MR imaging appearances of acromioclavicular joint dislocation

Area of Science:

• Orthopedic imaging
• Musculoskeletal radiology

Background:

• Acromioclavicular joint (ACJ) dislocations are common injuries.
• Accurate grading is crucial for treatment planning but challenging via clinical assessment.
• The Rockwood system classifies ACJ injuries into six grades.

Purpose of the Study:

• To evaluate the utility of magnetic resonance (MR) imaging in grading ACJ dislocations.
• To determine if MR imaging can improve the accuracy of ACJ injury classification compared to conventional methods.

Main Methods:

• MR imaging was performed in the coronal oblique plane parallel to the distal clavicle.
• This plane allows in-plane assessment of the acromioclavicular and coracoclavicular ligaments.
• Comparison with clinical and radiographic evaluations was performed.

Main Results:

• MR imaging accurately distinguished between Rockwood grades 2 and 3 ACJ injuries.
• Grade 1 injuries were diagnosed by identifying a ruptured superiodorsal acromioclavicular ligament.
• Ligament thickening on MR imaging identified chronic ACJ injuries.

Conclusions:

• MR imaging is a valuable tool for accurate grading of ACJ dislocations.
• This imaging modality enhances the distinction between different injury grades, aiding treatment decisions.
• MR imaging can identify both acute and chronic ACJ injuries.