Pedicle screw fixation of spinal column in patients with various spinal disorders has become increasingly popular over the past years particularly for treatment of spondylolisthesis. Management of spondylolisthesis is variable and depends on the underlying pathology. For asymptomatic cases surveillance is the treatment of choice while medical treatment is the first line of management for symptomatic cases. However, surgical treatment is reserved for cases who have failed the medical treatment or to patients with neurological deficits. Various surgical techniques have been used to deal with lumber spine spondylotic spondylolisthesis; basically focused on the concept of spinal fusion. Many have advocated the use of instrumentations with or without neural decompression or only neural decompression without surgical fixation with claim of variable results though [6, 7].
The reduction of vertebral step is still a matter of debate. In his study, Mikko et al concluded that patients who had surgical fixation without reduction ended with better outcome compared with patient who underwent surgical reduction and fixation. Yet, This conclusion was drawn on adolescent patients who had severe spondylolisthesis; the other face it might not be applicable on older patients or those with lower grade of spondylolisthesis . The results we concluded in our study have proved that the outcome is almost similar in patients who underwent instrumental fixation along side with neural decompression whether they had reduction of the spondylolisthetic segment or not. This draw a challenge to the results of Mikko et al when his conclusion is being applied on adult patients with low grade spondylolisthesis.
Furthermore, many authors have advocated that correction of sagittal spinal deformity in conjunction with arthrodesis will enhance the spinal biomechanics and results in a nerve root decompression. Besides that, it provides a mechanical protection for the spinal fusion from tensile and shearing forces that may be applied to the adjacent segments and this could prevent an early adjacent segment disease. What makes the slippage reduction in adults amenable and easy is the fact that the slip angle is usually small, and there are no dysplastic changes of adolescent high-grade slips, such as a rounded sacrum or trapezoidal L5 shape. How ever, these facts have been challenged by many authors [15–18].
Adjacent segment disease still a problem that may occur in a high rate on the long term follow up after lumbar spine fixation and estimated at in 36.1% of cases. This may be related to the pre operative abnormal sagittal configuration of the spine rather than to the surgical technique utilized or extension of the spinal fixation or even the existence of degenerative disease. Conversely, it seems that normal sacral inclination is the most important factor for having lower adjacent segment degeneration and Retrolisthesis is the most frequent degenerative type of adjacent segment disease seen .
Functional outcome following instrumental spinal surgery for spondylolisthesis in physically energetic patients is crucial. Molinari et al, had reviewed the functional outcome following instrumental surgery and concluded that patients with symptomatic low grade spondylolisthesis could return to high functional life with less back pain following a limited surgical intervention .
As a result, There is lack of studies in the literature that compares surgical outcome between patients with low grade spondylolisthesis who underwent surgical fixation with reduction of the vertebral shift and those who underwent only fixation in situ without having the step reduced. Though comparison studies between variable surgical techniques utilized to deal with symptomatic spondylolisthesis have been carried out by many authors. Apparently, the surgical outcome of various techniques used for spinal decompression and instrumental fixation seems to be almost the alike with trivial differences between these techniques in terms of surgical complications, rate of spinal fusion and satisfactory outcome in the short and long term follow up [21, 22].