Background: The management of radicular pain due to lumbar or sacral nerve root compromise remains controversial.

Caudal epidural steroid injections are widely employed although there is little hard evidence to confirm their efficacy. This empirical treatment still remains a matter of personal choice and experience.

Objectives: To investigate the clinical effectiveness of caudal epidural steroid injections (CESIs) in the treatment of sciatica and to identify potential predictors (clinical subgroups) of response to CESIs.

Main outcome measures: The primary outcome measure was the Oswestry Disability Questionnaire (ODQ). The Visual analogue score (VAS) and the Hospital Anxiety and Depression Scores (HADS) were also employed in all cases to measure pain relief, physical and psychological function.

Method: Prospective study. All patients with corresponding radicular pain received a course of three caudal epidural steroid injections, two weeks apart.

A standard mixture of 80 mgs of triamcinalone plus 7 mls of 1% lignocaine plus 5 mls of 0.9% saline used for all patients.

All patients reviewed at 3 months interval in a dedicated epidural follow up clinic.

The epidural database included age, BMI, duration of symptoms, smoking, employment status and source of referral, any pending litigation, i.e., work or accident related, MRI results, diagnosis and complications.

VAS scores documented both axial and limb pain for actual and comparative analysis. ODI and HADS were recorded prior to treatment and at three months follow up.

Overall patient satisfaction was recorded on a scale of 0–10 and complications noted.

Results: In the largest single series to date, we report on 628 consecutive patients, with 3 months follow up.

58 % were females, 24% smoked and 4.1% had ongoing litigation due to their pain.

The mean age was 56yrs with BMI ranging from 17 to 50 (mean=28).

7 (1%) patients required subsequent surgical intervention due to disc herniation.

BMI did not affect the outcome.

Mean VAS for axial pain reduced from 5.859 to 2.59 at three months.

Mean VAS for limb pain similarily reduced from 6.23 to 2.53.

Mean ODI reduced from 45.49 at first visit to 21.98 at 3 months.

Mean HADS also improved from 17 to 7.

Following treatment, overall Patient satisfaction ranged from 0–10 with mean of 5.4.

Conclusion: Significant improvement in both axial and limb pain in the short and intermediate terms was achieved facilitating onward referral for physical therapy, which is fundamental in optimising outcomes.

Long term follow-up is underway.

Subgroups predicting poor outcome are identified.

Positive primary care feedback encourages further recruitment.