Referred leg pain originating from the sacroiliac joint: 6-month outcomes from the prospective randomized controlled iMIA trial.

BACKGROUND: The first results from the randomized, controlled iFuse Implant System Minimally Invasive Arthrodesis (iMIA) trial showed that minimally invasive surgical management (MISM) of low back pain originating from the sacroiliac joint (SIJ) by placing transarticular triangular titanium implants reduced pain more effectively than conservative management (CM). We now conducted a separate analysis of the iMIA data to assess whether the referred leg pain (RLP) component of SIJ-associated pain may also be affected by MISM or CM. METHODS: Data from 101 patients, recruited between June 2013 and May 2015 at nine European spine care centers, were included. Forty-nine patients were randomized to CM and 51 patients to MISM. RLP was defined as pain below the gluteal fold and assessed using the visual analogue scale (VAS). Changes in RLP over 6 months were the primary endpoint. RESULTS: The prevalence of clinically significant RLP was 76.2 %. Over 6 months of follow-up, CM produced no significant change in RLP, which was 51.0 VAS points (interquartile range (IQR) 17.0-75.0) at baseline. In contrast, in the MISM cohort, we found a significant decrease in RLP from VAS 58.0 (IQR 24.5-80.0) at baseline to VAS 13.5 (IQR 0.0-39.3) after 6 months (p < 0.01). Improvement of RLP was associated only with the type of treatment (OR 5.04, p < 0.01), but not with patient age, sex, or different patterns of pain referral. CONCLUSIONS: Our analysis shows that RLP is a frequent phenomenon in patients with SIJ-associated pain. At 6 months of follow-up, MISM helped relieve RLP more effectively than CM. Clinical Trial Registration-URL: http://www.clinicaltrials.gov . Unique identifier: NCT01741025.

Risk Factors for Continued Opioid Use in Conservative Versus Surgical Management of Low Back Pain Originating From the Sacroiliac Joint.

STUDY DESIGN: Secondary analysis of data from a randomized controlled trial. OBJECTIVES: To identify risk factors for continued opioid use after conservative management (CM) or minimally invasive surgical management (MISM) of low back pain (LBP) originating from the sacroiliac joint. METHODS: Patients were randomized either to CM (n = 49) or MISM (n = 52). We documented opioid use, pain intensity (visual analogue scale [VAS]), Oswestry Disability Index (ODI), and the Zung depression score (Zung Self-Rating Depression Scale) at baseline and at months 3 and 6 after treatment initiation. RESULTS: Compared with opioid nonusers, opioid users at baseline had higher mean levels of disability (ODI 61.5, standard deviation [SD] 13.3 vs ODI 51.5, SD 12.8; P < .01) and higher depression scores (Zung 48.5, SD 8.5, vs Zung 42.2, SD 7.2; P < .01). At 6 months, opioid users had higher 6-month pain levels (VAS 60.4, SD 24.0, vs VAS 42.4, SD 28.2; P < .01), higher disability scores (ODI 50.5, SD 16.2, vs ODI 32.7, SD 19.3; P < .01) and higher depression scores (Zung 47.6, SD 8.0, vs Zung 38.8, SD 8.9; P < .01). Risk factors for continued opioid use at 6 months were patient age (odds ratio [OR] for age = 0.91; P = .02) and an increase in LBP (OR 1.08; P = .02) in the CM group and a lack of improvement in depression scores (OR 1.12; P = .03) in the MISM group. CONCLUSIONS: In our patient cohort, the risk of continued opioid use in the treatment of LBP increased not only with pain intensity but also with levels of depression during the course of treatment.