An evaluation of the effectiveness of platelet rich plasma epidural injections for low back pain suspected to be of disc origin - A pilot study with one-year follow-up.

Summary of background data: Low back pain of disc origin is common yet challenging to treat. Intradiscal platelet rich plasma (PRP) has been advocated, but is associated with risk of discitis. Epidural PRP is less invasive and avoids this risk. Few studies exist evaluating effectiveness and safety of epidural PRP for discogenic low back pain without radiculopathy and the follow-up of the studies tends to be short. Objective: Prospectively evaluate for 12 months the effectiveness of PRP epidural injections for patients with low back pain without radiculopathy, suspected to be of disc origin. Methods: 11 consecutive patients with refractory low back pain suspected to be of disc origin (compatible clinical assessment; negative lumbosacral medial branch blocks (MBBs) and/or magnetic resonance imaging (MRI) with high intensity zone (HIZ), Modic 1 or 2 changes) participated. Each underwent one (n = 5) or two (n = 6) epidural injections (caudal or interlaminar). The PRP was leukocyte/red cell depleted with an average platelet concentration of ∼2X whole blood. Numerical rating scale (NRS), Pain Disability Quality-Of-Life Questionnaire (PDQQ) score, Oswestry Disability Index (ODI) score, effect on analgesic intake, treatment satisfaction and endorsement were recorded prior to and at 3, 6 and 12-months post-treatment. Results: Significant improvements in pain and disability were documented post-treatment. Pre-, 3, 6, and 12-month post mean(sd) NRS scores were 7.8(1.8), 5.8(2.7), 5.1(2.5), 4.9(2.8) respectively (F = 7.2; p = 0.002). At 12 months post PRP epidural, the mean improvement in NRS was 36%, 36% had experienced ≥50% pain relief (95% confidence interval (CI): 2%, 70%), and 73% achieved minimal clinically important differences (MCID) (95% CI: 41%, 100%). Similar magnitude improvements in disability (PDQQ and ODI) were documented. At 1-year post, 50% of analgesic users had reduced intake, 91% were satisfied with the treatment and would recommend the procedure to family and friends. No complications were reported. Discussions/conclusion: This pilot project suggests that PRP epidural injections provide modest yet significant improvements in pain and disability that lasts at least 12 months in patients with low back pain suspected to be of disc origin. Additional research including larger sample size and robust study design is encouraged.