Question 135

Question:

A 27-year-old man is brought to the emergency room after sustaining a knife wound in the back. His vital signs are within normal limits. On exam, you appreciate a 4 cm long laceration that runs parallel to the inferior medial border of the scapula, and is 2cm from the spinous process of T5. The laceration has visibly penetrated at least 1 cm into the muscle tissue. Which muscle is most likely affected?

Correct Answer: D.  Rhomboid major

The insertion of the rhomboid major (D) is the medial border of the scapula (it arises from the spinous processes of T2 to T5, as well as the supraspinous ligament). The deltoid (A) originates at the spine of the scapula and goes laterally to insert on the humerus. The infraspinatus (B) originates at the posterior scapula and goes laterally to form part of the rotator cuff (remember: SITS). The levator scapulae (C) inserts at the superior medial border of the scapula and goes superiorly. The triceps brachii (E) originates at the lateral scapula and inserts on the humerus.