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.
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.
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).
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.