1. Intradural Extension of a Pyogenic Epidural Abscess by Philip J. Rosinsky, Oren Zimhony, Pnina Ciobotaro, Shaul Sagiv, and Peleg Ben- Galim JBJS Case Connect Volume 5(3):e76 September 9, 2015 ©2015 by The Journal of Bone and Joint Surgery, Inc.

2. The CT scan, made at the time of presentation, was initially interpreted as normal besides degenerative changes. Philip J. Rosinsky et al. JBJS Case Connect 2015;5:e76 ©2015 by The Journal of Bone and Joint Surgery, Inc.

3. Sagittal MRI scan acquired before surgery demonstrates the hyperintense signal of the meninges and nerve roots at L1-L3 (solid white arrow), which was found to represent an inflammatory meningeal reaction that served as a sealant to a cerebrospinal fluid le... Philip J. Rosinsky et al. JBJS Case Connect 2015;5:e76 ©2015 by The Journal of Bone and Joint Surgery, Inc.

4. Axial MRI scan demonstrating the intradural extension (dashed red arrow), implying an intradural pocket of pus. Philip J. Rosinsky et al. JBJS Case Connect 2015;5:e76 ©2015 by The Journal of Bone and Joint Surgery, Inc.

5. On laminectomy, a small amount of pus was seen emerging from within the canal around the S1 nerve root, spreading to the paraspinal muscles. Philip J. Rosinsky et al. JBJS Case Connect 2015;5:e76 ©2015 by The Journal of Bone and Joint Surgery, Inc.

6. Inflamed dura with pus (arrow) emerging from within the thecal sac through pockets and perforations in the dura. Philip J. Rosinsky et al. JBJS Case Connect 2015;5:e76 ©2015 by The Journal of Bone and Joint Surgery, Inc.

7. A large perforation in the dura (dashed arrow) is probed. Philip J. Rosinsky et al. JBJS Case Connect 2015;5:e76 ©2015 by The Journal of Bone and Joint Surgery, Inc.