Decisions in medicine, like most things, are based on risk versus benefit. There are life-saving procedures and surgeries that clearly are needed, but are many doctors doing more harm in non-emergency situations?  A recent study looks at the potential damage done to the multifidus muscles during common back-fusion surgery.

What is the multifidus, and why should a patient care? The spine is like a series of stacked blocks that creates a structure to contain and protect the spinal cord. It’s held together by ligaments and kept stable by a series of muscles called multifidus. Damage to the ligaments and atrophy of the multifidus can cause instability. Fusion surgery is done when vertebrae become so unstable that they allow the type of movement that affects the nerves or causes pain. The surgery basically involves using hardware and screws to hold two or more vertebrae together in order to create an immovable section of the spine.

A study reported May 13, 2015, in European Spine Journal observed six patients who underwent lumbar-fusion surgery. Ten healthy individuals were used as a control group. Each subject received pre-operative and post-operative cross-sectional area MRIs to evaluate the condition and contractibility of his or her multifidus at all levels of the lumbar spine. The results showed significant damage to the multifidus at the operated levels. Given that other studies have shown that the amount of multifidus damage is directly related to the length of time a surgical retractor is used, this result isn’t surprising. The study also showed that the muscles that help to move the back (the paraspinals) were smaller and damaged in patients who underwent fusions.

“Fixing” two or more vertebrae by making them immovable simply puts more stress and load on the vertebrae above and below the fusion, which causes degenerative osteoarthritis. In order for the level of instability to develop that would necessitate a fusion, the multifidus muscles would not be functioning properly. Cutting through them to reach and fuse the vertebrae irrevocably damages the multifidus. The non-surgical alternative is stabilizing the ligaments and multifidus muscles through targeted injections and exercises.

“Back Fusion Outcome: Fusion Leads to Dead Multifidus” first appeared as a post on the Regenexx blog.