Objectives: To evaluate the efficacy of caudal ultrasound guided PrP injections in patients with epidural fibrosis after emi-laminectomy (FBSS).

Study design: Observational study

Methods: 15 patients with lumbar fibrosis after emilaminectomy for lumbar decompression or microdiscectomy that had previously been treated with epidural steroids injections (more than 1 month before) were treated with caudal epidural PrP injection. The PrP was isolated by 20 ml of autologous blood and the purified part (10 ml) was injected via caudal hiatus using a 20G Thuoy needle with ultrasound guidance. NRS and Oswestry Disability Index (ODI) were registered before the treatment (T0) and after 2 days (T1), 7 days (T2), 1 month (T3), 3 months (T4)  and 6 months (T5).

Results: A statistically significant improvement was found in NRS and ODI values during the period of study, with a good decrease in Pain that started immediately (T1 values after 2 days were decreased compared with T0, mean NRS value at T0 were 6,1 (+/- 2,1) and  ODI value was 30 (+/- 11: mean NRS value at T1 was 3,2 (+/- 1,1) and  ODI value was 20 (+/- 9) and lasted for 3 months. The values at 6 months showed a slight decrease in the efficacy of the treatment (mean NRS value at T5 were 5,4 (+/- 1,7) and ODI value was 28 (+/-8)

Conclusion: The result of Ultrasound Guided PrP injections via caudal hiatus in patients with fibrosis after emi-laminectomy were good in terms of pain relief. The efficacy of the injection was observed after few hours and lasted for 3 months. Probably it could be a good option to program one treatment every 3 months in the first period.