[Changes in the paravertebral musculature following a traditional herniated lumbar diskectomy. A computed tomographic and magnetic resonance study].

On the basis of previous EMG data, a retrospective study was carried out on the CT and MR features of the paravertebral musculature after lumbar spine surgery through the posterior approach. The authors reviewed the CT scans and some MR images of 35 symptomatic patients hospitalized 7 months to 42 years after operation for disc herniation. Changes in the paraspinal musculature were apparent in all of them on the surgical side. The changes were minimal or very slight in 14 patients, moderate in 13 and severe in 8. A close correlation was observed between the above changes and the surgical procedure used in every single case. Histology showed atrophy and degeneration of the muscle fibres and fibrofatty substitution. The possible responsible causes of damage to the postvertebral muscles during spinal surgery are briefly mentioned and practical implications discussed.