Study Links Failed Back Surgery Syndrome to Fibromyalgia

APRIL 5, 2017

San Diego—A new study shows that one in four patients with failed back surgery syndrome (FBSS) also has a diagnosis of fibromyalgia. According to the retrospective analysis, patients with FBSS and fibromyalgia also had more surgeries than patients with FBSS alone.

The association between fibromyalgia and FBSS is significant, the authors noted, with 25% of FBSS patients having a diagnosis of fibromyalgia compared with 1.75% in the general population (PLoS One 2015;10:e0138024).

“The impact of FBSS is tremendous, with direct costs ranging between $30,000 and $40,000 per patient, and high incidence of disability, decreased quality of living and unemployment,” said Esther Caballero-Manrique, MD, an anesthesiology resident at the University of Vermont Medical Center, in Burlington. “Given increasing rates of lumbar surgeries and high rates of failure, it is critical to identify patients with fibromyalgia prior to surgery and educate them regarding worsening symptoms and realistic expectations.”

As Dr. Caballero-Manrique reported at the 2016 annual meeting of the American Society of Regional Anesthesia and Pain Medicine (abstract 2886), fibromyalgia is the prototypical disease of centralized pain.

“Since studies have shown that patients with fibromyalgia or fibromyalgia symptoms have less improvement in pain scores following orthopedic procedures such as knee or hip replacement, we thought it might be the same case with back surgery,” she said.

Study Design and Results

Using International Classification of Diseases, Ninth Revision (ICD-9) and ICD-10 codes for fibromyalgia and FBSS, Dr. Caballero-Manrique and her colleagues searched all patients seen at the University of Vermont Medical Center from Jan. 1, 2010, through Dec. 31, 2015. The researchers then quantified the total number of surgeries per patient and classified the surgical procedures according to type.

Although estimated rates of fibromyalgia in the general population range from 1.7% to 6%, results of the retrospective analysis revealed that 25% of patients with FBSS at the center also had a diagnosis of fibromyalgia.

“One in four patients with failed back surgery syndrome has fibromyalgia, which is a significant finding,” Dr. Caballero-Manrique said. “We also found a significant association between the number of surgeries and a diagnosis of fibromyalgia.”

According to the data, 49% of patients diagnosed with both fibromyalgia and FBSS had undergone at least four surgeries. For patients without a diagnosis of fibromyalgia, however, that rate was only 30.5%.

In patients with both fibromyalgia and FBSS, researchers also observed a greater variety of surgeries performed. All patients in this group had at least one back (thoracic or lumbar) or neck (cervical) surgery performed. In addition, patients with fibromyalgia had a significantly higher number of surgeries classified as “other joint,” the authors noted.

Dr. Caballero-Manrique hypothesized that patients with central sensitization undergo a high number of procedures in an effort to ameliorate their symptoms. However, given the central, rather than peripheral, nature of their pain, she said, surgeries are less likely to solve their problems. In fact, she added, surgery can lead to worsening pain, as acute-phase nociceptors lead to neuroplasticity with decreased inhibitory neurons and increased nociceptive signals (Br J Anaesth 2010;105:69-85).

“We were really motivated to do this study because the impact of failed back surgery syndrome can be devastating,” she explained. “It’s not just the high cost for patients; there’s a high incidence of disability, unemployment and decreased quality of life.”

Although the study was limited by its retrospective nature and the inability to identify all patients with fibromyalgia or FBSS, Dr. Caballero-Manrique was encouraged by the results.

“We feel there’s a lot more to do,” she said, “but this is a good start.”

Charles Berde, MD, PhD, division chief of pain medicine and pain treatment service at Boston Children’s Hospital and professor of pediatric anesthesia at Harvard Medical School, also in Boston, referenced the works of Daniel Clauw, MD, and Chad Brummett, MD, from the University of Michigan, in Ann Arbor, who have studied the effect of “fibromyalgia-like phenotype” on surgical outcomes.

“The notion of fibromyalgia as a spectrum or continuum is not a bad concept,” Dr. Berde said. “The cutoffs are somewhat arbitrary, but there is definitely support for fibromyalgia-like symptoms as a predictor of response to both surgery and interventions for chronic pain.”

—Chase Doyle

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