Final answer:
Rib resection for Thoracic Outlet Syndrome is a surgical procedure where part of the first rib is removed to reduce compression of nerves or blood vessels, which can alleviate symptoms of pain and numbness in the arm.
Step-by-step explanation:
Thoracic Outlet Syndrome (TOS) occurs when blood vessels or nerves between the collarbone (clavicle) and the first rib are compressed, causing pain and arm numbness. Rib resection is a surgical procedure to treat TOS, where part of the first rib is removed to relieve the compression. The ribs are thin, curved bones of the chest wall that form a protective cage for the vital organs in the thorax. During this procedure, the angle of the rib, which is the portion of the rib with the greatest curvature, might be addressed to reduce the pressure on the neurovascular structures. The retraction movement mentioned in the question is a mechanism where a joint moves back into position after stretching out, although it is not directly related to rib resection.
The angle of the mandible is the rounded corner located at the outside margin of the body and ramus junction, and the ramus of the mandible refers to the vertical portion of the mandible, but these are unrelated to TOS.
The sacral canal is a bony tunnel that runs through the sacrum, part of the spine. The costal cartilage connects the ribs to the breastbone (sternum), but in the context of TOS, the focus is on bone resection rather than cartilage. The tubercle of the rib is a small bump on the posterior side of a rib for articulation with the thoracic vertebra, which may be involved in rib removal if it contributes to neurovascular compression in TOS.