We evaluated radiographical changes in 14 cases after percutaneous discotomy (PD) for lumbar disc herniation. The subjects consisted of 12 males and 2 females, aged between 17 to 64 (average age; 38.1 years). The length of follow-up ranged from 5 years to 7.8 years (average; 6.5 years). The mean decrease in disc height was 15.1%. In 4 cases, the decrease in the disc height was more than 20%. These cases were inclined to show poor clinical results.
Only 1 case developed instability of the lumbar spine after surgery, but the amount of resected disc correlated with the spinal segmental motion. Indicating that a large amount of resected disc may lead to spinal instability.
