1. G Swamy, A Bishnoi, H Majeed, Z Klezl, D Calthorpe, R Bommireddy Royal Derby Hospital

2.  Caudal epidural steroid injections widely used for lumbo-sacral radicular pain.  No literature to investigate the use of caudal route in the presence of a sacral tarlov cyst. Purpose To investigate the clinical effectiveness of caudal epidural steroid injections in patients with an MRI proven sacral tarlov cyst.

3.  A Prospective case control study  All patients with MRI proven diagnosis  Course of three caudal epidural steroid injections  Patients reviewed at 3 months  Data-base to include demographics, diagnosis and complications. MAIN OUTCOME MEASURES 1. Oswestry Disability Index (ODI). 2.Visual analogue score (VAS) 3.Hospital Anxiety and Depression Scores (HADS)

4. 78 patients with 3 month follow up Sacral cyst group n=38 Control group n=40 Mean age was 56 years 58% females BMI from 17 to 44 4.1% had ongoing litigation 1 patient required surgery 3 patients had transient hypotension

5. Before injection [1]  Back: Mean = 5.895 Median = 6  Leg: Mean = 6.23 Median = 7 At 3 months [2]  Back: Mean = 2.59 Median = 0  Leg: Mean = 6.2.52 Median = 0

6. ODI HADS

7. In our study  The presence of a sacral tarlov cyst was not a contraindication for caudal epidural steroid injection  Comparable significant improvement in limb pain achieved in both groups  No major complications noted