The clinical efficacy of platelet-rich plasma therapy for back pain: A systematic review and meta-analysis   

Objective: 

Low back pain (LBP) is one of the most common sources of chronic pain for all ages and socioeconomic strata [1]. LBP is the leading cause of activity limitation, work absence, and the highest percentage of primary care visits and referrals to physical therapy[2-4]. Platelet-rich plasma (PRP) has shown promising results as a biological agent to repair ligaments, cartilage, and tendons [5]. In this meta-analysis, we aimed to evaluate the clinical efficacy of PRP injections for back pain.

Methods: 

We thoroughly screened Embase and Web of Science for English papers that utilized PRP in back pain. Our inclusion criteria were strict, focusing on prospective randomized controlled trials of patients older than 18 years with vertebrogenic or discogenic pain. Since the use of PRP in chronic pain is an emerging and novel method, we included all indications and sites of injections for chronic back pain in both groups and steroid, local anesthesia, or contrast agent for the contrast group. Statistical analysis was performed using R software version R-4.3, with a P value < 0.05 considered statistically significant.   

 Results: 

This meta-analysis included six articles, resulting in 178 cases and 173 controls. Patients in the case group underwent intradiscal, transforaminal, or epidural autologous PRP injections for chronic back pain. Control patients underwent corticosteroid and/or local anesthesia injections or only contrast agent injections at the correlating injection site. Subjective pain report was evaluated with the Visual Analogue Score (VAS) or numerical pain scale at four weeks, three months, and six months. Disability score was reported with the Oswestry Disability Index (ODI) score at four weeks, three months, and six months.

After four weeks, PRP worsened the pain score with no statistically significant difference (MD=0.19, 95%CI [-0.3762; 0.7636], P=0.505). However, PRP improved the pain level with a statistically significant difference at three months for the same sample size of cases and control (MD= -0.4851, 95%CI [-0.7797; -0.1906], P=0.001). This improvement was not statistically significant after six months (MD=-0.0074, 95%CI [-1.3548; 1.3401], P=0.991), although follow-up after six months was reported in a smaller number of cases (N=129) and control (N=135). 

Disability scoring was reported for 104 cases and 110 controls. There was a significant worsening of disability following PRP injection at four weeks compared to the control group (MD=0.5316, 95%CI [0.0966; 0.9666], P=0.0166). After three months, PRP improved the disability, although there was no statistical significance (MD=-0.0836, 95%CI [-0.4421; 0.2749], P=0.647), same as follows up at six months (MD=-0.5821, 95%CI [-1.3328;  0.1685], P=0.128). 

Conclusion: 

After one month, PRP injection worsened the pain level and disability for back pain compared to the control group. However, after three months, PRP improved both pain level and disability compared to local corticosteroids and/or local anesthesia. More randomized-controlled clinical trials with longer follow-up periods are needed to investigate the clinical significance of PRP injection in back pain.