Answer to Top Gun Pilot
Correct answer is D. The pilot’s fall from the airplane and snagging of the branch may have produced a small tear in his glenohumeral joint that was exacerbated in the fall in the shower. The trainee simply compounded the issue by pulling on the arm. The pilot clearly is exhibiting an anterior shoulder separation, much more common than a posterior one.
An anterior shoulder separation can injure any nerve of the brachial plexus, but the axillary nerve is primarily injured in these types of injury. The axillary nerve is one of the terminal branches of the posterior cord. The other being the radial nerve. Injury of the axillary nerve eliminates the ability of the pilot to abduct his arm, the deltoid is not usable; hence, the arm goes “limp”.
The ideal way for returning the head of the humerus to its proper location is to “recreate the injury”. That is, abduct the arm, retract, then protract the humerus until the head falls back into the glenoid cavity. Biting a bullet during the procedure is essential (others prefer bourbon), and pain usually goes away if the humerus falls back into place correctly.
Material for this question is discussed in lectures 3 and 6 of the upper limb lecture.
Correct answer is D.
Labeled nerves are as follows:
Long thoracic
Thoracodorsal
Musculocutaneous
Axillary
Radial