Early post-operative MR appearance of the acetabular labrum after arthroscopic repair
Zachary Elijah Stewart1, Andrea M Spiker2, John S Symanski3
1Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Boston, MA, USA. zstewart@mgh.harvard.edu.
Objective:
Describe the early non-arthrographic MRI appearance of the acetabular labrum after arthroscopic surgery for femoroacetabular impingement and labrum repair.
Methods:
Eleven subjects (12 hips, 8 hips of females; mean age: 25.8 years, SD: 3.0) with a pre-operative MRI demonstrating a labrum tear and symptoms of femoroacetabular impingement were prospectively enrolled. Non-arthrographic images were obtained on a 3 T MRI scanner < 4 weeks after arthroscopic surgery for femoroacetabular impingement. Imaging features of the labrum, capsule, and cartilage were systematically assessed by two independent fellowship-trained musculoskeletal radiologists. Disagreements were resolved through consensus mediated by a musculoskeletal radiologist with 20 + years of experience and expertise in hip imaging.
Results:
The appearance of a persistent labral tear and increased intrasubstance signal was observed in all hips. The labrum appeared shortened in 92% (11/12). The geographic distribution of abnormal labral signal corresponded to the same number of labrum quadrants treated surgically in 67% (8/12). There was an even distribution of hips showing abnormal signal across a smaller and larger portion of the labrum than was treated arthroscopically, seen in 17% (2/12), respectively. The appearance of a capsular defect was observed in 92% (11/12).
Conclusion:
In the first 4 weeks after arthroscopic labrum repair surgery for femoroacetabular impingement, it is common for the labrum to appear shortened with a persistent appearance of a labrum tear and increased signal in the repaired segment. The capsule often appears discontinuous, even when capsular closure is performed.
