Imaging-guided lumbar facet injections: is there a difference in outcomes between low back pain patients who remember to return a postal questionnaire and those who do not?

Predictors of Outcomes After Lumbar Intra-Articular Facet Joint Injections and Medial Branch Blocks: A Scoping Review

STUDY DESIGN

A scoping review.

OBJECTIVE

We aimed to identify and describe the factors associated with the patient-reported response after lumbar intra-articular facet joint (FJ) injections or medial branch blocks (MBBs).

SUMMARY OF BACKGROUND DATA

FJ osteoarthritis is among the most common causes of chronic low back pain. Management often includes FJ intra-articular injection and MBBs (which may be followed by radiofrequency ablation of the nerves innervating these joints). However, the success of these approaches is variable, prompting interest in identifying patient characteristics (imaging features, clinical signs, and among others) associated with response to these types of facet injections.

MATERIALS AND METHODS

We performed a literature search on factors associated with patient-reported outcomes after lumbar FJ intra-articular injections or MBBs for patients with low back pain published in English or Spanish between 2000 and 2023. We excluded duplicate papers that did not describe factors associated with outcomes or those describing other interventions. We collected data on the association of these factors with patient-reported outcomes.

RESULTS

Thirty-seven studies met the inclusion criteria and were analyzed. These studies evaluated factors, such as age, depression, and single photon emission computed tomography (SPECT), and among variables. Age and imaging findings of facet arthropathy were the most frequently described factors. Imaging findings of FJ arthropathy and positive SPECT were often associated with positive results after intra-articular FJ injections or MBBs. In contrast, younger age and smoking were frequently associated with less favorable clinical outcomes.

CONCLUSION

Numerous factors were considered in the 37 studies included in this review. Imaging findings of facet arthropathy, duration of pain, and positive SPECT were consistently associated with favorable results after facet interventions.

Comparison of Chiropractic Treatment Outcomes Depending on the Language Region in Switzerland: A Prospective Outcomes Study

OBJECTIVES

Switzerland has optimal conditions for research of language-based cultural influences on low back pain (LBP). The aim of this study was to compare LBP treatment outcomes after chiropractic care between patients from the German- and French-speaking regions of Switzerland.

METHODS

Baseline Numeric Rating Scale for pain (NRS), demographic, and Oswestry Disability Index (ODI) data were collected from patients presenting to 51 Swiss-German and 12 Swiss-French chiropractors. Prospective outcome data included the proportion reporting clinically relevant improvement on the Patient Global Impression of Change scale and the NRS change scores collected at 1 week; 1, 3, and 6 months; and 1 year. ODI change scores were collected until 3 months. The proportion improved between the 2 groups was compared using the χ² test. NRS and ODI change scores were compared using the unpaired t test.

RESULTS

At baseline, only patient age comparing 853 Swiss-German and 215 Swiss-French patients revealed a significant difference. The Patient Global Impression of Change, NRS, and ODI had no significant differences between both patient groups up to 6 months. Between 6 months and 1 year the proportion reporting improvement continued to increase to 83.5% for German-speaking Swiss but reduced to 73.1% for French-speaking Swiss (P = .01). The NRS change scores were also higher for German speaking Swiss at 1 year compared with Swiss-French citizens (P = .01).

CONCLUSION

Treatment outcome data for LBP are comparable in the German and French parts of Switzerland until the 1-year time point, when people located in the French-speaking regions are more likely to have an increase in pain levels.

Cervical Facet Joint Imaging-Guided Injections: A Comparison of Outcomes in Patients Referred Based on Imaging Findings Vs Palpation for Pain

OBJECTIVES

The purpose of this study was to compare outcomes of patients referred for cervical facet joint injections by either a medical doctor (MD) primarily basing the selection of facet levels on structural changes found on imaging vs a doctor of chiropractic (DC) selecting the levels for injection based on palpation for pain.

METHODS

This was a prospective cohort outcome study including 121 consecutive patients receiving cervical facet injections with completed outcomes questionnaires. Medical doctors referred 91 patients and DCs referred 30 patients. Baseline pain numerical rating scale (NRS) data were collected. Outcomes collected at 1 day, 1 week, and 1 month after injection included NRS pain levels and overall "improvement" using the Patient Global Impression of Change scale (primary outcome). The responses "much better" and "better" were considered "improved." The proportion improved was compared between the 2 groups using the χ(2) test. NRS change scores for the 2 groups were compared using the unpaired t test.

RESULTS

At 1 day, "improvement" was reported in 44.8% of DC-and 29.7% of MD-referred patients (P = .17). At 1 week, 37.9% of DC-and 21.3% of MD-referred patients reported improvement (P = .03). At 1 month, 50.0% of DC-and 31.0% of MD-referred patients reported improvement (P = .1).

CONCLUSIONS

A greater proportion of DC-referred patients (injection level based on palpation for pain) reported "improvement" at all follow-up time points. This finding reached statistical significance at 1 week. These findings may be because DCs use palpation for pain to determine injection level whereas MDs rely more on imaging findings. The results suggest that the reported moderate results of facet injections partially may be due to the inaccurate selection of the spinal level treated.

Is there a difference in treatment outcomes between epidural injections with particulate versus non-particulate steroids?

OBJECTIVES

To compare the outcomes of patients after interlaminar computed tomography (CT)-guided epidural injections of the lumbar spine with particulate vs. non-particulate steroids.

METHODS

531 consecutive patients were treated with CT-guided lumbar interlaminar epidural injections with steroids and local anaesthetics. 411 patients received a particulate steroid and 120 patients received a non-particulate steroid. Pain levels were assessed using the 11-point numerical rating scale (NRS) and overall reported 'improvement' was assessed using the Patients Global Impression of Change (PGIC) at 1 day, 1 week and 1 month post-injection. Descriptive and inferential statistics were applied.

RESULTS

Patients receiving particulate steroids had statistically significantly higher NRS change scores (p = 0.0001 at 1 week; p = 0.0001 at 1 month). A significantly higher proportion of patients receiving particulate steroids reported relevant improvement (PGIC) at both 1 week and 1 month post injection (p = 0.0001) and they were significantly less likely to report worsening at 1 week (p = 0.0001) and 1 month (p = 0.017).

CONCLUSION

Patients treated with particulate steroids had significantly greater pain relief and were much more likely to report clinically relevant overall 'improvement' at 1 week and 1 month compared to the patients treated with non-particulate steroids.

KEY POINTS

• CT-guided epidural injections of the lumbar spine with particulate vs. non-particulate steroids. • Good outcomes with particulate steroids. • Less pain relief in patients with non-particulate steroids. • Less improvement in patients with non-particulate steroids.

Are the presence of MODIC changes on MRI scans related to "improvement" in low back pain patients treated with lumbar facet joint injections?

BACKGROUND

Modic changes (MC) have been linked with low back pain (LBP) and worse outcomes from some treatments. No studies have investigated the impact that MCs may have on patient outcomes from lumbar facet injections. Therefore, the purpose of this study is to investigate whether the presence of Modic changes is related to 'improvement' in patients undergoing imaging-guided lumbar facet injection therapy.

METHODS

Outcomes from 226 patients with MRI scans within 3 months of their imaging-guided lumbar facet injections were investigated to determine whether MCs are related to 'improvement' post injection. At 1 day, 1 week and 1 month post injection the Patients Global Impression of Change scale answers were collected by postal questionnaire. This was the primary outcome measure. The numerical rating scale for pain data was collected prior to treatment and at the same post injection time points. The MRI scans were independently evaluated by two examiners for the presence/absence of Modic changes and the type of Modic change if present. Kappa statistics were used for reliability of diagnosis analysis. Chi-squared test and logistic regression analysis tested MCs with 'improvement'.

RESULTS

Intra- and inter-examiner reliability for the diagnosis of MCs was Kappa = 0.77 and 0.74. Intra- and inter-examiner reliability for categorizing MCs was K = 0.77 and K = 0.78. At 1 month post injection 45.2 % of patients without MCs reported clinically relevant 'improvement' compared to 34.2 % of patients with MC I and 32.1 % of patients with MC II. However, this did not reach statistical significance. Logistic regression found that Modic changes were not predictive of 'improvement'.

CONCLUSIONS

There was a tendency for patients without MCs to have better outcomes but this did not reach statistical significance. The reliability of diagnosing MCs was substantial.

The development and implementation of an outcomes database for imaging-guided therapeutic musculoskeletal injections

OBJECTIVES

To present the process of creating an imaging-guided injections outcomes database and to reflect on how this database has affected the scientific activities of the radiology department.

MATERIALS AND METHODS

The literature was searched to identify studies on the effectiveness of musculoskeletal therapeutic injections, areas where research is lacking, and relevant outcome measures. Validated outcome measures were chosen and tested in a pilot study. Data collection time points of 1 day, 1 week and 1 month post-injection were determined and the post-pilot study postal questionnaires were created. The data collection process began and has been ongoing for over 4 years. Critical reflection on the process and outcomes from the database occurred.

RESULTS

The 9 steps to creating this outcomes database are presented. The numerical rating scale for pain (NRS) and the Patient's Global Impression of Change (PGIC) were identified as the most valid, reliable, and time-effective outcome measures. At most, 50% of patients return their postal questionnaire. The database has facilitated the publication of numerous research projects.

CONCLUSIONS

Setting up an outcomes database is straightforward and productive. The NRS and PGIC were considered the most useful outcome measures. This database facilitated critical reflection on current practice and provides the foundation for several research studies.