Open door laminoplasty using plates is a safe and effective procedure for multi-level cord compression. To achieve stable laminar arch, various types of plate have been developed and used. Now, we introduce two rare complications related to the laminar shelf of plate.

In the first case, we used the wider laminar shelf plate because the elevated lamina did not fit well into the usual laminar shelf. During follow-up, cord compression due to laminar shelf was observed.

And in the second case, the laminar shelf of plate did not fit into the elevated lamina, so we inserted it with a little bit of force. But the patient’s symptom was not improved. On CT image, the inner cortical bone of the lamina was fractured.

To prevent these complications, surgeons need to consider the thickness of the lamina and the size of the laminar shelf before surgery.

Knotting of an epidural catheter occurs very rarely with an estimated incidence of 0.0015%. We present a case of an epidural catheter knot formed at removal of an epidural catheter following a forceful insertion of the catheter against resistance met at the entrance of the epidural space during threading of the catheter through Tuohy needle placed uneventfully in a 65 year-old male patient undergoing epidural anesthesia. During removal of the epidural catheter, significant resistance was encountered on traction and it was found that approximately 1.5 ㎝ portion of the catheter had been retained within the patient's subcutaneous tissue. Firm traction was employed to withdraw the catheter against the resistance. The catheter was pulled out uneventfully from the patient. A knot estimated to be formed during removal of the catheter was observed at 0.6 ㎝ proximal to the catheter tip. No complications and side effects were noted until the patient's discharge.