Intradiscal Injection of Autologous Platelet-Rich Plasma Releasate to Treat Discogenic Low Back Pain: A Preliminary Clinical Trial

Abstract

Study design: Preliminary clinical trial.

Purpose: To determine the safety and initial efficacy of intradiscal injection of autologous platelet-rich plasma (PRP) releasate in patients with discogenic low back pain.

Overview of literature: PRP, which is comprised of autologous growth factors and cytokines, has been widely used in the clinical setting for tissue regeneration and repair. PRP has been shown in vitro and in vivo to potentially stimulate intervertebral disc matrix metabolism.

Methods: Inclusion criteria for this study included chronic low back pain without leg pain for more than 3 months; one or more lumbar discs (L3/L4 to L5/S1) with evidence of degeneration, as indicated via magnetic resonance imaging (MRI); and at least one symptomatic disc, confirmed using standardized provocative discography. PRP releasate, isolated from clotted PRP, was injected into the center of the nucleus pulposus. Outcome measures included the use of a visual analog scale (VAS) and the Roland-Morris Disability Questionnaire (RDQ), as well as X-ray and MRI (T2-quantification).

Results: Data were analyzed from 14 patients (8 men and 6 women; mean age, 33.8 years). The average follow-up period was 10 months. Following treatment, no patient experienced adverse events or significant narrowing of disc height. The mean pain scores before treatment (VAS, 7.5±1.3; RDQ, 12.6±4.1) were significantly decreased at one month, and this was generally sustained throughout the observation period (6 months after treatment: VAS, 3.2±2.4, RDQ; 3.6±4.5 and 12 months: VAS, 2.9±2.8; RDQ, 2.8±3.9; p<0.01, respectively). The mean T2 values did not significantly change after treatment.

Conclusions: We demonstrated that intradiscal injection of autologous PRP releasate in patients with low back pain was safe, with no adverse events observed during follow-up. Future randomized controlled clinical studies should be performed to systematically evaluate the effects of this therapy.

Keywords: Clinical trial; Intervertebral disc degeneration; Low back pain; Platelet-rich plasma.

Conflict of interest statement

Conflict of Interest: No potential conflict of interest relevant to this article was reported.

Figures

Fig. 1. Preparation of platelet-rich plasma (PRP) releasate. (A) Following the two-stage centrifugation of whole blood, PRP (asterisk) was transferred to a storage bag using a sterile blood collection bag system. (B) A mixture of autologous serum and 2% CaCl2 was added to PRP for clot (gel) formation (arrow).

Fig. 2. Lumbar radiograph (A, anteroposterior view; B, lateral view) at the injection site of platelet-rich plasma releasate. Under fluoroscopy, a spinal needle was inserted into the center of the targeted disc (L4/L5).

Fig. 3. Visual analog scale (VAS) scores of individual patients (A) and mean VAS scores (B) before and after intradiscal injection of platelet-rich plasma (PRP) releasate.

Fig. 4. Roland-Morris disability questionnaire (RDQ) scores of individual patients (A) and mean RDQ scores (B) before and after intradiscal injection of platelet-rich plasma (PRP) releasate.

Fig. 5. Representative lumbar radiographs before and after the intradiscal injection of platelet-rich plasma (PRP) releasate. Lumbar lateral radiographs of patient #06. Pre-treatment (A), two (B), four (C), six (D), eight (E), 10 (F), and 12 (G) months after injection of PRP releasate.

Fig. 6. Radiographic assessments. (A) Change in disc height. The % DHI of PRP releasate-injected discs and the control (L3/L4) discs had similar changes during the follow-up period. (B) Change in the angle of lumbar lordosis (L1-S angle). BL, baseline; DHI, disc height index; PRP, platelet-rich plasma.

Fig. 7. Quantitative magnetic resonance imaging T2 values. Representative sagittal T2 maps at baseline (A) and the early stage (B). There were no significant changes in normalized T2 values between those at baseline (BL) and follow-ups of both nucleus pulposus (C) and anulus fibrosus (D) tissues.