Lateral Approach to Distal Humerus indications:

The lateral approach to distal humerus exposes the lateral epicondyle and the origin of the wrist extensors.

Lateral approach to distal humerus uses include the following:

  1. Open reduction and internal fixation of fractures of the lateral condyle.
  2. Surgical treatment of tennis elbow (lateral epicondylitis) .

Position of the Patient

  • The patient is placed supine on the operating table with arm lying across chest.

Landmarks and Incision

  • Landmarks:
    1. Lateral epicondyle.
    2. The lateral supracondylar ridge of the humerus .
  • Incision:
    • Make a 4- to 6-cm curved or straight incision on the lateral aspect of the elbow over the lateral supracondylar ridge.
Lateral Approach to the Distal Humerus
Landmarks and Incision

Internervous plane

  • There is No Internervous plane for Lateral Approach to Distal Humerus.
  • The dissection is carried out between the triceps muscle and brachioradialis muscle which is both are innervated by the radial nerve.
Lateral Approach to the Distal Humerus
Internervous plane for The lateral approach to distal humerus

Superficial dissection

  • Incise the deep fascia in line with the skin incision.
  • Identify the plane between the brachioradialis and triceps muscles,
    • Cut in between these two muscles down to bone.
    • Reflect the triceps muscle posteriorly and the brachioradialis muscle anteriorly.

Deep dissection

  • The common extensor origin can be released off the lateral humerus and the triceps can be similarly elevated posteriorly.
Lateral Approach to the Distal Humerus
Deep dissection

Approach Extension

Proximal Extension:

  • Proximal extension is not possible, because the radial nerve crosses the proposed line of dissection.

Distal Extension:

  • The lateral approach can be extended to the radial head only by using the intramuscular plane between the anconeus muscle (which is supplied by the radial nerve) and the extensor carpi ulnaris muscle (which is supplied by the posterior interosseous nerve).
  • The Lateral approach to distal Humerus cannot be extended further distally due to the presence of the posterior interosseous nerve winding round the neck of the proximal radius.

Dangers

  • The radial nerve is at risk with proximal extension of the lateral approach to distal humerus, as the nerve pierces the lateral septum in the distal third of the arm.

Related Anatomy

Radial Nerve Anatomy

  • The radial nerve is the continuation of the posterior cord of the brachial plexus. It begins behind the axillary artery at the shoulder, runs along the posterior wall of the axilla (on the subscapularis, latissimus dorsi, and teres major muscles), and then passes through the triangular space between the long head of the triceps muscle and the shaft of the humerus beneath the teres major muscle.
  • In the arm, the nerve lies in the spiral groove on the posterior aspect of the humerus between the lateral and medial (deep) heads of the triceps muscle. After crossing the back of the humerus and giving off branches to the lateral head and the lateral part of the medial head of the triceps, the radial nerve pierces the lateral intermuscular septum, entering the anterior compartment. At this point, the nerve may be vulnerable to distal locking bolts inserted from the lateral side of the arm.
  • The nerve lies between the brachioradialis and brachialis muscles as it crosses the elbow joint. There, it supplies the brachioradialis, extensor carpi radialis longus, extensor carpi radialis brevis, and anconeus muscles.
  • The vast majority of radial nerve palsy are due to a neurapraxia. Exploration of the nerve is, therefore, not mandatory if a nerve palsy is present following fracture.
  • The presence of a nerve palsy following reduction in a patient without an initial neurological lesion is a good indication for exploration as the nerve may have become trapped between the bony fragments during reduction.
Radial Nerve Anatomy

References

  • Surgical Exposures in Orthopaedics book – 4th Edition
  • Campbel’s Operative Orthopaedics book 12th
  • Images are from Orthobullets