FIGURE 11–4 The brachioradialis lifted anteriorly exposing the radial nerve just underneath it. The nerve has not yet divided at this point.
FIGURE 11–5 The nerve and brachioradialis retracted anteriorly. The triceps is posterior. The capitellum is easily visualized, as is the radial head.
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POSTEROLATERAL/ANCONEUS APPROACH
USES
This approach to the radial head is easy and safe. It is generally used for radial head resections or open reduction internal fixation of radial head fractures.
ADVANTAGES
This approach is easy.
DISADVANTAGES
This approach is limited to the radial head or capitellum. It is not suitable for proximal or distal extension.
STRUCTURES AT RISK
It is difficult to get lost with this exposure. The radial nerve is at risk anteriorly, but you would need to be far anterior to reach it. The posterior interosseous branch in the supinator muscle is at risk if the dissection is carried distal to the annular ligament. Pronation of the forearm moves this nerve farther away from the approach.
TECHNIQUE
The incision starts at the lateral epicondyle and then proceeds at a 45-degree angle in relation to the axis of the humerus toward the ulna. After splitting the subcutaneous tissue, the oblique fibers of the anconeus are identified. The capsule is opened along the anterior aspect of those fibers, exposing the radial head and the capitellum.
TRICKS
The only significant trick to this approach is finding the interval between the anconeus and the extensor musculature by looking at the fiber orientation. As you come to the superficial fascia, the anconeus fibers run obliquely toward the ulna, whereas the extensor muscles run parallel to the ulna down the forearm.
HOW TO TELL IF YOU ARE LOST
If you are too far posterior, you will split the fibers of the anconeus. If you run into the longitudinal fibers of the triceps, you are far posterior. Anteriorly, you will see longitudinal fibers of the extensor origin running parallel to the ulna. As long as you see the anterior edge of the oblique fibers and stay out of the longitudinal fibers, this is an easy approach.
FIGURE 12–1 Skin incision and lateral epicondyle is at the top.
FIGURE 12–2 The subcutaneous tissue retracted out of the way and the fibers of the anconeus running from the area of the lateral epicondyle down toward the ulna. The fiber orientation is critical for identifying the muscle versus the extensors.
FIGURE 12–3 The anconeus retracted in a posterior direction, exposing the soft tissue overlying the elbow.
FIGURE 12–4 The elbow open. The capitellum and radial head are clearly visible.
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POSTEROMEDLAL APPROACH TO THE ULNAR NERVE
USES
This approach is used primarily for neurolysis of the ulnar nerve or anterior transposition of the nerve; however, this is a common enough procedure that this approach needs to be mastered. The approach can also be used for medial collateral ligament repairs of the elbow and coronoid fracture fixation. Campbell describes this approach combined with an osteotomy of the medial epicondyle.
ADVANTAGES
The posteromedial approach provides good visualization of the nerve and is easily extended proximally and distally.
DISADVANTAGES
This approach does not allow good access to the anterior or posterior elbow joint.
STRUCTURES AT RISK
If not done carefully, the ulnar nerve can be damaged. The motor branches of the ulnar nerve come off the nerve posteriorly. The branch to the flexor carpi ulnaris muscle can come off proximal to the elbow joint and must be avoided. When doing an anterior transposition of the ulnar nerve, the sensory branch going into the elbow joint frequently is not long enough to be salvaged. The motor branches to the flexor carpi ulnaris muscle must be saved. It is very helpful if this surgery is done with the patient not paralyzed and with the nerve stimulator used to identify the motor branches, which can be very small. A pure motor nerve has a small number of axons in it and so may not appear very nervelike. Sensory nerves have sensory axons for each sensory modality and are bigger and easier to identify. It is a pure motor nerve that is mistaken for other tissue and is at risk.
TECHNIQUE