Efficacy of Platelet-Rich Plasma in Retarding Intervertebral Disc Degeneration: A Meta-Analysis of Animal Studies.

Objectives. Several animal studies have demonstrated the positive effects of platelet-rich plasma (PRP) on disc degeneration retardation. The presentmeta-analysis was to verify the efficacy of PRP in retarding disc degeneration in animal. Methods. Relevant studies were identified and evaluated according to our inclusion and exclusion criteria. The standardized mean difference (SMD) and related 95% confidence interval (95% CI) were estimated to assess PRP efficiency. Results. In total, eleven studies were included in this meta-analysis. Significant differences were found in the PRP treatment group, which showed increased disc height (SMD = 2.66, 95% CI: 1.86, 3.47, p = 0.000), increased MRI T2 signal intensity (SMD = -3.29, 95% CI: -4.44, -2.13, p = 0.000), and decreased histological degeneration grade (SMD = -4.28, 95% CI: -5.26, -3.30,.. = 0.000). However, no significant increase in collagen II expression was found (SMD = 25389.74, 95% CI: -27585.72, 78365.21, p = 0.348). Apart from the subgroup analysis of the disc height based on animal species (pig) and disc degenerationmodel (chymopapain induction), other subgroup analysis based on animal species (rabbit and rat), study design, disc degeneration model, and follow-up period demonstrated that PRP treatment can significantly restore disc height and increase MRI T2 signal intensity. Conclusions. PRP treatment is potentially effective in restoring disc height of rodent rabbit and rat, reducing histological degeneration grade, and increasing MRI T2 image signal. PRP injection may be promising therapy for retarding disc degeneration.