The objective of this study is to evaluate the fusion rate after the use of platelet rich plasma with autolgus bone graft and comparing it with bone graft alone

The study will be submitted for approval by the Ethics Committee of Faculty of Medicine, Assiut University, and written informed consent will be obtained from all patients prior to enrollment. The study population will be selected from patients attending the Department of Orthopedics and Trauma surgery, Assiut University hospitals.

A total of 104 patients treated with single level degenerative or lytic lumbar Spondylolisthesis indicated for PLF will be included ,patients will be classified into 2 groups Group A:Of 52 patients PLF + autologus bone graft+ PRP Group B: Of 52 patients treated with PLF + autologus bone graft only without adding PRP

Methods of evaluation

• History taking.
• Full clinical and neurological examination
• Radiological evaluation by x-ray (antero posterior, lateral, and, CT scans provide excellent views of bony detail) and MRI if needed Method of randomization By shuffling cards method the candidate patient will choose one card from104 cards 52 of them containing fusion with PRP and the other 52 contaning Fusion without PRP

Platelet-rich plasma (PRP is obtained using a two-stage centrifugation process:

Whole blood sample will be drawn from the participant and be collected in a sterile tube containing anticoagulant (sodium citrate 3.8% or Ethylenediaminetetra acetic acid). The tube will be centrifuged at 160xg relative centrifugal force (about 1000 round per minute) for 10 min in a centrifugal apparatus. The first spin will separate platelet poor plasma at the top from red blood cells at the bottom and platelet rich plasma above (mixed with the white blood cells in the buffy coat). The Platelet poor plasma, Platelet rich plasma and a few red blood cells will be aspirated into a new tube, mixed and in the second spin, the tube will be centrifuged at 400xg relative centrifugal form (about 1500 round per minute) for another 10 minutes. The upper section will consist of Platelet poor plasma and the Platelet rich plasma will be collected at the bottom of the tube in the form of pellet. Then, Platelet poor plasma and Platelet rich plasma will be aspirated and mixed (discarding the upper portion). Prior to treatment calcium chloride 3% will be added to activate platelets specimen

Inclusion Criteria:

degenerative or lytic Spondylolisthesis.

Degenerative disc disease requiring posterior lumbar fusion not responding to medical treatment for 1 year.

Age between 20 & 75 years.

Single level fusion

Exclusion Criteria:

Multiple levels patient Traumatic Spondylolisthesis Previous lumbar spine surgery. Other lumbar spine pathology severe osteoporosis Patients younger than 20 years old. Patients older than 75 years old. Immunocompromised patients (eg. Chronic renal failure)

the person performing the statistical analysis shall be masked