A study that compares between Open TLIF and Minimally invasive TLIF regarding patients' functional status(Oswestry Disability index)as a primary outcome measure.

The first randomized controlled trial comparing minimally invasive TLIF and open TLIF.

Inclusion Criteria:

• Adults more than 18 years of age and less than 65 years of age..
• Degenerative or isthmic spondylolithesis Grade 1,2 and 3.
• Recurrent Symptomatic recurrent lumbar disc prolapsed with or without evident neural compression.
• Single level pathology involving L2-3, L3-4, L4-5 and or L5-S1.
• Symptoms not responding to conservative treatment for at least 3 months.

Exclusion Criteria:

• Previous spinal fusion or instrumentation.
• Spinal tumours, infection and fractures.
• Patients with severe osteoporosis
• BMI more than 35.
• Non-ambulant patients and patients with severe preoperative neurological affection (Cauda Equina Syndrome)
• Patients not willing to participate in the study