the study aims to determine the effect of using Autologous platelet rich plasma on both the quality & rate of posterior lumbar interbody fusion & its outcome on the Patient regarding postoperative lumbar pain & functional outcome

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.

Sixty patients will be selected for the study and will be randomized into two group one receiving posterior lumbar interbody fusion with Autologous platelet rich plasma and the other group will receive posterior lumbar interbody fusion without Autologous platelet rich plasma.

Methodology pre-operative preparation: Prior to the operation the selected patients will perform lumbar spine Computarised tomography and X ray films. Both the visual analogue scale of pain and the Oswestry disability index will be collected from the patients

Autologous platelet rich plasma preparation:

Autologous Platelet rich plasma 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 Ethylenediaminetetraacetic 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 immediately before its application to avoid coagulation of the specimen (for every 1.5 milliliter plasma, 1 milliliter calcium chloride 3% is added).

Surgery:

A posterior lumbar interbody fusion with posterior pedicle screw fixation will be performed through a midline posterior approach. Trans-pedicular screws will be placed under fluoroscopic guidance, followed by discectomy. The vertebral body endplates will be prepared by curetting until point bleeding was seen.

Autologous cancellous bone chips will be harvested unilaterally from the iliac wing, approached through the midline posterior incision. The bone chips will be steeped in the plasma solution until clotting occurred visually (approximately 10 minutes). In the control group, the bone chips will be filled with autologous bone in the same way and were implanted after approximately 10 minutes without incubation in a plasma solution.

Inclusion Criteria:

• Spondylolisthesis.
• Degenerative disc disease requiring posterior lumbar interbody fusion not responding to medical treatment for 1 year.
• Age between 20 & 70 years.
• Single or multiple level fusions.

Exclusion Criteria:

• Previous lumbar spine surgery.
• Other lumbar spine pathology
• severe osteoporosis
• Chronic use of steroid or non-steroidal anti-inflammatory drugs (more than one year)
• Patients younger than 20 years old.
• Patients older than 70 years old.
• Immunocompromised patients (eg. Chronic renal failure)

the person performing the statistical analysis shall be masked