Nyheder

Puncture of a disc and application of nucleus pulposus induces disc herniation-like changes and osteophytes

An experimental study in rats. It has been observed that puncture of a lumbar disc may induce formation of a nodule on the surface of the disc and osteophytes. It is not known if this is based on the presence of a foreign tissue or specifically by the presence of nucleus pulposus or on the disc injury. In this study these mechanisms were separated by comparing disc puncture with application of nucleus pulposus without disc injury, with superficial disc injury without nucleus pulposus and with application of fat. Fifty rats underwent facetectomy of the left L4-5 facet. Ten additional rats were used as donor rats. The rats were exposed to disc puncture (n=10), application of homologous nucleus pulposus (n=10), application of homologous fat tissue (n=10), superficial disc injury (n=10) and ten rats served as control. After 3 weeks the rats were examined macroscopically regarding presence of disc nodules and osteophytes. A limited histological analysis was performed to obtain a microscopic overview of any observed changes. In rats with application of fat, superficial disc injury and in sham controls there were almost no changes observed. However, in rats with disc puncture and applied nucleus pulposus there were clear disc nodules and osteophytes noted. Microscopically the nodules comprised granulation tissue and the osteophytes cortical bone. In conclusion, the data indicate that the presence of nucleus pulposus is more likely to be responsible for the formation of disc nodules and osteophytes than disc injury or the presence of a foreign tissue. This may provide new insights in the mechanisms regarding the formation of disc herniations and osteophytes. Olmarker K. Open Orthop J. 2011 Apr 28;5:154-9.

MR imaging and CT in osteoarthritis of the lumbar facet joints

With regard to osteoarthritis of the lumbar facet joints there is moderate to good agreement between MR imaging and CT. When differences of one grade are disregarded agreement is even excellent. Therefore, in the presence of an MR examination CT is not required for the assessment of facet joint degeneration. Weishaupt D, Zanetti M, Boos N, Hodler J. Skeletal Radiol. 1999 Apr;28(4):215-9.

A consensus approach toward the standardization of back pain definitions for use in prevalence studies

These definitions provide standards that may improve future comparisons of low back pain prevalence figures by person, place and time characteristics, and offer opportunities for statistical summaries. Dionne CE et al. Spine (Phila Pa 1976). 2008 Jan 1;33(1):95-103.