Final answer:
The conjoined tendon is composed of the tendons of the short head of the biceps brachii and the coracobrachialis muscles. These structures are intimately involved in the Latarjet procedure, which is used to treat shoulder joint instability.
Step-by-step explanation:
The two tendons that make up the conjoined tendon are those of the short head of the biceps brachii and the coracobrachialis muscles. These muscles are critical to shoulder stability and are involved in the Latarjet procedure, a surgical intervention typically used to address shoulder instability, such as recurrent shoulder dislocations. In this procedure, the conjoined tendon is left attached to the coracoid process, which is transferred to the shoulder joint to improve joint stability.
The biceps brachii muscle is better known for its long head, which extends up to the top of the shoulder joint, but its short head, along with the coracobrachialis, forms the conjoined tendon that plays a pivotal role in this surgical repair. The coracoid process, to which these tendons are attached, is a hook-like structure projecting from the scapula that serves as an attachment point for important tendons and ligaments within the shoulder.