Caudal epidural injection for L4-5 versus L5-S1 disc prolapse: is there any difference in the outcome?

One hundred seventy-seven patients with radicular pain due to disc prolapse treated with caudal epidural injection were included in our study. All the injections were carried out between January 2000 and December 2004. Inclusion criteria include symptomatic disc prolapse diagnosed with magnetic resonance imaging scan, disc prolapse of 1 level only either L4-5 or L5-S1, leg pain for more than 4 wk and age more than 18. Exclusion criteria include multiple disc levels, spondylolithesis, spinal stenosis, cauda equina, and progressive neurologic deficits. Outcome Measures include Oswestry score and patient satisfaction and final outcome patient satisfaction either excellent (complete pain relief), good (minimal symptoms), moderate (some symptoms), no relief (symptoms unchanged), and worse (symptoms deteriorated). The final outcome is excellent (more than 6 mo pain relief), very good (3 to 6 mo pain relief), good (6 wk to 3 mo pain relief), fair (4 to 6 wk pain relief), brief (less than 4 wk pain relief), and no relief postal questionnaire sent and telephone interview done with the nonresponders. Ninety-six answered the postal questionnaire and this number increased to 136 after telephone interview. Forty-nine percent females and 51% males. Eighty-nine with L5-S1 disc prolapse and 47 with L4-5 disc prolapse. Caudal epidural not only relieve leg pain but also relieve back pain. There is no significant difference in the Oswestry disability index nor in the patient satisfaction nor the final outcome after caudal epidural injections for patients with disc prolapse L5-S1 and L4-5 ones. The number of patients who required surgery were much less than the literature figures 3.05%. There is no significant difference in the response after caudal epidural injection considering the sex only. The longest the back pain before injection is associated with the worst Oswestry disability index.