Multivariable analyses of the relationships between age, gender, and body mass index and the source of chronic low back pain.

OBJECTIVE: To examine the combined relationships between age, gender, and body mass index (BMI) and the specific source of chronic low back pain. DESIGN: Retrospective chart review. SETTING: University spine center. PATIENTS: Charts from 378 cases from 358 consecutive patients were reviewed and 157 independent cases from 153 patients who underwent definitive diagnostic injections were analyzed. INTERVENTIONS: Discography, dual diagnostic facet joint blocks, sacroiliac joint injections, anesthetic interspinous ligaments/opposing spinous processes/posterior fusion hardware injections, percutaneous augmentation. OUTCOME MEASURES: Chronic low back pain source was the primary outcome variable. Predictor variables included age at initial presentation, gender, and BMI. RESULTS: Age, gender, and BMI were each significantly associated with the source of chronic low back pain, after controlling for the effects of each other. Increases in age were associated with significant decreases in the odds of internal disc disruption (IDD) vs facet joint pain (FJP), sacroiliac joint pain (SIJP), and other sources and decreases in the odds of FJP and SIJP vs other sources. Being female was associated with significant increases in the odds of SIJP vs IDD, FJP, and other sources. Increased BMI was associated with significant increases in the odds of FJP vs SIJP. CONCLUSIONS: These findings suggest a significant relationship among gender, age, and BMI and structural causes of chronic low back pain. Lumbar IDD is more prevalent in young males while FJP is more prevalent in females with increased BMI. Female gender and low BMI are associated with SIJP.

What is the source of chronic low back pain and does age play a role?

OBJECTIVE: The objective of this study was to estimate the prevalence, mean age, and association of prevalence and age of lumbar internal disc disruption (IDD), facet joint pain (FJP), sacroiliac joint pain (SIJP), spinal and pelvic insufficiency fractures, interspinous ligament injury/Baastrup's Disease, and soft tissue irritation by fusion hardware. DESIGN: The study's design was a retrospective chart review. SETTING: The study was set in an academic spine center. PATIENTS: A total of 378 cases from 358 patients were reviewed of which 170 cases from 156 patients who underwent diagnostic procedures were included. INTERVENTIONS: Discography, dual diagnostic facet joint blocks, intra-articular sacroiliac joint injections, anesthetic injections of painful interspinous ligaments/opposing spinous processes/posterior fusion hardware, or percutaneous augmentation were performed. OUTCOME MEASURES: Prevalence and age were analyzed for each diagnosis group. METHODS: Patients with recalcitrant low back pain underwent diagnostic procedures based on their clinical presentation until the pain source was identified. RESULTS: The prevalence of internal disc disruption, facet joint pain and sacroiliac joint pain was 42%, 31%, and 18%, respectively. Patients with internal disc disruption were significantly younger than those with facet joint pain or sacroiliac joint pain. Increased age was associated with a decreased probability of internal disc disruption and increased probabilities of facet joint pain and sacroiliac joint pain as the source of low back pain until approximately age 70. CONCLUSION: Our data confirm the intervertebral disc as the most common etiology of chronic low back pain in adults. Based on our sample, the younger the patient, the more likely low back pain is discogenic in origin. Facetogenic or sacroiliac joint pain is more likely in older patients.

Structural etiology of chronic low back pain due to motor vehicle collision.

OBJECTIVE: To estimate prevalence rates of discogenic, facet, and sacroiliac joint pain, and describe clinical features of chronic low back pain patients whose symptoms were initiated by motor vehicle collisions. DESIGN: Retrospective chart review. SETTING: Academic spine center. PATIENTS: Twenty-seven motor vehicle collision-induced chronic low back pain patients were included after undergoing diagnostic procedures. INTERVENTIONS: Lumbar provocation discography, dual diagnostic facet joint blocks, and intra-articular sacroiliac joint injections. METHODS: Enrolled patients underwent diagnostic procedures based on clinical presentation until the pain source was identified. The prevalence of each source of low back pain was estimated. Clinical, categorical, and continuous characteristics within the source groups were calculated with SAS v.9.2 (SAS Institute Inc., Cary, NC). OUTCOME MEASURES: Etiology and prevalence were analyzed for each diagnosis group. RESULTS: Of the 27 patients, 15/27 (56%) were diagnosed with discogenic pain, 7/27 (26%) with sacroiliac joint pain, and 5/27 (19%) with facet joint pain. Seventy-eight percent were female. Mean age was 42.5 years (standard deviation = 10.4) with median duration of symptoms of 24 months (interquartile range = 6-48). CONCLUSIONS: Our study is the first to demonstrate that diagnostic spinal injections can identify particular spinal structures, namely the intervertebral disc, facet joint, and sacroiliac joint, as the specific source of chronic low back pain due to inciting motor vehicle collisions. The most common source of motor vehicle collision-induced chronic low back pain appears to be the disc followed by the sacroiliac and facet joints.

Etiology of chronic low back pain in patients having undergone lumbar fusion.

OBJECTIVE: To estimate the prevalence of lumbar internal disc disruption, zygapohyseal joint pain, sacroiliac joint pain, and soft tissue irritation by fusion hardware in post-fusion low back pain patients compared with non-fused patients utilizing diagnostic spinal procedures. DESIGN: Retrospective chart review. SETTING: University spine center. PATIENT SAMPLE: Patients presenting to a community-based, multidisciplinary, academic spine center (65.9% female, mean age 54.4 years, median pain duration 12 months). INTERVENTIONS: Charts of consecutive low back pain cases completing diagnostic spinal procedures including provocation discography and zygapohyseal joint, sacroiliac joint, and fusion hardware blockade were retrospectively reviewed. OUTCOME MEASURES: Based on the results of discography and/or diagnostic blockades, subjects were classified with internal disc disruption, zygapohyseal joint pain, sacroiliac joint pain, or fusion hardware related pain. RESULTS: The diagnoses of 28 fusion cases identified from 170 low back pain patients undergoing diagnostic procedures included 12 with sacroiliac joint pain, seven with internal disc disruption, five with zygapohyseal joint pain, and four due to soft tissue irritation from fusion hardware. No significant differences were noted in zygapohyseal joint mediated pain with and without fusion history. Mean ages of patients were similar with and without fusion history for cases diagnosed as internal disc disruption. CONCLUSION: In patients' recalcitrant to non-interventional care, the sacroiliac joint is the most likely source of low back pain after lumbar fusion followed by internal disc disruption, zygapohyseal joint pain, and soft tissue irritation due to fusion hardware. Sacroiliac joint pain is more common after fusion, while internal disc disruption is more common in non-fusion patients.

Multivariable analysis of the relationship between pain referral patterns and the source of chronic low back pain.

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.

Is the history of a surgical discectomy related to the source of chronic low back pain?

BACKGROUND: Recurrent or persistent low back pain (LBP) after surgical discectomy (SD) for intervertebral disc herniation has been well documented. The source of low back pain in these patients has not been examined. OBJECTIVE: To compare the distribution of the source of chronic LBP between patients with and without a history of SD. STUDY DESIGN: Retrospective chart review. SETTING: Academic spine center. PATIENTS: Charts from 358 consecutive patients were reviewed. Charts noting the absence/presence of SD in patients who subsequently underwent diagnostic injections to determine the source of chronic LBP were included resulting in 158 unique cases for analysis. METHODS: Patients underwent either dual diagnostic facet joint blocks, intra-articular diagnostic sacroiliac joint injections, provocation lumbar discography, or anesthetic injection into putatively painful interspinous ligaments/opposing spinous processes/posterior fusion hardware. If the initial diagnostic procedure was negative, the next most likely structure in the diagnostic algorithm was interrogated. Subsequent diagnostic procedures were not performed after the source of chronic LBP was identified. OUTCOME: The source of chronic LBP was diagnosed as discogenic pain (DP), facet joint pain (FJP), sacroiliac joint pain (SIJP), or other sources of chronic LBP. RESULTS: Based on a Fisher's exact test, there was marginal evidence the distribution of the source of chronic LBP differed for those with and without a history of SD (P = 0.080). Post-hoc comparisons suggested that patients with a history of SD have a higher probability of DP compared to those without a history of SD (82% versus 41%; P = 0.011). Differences in the probability of FJP, SIJP, or other sources between the SD history groups were not significant. LIMITATIONS: Small sample size, restrospective design, and possible false-positive results. CONCLUSIONS: This is the first published investigation of the tissue source of chronic LBP after SD. It appears that DP is the most common reason for chronic LBP after SD. If more rigorous study confirms our findings, future biologic treatments may hold value in repairing symptomatic annular fissures after SD.

Does the location of low back pain predict its source?

OBJECTIVE: To evaluate the predictive utility of the pattern of low back pain (LBP) in detecting the source of LBP as internal disk disruption (IDD), facet joint pain (FJP), or sacroiliac joint pain (SIJP). DESIGN: Retrospective chart review. SETTING: University spine center. PATIENT SAMPLE: A total of 170 cases from 156 patients presenting with LBP whose low back disorder was definitively diagnosed. The mean age was 54.4 years (SD, 16.2) and median duration of LBP was 12 months (interquartile ranges, 6-32). METHODS: Charts of consecutive LBP patients who underwent definitive diagnostic spinal procedures including provocation diskography, facet joint blocks, and sacroiliac joint blocks were retrospectively reviewed. Each patient with LBP was queried as to the exact location of their LBP: midline, defined as in-line with the spinous processes, and/or paramidline, defined as lateral to 1 fingerbreadth adjacent to the midline. OUTCOME MEASURES: In patients with a definitive diagnosis for the source of LBP, the proportion of each diagnosed source of pain was calculated. χ(2) tests were used to identify differences in the percentages of midline and paramidline LBP among the groups of patients testing positive for IDD, FJP, or SIJP. Diagnostic measures of sensitivity, specificity, positive and negative predictive values, diagnostic accuracy, and likelihood ratios of positive and negative tests using the presence/absence of midline and paramidline pain for the diagnosis of IDD, FJP, and SIJP were estimated. RESULTS: With cases of IDD, significantly greater percentages of patients reported midline LBP (95.8%; χ(2) = 101.4, df = 2, P < .0001) as compared with cases of FJP (15.4%) or SIJP (12.9%). In cases of IDD, significantly lower percentages of patients reported paramidline pain (67.3%; χ(2) = 16.1, df = 2, P = .0003) as compared with cases of FJP (95.0%) or SIJ (96.0%). In cases of IDD, significantly greater percentages of patients reported midline LBP (95.8%; χ(2) = 101.4, df = 2, P < .0001) as compared with cases of FJP (15.4%) or SIJP (12.9%). The specificity of midline LBP for IDD, FJP, and SIJP was 74.8% (95% CI = 65.0%-82.9%), 28.0% (20.1%-37.0%), and 36.0% (28.0%-44.5%), respectively. The negative predictive value of paramidline LBP for IDD, FJP, and SIJP was 29.2% (95% CI = 12.6%-51.1%), 91.7% (73.0%-99.0%), and 95.8% (78.9%-99.9%). The diagnostic accuracy of midline LBP for IDD, FJP, and SIJP was 83.5%, 24.1%, and 31.8%, respectively. CONCLUSIONS: The presence of midline LBP increases the probability of lumbar IDD and reduces the probability of symptomatic FJ and SIJ dysfunction. The presence of isolated paramidline LBP increases the probability of symptomatic FJ or SIJ but mildly reduces the likelihood of lumbar IDD.