الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 60 |  |  |
| | | from | 60 | | |
Abstract
Posterior lumbar interbody fusion (PLIF), described by Cloward in 1943, is the gold standard nowadays in the treatment of spondylolisthesis and degenerative disc disease. The benefits of the procedure are secure fixation of the vertebral body, maintaining the intervertebral space height, and supporting the anterior column, thus providing satisfactory bone fusion while maintaining biomechanical stability.
Traditionally, an open approach is required, using bilateral pedicle screw/rod fixation to provide stability as the gold standard. However, the increased stiffness of the fused segments will reduce the bone mineral content in adjacent vertebrae, and biomechanical studies have indicated that increased stress at the levels adjacent to the fusion may increase adjacent segment disease (ASD). The unilateral pedicle screw PLIF has similar outcomes clinically. However, because the unilateral pedicle screw involves a shorter surgical time, less blood loss, decreases the stiffness of the instrumented segment, and leaving the muscles on one side undisturbed decreases postoperative pain and helps better rehabilitation.
Several techniques for PLIF have been developed. The use of the laminectomy bone as bone grafts to fill the disc space showed promising results, as they are formed of cancellous bone surrounded by cortical bone, this may be the reason behind the good fusion rates. It also decreases donor site morbidity in the case of iliac crest bone graft harvesting, and thus decreases complications.
Another method was the use of foreign implants for grafting (cages). These cages are made of different materials such as Poly Ether Ether Ketone (PEEK), titanium mesh, and carbon fiber. However, with the use of these implants, adequate removal of the cartilaginous endplate is required, but the removal of the bony endplate carries the risk of penetration of the cage into the vertebral body when put under axial load.
The study aims to compare retrospectively two groups that were treated by PLIF one with unilateral PS fixation and the other with bilateral PS fixation in the correction of the local COBB angle by measuring the pre and postoperative angle using computer software.
Patients included in this study are include 66 patients with degenerative lumbar disc disease; 33 of whom underwent PLIF with bilateral PS fixation while the other 33 underwent PLIF with unilateral PS fixation. All patients were done at the spine unit at El-Hadra Orthopaedic University Hospital, Alexandria, Egypt.
The data obtained from the records of the spine orthopedic unit of El-Hadarda Alexandria university hospital. The data was arranged by demographic data, surgeon and level affected. Then, the data radiologically evaluated by obtaining lateral view pre and post-operative, the lateral views of each patient pre-operative and post-operative were put in surgimap software to measure the local Cobb angle and the measure is then tabulated in an excel sheet to be ready for statistical analysis. The Cobb angle will be measured between the upper and lower endplates of the operated segment. A lordotic angle is considered positive while a kyphotic angle is considered negative. The data then calculated using Microsoft SPSS software and showed the following results.
This study shows the difference in angle in PLIF with bilateral PS fixation group was significantly higher than PLIF with unilateral PS fixation group, in PLIF with unilateral PS fixation group the difference was 4.95±3.13, while in PLIF with bilateral PS fixation group was 6.48±3.59 (p <0.05). This study suggests that the conventional PLIF with bilateral PS fixation difference in Cobb’s angle is significantly higher than the PLIF with unilateral PS fixation, which means that the Bilateral group is better in the restoration of their local lordotic angle in the lumbar area with better disc height.