The purpose of this study was to compare standard open laminectomy with ULBD approach in regard to efficiency, safety, and clinical outcome.

Lumbar stenosis is one of the common spinal pathologies; it presents with back pain, leg pain, and neurogenic claudication . Although different surgical modalities are available, the main objective of the operation is decompression of nerve roots and the spinal cord.

Minimally invasive surgical procedures and microsurgical unilateral laminotomy with bilateral spinal canal decompression (ULBD) have been reported to achieve this goal .

The objective of lumbar decompression is to decompress the neural elements while preserving stability and the spinous processes.

The object of this study is to compare outcomes following minimally invasive unilateral laminectomy for bilateral decompression (ULBD) to a standard "open" laminectomy for LSS.

Inclusion Criteria:

1. age:40-80 years
2. sex:both sexes
3. symptomatic LSS with radiculopathy , neurogenic claudication , or urinary dysfunction.
4. radiologically confirmed LSS , caused by degenerative changes
5. canal stenosis at a maximum of 2 levels

Exclusion Criteria:

1. were to undergo a concomitant fusion or instrumentation placement;
2. had had previous lumbar surgeries at the same level;
3. had spondylolisthesis of any grade or degenerative scoliosis;
4. had evidence of instability on dynamic radiographs.