SURGICAL
APPROACHES TO THE UPPER ARM AND ELBOW
The most common surgical
approaches to the upper arm and elbow include the anterolateral approach to the
humerus, the lateral or Kocher approach to the elbow, and posterior approaches
to the elbow. Arthroscopic elbow techniques are also becoming more frequently
used.
The anterolateral approach to
the humerus is most commonly used for plating fractures of the humeral shaft.
The incision is made at the deltopectoral interval proximally and then runs
along the lateral border of the biceps muscle distally. An internervous plane
is utilized between the deltoid (axillary nerve) and pectoralis major (medial
and lateral pectoral nerves) proximally. More distally, after retracting the
biceps medially, the brachialis muscle is split longitudinally along the outer
third of the muscle, utilizing an internervous plane between its medial
(musculocutaneous nerve) and lateral fibers (radial nerve). Neurovascular
structures at risk with this approach include the axillary nerve and anterior
humeral circumflex vessels proximally; the radial nerve as it runs in the
spiral groove on the posterior surface of the midshaft of the humerus and more
distally as it emerges between the brachioradialis and brachialis muscles laterally;
and the musculocutaneous nerve, in its location on the surface of the
brachialis muscle and deep to the biceps muscle. More distal fractures of the
humeral shaft may be difficult to expose with the anterolateral approach, owing
to the proximity. In these situations, a posterior approach to the humerus may
afford better exposure. The humeral shaft can be exposed posteriorly either by
splitting the triceps muscle down the midline, by taking care to identify the
radial nerve, or by elevating the triceps muscle along its lateral border and
reflecting all three heads of the muscle medially. The radial nerve is
identified in the latter technique as it passes through the lateral
intermuscular septum from posterior to anterior.
The lateral or Kocher approach
to the elbow is commonly used for many procedures on the lateral side of the
elbow, such as fracture fixation (radial head, capitellum), radial head
replacement, and lateral collateral ligament repair or reconstruction. The
approach utilizes the internervous plane between the extensor carpi ulnaris
(posterior interosseous nerve) anteriorly and the anconeus (radial nerve)
posteriorly. Neurovascular structures at risk include the posterior
interosseous nerve and radial nerve. The posterior interosseous nerve can be
protected by keeping the forearm pro- nated, and the radial nerve is avoided by
not straying too far proximally or anteriorly.
Posterior approaches to the
elbow can involve mobilization of the triceps tendon or leave the triceps
intact. The most common method of moving the triceps is by olecranon osteotomy.
This technique reflects the olecranon and triceps insertion proximally to
expose the distal humerus and elbow joint. Outstanding exposure of the joint is
achieved, and the approach is particularly useful in fixation of complex,
intra-articular distal humerus fractures and total elbow arthroplasty. Non-union
of the olecranon osteotomy site is a risk with this technique, however. The
Bryan-Morrey posterior approach is an alternative to olecranon osteotomy and
involves reflection of the extensor mechanism laterally, including the triceps
and anconeus. This approach can be used for similar indications as an olecranon
osteotomy. Although joint exposure is not quite as good, there is no risk of
osteotomy nonunion with this technique.
Elbow arthroscopy is more
commonly being used as a surgical technique. Correct portal placement is essential to avoid neurovascular injuries. The proximal anterolateral and proximal
anteromedial portals are most commonly utilized to visualize the anterior compartment
of the elbow. The anteromedial portal is made approximately 2 cm proximal to
the medial epicondyle and anterior to the intermuscular septum. The ulnar nerve
and medial antebrachial cutaneous nerve are at risk with this portal. The
anterolateral portal is similarly made on the lateral side of the elbow, taking
care to stay anterior to the humerus. The radial nerve is most at risk with
this portal. The posterocentral and posterolateral portals are most commonly employed
to visualize the posterior compartment of the elbow. Both portals are made
approximately 3 cm proximal to the tip of the olecranon. Finally, the direct
lateral “soft spot” portal is made at the “soft spot” on the lateral side
of the elbow to help with visualization and
instrumentation in the lateral gutter, such as when working on a capitellar
osteochondritis dissecans. The posterior a
tebrachial cutaneous nerve is at risk with this portal.
