http://www.medical-look.com/human_anatomy/organs/Brachium.html

This patient has fractures of the neck of humerus and greater tuberosity. The humeral head is subluxed inferiorly and this subluxation is likely to be caused by distension of the joint by joint effusion (haemarthrosis). There is a fat/fluid level consistent with lipohaemarthrosis of the shoulder joint (white arrow). This indicates the presence of intraarticular injury. A lipohaemarthrosis will only be seen when patients are imaged with a horizontal beam (i.e. erect).

http://www.msdlatinamerica.com/ebooks/PracticalOrthopaedicSportsMedicineArthrocopy/sid280790.html

Transthoracic Lateral

The transthoracic lateral projection of the shoulder/proximal humerus is a technique that is not commonly practiced by most radiographers. The technique is a valid method for radiographic demonstration of the proximal humerus and is worthy of inclusion in the radiographers' technique toolkit. The reasons for the lack of favour of this technique are likely to be the inherent superimposition of the anatomy over the patient's chest the need for the patient to hold very still during a relatively long exposure and the fact that it is a very operator-dependent technique.. it takes some practice to master Further information here

	This 25 year old female presented to the Emergency Department following a fall from a pushbike. She was assessed in the resus room and radiography including her right shoulder was requested. AP shoulder radiography was performed with a wireless DR-X system using a bucky tray.There is a fracture of the surgical neck of humerus.
	The patient could not easily be positioned for lateral scapula or IS shoulder radiography. The radiographer performed a transthoracic lateral view of the right shoulder to demonstrate alignment of the fracture. This technique does not demonstrate detailed bony anatomy but is valuable in demonstrating the true alignment/position of the fracture in a true lateral position. A DRX-1 wireless Digital X-ray Imaging System was utilised without stationary grid. A long exposure time technique was employed.
	Considerable foreshortening and angulation at the fracture site was demonstrated in the transthoracic lateral projection.
	An IS projection was considered worthwhile in terms of demonstrating bony detail.
	Proximal humerus fractures can be treated conservatively with a collar-and-cuff or operatively with ORIF. The decision will be influenced by the radiographic assessment of the position of the fracture fragments. The supine transthoracic lateral does not give a true representation of the position that the fracture is likely to heal in- the reason for this is that the collar-and-cuff treatment uses the weight of the patient's arm as a method of reducing the fracture with the patient in the erect position. What is required is a radiographic demonstration of the fracture in the position that it would heal in if treated conservatively. Following further assessment of the patient's injuries, it was considered safe for the patient to be positioned in an erect sitting position. The transthoracic lateral projection was repeated with the patient in the erect position. Whilst the technique has limitations, the fracture is shown with improved alignment in the erect position when compared to the supine position above.
	The erect AP shoulder showed no improvement in the alignment of the neck of humerus fracture.