Image-Guided Minimally Invasive Treatment Options for Degenerative Lumbar Spine Disease: A Practical Overview of Current Possibilities

Lumbar back pain is one of the main causes of disability around the world. Most patients will complain of back pain at least once in their lifetime. The degenerative spine is considered the main cause and is extremely common in the elderly population. Consequently, treatment-related costs are a major burden to the healthcare system in developed and undeveloped countries. After the failure of conservative treatments or to avoid daily chronic drug intake, invasive treatments should be suggested. In a world where many patients reject surgery and prefer minimally invasive procedures, interventional radiology is pivotal in pain management and could represent a bridge between medical therapy and surgical treatment. We herein report the different image-guided procedures that can be used to manage degenerative spine-related low back pain. Particularly, we will focus on indications, different techniques, and treatment outcomes reported in the literature. This literature review focuses on the different minimally invasive percutaneous treatments currently available, underlining the central role of radiologists having the capability to use high-end imaging technology for diagnosis and subsequent treatment, allowing a global approach, reducing unnecessary surgeries and prolonged pain-reliever drug intake with their consequent related complications, improving patients' quality of life, and reducing the economic burden.

Effects of Repeated Intracordal Glucocorticoid Injection on the Histology and Gene Expression of Rat Vocal Folds

OBJECTIVES

Local injection of glucocorticoids (GCs) into the vocal folds has been used for treating the vocal fold lesions. While the positive effects on vocal fold nodules, polyps, or scarring have been clinically reported, some concern remains around the potential adverse effects such as vocal fold atrophy, and the mechanisms remain unclear. The present study examined the histology and gene expression of locally injected GC into the vocal folds in rats.

METHODS

Thirteen-week-old male Sprague-Dawley rats were used in the experiments. Triamcinolone acetonide (TAA) or saline were administered repeatedly to the right vocal folds at a weekly interval, and rats were euthanized one week after the last administration for histological examination. Genetic examination was assessed hyaluronic acid (HA) metabolism at 1 or 3 days after a single TAA injection by quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

The group which underwent four TAA injections showed a significant decrease in HA in the lamina propria (LP), thickness of the LP and total cell numbers of the LP compared with the saline group. In contrast, there was no significant difference in the area of collagen accumulation and the thyroarytenoid muscle, although there was a tendency of atrophy of the muscle. After single injection of TAA, qRT-PCR showed a significant decrease in the expression of HA synthases, Has2 and Has3.

CONCLUSIONS

The current animal study first demonstrates that repeated intracordal injection of GCs may lead to atrophy of vocal folds caused by decrease of deposition of HA in the LP and decrease of gene expression of Has.

Relationship of Imaging-guided Corticosteroid Injections to COVID-19 Incidence in the Pandemic Recovery Period

Background Corticosteroids injected for the treatment of musculoskeletal pain are systemically absorbed and can affect the immune response to viral infections. Purpose To determine the incidence of symptomatic COVID-19 disease in individuals receiving image-guided corticosteroid injections for musculoskeletal pain compared with the general population during the pandemic recovery period. Materials and Methods In this prospective cohort multicenter study, adults with a history of musculoskeletal pain who underwent imaging-guided intra-articular and spine corticosteroid injections from April 2020 to February 2021 were consecutively enrolled. Participants were followed for a minimum of 28 days through their electronic medical record (EMR) or by direct phone communication to screen for COVID-19 test results or symptoms. Clinical data, including body mass index (BMI), were also obtained from the EMR. The incidence of COVID-19 in the state was obtained using the Massachusetts COVID-19 Response Reporting website. The Student t test was used for continuous variable comparisons. Univariable analyses were performed using the Fisher exact test. Results A total of 2714 corticosteroid injections were performed in 2190 adult participants (mean age, 59 years ± 15 [SD]; 1031 women). Follow-up was available for 1960 participants (89%) who received 2484 injections. Follow-up occurred a mean of 97 days ± 33 (range, 28-141 days) after the injection. Of the 1960 participants, 10 had COVID-19 within 28 days from the injection (0.5% [95% CI: 0.24, 0.94]) and 43 had COVID-19 up to 4 months after the injection (2.2% [95% CI: 1.6, 2.9]). These incidence rates were lower than that of the population of Massachusetts during the same period (519 195 of 6 892 503 [7.5%], P < .001 for both 28 days and 4 months). Participants diagnosed with COVID-19 (n = 10) within 28 days from the injection had a higher BMI than the entire cohort (n = 1960) (mean, 32 kg/m² ± 10 vs 28 kg/m² ± 6; P = .04). Conclusion Adults who received image-guided corticosteroid injections for pain management during the pandemic recovery period had a lower incidence of symptomatic COVID-19 compared with the general population. © RSNA, 2022 Online supplemental material is available for this article.

Are Corticosteroid Injections Associated With Secondary Adrenal Insufficiency in Adults With Musculoskeletal Pain? A Systematic Review and Meta-analysis of Prospective Studies

BACKGROUND

Corticosteroid injection is a common treatment for individuals experiencing musculoskeletal pain, and it is part of the management of numerous orthopaedic conditions. However, there is concern about offering corticosteroid injections for musculoskeletal pain because of the possibility of secondary adrenal insufficiency.

QUESTIONS/PURPOSES

In this systematic review and meta-analysis of prospective studies, we asked: (1) Are corticosteroid injections associated with secondary adrenal insufficiency as measured by 7-day morning serum cortisol? (2) Does this association differ depending on whether the shot was administered in the spine or the appendicular skeleton?

METHODS

We searched the Allied and Complementary Medicine (AMED), Embase, EmCare, MEDLINE, CINAHL, and Web of Science from inception to January 22, 2021. We retrieved 4303 unique records, of which 17 were eventually included. Study appraisal was via the Downs and Black tool, with an average quality rating of fair. A Grading of Recommendations, Assessment, Development, and Evaluations assessment was conducted with the overall certainty of evidence being low to moderate. Reflecting heterogeneity in the study estimates, a pooled random-effects estimate of cortisol levels 7 days after corticosteroid injection was calculated. Fifteen studies or subgroups (254 participants) provided appropriate estimates for statistical pooling. A total of 106 participants received a spine injection, and 148 participants received an appendicular skeleton injection, including the glenohumeral joint, subacromial bursa, trochanteric bursa, and knee.

RESULTS

Seven days after corticosteroid injection, the mean morning serum cortisol was 212 nmol/L (95% confidence interval 133 to 290), suggesting that secondary adrenal insufficiency was a possible outcome. There is a difference in the secondary adrenal insufficiency risk depending on whether the injection was in the spine or the appendicular skeleton. For spinal injection, the mean cortisol was 98 nmol/L (95% CI 48 to 149), suggesting secondary adrenal insufficiency was likely. For appendicular skeleton injection the mean cortisol was 311 nmol/L (95% CI 213 to 409) suggesting hypothalamic-pituitary-adrenal axis integrity was likely.

CONCLUSION

Clinicians offering spinal injections should discuss the possibility of short-term secondary adrenal insufficiency with patients, and together, they can decide whether the treatment remains appropriate and whether mitigation strategies are needed. Clinicians offering appendicular skeleton injections should not limit care because of concerns about secondary adrenal insufficiency based on the best available evidence, and clinical guidelines could be reviewed accordingly. Further research is needed to understand whether age and/or sex determine risk of secondary adrenal insufficiency and what clinical impact secondary adrenal insufficiency has on patients undergoing spinal injection.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Overcoming barriers for intra-articular delivery of disease-modifying osteoarthritis drugs

Despite four decades of research in intra-articular drug delivery systems (DDS) and two decades of advances in disease-modifying osteoarthritis drugs (DMOADs), there is still no clinically available disease-modifying therapy for osteoarthritis (OA). Multiple barriers compromise intra-articular DMOAD delivery. Although multiple exciting approaches have been developed to overcome these barriers, there are still outstanding questions. We make several recommendations that can help in fully overcoming these barriers. Considering OA heterogeneity, we also propose a patient-centered, bottom-up workflow to guide preclinical development of DDS-based intra-articular DMOAD therapies. Overall, we expect this review to inspire paradigm-shifting innovations for developing next-generation DDS that can enable clinical translation of intra-articular DMOADs.

A novel approach to improve detection of glucocorticoid doping in sport with new guidance for physicians prescribing for athletes

The systemic effect of glucocorticoids (GCs) following injectable routes of administration presents a potential risk to both improving performance and causing harm to health in athletes. This review evaluates the current GC antidoping regulations defined by the World Anti-Doping Agency and presents a novel approach for defining permitted and prohibited use of glucocorticoids in sport based on the pharmacological potential for performance enhancement (PE) and risk of adverse effects on health. Known performance-enhancing doses of glucocorticoids are expressed in terms of cortisol-equivalent doses and thereby the dose associated with a high potential for PE for any GC and route of administration can be derived. Consequently, revised and substance-specific laboratory reporting values are presented to better distinguish between prohibited and permitted use in sport. In addition, washout periods are presented to enable clinicians to prescribe glucocorticoids safely and to avoid the risk of athletes testing positive for a doping test.

Symptomatic COVID-19 infections in outpatient image-guided corticosteroid injection patients during the lockdown phase

BACKGROUND

Musculoskeletal pain is a debilitating problem treated with image-guided corticosteroid injections. During the COVID-19 pandemic, multiple societies issued caution statements because of the unknown effect of corticosteroids on the patient's immune system. The purpose is to determine if image-guided corticosteroid injections administered during the COVID-19 lockdown phase were associated with a higher infection rate compared to the general population.

MATERIALS AND METHODS

In a prospective study, patients undergoing image-guided corticosteroid injections for pain management during the lockdown phase between April 15 and May 22, 2020, were enrolled. One month after the injection, patients were surveyed by telephone for any COVID-19-related symptoms, and the electronic medical record (EMR) was reviewed for symptoms and test results.

RESULTS

Seventy-one subjects were recruited, 31 (44%) females, 40 (56%) males, ages 58 ± 17 (20-92) years. Follow-up was available in 66 (93%) of subjects, 60 (91%) by phone survey and EMR, 6 (9%) by EMR only, 45 ± 22 (19-83) days after injection. One (1/66, 1.52%; 95% CI 0.04-8.2%) 25-year-old male subject developed symptomatic infection 19 days after a tibiotalar injection. The prevalence of COVID-19 cases in the state of Massachusetts was 0.91% (62,726/6,892,503) during the study period. There was no significant difference in the rate of occurrence of new cases of COVID-19 infection between the corticosteroid injection group and the general population (p = 0.44).

CONCLUSION

Image-guided corticosteroid injections for pain management performed during the lockdown phase of the COVID-19 pandemic were not associated with a higher infection rate compared to the general population.

IATROGENIC CUSHING SYNDROME IN AN HIV-INFECTED PATIENT SECONDARY TO CONCOMITANT THERAPY WITH GENVOYA AND EPIDURAL TRIAMCINOLONE

OBJECTIVE

We report the first known case of Cushing syndrome and secondary adrenal insufficiency in a patient with concomitant use of epidural triamcinolone and Genvoya® (elvitegravir 150 mg/cobicistat 150 mg/emtricitabine 200 mg/tenofovir alafenamide 10 mg) for the human immunodeficiency viruses (HIV). The prompt recognition of this drug-drug interaction is critical to avoid adverse outcomes when glucocorticoids are used with anti-retroviral treatment containing cobicistat, a potent cytochrome P450 3A (CYP3A4) inhibitor.

METHODS

The patient was evaluated by determining morning serum cortisol concentrations, the serum cortisol response to cosyntropin, and a urine synthetic glucocorticoid panel that is capable of measuring triamcinolone. We also employed the Naranjo Nomogram for Causality as well as a Drug Interaction Probability scale to assess medication-related adverse effects. Long term outcome was assessed by measuring morning serum cortisol and adrenocorticotropic hormone levels.

RESULTS

A 76-year-old female with HIV on Genvoya® presented with fatigue, weight loss, and hyperglycemia. She had received multiple epidural triamcinolone injections for chronic back pain before her presentation. We hypothesized that the patient's presentation of Cushing syndrome and adrenal insufficiency was caused by the inhibition of triamcinolone metabolism by cobicistat. The patient's antiretroviral therapy was changed to a regimen without cobicistat. She was started on maintenance hydrocortisone to prevent an adrenal crisis. A repeat urine glucocorticoid panel, within 3 days of the patient's HIV regimen being changed, showed a significant decrease in triamcinolone levels.

CONCLUSION

It is essential to avoid drugs that include cobicistat when administering glucocorticoids that are metabolized via the CYP3A4 pathway due to the risk of developing Cushing syndrome and secondary adrenal insufficiency.

Effects of intra-articular corticosteroid injections on lumbar trabecular density

PURPOSE

To determine the effect of intra-articular corticosteroid injections on lumbar spine trabecular density.

MATERIALS AND METHODS

This retrospective study was IRB-approved and HIPAA-compliant. We identified 50 patients (26 F, 24 M, mean age 69 ± 14 years) who had undergone at least three medium or large joint corticosteroid injections using insoluble corticosteroids and a subsequent non-contrast abdominal CT within 5 years of the first injection. About 126 age- and sex-matched controls without history of prior corticosteroid use who had undergone non-contrast abdominal CT were identified. Cumulative corticosteroid dose was calculated. Density measurements (HU) of trabecular bone of L1 to L4 were performed, and measurements of L1 were compared to established normative data. Groups were compared using a two-sided paired t-test or a chi-squared test. Linear regression analysis between cumulative corticosteroid dose and trabecular density was performed.

RESULTS

Patients underwent a mean of 4 corticosteroid injections (range 3 to 11) with a mean cumulative corticosteroid dose of 232 ± 100 mg triamcinolone equivalent (range 120 mg to 480 mg). There was no significant difference in trabecular density of L1 to L4 between cases and controls, and there was no significant difference in trabecular density at L1 compared to normative data (p > 0.2). There was no association between cumulative intra-articular corticosteroid dose and mean lumbar trabecular density (p > 0.3).

CONCLUSION

Patients who underwent repetitive intra-articular insoluble corticosteroid injections showed no increased risk of bone loss compared to controls. Cumulative intra-articular corticosteroid dose was not associated with lumbar trabecular density.