OBJECTIVE: To determine whether single injections of autologous platelet-rich plasma (PRP) into symptomatic degenerative intervertebral disks will improve participant-reported pain and function. DESIGN: Prospective, double-blind, randomized controlled study. SETTING: Outpatient physiatric spine practice. PARTICIPANTS: Adults with chronic (≥6 months), moderate-to-severe lumbar diskogenic pain that was unresponsive to conservative treatment. METHODS: Participants were randomized to receive intradiskal PRP or contrast agent after provocative diskography. Data on pain, physical function, and participant satisfaction were collected at 1 week, 4 weeks, 8 weeks, 6 months, and 1 year. Participants in the control group who did not improve at 8 weeks were offered the option to receive PRP and subsequently followed. MAIN OUTCOME MEASURES: Functional Rating Index (FRI), Numeric Rating Scale (NRS) for pain, the pain and physical function domains of the 36-item Short Form Health Survey, and the modified North American Spine Society (NASS) Outcome Questionnaire were used. RESULTS: Forty-seven participants (29 in the treatment group, 18 in the control group) were analyzed by an independent observer with a 92% follow-up rate. Over 8 weeks of follow-up, there were statistically significant improvements in participants who received intradiskal PRP with regards to pain (NRS Best Pain) (P = .02), function (FRI) (P = .03), and patient satisfaction (NASS Outcome Questionnaire) (P = .01) compared with controls. No adverse events of disk space infection, neurologic injury, or progressive herniation were reported following the injection of PRP. CONCLUSION: Participants who received intradiskal PRP showed significant improvements in FRI, NRS Best Pain, and NASS patient satisfaction scores over 8 weeks compared with controls. Those who received PRP maintained significant improvements in FRI scores through at least 1 year of follow-up. Although these results are promising, further studies are needed to define the subset of participants most likely to respond to biologic intradiskal treatment and the ideal cellular characteristics of the intradiskal PRP injectate.
