Nine studies were included (n=208 patients). These included three RCTs (n=68 patients), one non-randomised controlled trial (n=20 patients) and five prospective case series (n=120 patients). Sample size ranged from eight to 36 patients. The authors stated that controlled studies were of moderate to high quality, with Delphi scores ranging from 5 to 9 out of 9 points on the Delphi scale.
Over all studies, percentage improvements with interventions ranged from 51 to 94% compared with baseline; Cohen’s d effect sizes ranged from 0.68 to 6.68, reflecting a strong effect.
Polidocanol (one RCT and one case series): The double-blind RCT (n=36 patients) reported no significant difference between prolotherapy and control in visual analogue scale (VAS) pain scores at three months. The case series (n=11 patients) reported a significant improvement in VAS pain scores at three and eight months compared to baseline.
Prolotherapy (two RCTs and one case series): Both the RCTs (n=32 patients) reported improvements in the intervention groups compared with saline treatment groups, but the difference was only statistically significant in the larger RCT (n=24 patients). The case series (n=20 patients) reported a significant improvement from baseline.
Autologous whole blood (three case series): All three case series (n=89 patients) reported statistically significant improvements from baseline.
Platelet-rich plasma (one non-randomised controlled trial): The controlled trial (n=20 patients) reported significantly greater improvements in the intervention compared to the control group.