Low back pain is very common problem, variable modalities have been introduced to control such problem. One of the emerging modalities is the ozone - oxygen (O2-O3 ) mixture that could reduce the herniation disk size and inflammation.

Intervertebral disc herniation is the most common problem which induces low back pain LBP. The number of patients seek surgical and or alternative therapy increases. The rate of re-operation is between 7-9% at 2 years and increases up to 10-25% at ten years postoperative.

Epidural injections with local anesthetics and steroids are one of the most commonly used interventions in managing chronic low back pain and lower extremity pain of various causes. However, despite their extensive use, debate continues on this medications effectiveness due to the lack of well-designed, randomized, controlled studies to determine the effectiveness of epidural injections in general, and caudal epidural injections in particular.

Ozone in mixture with oxygen has been justified in multiple studies have been done, this study aims to evaluate variable doses of this mix upon patient satisfaction, pain alleviation over 12 month follow up period .

Inclusion Criteria:

• All patients Suffered radicular leg pain and some reported additional back pain.
• All patients are non-responsive to conservative treatment modalities with VAS more than 7.

Exclusion criteria

• presence of bleeding disorder
• local infection
• uncontrolled or degenerative spine disease
• pregnancy
• multilevel disk involvement
• patient refusal.