NEW YORK (Reuters Health)—Use of epidural steroid injections (ESIs) “should be approached with prudence,” particularly in patients who are at risk for osteoporotic fractures, such as women of postmenopausal age, according to authors of a systematic review.
Although the literature presents a mixed picture, ESIs in doses as low as 80 mg methylprednisolone equivalents seem to reduce bone mineral density (BMD), both locally (in the lumbar spine) and systemically (in the femoral neck), and ESIs also increase the risk of vertebral fracture, the researchers conclude. They recommend that use of an anti-osteoporotic medication be considered before giving an ESI.
The authors believe that their report, published online Jan. 2 in Pain Medicine, is the first systematic review of all available studies about ESIs’ effects on BMD and vertebral fracture risk.1
“The risk of fracture suggested by these studies is overall quite small, likely not outweighing the potential benefits from pain relief provided by these injections for the majority of patients,” corresponding author Dr. Mohamad Bydon of Mayo Clinic in Rochester, Minn., tells Reuters Health by email.
Nonetheless, he adds, “at this time, there is not enough evidence to provide clinical practice guidelines recommending which patients with known risk factors for diminished BMD are safe candidates for repeated ESIs.”
The new review encompassed eight studies involving 7,233 patients (mean ages, 49 to 74) with average follow-ups of 6 to 60 months. The steroids included triamcinolone, dexamethasone and methylprednisolone; the mean number of injections ranged from 1 to 14.7, with an average cumulative dose between 80 mg and 8,130 mg of methylprednisolone equivalents.
“Significant reductions in BMD” were associated with a cumulative methylprednisolone equivalents dose of 200 mg over one year and 400 mg over three years. However, such reductions were not found with methylprednisolone equivalent doses of <200 mg for postmenopausal women or of at least 3 grams for healthy men.
Overall, the risk of osteopenia and osteoporosis was lower in patients who were also receiving anti-osteoporotic medication.
The report also notes that the reviewed studies “suggest that adverse outcomes in terms of vertebral fracture risk or compromised BMD may differ considerably between men and women, although this has never been directly studied.”
To mitigate systemic effects, including fracture risk, several institutions, including the Mayo Clinic, do not administer more than three to four spinal injections in a given year, Dr. Bydon says.
In discussions with patients about the risks, benefits and alternative to ESIs, he adds, “factors such as older age, low bone density, or history of fracture should be considered. … But if over-administration of steroid increases the risk of injury, such as fracture, we may need to consider which patients are at higher risk for adverse outcomes with repeated doses of steroid.”
“It is also important to consider other (non-epidural) injected steroids the patient may receive, as large joint injections, for example, may contribute to any systemic effect on fracture risk as well as other endocrine side effects,” Dr. Bydon cautions.
This study’s findings are “consistent with known effects of corticosteroids on bone,” Dr. Roger Chou, director of the Pacific Northwest Evidence-based Practice Center at Oregon Health & Science University, told Reuters Health by email.
He notes, however, the uncertainty about whether ESIs have negative bone effects, “[because] the effects of corticosteroids are presumed to be mostly from systemic effects, and most of the corticosteroid that is injected into the epidural space is probably not having systemic effects; rather it has local effects in the epidural space.”
Dr. Chou cautions that all the studies in this review were observational. “The results should also be interpreted in the context of studies showing that the benefits of epidural steroid injections are small and short-lived,” he says.
- Kerezoudis P, Rinaldo L, Alvi MA, et al. The effect of epidural steroid injections on bone mineral density and vertebral fracture risk: A systematic review and critical appraisal of current literature. Pain Med. 2018 Jan 2. doi: 10.1093/pm/pnx324. [Epub ahead of print]