Fig. 4

Magnetic resonance imaging (MRI) grading scores. MRI was performed 16 weeks after condoliase injection and 12 weeks after saline and platelet-rich plasma (PRP)-releasate injections. a Representative sagittal images of MRI. b MRI grading scores using the modified Pfirrmann grading system [20]. Data are presented as mean ± standard error of the mean (SEM). Non-injection control, n = 11 discs; saline, n = 11 discs; PRPr, n = 11 discs. **P < 0.01