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Trial Lecture – time and place
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Adjudication committee
- First opponent: Professor Mikael Boesen, University of Copenhagen, Denmark
- Second opponent: Associate Professor Ivar Rossvoll, NTNU - Norwegian University of Science and Technology, Norway
- Third member and chair of the evaluation committee: Professor II Heidi Beate Eggesbø, University of Oslo
Chair of the Defence
Associate Professor Knut Magne Augestad, University of Oslo
Principal Supervisor
Professor Anne Negård, University of Oslo
Summary
Lumbar spinal stenosis (LSS) is an important cause of back pain, leg pain, and disability in older individuals. The condition arises from degenerative changes in the supporting structures of the lumbar spine, which leads to a narrowing of the space available for nerves and blood vessels. The prevalence of LSS in the general population stands at around 10%, making it the leading cause of spine surgery in adults.
While a thorough clinical examination can aid in diagnosing LSS, magnetic resonance imaging (MRI) is frequently employed as a crucial diagnostic tool. It not only confirms the diagnosis but also evaluates the cause of the stenosis and rules out other conditions that may mimic the symptoms of LSS. Both radiologists and spine surgeons are well-versed in interpreting lumbar MRI examinations for these patients.
The objectives of this thesis were to assess the inter- and intraobserver reliability of commonly used MRI methods for diagnosing and evaluating the severity of LSS. Another aim was to evaluate the reliability of a novel MRI method (the muscle fat index, MFI) for quantitatively assessing the extent of fatty infiltration in the paraspinal muscles. Additionally, the thesis sought to evaluate the association between fatty infiltration of the paraspinal muscles and pain and disability both before and two years after surgery for LSS.
The MRI methods employed in the diagnosis of LSS demonstrated good inter- and intraobserver reliability, except for facet joint osteoarthritis evaluation. The novel MFI also exhibited high inter- and intraobserver reliability. However, no statistically significant association was found between fatty infiltration of the paraspinal muscles (as assessed by the MFI) and pain or disability prior to surgery. Nevertheless, a significant correlation was observed between this fatty infiltration and a lesser improvement in leg pain two years after LSS surgery.
Additional information
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