A watertight sac of tissue (dura mater) covers the spinal cord and the spinal nerves. A tear in this covering can occur during surgery. It is not uncommon to have a dural tear during any type of spine surgery. If noticed during the surgery, the tear is simply repaired and usually heals uneventfully. If it is not recognized, the tear may not heal and may continue to leak spinal fluid, which can cause problems later. The leaking spinal fluid may cause a spinal headache. It can also increase the risk of infection of the spinal fluid (spinal meningitis). If the dural leak does not seal itself off fairly quickly on its own, a second operation may be necessary to repair the tear in the dura.