia along the medial border of the brachioradialis (see Fig. 3-26). Identify the radial nerve proximally at the level of the elbow joint between the brachialis and the brachioradialis. It lies deep between the two muscles and cannot be seen fully until they are separated. The intermuscular plane is oblique with the brachioradialis overlying the brachialis muscle. Develop the plane between the two muscles using your finger, retracting the brachioradialis laterally and the brachialis and the overlying biceps brachii medially (Fig. 3-27).

Follow the radial nerve distally along the intermuscular interval until it divides into its terminal branches: The posterior interosseous nerve enters the supinator muscle, the sensory branch passes down the forearm

behind the brachioradialis, and the motor branch to the extensor carpi radialis brevis enters that muscle almost immediately. Below the division of the nerve, develop a plane between the brachioradialis on the lateral side and the pronator teres on the medial side. Ligate the recurrent branches of the radial artery and the muscular branches that enter the brachialis just below the elbow so that the muscle can be retracted adequately. Ligation also allows the radial artery, which runs down the proximal third of the forearm on the pronator teres, to be retracted medially (Fig. 3-28).

 

Deep Surgical Dissection

 

To expose the capitulum and the lateral compartment of the elbow, make a longitudinal incision in the anterior capsule of the joint between the radial nerve laterally and the brachialis medially (Fig. 3-29).

To expose the proximal radius, fully supinate the forearm; note that the origin of the supinator muscle moves anteriorly. Incise the origin of the supinator down the bone, staying just lateral to the insertion of the biceps tendon. Complete the exposure of the proximal radius by circumferential subperiosteal dissection (see Fig. 3-29, inset, and Anterior Approach to the Radius in Chapter 4).

 

 

Dang

 

 

Nerves

The radial nerve must be identified in the interval between the brachioradialis and brachialis muscles before this interval is developed fully. Note that the nerve lies anteromedial to the brachioradialis, within the fascial compartment of that muscle. If it is being sought at the level of the distal humerus or elbow, the intermuscular interval is the best place to find it.

 

 

Figure 3-27 Identify the interval between the brachioradialis and brachialis muscles. Retract the brachioradialis laterally and the brachialis medially, and identify the radial nerve.

 

 

Figure 3-28 The radial nerve divides into its terminal branches: the posterior interosseous nerve, the sensory branch (which appears under the brachioradialis), and a motor branch to the extensor carpi radialis brevis. Develop a plane between the brachioradialis and the pronator teres.

 

 

Figure 3-29 Deep surgical dissection. Make a longitudinal incision in the anterior capsule of the joint between the radial nerve and the brachialis muscle to expose the radial head and capitulum. To expose the radius further, remove the supinator muscle distally in a subperiosteal manner (inset).

 

 

Figure 3-30 Place the forearm in supination to move the posterior interosseous nerve lateral to the incision into the radiohumeral joint and away from the incision into the origin of the supinator muscle, protecting it.

 

The posterior interosseous nerve is vulnerable to injury as it winds around the neck of the radius within the substance of the supinator muscle. To prevent damage to the nerve, ensure that the supinator is detached from its origin on the radius with the forearm in supination. Do not cut through the muscle body to expose the bone (see Anterior Approach to the Radius in Chapter 4; Fig. 3-30; see Fig. 3-42).

The lateral cutaneous nerve of the forearm must be identified and its continuity preserved in the interval between the brachialis and biceps brachii muscles; retract it with the medial skin flap (see Fig. 3-26).

Vessels

Recurrent branches of the radial artery must be ligated so that the brachioradialis can be mobilized fully. Because there are many branches this procedure may be time consuming but ligation also reduces postoperative bleeding and avoids the risk of an ischemic contracture developing postoperatively as a result of the pressure caused by a postoperative bleed (see Fig. 3-28).

How to Enlarge the Approach

Extensile Measures

 

Proximal Extension. The anterolateral approach can be extended easily into an anterolateral approach to the distal humerus by developing the plane between the brachialis and the triceps muscles. Remember that the radial nerve crosses the lateral border of the humerus about one handbreadth above the lateral epicondyle. (For details, see Anterolateral Approach to the Distal Humerus.)

 

Distal Extension. The anterolateral approach can be extended easily to expose the entire anterior surface of the radius by developing the plane proximally between the brachioradialis muscle (which is supplied by the radial nerve) and the pronator teres muscle (which is supplied by the median nerve), and distally between the brachioradialis muscle (which is supplied by the radial nerve) and the flexor carpi radialis muscle (which is supplied by the median nerve). (For details, see Anterior Approach to the Radius in Chapter 4.)

 

Anterior Approach to the Cubital Fossa

The anterior approach may be the least commonly used surgical approach to the elbow and provides access to the neurovascular structures that are found in the cubital fossa. Its uses include the following:

1. Repair of lacerations to the median nerve

2. Repair of lacerations to the brachial artery

3. Repair of lacerations to the radial nerve

4. Reinsertion of the biceps tendon into the bicipital tuberosity of the radius

5. Repair of lacerations to the biceps tendon

6. Release of posttraumatic anterior capsular contractions

7. Excision of tumor

 

Position of the Patient

 

Place the patient supine on the operating table with the arm in the anatomic position. Exsanguinate the limb either by elevating it for 3 to 5

minutes or by applying a soft rubber bandage or exsanguinator. Then, inflate a tourniquet (see Fig. 3-23).

 

Landmarks and Incision

Landmarks

The brachioradialis is a fleshy muscle that forms the lateral border of the supinated forearm.

The tendon of the biceps is a taut, easily palpable, band-like structure that runs downward across the anterior aspect of the cubital fossa.

Incision

Make a curved, “boat-race” incision∗ over the anterior aspect of the elbow. Begin 5 cm above the flexion crease on the medial side of the biceps. Curve the incision across the front of the elbow, then complete it by incising the skin along the medial border of the brachioradialis muscle. Curving the incision avoids crossing the flexion crease at 90 degrees (Figs. 3-31 and 3-32).

 

Internervous Plane

 

Distally, the internervous plane lies between the brachioradialis muscle (which is supplied by the radial nerve) and the pronator teres muscle (which is supplied by the median nerve) (Fig. 3-33).

Proximally, the plane lies between the brachialis muscle (which is supplied by the radial and musculocutaneous nerves) and the pronator teres (which is supplied by the median nerve).

 

 

Figure 3-31 Superficial view of the elbow and forearm, showing superficial veins and nerves.

 

 

 

Figure 3-32 Incision for the anterior approach to the cubital fossa.

 

Superficial Surgical Dissection

Mobilize the skin flaps widely. Incise the deep fascia in line with the skin incision and ligate the numerous veins that cross the elbow in this area.

The lateral cutaneous nerve of the forearm (the sensory branch of the musculocutaneous nerve) must be preserved. To find it, locate the interval between the biceps tendon and the brachialis muscle. The nerve emerges there to run down the lateral side of the forearm subcutaneously (Fig. 3-34).

 

 

 

Figure 3-33 Internervous plane. Distally, the plane is between the brachioradialis (radial nerve) and the pronator teres (median nerve); proximally, it is between the brachialis (musculocutaneous nerve) and pronator teres.

 

 

Figure 3-34 Superficial surgical dissection. Locate the lateral cutaneous nerve of the forearm, in the interval between the biceps tendon and the brachialis and preserve it.

 

Next, identify the bicipital aponeurosis (lacertus fibrosus), which is a band of fibrous tissue coming from the biceps tendon and swinging medially across the forearm, running superficial to the proximal part of the superficial flexor muscles (see Fig. 3-34). Cut the aponeurosis close to its origin at the biceps tendon and reflect it laterally. Be careful not to injure the brachial artery, which runs immediately under the aponeurosis (Fig. 3-35).

Identify the radial artery as it passes the biceps tendon and trace it proximally to its origin from the brachial artery. Note that both the brachial vein and the median nerve lie medial to the artery. To identify the radial nerve, look between the brachialis and the brachioradialis; the nerve crosses in front of the elbow joint.

 

 

Figure 3-35 After cutting the bicipital aponeurosis (lacertus fibrosus), identify the brachial artery. Note that the median nerve lies medial to the artery. The brachial vein, which accompanies the artery, consists of a series of small, fine vessels, the venae comitantes.

 

Identifying these structures and understanding their relationship are the keys to operating successfully in the cubital fossa (see Fig. 3-35).

 

Deep Surgical Dissection

 

If the anterior approach is to be used only for exploration of the neurovascular structures, deep dissection is not required. If you require access to the anterior capsule of the elbow joint, retract the biceps and brachialis muscle medially and the brachioradialis muscle laterally. Fully supinate the forearm and identify the origin of the supinator muscle from the anterior aspect of the radius. Incise the origin of this muscle and dissect it off the bone in a subperiosteal plane, carefully reflecting it laterally. Take care not to insert a retractor on the lateral aspect of the proximal radius as this may compress the posterior interosseous nerve. The anterior capsule of the elbow joint is now exposed and may be incised to expose the anterior aspect of the elbow joint (see Fig. 3-37).

Dang

 

 

Because this approach exposes the neurovascular structures of the fossa so quickly, they may be damaged if care is not taken.

points are crucial, as follows:

1. The lateral cutaneous nerve of the forearm (the sensory branch of the musculocutaneous nerve; see Fig. 3-34) is vulnerable to injury in the distal fourth of the arm during incision of the deep fascia. Pick it up in the interval between the biceps and brachialis muscles in the arm, trace it downward, and preserve it (see Fig. 3-34).

2. The radial artery lies immediately deep to the bicipital aponeurosis; the aponeurosis must be incised carefully to avoid damage to the artery (see Fig. 3-35).

3. The posterior interosseous nerve is vulnerable to injury as it winds round the neck of the radius within the substance of the supinator muscle. To prevent damage to the nerve, ensure that the supinator is detached from its origin on the radius with the forearm in supination (see Fig. 3-29).

 

How to Enlarge the Approach

Extensile Measures

The approach may be extended for more extensive exposure of the neurovascular structures.

Median Nerve

Proximal Extension. Extend the incision superiorly along the medial border of the biceps, and incise the deep fascia in line with the incision. The brachial artery lies immediately under the fascia, between the biceps muscle and the underlying brachialis muscle. The median nerve runs with the artery.

 

 

Figure 3-36 Trace the median nerve distally into the pronator teres. Incise a portion of the muscle superficial to the nerve, if necessary, to expose the nerve. The incision lies between the humeral and ulnar heads of the pronator teres.

 

 

Figure 3-37 Retract the biceps tendon and carefully detach and retract the proximal supinator muscle to gain access to the anterior joint capsule, which may be incised to expose the elbow joint.

 

Distal Extension. Trace the median nerve as it disappears into the pronator teres muscle. Simple retraction of the muscle may provide adequate exposure. Take care not to cut any branches of the median nerve going to the flexor-pronator group of muscles that pass from the medial side of the median nerve at the level of the elbow joint. This incision lies between the humeral and ulnar heads of the pronator teres and allows the plane between the two heads to be developed for the distal exposure of the nerve (Fig. 3-36).

 

Brachial Artery. The brachial artery runs with the median nerve and is exposed in the same way.

 

Radial Artery. To expose the radial artery, trace it distally as it crosses the surface of the pronator teres, running toward the lateral side of the forearm. Developing the plane proximally between the pronator teres and brachioradialis muscles, and distally between the flexor carpi radialis and brachioradialis muscles allows the artery to be followed to the wrist.

Posterolateral Approach to the Radial Head

 

 

The posterolateral approach to the radial head12 is useful for all surgeries to the radial head. These include open reduction and internal fixation of radial head and neck fractures,13,14 excision of the radial head and insertion of a prosthetic replacement.15,16

Because the incision cannot be extended below the annular ligament without risking damage to the posterior interosseous nerve, avoid extending the incision to the upper part of the radial shaft.

 

Position of the Patient

 

Place the patient supine on the operating table, with the affected arm positioned over the chest. Pronate the forearm.17 Exsanguinate the limb either by applying a soft rubber bandage or an exsanguinator or by elevating it for 3 to 5 minutes. Then, inflate a tourniquet (Fig. 3-38).

 

 

Figure 3-38 Position of the patient on the operating table.

 

Landmarks and Incision

Landmarks

One of the landmarks is the lateral humeral epicondyle.

To identify the radial head, palpate the lateral epicondyle of the humerus, moving the fingers 2.5 cm distally until a depression is detected. The radial head lies deep within this depression. It is palpable through the muscle mass of the wrist extensors. As the forearm is pronated and supinated, movement of the radial head can be felt beneath the surgeon’s fingers. In cases of fracture of the radial head, the normal landmarks are lost because of hemorrhage and swelling. Crepitus at the fracture site often is quite obvious and helpful in placing the incision.

The olecranon is the proximal subcutaneous end of the ulna.

Incision

Make a gently curved incision, beginning over the posterior surface of the

lateral humeral epicondyle and continuing downward and medially to a point over the posterior border of the ulna, about 6 cm distal to the tip of the olecranon.

Alternatively, make a 5-cm longitudinal incision based proximally on the lateral humeral epicondyle. This incision follows the skin fold and lies directly over the radial head (Fig. 3-39).

 

Internervous Plane

 

The internervous plane lies between the anconeus, which is supplied by the radial nerve, and the extensor carpi ulnaris, which is supplied by the posterior interosseous nerve (Fig. 3-40).

 

 

 

Figure 3-39 Make a longitudinal incision based proximally on the lateral humeral epicondyle.

 

 

Figure 3-40 The internervous plane lies between the anconeus (radial nerve) and the extensor carpi ulnaris (posterior interosseous nerve).

 

Superficial Surgical Dissection

 

Incise the deep fascia in line with the skin incision. To find the interval between the extensor carpi ulnaris and the anconeus, look distally where the plane is easy to identify; proximally, the two muscles share a common aponeurosis (Fig. 3-41). Detach part of the superior origin of the anconeus as it arises from the lateral epicondyle of the humerus. Then, separate the anconeus and extensor carpi ulnaris muscles, using retractors (Fig. 3-42).

In cases of trauma, there often has been bleeding and contusion in this area, and it is difficult to identify the interval between the extensor carpi ulnaris and anconeus muscles. In this case, it is safe to dissect straight down onto the lateral epicondyle of the humerus, because this structure always can be palpated easily.

 

Deep Surgical Dissection

Fully pronate the forearm to move the posterior interosseous nerve away from the operative field (see Fig. 3-42, inset).

Incise the capsule of the elbow joint longitudinally to reveal the underlying capitulum, the radial head, and the annular ligament. Do not incise the capsule too far anteriorly; the radial nerve runs over the front of the anterolateral portion of the elbow capsule. Do not continue the dissection below the annular ligament or retract vigorously, distally, or anteriorly, because the posterior interosseous nerve lies within the substance of the supinator muscle and is vulnerable to injury (Fig. 3-43).

 

 

Dang

 

 

Nerves

The posterior interosseous nerve is in no danger as long as the dissection remains proximal to the annular ligament. Pronation of the forearm keeps the nerve as far from the operative field as it possibly can be (see Fig. 3-42, inset). To ensure the safety of the nerve, take great care to place the retractors directly on bone and be careful in their placement. Because the posterior interosseous nerve actually may touch the bone of the radial neck, directly opposite the bicipital tuberosity, placing retractors behind it poses a risk.18

The radial nerve is safe as long as the elbow joint is opened laterally and not anteriorly.

 

 

Figure 3-41 Find the interval between the extensor carpi ulnaris and the anconeus distally. Proximally, the two muscles merge.

 

 

 

Figure 3-42 Detach the superior origin of the anconeus from the lateral epicondyle, and separate the anconeus and the extensor carpi ulnaris. Pronation of the forearm moves the posterior interosseous nerve medially away from the operative field (insets).

 

 

Figure 3-43 Incise the joint capsule longitudinally to expose the capitulum and radial head.

 

How to Enlarge the Approach

Local Measures

For more complete exposure of the lateral half of the distal humerus, extend the superficial dissection by cutting down on the lateral supracondylar ridge. Strip the tissues off subperiosteally both anteriorly and posteriorly to gain access to the distal humerus and to expose the capitulum. Apply a varus force to open up the lateral compartment of the joint. The extension is most useful for fixing fractures internally and for removing loose bodies in the lateral compartment of the elbow (see Anterolateral Approach to the Distal Humerus in Chapter 2).

Extensile Measures

There is no way to extend this approach profitably in any direction.

 

Applied Surgical Anatomy

Overview

 

The elbow is the hinge (ginglymus) joint between the lower end of the humerus and the upper end of the radius and ulna. It communicates with the superior radioulnar joint.

The lower end of the humerus articulates in two areas:

1. The lateral capitulum articulates with the radial head. Its shape is reminiscent of a hemisphere.

2. The medial trochlea articulates with the ulna. Its shape resembles a spool of thread. It extends further distally than the capitulum, resulting in a configuration that gives a tilt to the lower end of the humerus and produces the “carrying angle” of the joint. The trochlea is grooved; the groove’s boundaries are marked medially by a prominent, sharp ridge and laterally by a lower, more blunted ridge.

The two articulations are separated by a ridge of bone.

The elbow is supported by strong medial and lateral collateral ligaments. The anterior and posterior ligaments are mainly thickened sections in the capsule, which is exactly what would be expected from a hinge joint. The shape of the bones that comprise the elbow joint and the presence of the strong collateral ligaments make it difficult to explore the joint completely without extensive dissection. Medial and lateral approaches to the joint provide limited access unless they are extended. Complete exposure is obtained most easily through a posterior approach. Four groups of muscles cross the elbow joint:

1. Anteriorly, the flexors of the elbow, which are supplied by the musculocutaneous nerve.

2. Posteriorly, the extensor of the elbow, which is supplied by the radial nerve.

3. Medially, the flexor-pronator group of muscles (the flexors of the wrist and fingers, and the pronators of the forearm), which are supplied by the median and ulnar nerves. They arise from the medial epicondyle of the humerus.

4. Laterally, the extensors of the wrist and fingers, and the supinators of the forearm, which are supplied by the radial and posterior interosseous nerves. They arise from the lateral epicondyle of the humerus.

Between each pair of muscle groups is an intermuscular plane; two are internervous planes and can be explored. A third internervous plane lies

within the lateral group. The internervous planes are as follows:

1. Between the anterior and lateral muscle groups, which are supplied by the musculocutaneous and radial nerves, respectively. The anterolateral approach uses the interval between the brachialis and brachioradialis muscles (see Fig. 3-25).

2. Between the anterior and medial muscle groups, which are supplied by the musculocutaneous and median nerves, respectively. The medial approach uses the interval between the brachialis and pronator teres muscles (see Figs. 3-13 and 3-33).

3. Between two members of the lateral group: The anconeus muscle (which is supplied by the radial nerve) and the extensor carpi ulnaris muscle (which is supplied by the posterior interosseous nerve, a major branch of the radial nerve; see Fig. 3-40). The posterolateral approach to the radial head uses this plane.

The intermuscular plane between the lateral and posterior groups of muscles is not an internervous plane, because both groups are supplied by the radial nerve. The plane is useful, though, because the radial nerve gives off its branches well proximal to the elbow. This pseudointernervous plane, which is used in the lateral approach, falls in the interval between the brachioradialis and triceps muscles (see Fig. 2-31A).

The medial and lateral groups of muscles converge in the forearm, forming a triangular fossa known as the cubital fossa, which is bordered by the pronator teres medially and the brachioradialis laterally. The superior border of the triangle consists of an imaginary line joining the medial and lateral epicondyle of the humerus.

 

Neurovascular Structures

Nerves

The median nerve crosses the front of the joint on its medial side and is covered by the bicipital aponeurosis (lacertus fibrosus) in the cubital fossa. It disappears between the two heads of the pronator teres muscle as it leaves the fossa and runs down the forearm, adhering to the deep surface of the flexor digitorum superficialis muscle (see Fig. 4-12).

The radial nerve crosses the front of the elbow joint in the interval between the brachialis and brachioradialis muscles. It divides in the cubital fossa at the radiohumeral joint line into the posterior interosseous nerve (which enters the substance of the supinator muscle) and the superficial

radial nerve (which descends the lateral side of the forearm under cover of the brachioradialis muscle; see Fig. 3-28).

The ulnar nerve crosses the joint in the groove on the back of the medial epicondyle, where it is easy to palpate. The nerve enters the anterior compartment of the forearm by passing between the two heads of the flexor carpi ulnaris muscle, which it supplies and where it may be entrapped. It then runs down the forearm on the anterior surface of the flexor digitorum profundus (see Figs. 3-49). In the proximal third of the forearm, it supplies the ring and little fingers.

Vessels

The brachial artery enters the cubital fossa, running on the lateral side of the median nerve and lying on the brachialis muscle. The median nerve passes under the bicipital aponeurosis, which separates it from the median basilic vein, a frequent site of venous puncture (see Fig. 3-31). In the days when bleeding was a recognized form of treatment and venesection was done with lancets rather than with needles, this site was a frequent one used by barber surgeons. The reason this site was preferred is because the bicipital aponeurosis protects the vital structures of the artery and nerve, which provided these early practitioners with a margin of safety, because their patients often moved on insertion of the lancet. Halfway down the cubital fossa, the artery divides into two terminal branches: The radial and ulnar arteries. Similar to the median nerve, the artery may be damaged in supracondylar fractures of the humerus (see Fig. 3-35).

The radial artery passes medial to the biceps tendon before turning anteriorly, lying on the supinator muscle and the insertion of the pronator teres muscle. In the upper forearm, it lies under the brachioradialis muscle (see Fig. 4-11).

The ulnar artery usually disappears from the cubital fossa by passing deep to the deep head of the pronator teres, the muscle that separates it from the median nerve (see Fig. 4-13).

 

Applied Surgical Anatomy of the Medial Approaches

 

Five flexor muscles of the forearm fan out from the common flexor origin on the medial epicondyle of the humerus:

1. The pronator teres (humeral head)

2. The flexor carpi radialis

3. The flexor digitorum superficialis (humeral head)

    

    

   Figure 3-44 Medial view of the elbow. Note the sensory nerves and veins on the medial side of the elbow joint.

    

4. The palmaris longus

5. The flexor carpi ulnaris (humeral head) (Fig. 3-45)

The first four muscles are supplied by the median nerve; the flexor carpi ulnaris is supplied by the ulnar nerve. The pronator teres, the most proximal muscle, forms the medial border of the cubital fossa.

All five muscles are retracted distally after osteotomy of the medial epicondyle. They can be retracted only a short distance because the median nerve, passing through the pronator teres muscle, “anchors” the group and prevents distal retraction (Figs. 3-44 to 3-48).

 

Applied Surgical Anatomy of the Anterolateral Approach to the Elbow

 

Two groups of muscles arise from the lateral epicondyle and the supracondylar ridge of the humerus (see Applied Surgical Anatomy of the Posterior Approach to the Radius in Chapter 4):

 

 

Figure 3-45 The five muscles of the forearm have a common flexor origin on the medial epicondyle. All five are supplied by the median nerve. The ulnar nerve passes between the two heads of the flexor carpi ulnaris. The median nerve runs beneath the bicipital aponeurosis.

 

 

 

Figure 3-46 The flexor-pronator group has been resected, revealing the course of the ulnar nerve as it runs around the medial epicondyle, passing distally before entering the plane between the flexor carpi ulnaris and the flexor digitorum profundus.

 

 

Figure 3-47 The flexor muscles have been resected further. The medial epicondyle has been subjected to osteotomy. Distally, the ulnar nerve crosses the forearm between the flexor carpi ulnaris and the profundus. The median nerve enters the forearm between the two heads of the pronator teres, lying on the tendon of the brachialis.

 

 

 

Figure 3-48 The joint capsule has been opened. The brachialis is elevated from the capsule.

 

1. The mobile wad of muscles, consisting of the brachioradialis, the extensor carpi radialis longus, and the extensor carpi radialis brevis

2. Four muscles arising from the common extensor origin: The extensor

digitorum communis, the extensor digiti minimi, the extensor carpi ulnaris, and the anconeus

The anconeus is purely a muscle of the elbow; Its function is unclear. Its more distal fibers run almost vertically and act as a weak extensor of the elbow, whereas its proximal fibers are almost horizontal and abduct and rotate the ulna. This unlikely movement occurs to a slight degree at the elbow. Electromyographic studies suggest that the muscle is most active during extension,19,20 but it probably functions more as a stabilizer while other muscles act on the elbow as prime movers, functioning in much the same way as does the rotator cuff in the shoulder.21

Its major surgical importance lies in the fact that it forms one boundary of the internervous plane that is used in the posterolateral approach to the radial head.

 

Applied Surgical Anatomy of the Anterior Approach to the Cubital Fossa

 

Two flexors, the brachialis and biceps brachii muscles, cross the anterior aspect of the elbow joint. Both are supplied by the musculocutaneous nerve, which runs between the biceps and the brachialis in the upper arm. In front of the elbow, they diverge; the biceps runs laterally to the bicipital tuberosity of the radius, and the brachialis runs medially to the coronoid process of the ulna.

In front of the elbow, the biceps brachii develops a flat tendon, which also overlies the brachialis. The tendon rotates so that its anterior surface faces laterally as it passes between the two bones of the forearm before inserting into the back of the radius at the bicipital tuberosity. A bursa separates the tendon from the anterior part of the tuberosity.

As the biceps tendon crosses the front of the elbow, it gives off fibrous tissue from its medial side. This bicipital aponeurosis, or lacertus fibrosus, sweeps across the forearm by way of the deep fascia to insert into the subcutaneous border of the upper end of the ulna.

The bicipital aponeurosis forms part of the roof of the cubital fossa. It separates superficial nerves and vessels from deep ones. Lying superficial are the median cephalic vein, the median basilic vein, and the medial cutaneous nerve of the forearm. Lying deep are the median nerve and the brachial artery.

The relationship of the median nerve, brachial artery, and brachial vein can be remembered easily through the mnemonic “VAN” (vein, artery, nerve), which labels the structures from the lateral to the medial aspect.

They all pass medial to the biceps tendon under the lacertus fibrosus (see Fig. 3-36).

 

Applied Surgical Anatomy of the Posterior Approaches to the Elbow

 

See Figures 3-49 to 3-52.

 

 

 

Figure 3-49 Superficial view of the posterior aspect of the elbow. The triangular aponeurosis of the triceps runs down to its triangular insertion into the ulna. The ulnar nerve lies in its groove on the posterior aspect of the elbow. The posterior antebrachial cutaneous nerve crosses the intermuscular septum on the posterior aspect of the elbow. Anconeus. Origin. Lateral epicondyle of humerus and posterior joint capsule of elbow. Insertion. Lateral side of olecranon and posterior surface of ulna. Action. Extensor of elbow. Nerve supply. Radial nerve.

 

 

Figure 3-50 The distal part of the triceps, the origins of the flexors and flexor carpi ulnaris, and the extensor tendons have been resected. The ulnar nerve enters the plane between the two heads of the flexor carpi ulnaris. On the radial side, the radial nerve lies anterior to the intermuscular septum, between the brachioradialis and brachialis muscles.

 

 

 

Figure 3-51 The insertion of the anconeus, the origin of the extensor carpi ulnaris, and the common extensor origin are revealed. The radial nerve divides into its

main continuation, the posterior interosseous nerve, as it enters the supinator muscle through the arcade of Frohse. The superficial branch (sensory branch) of the radial nerve enters the undersurface of the brachioradialis. The ulnar nerve gives off its branches to the flexor carpi ulnaris immediately after it passes around the groove between the olecranon and the medial epicondyle.

 

 

 

Figure 3-52 The supinator muscle has been resected, revealing the distal course of the posterior interosseous nerve through its distal portion. The annular portion of the radiohumeral ligament is defined clearly.

 

REFERENCES

1. CASSEBAUM WH: Operative treatment of T and Y fractures of the lower end of the humerus. Am J Surg. 1952;83:265–270.

2. DE BOER P, STANLEY D: Surgical approaches to the elbow. In: Stanley D, Kay N, eds. Surgery of the Elbow: Practical and Scientific Aspects. London: Arnold; 1998.

3. MULLER ME, ALLGOWER M, WILLENEGGER H: Manual of internal fixation. New York, NY: Springer-Verlag; 1970.

4. JOHANSSON H, OLLERUD S: Operative treatment of intercondylar fractures of the humerus. J Trauma. 1971;11:836–843.

5. JONES TB, KARENZ AR, WEINHOLD PS, ET AL: Transcortical screw fixation of the olecranon shows equivalent strength and improved stability compared with tension band fixation. J Orthop Trauma.

   2014;28(3):137–142.

6. BRYAN RS, MORREY BF: Extensive posterior exposure of the elbow. A triceps-sparing approach. Clin Orthop Relat Res. 1982;(166):188–192.

7. WOLFE SW, RANAWAT CS: The osteo-anconeus flap. An approach for total elbow arthroplasty. J Bone Joint Surg Am. 1990;72(5):684–688.

8. CAMPBELL WC: Incision for exposure of the elbow joint. Am J Surg.

   1932;15:65–67.

9. MOLESWORTH HW: Operation for complete exposure of the elbow joint. Br J Surg. 1930;18:303–307.

10. HUH J, KRUEGER CA, MEDVECKY MJ, ET AL: Skeletal Trauma Research Consortium: Medial elbow exposure for coronoid fractures: FCU-split versus over-the-top. J Orthop Trauma. 2013;27(12):730–734.

11. MARCHESSAULT JA, DABEZIES EJ: Posteromedial elbow approach for treatment of olecranon and coronoid fractures. Orthopedics. 2006;29(3):249–253.

12. KOCHER T: Textbook of Operative Surgery. 3rd ed. In: Stiled HL, Paul CB, trans. London: Adam and Charles Black; 1911.

13. DUCKWORTH AD, MCQUEEN MM, RING D: Fractures of the radial head.

    Bone Joint J. 2013;95-B(2):151–159.

14. RUCHELSMAN DE, CHRISTOFOROU D, JUPITER JB: Fractures of the radial head and neck. J Bone Joint Surg Am. 2013;95(5):469–478.

15. MACKAY S: Silastic replacement of the head of the radius in trauma. J Bone Joint Surg Br. 1979;61:494–497.

16. SWANSON AB, JAEGER SH, LAROCHELLE D: Comminuted fractures of the radial head. The role of silicone implant replacement arthroplasty. J Bone Joint Surg Am. 1981;63:1039–1049.

17. STRACHAN JC, ELLIS BW: Vulnerability of the posterior interosseous nerve during radial head excision. J Bone Joint Surg Br. 1971;53:320–323.

18. SPINNER M: Injuries to the Major Peripheral Nerves of the Forearm, Section VII. 2nd ed. Philadelphia, PA: WB Saunders; 1978.

19. TRAVEILLE AA: Electromyographic study of the extensor apparatus of the forearm. Anat Rec. 1962;144:373–376.

20. GLEASON TF, GOLDSTEIN WM, RAY RD: The function of the anconeus muscle. Clin Orthop Relat Res. 1985;(192):147–148.

21. PEREIRA BP: Revisiting the anatomy and biomechanics of the anconeus

muscle and its role in elbow stability. Ann Anat. 2013;195(4):365–370.

 

 

∗The term boat-race refers to the annual Oxford and Cambridge boat race held in London, England. Because the course from Putney to Mortlake contains large bends, the term can be used for any incision that involves multiple curves.