Question

Match List I with List II.

List I	List II
A. Type III AC joint injury B. Type IV AC joint injury C. Type V AC joint injury D. Type VI AC joint injury	I. Clavicle is dislocated inferiorly under the coracoid process and posterior to the conjoined tendons II. Clavicle displaced posteriorly through the fibers of the trapezius III. Shoulder complex displaced inferiorly IV. Vertical separation of clavicle, massive inferior displacement of the upper extremity with a very prominent clavicle

Choose the correct answer from the options given below:

• A. A-IV, B-I, C-II, D-III
• B. A-II, B-III, C-I, D-IV
• C. A-III, B-II, C-IV, D-I
• D. A-III, B-I, C-II, D-IV

Hint:

Type III = downward shoulder, Type IV = posterior clavicle, Type V = severe vertical deformity, Type VI = inferior clavicle (rare)

Answer 1

The Correct Option is C

Concept:
Acromioclavicular (AC) joint injuries are classified (Rockwood classification) based on the degree and direction of displacement of the clavicle and associated ligament damage. Understanding each type is essential to correctly match clinical presentation with anatomical displacement.

Step 1: Type III AC joint injury.

• Complete disruption of AC and coracoclavicular ligaments
• Leads to noticeable separation
• Shoulder girdle drops downward due to gravity Thus: \[ A \rightarrow III \; (\text{Shoulder complex displaced inferiorly}) \]

Step 2: Type IV AC joint injury.

• Clavicle displaced posteriorly
• Penetrates or moves through trapezius muscle Thus: \[ B \rightarrow II \; (\text{Posterior displacement through trapezius}) \]

Step 3: Type V AC joint injury.

• Severe exaggeration of Type III
• Massive vertical displacement
• Prominent clavicle due to upward displacement Thus: \[ C \rightarrow IV \]

Step 4: Type VI AC joint injury.

• Rare injury
• Clavicle displaced inferiorly (subcoracoid or subacromial) Thus: \[ D \rightarrow I \]

Step 5: Final mapping.
\[ A\!-\!III,\; B\!-\!II,\; C\!-\!IV,\; D\!-\!I \] \[ \boxed{\text{Correct answer = Option (3)}} \]