Table 1.

Characteristics of the Included Studies

Publication Year	Design	Included Patients (n)	Disease Duration, Months	PRP Protocol	Outcome Assessment Time
Levi et al,2 2016	Prospective observational study	22	90 (median) 26–120 (IQR)	Spin for 14 minutes, 0.5–1.5mL per disc	Pre-treatment, 1, 2, and 6 months after treatment
Tuakli-Wosronu et al,4 2016	Randomized controlled trial	Treatment group:control group (29:18)	All patients ≥6	1–2mL per disc	Pre-treatment, 1 week, 1 and 2 months after treatment
Jain et al,1 2020	Prospective observational study	20	All patients > 6	2000 RPM for 12 minutes + 2400 RPM for 6 minutes, 1–2mL per disc	Pre-treatment, 3 and 6 months after treatment