Usefulness of pain distribution pattern assessment in decision-making for the patients with lumbar zygapophyseal and sacroiliac joint arthropathy

There are currently no initial guides for the diagnosis of somatic referred pain of lumbar zygapophyseal joint (LZJ) or sacroiliac joint (SIJ). We developed a classification system of LZJ and SIJ pain, the "pain distribution pattern template (PDPT)" depending on the pain distribution patterns from a pool of 200 patients whose spinal pain source was confirmed. We prospectively applied the PDPT to determine its contribution to clinical decision-making for 419 patients whose pain was presumed to arise from the LZJs (259 patients) or SIJs (160 patients). Forty-nine percent (128/259) of LZJ and 46% (74/160) of SIJ arthopathies diagnosed by PDPT were confirmed by nerve blocks. Diagnostic reliabilities were significantly higher in Type A and C patterns in LZJ and Type C in SIJ arthropathies, 64%, 80%, and 68.4%, respectively. For both LZJ and SIJ arthropathies, favorable outcome after radiofrequency (RF) neurotomies was similar to the rate of positive responses to diagnostic blocks in Type A to Type D, whereas the outcome was unpredictable in those with undetermined type (Type E). Considering the paucity of currently available diagnostic methods for LZJ and SIJ arthropathies, PDPT is useful in clinical decision-making as well as in predicting the treatment outcome.