OPLL stand for ossification of the posterior longitudinal ligament. OPLL is a condition in which the long ligament along the back of the spinal column ossifies or turns to bone. Pressure on the spinal cord from this problem brings the patient to the surgeon for treatment. But removing the ligament isn't always easy or successful.
The spinal cord can become damaged during the operation. Paralysis can occur if the spine shifts its alignment. Surgeons in Japan report on 51 cases of OPLL treated by one of three operations. They report the best results when the spine was fused after removing the ligament and/or the bone around the spinal cord. Paralysis was rare when fusion was done.
Paralysis was reversed in some patient who had the ligament or bone removed but the spine wasn't fused. Fusing the spine in a more upright position took the pressure off the spinal cord and returned motor and sensory function in the legs.
In a few cases, reversal of paralysis wasn't possible. Most of these patients had severe spinal cord compression and damage before the first operation.