Fifty MRI scans of patients with chronic lumbar back pain were graded radiologically using a wide range of classification and measurement systems. The reported effect of facet joint injections at the site was recorded and a comparative analysis performed.

Inclusion Criteria:

• patients who had received inpatient gradual diagnostics for chronic lumbar back pain
• monosegmental facet joint infiltration on the first day of inpatient gradual diagnostics
• clearly stated pain relief in percentage (%) for that specific infiltration in the medical documentation
• pain level prior to infiltration needed to be clearly documented
• a high-quality MRI available before infiltration.

Exclusion Criteria:

• ositive history of lumbar surgery or the presence of artificial implants in the area of interest

All patients who had received inpatient gradual diagnostics in our department

General data file from which statistical analyses were performed may be requested from the authors after publication