Discomanometry in lumbar intervertebral discs: an experimental study.

A new discomanometry system was developed and evaluated for application in the lumbar spine. The diagnostic reliability of discography, manometry and discomanometry (a combination of both methods) was assessed in 20 lumbar cadaver spines (95 intervertebral discs) with regard to the diagnosis of non-contained intervertebral discs. The sensitivity was 92% for manometry and 78% for discography. This indicates that 22% of the non-contained discs could not be correctly identified with common discography. The specificity was 98% for manometry and 100% for discography, indicating that contained discs could be easily identified with both methods. A combination of manometry and discography provides a high sensitivity (98%) as well as high specificity (98%). It is concluded that discomanometry is a simple, cost-effective and reliable diagnostic procedure which can precede percutaneous nucleotomy without additional risks or relevant efforts. It allows the differentiation between contained and non-contained intervertrebral discs with a high degree of diagnostic reliability in an experimental setting, which justifies its further application in patients.