\- To compare the clinical outcomes of bilateral straight cages and unilateral banana cage insertion in lumbar interbody fusion surgery, assess radiological outcomes, including intervertebral disc height, lumbar lordosis angle, and radiographic evidence of fusion, evaluate the rate of complications, such as cage migration, subsidence, pseudoarthrosis, and adjacent segment degeneration and analyze differences in operative time, blood loss, and length of hospital stay between the two techniques
• Symptomatic discogenic low back pain with Radiological evidence of disc degeneration, instability, or spondylolisthesis
Failed medical treatment > 6 months
• Patients unfit for surgery .
Active spinal infection ,Osteoporosis