Humeral Shaft

Question 1

What is the relationship of the radial nerve to the humerus?

Answer 1

Starts anteromedially, travels posteriorly in the spiral groove (10-15cm above the articular surface), exits anterolaterally btw the brachialis and brachioradialis

Question 2

What is the relationship of the ulnar nerve to the humerus?

Answer 2

Proximally travels anterior to the medial intermuscular septum and enters the posterior compartment at the Arcade of Struthers (8cm from the medial epicondyle), travels posterior to medial epicondyle in the cubital canal, gives off dorsal articular br then enters the two heads of FCU

Question 3

Where are the median n. and brachial a. in the elbow?

Answer 3

between the the pronator teres and biceps tendon

Question 4

What is the innervation of the brachialis?

Answer 4

Lateral third- radial n.

Medial two thirds- musculocutaneous n.

Question 5

What approaches are available to the humerus?

Answer 5

Proximal:

1) Deltopectoral- btw deltoid (axillary n.) and pectoralis major (medial and lateral pectoral nn.
2) Deltoid splitting- axillary n. is 5cm from acromion
3) posterior- less common

Shaft:

1) Anterolateral (extended deltopectoral)- splits brachialis
2) Posterior-radial n. is 14cm proximal to lateral epicondyle and pierces the lateral intermuscular spetum 10cm from joint

Distal:
1) posterior

Question 6

What vessels make up the “three sisters” seen during the deltopectoral or anterior approach to the humerus?

Answer 6

Anterior circumflex humeral a. and its two venous communicantes

Question 7

The anterolateral approach to the humerus uses what muscular interval?

Answer 7

Is a continuation of the deltopectoral approach; splits the lateral third and middle third of the brachialis (lateral innervated by radial n., middle/medial thirds innervated by musculocutaneous n.)

Question 8

What nerve branch of the radial nerve runs on the lateral intermuscular septum as the nerve exits the spiral groove?

Answer 8

Posterior brachial cutaneous

Question 9

Which posterior approach to the humerus gives the most exposure of the humeral shaft?

Answer 9

Lateral paratricipital; uses tissue plane btw lateral head of triceps and lateral intermuscular septum; exposes 94% of the humeral diaphysis

Question 10

How much of the humerus can be exposed with the triceps splitting approach?

Answer 10

If the radial nerve is not exposed 55%, if mobilized 76%

Question 11

The paratricipital approach to the the distal humerus is excellent for what procedure?

Answer 11

TEA; olecranon osteotomy is relatively contraindicated