Background: Discogenic, facet joint, and sacroiliac joint mediated axial low back pain may
be associated with overlapping pain referral patterns into the lower limb. Differences between
pain referral patterns for these three structures have not been systematically investigated.
Objective: To examine the individual and combined relationship of age, hip/girdle pain, leg
pain, and thigh pain and the source of internal disc disruption (IDD), facet joint pain (FJP), or
sacroiliac joint pain (SIJP) in consecutive chronic low back pain (CLBP) patients.
Design: Retrospective chart review.
Setting: Community based interventional spine practice.
Patients: 378 cases from 358 consecutive patients were reviewed and 157 independent
cases from 153 patients who underwent definitive diagnostic injections were analyzed.
Methods: Charts of consecutive low back pain patients who underwent definitive diagnostic
spinal procedures were retrospectively reviewed. Patients underwent provocation lumbar
discography, dual diagnostic medial branch blocks, or intra-articular diagnostic sacroiliac
joint injections based on clinical presentation. Some subjects underwent multiple diagnostic
injections until the source of their chronic low back pain (CLBP) was identified.
Main Outcome Measurements: Based on the results of diagnostic injections, subjects
were classified as having IDD, FJP, SIJP, or other. The mean age/standard deviation and the
count/percentage of patients reporting hip girdle pain, leg pain, or thigh pain were estimated
for each diagnostic group and compared statistically among the IDD, FJP, SIJP, and other source
groups. Next, the 4 predictor variables were simultaneously modeled with a single multinomial
logistic regression model to explore the adjusted relationship between the predictors and the
source of CLBP.
Results: The mean age was significantly different among the source groups. IDD cases were
significantly younger than FJP, SIJP, and other source groups and FJP cases were significantly
younger than other sources. The age by thigh pain interaction effect was statistically significant
(P = 0.021), indicating that the effect of age on the source of CLBP depends on thigh pain, and
similarly, that the effect of thigh pain on the source of CLBP depends on age.
Limitations: Retrospective study design.
Conclusions: The presence or absence of thigh pain possesses a significant correlation
on the source of CLBP for varying ages, whereas the presence of hip/girdle pain or leg
pain did not significantly discriminate among IDD, FJP, or SIJP as the etiology of CLBP.
Younger age was predictive of IDD regardless of the presence or absence of thigh pain.
Key words: low back pain, intervertebral disc, zygapophyseal joint, sacroiliac joint, pain
referral patterns
Use of Ultrasound-Guided Platelet-Rich Plasma Injection of the Sacroiliac Joint as a Treatment for Chronic Low Back Pain