Influence of cross‐sectional area and fat infiltration of paraspinal muscles on analgesic efficacy of epidural steroid injection in elderly patients

Abstract

Background: An assessment of paraspinal muscle degeneration based on magnetic resonance imaging has been used to investigate both sarcopenia and myosteatosis.The morphologic changes in cross-sectional area and fat infiltration of the paraspinal muscles can affect pain outcomes after epidural steroid injection.Methods: Patients ≥65 years of age who underwent fluoroscopy-guided lumbar epidural steroid injections were enrolled. Good analgesia was defined as ≥50% reduction in pain score at 4 weeks after injection. Cross-sectional area and grade of fat infiltration of the paraspinal muscles on magnetic resonance images at the level of L3-L4 disc were measured. Patient demographics, pain-related factors, clinical factors, and paraspinal muscle measurements were compared between good and poor analgesia groups. The factors associated with pain outcomes after injection were identified using multivariate analysis.Results: A total of 245 patients consisting of 149 and 96 patients in the good and poor analgesia groups, respectively, fully satisfied the study criteria for analysis.Patients of older age, opioid use, and high-grade foraminal stenosis were frequently observed in the poor analgesia group. The grade of fat infiltration of the paraspinal muscles was significantly higher in the poor analgesia group (Grade 2, 20.8% vs. 42.7%, p < 0.001), and this result was predominantly observed in female patients.However, there was no difference in the muscle cross-sectional area between the two groups (18.29 ± 3.16 vs. 18.59 ± 3.03 cm 2 /m 2 , p = 0.460). The percentage of patients with good analgesia decreased as the grade of fat infiltration increased (Grade 0 = 75.0%, Grade 1 = 65.8%, Grade 2 = 43.0%, p < 0.001). Multivariate logistic regression analysis revealed that preinjection opioid use [adjusted odds ratio (aOR) = 1.926, 95% confidence interval (CI) = 1.084-3.422, p = 0.025], moderate to severe foraminal stenosis (aOR = 2.859, 95% CI = 1.371-5.965, p = 0.005), and high-grade fat infiltration of the paraspinal muscles (aOR = 4.258, 95% CI = 1.805-10.043, p = 0.001) were significantly associated with poor analgesia after injection. Conclusion:High fat infiltration of the paraspinal muscles at the mid-lumbar region appeared to be an independent factor associated with poor analgesia after epidural steroid injection in elderly patients with symptomatic degenerative lumbar spinal disease receiving conservative care. However, the cross-sectional area of the paraspinal muscles was not associated with pain relief after injection.

Association between fatty infiltration in the cervical multifidus and treatment response following cervical interlaminar epidural steroid injection

“…In the additional analysis stratified by fatty infiltration severity, only age was significantly associated with the severity of multifidus fatty infiltration, which corresponds with the prior study [ 16 ]. Although intramuscular adipose tissues compositionally varied in different body locations depending on sex and BMI [ 42 , 43 ], they did not have a significant association with fatty infiltration severity in this study, which was consistent with the results of a prior lumbar-related study [ 8 ].…”

“…As patients with cervical radiculopathy have significantly larger amounts of fatty infiltration in their muscles compared with healthy controls [ 3 ], this study revealed that high-grade fatty infiltration in the multifidus muscle might have adverse impacts on the response to CIESI in patients with cervical radicular pain. Similarly, a recent study found that high fatty infiltration of the paraspinal muscles in the lumbar area was independently associated with poor response to lumbar epidural steroid injections in patients with lumbar spondylosis [ 8 ]. The underlying mechanisms of multifidus fatty infiltration in spinal disorders are not well-understood.…”

“…Cervical interlaminar epidural steroid injections (CIESIs) have been widely used for symptom relief in cases of cervical radicular pain [ 7 ]. Aside from being linked to poor outcomes following lumbar spine surgery, high-grade fatty infiltration of paraspinal muscles in the lumbar region was significantly associated with poor response to epidural steroid injections in elderly patients [ 8 ]. To the authors’ knowledge, however, no studies have investigated the relationship between fatty infiltration of the paraspinal muscles and treatment outcomes after CIESI.…”

Impact of Sarcopenia on Percutaneous Epidural Balloon Neuroplasty in Patients with Lumbar Spinal Stenosis: A Retrospective Analysis

“…Secondly, we only measured the CSA and did not consider the fat infiltration of the psoas muscles. Changes in muscle function and quality have been emphasized in the diagnosis of sarcopenia recently [ 24 ]. Therefore, further studies about the impact of fat infiltration on PEBN are needed.…”

“…Although sarcopenia is known to be associated with poor prognosis after lumbar spine surgeries [ 21 , 22 , 23 ], only a few studies exist on sarcopenia’s effect in epidural procedures [ 24 ]. In addition, there is no study on the effect of sarcopenia in patients with LSS who underwent PEBN.…”