Platelet Rich Plasma (PRP) for Facet Mediated Lumbar Low Back Pain

This randomized controlled trial will determine the efficacy of platelet rich plasma vs. Control/Placebo. 170 healthy, physically active individuals with facet mediated lumbar low back pain will be recruited to participate in the study. Part of the formal screening procedures, consented participants will undergo a fluoroscopic guided diagnostic lumbar medial branch block (MBB) within 60 days after consent. The results of the diagnostic MBB will determine if they meet final eligibility criteria (facetogenic pathology) and should continue on with the therapeutic injection. In the rare case that there is a positive MBB within the past three months, then it will not be repeated. To clarify, the diagnostic MBB will determine if the procedure will be beneficial to the participant by confirming they have facet-mediated low back pain and that the experimental procedure may benefit them. This avoids participants continuing in the study who would not benefit from the PRP injection.

Participants will be asked to complete a standard pain diary following the lumbar MBB procedure. Participants who experience a positive test result from the MBB (as indicated by a reduction of ≥50% in pain symptoms using the 8 hour pain diary) will be eligible to proceed with the study. Following the stated inclusion/exclusion criteria, participants who do not experience a positive test result (indicate a reduction < 50% in pain symptoms) will be formally withdrawn from the study at this point and will resume normal care with their referring physician to explore their best treatment option(s).

Any female participant of child-bearing age will also be required to have a urine hCG test performed prior to the diagnostic or therapeutic injection being performed. If the urine hCG indicates the participant is pregnant, per stated inclusion/exclusion criteria, they will be formally withdrawn from the study at this point and will resume normal care with their referring provider.

Participants who meet final eligibility criteria (positive lumbar MBB and, if applicable, negative pregnancy test) will be randomized to a study arm within one week of the MBB. A computer-generated randomization program prepared by the study biostatistician will be used to assign participants 1:1 across both study arms (PRP vs. Control/Placebo).

The target area for either the PRP or saline injection will be the intra-articular facet joint. During this time, adequate amount of peripheral blood will be drawn by a clinic nurse; either 30ml if injecting single side, or 60ml will be drawn if injecting both sides. PRP mixture will be prepared using a point of care centrifuge system. Participants in the PRP group will receive 1 ml of PRP mixture for each facet joint. Participants in the control/placebo group will receive 1 ml of normal saline for each facet joint.

In order to facilitate blinding, both groups will have at least 30ml of blood drawn on the same day as the injection (PRP or saline). The blood drawn from participants in the control group will be safely discarded per standard protocols. For the PRP group, a small sample will be processed by point of care cell counter located within the Pain Clinic to establish baseline platelet, white blood cell, and hemoglobin level and hematocrit of the peripheral blood. In addition, a small sample of the actual prepared PRP solution will be processed to check for concentrated platelet, white blood cell and hemoglobin level.

All participants will be instructed to avoid other invasive treatments (including acupuncture) while participating in this study. In order to prevent a potential blunting-effect of the PRP treatment, participants will also be instructed to avoid non-emergent use of NSAIDs for treating typical pain symptoms for at least the first 3-months following the study intervention/injection to help the patient accurately reflect their perception of pain. NSAIDs may reduce the effectiveness of PRP. If a participant needs additional analgesia, acetaminophen is the preferred agent. Concomitant medications will be recorded at each follow up visit. If necessary, participants will received pain medication that is provided as SOC post-procedure.

Patients will be given appropriate temporary profile (if active duty) to protect them from aggravating activities (such as airborne operation, ruck marches, formation running for at least 3 months after the injection. All patients will be ask to enroll in pre and post procedure physical therapy sessions for body mechanics training/rehabilitative protocol, for total of up to 8 sessions during the study period. Participants will be evaluated by experienced physical therapist specializing in chronic pain. The pre-procedure rehabilitation will occur within a week prior to the procedure. The 1st post-procedure rehabilitation visit will take place within 10-14 days of the procedure, with encouragement to begin the home exercise program within 48-72 hours post-procedure. Additionally, all participants will be offered optional rehabilitative and/or complementary techniques available as standard of care such as aquatics, yoga, biofeedback, and pain psychology support, based on availability and as SOC.

The day of the treatment/injection will be considered study time point 0. Participants will return to clinic for follow up visits at 1 month (+/- 7 days), 3 months (+/- 14 days), 6 months (+/- 14 days) postinjection for PRP participants. Control participants will be given the option to received PRP treatment at the 3-month visit (more below). If participants opt for the injection, they will also come for a visit at 3 months (+/- 14 days) and 6 months (+/- 14 days) post-PRP injection. If they do not opt for the PRP injection, they will come 6-month (+/- 14 days) post-saline injection. At each follow-up visit, participants will undergo a standard physical examination by the provider who did not do the procedure (i.e. the AI or PI within the pain clinic) and the participant will assess current pain and functional level using the Numeric Pain Rating Scale (NRS-Pain) and the Defense Veteran Pain Rating Scale (DVPRS) Supplemental Questions.

Participants will also complete the Oswestry Disability Index (ODI), Global Rate of Change (GROC), PROMIS Pain Interference, Anxiety, Depression, Fatigue, Sleep Disturbance, Ability to participate in Social Roles and Activities, and the Work Productivity and Activity Impairment Questionnaire for Low Back Pain (WPAI:LBP). At each follow up visit, participants will be evaluated for adverse events and any additional treatment, therapy, and concomitant medications will be documented.

Study Blinding:

Participants will be blinded to assigned treatment arm (i.e. saline vs. PRP) until 3 months post-injection. Blinding will be revealed to participants at the end of their 3 month post-injection follow up visit after they complete all required follow up questionnaires. At this time, participants assigned to the control (saline injection) arm will be offered the option to receive PRP injections. Control participants who elect to receive PRP injections will remain in the study and will continue follow up with the research team until 6-months post PRP injection. Control participants that do not opt to receive PRP-injection at the 3- months post-saline injection, will remain in the study until 6 months post saline-injection.

Control participants who are not interested in receiving PRP injections and that would like to be treated with additional medical management (i.e. radiofrequency ablation) will resume normal care with their attending physician who will guide additional treatment options. Participants electing not to receive PRP will still be evaluated at 6-months post-injection visit.