A comparative study of the slippage distance in static and dynamic lumbar radiographs for spondylolisthesis patients at the MTRH spine clinic, Eldoret, Kenya

Background: Low back pain is a common presenting complaint for patients seeking healthcare, the age standard prevalence of lower back pain was around 8.20% in 1990 and declined slightly to about 7.5% in 2017. Therefore, lower back pain represents a huge burden in terms of years lived with disability. Spondylolisthesis presents a common cause of lower back pain. Spondylolisthesis which is the anterior slippage of a vertebrae on the immediate inferior vertebrae, leads to disruption in normal vertebrae dynamics which then may present as lower back pain. There is need to accurately diagnose spondylolisthesis. The main imaging modalities used to diagnose spondylolisthesis are X-ray, CT scan and MRI, with X-ray being to cheapest and most used modality. Different studies have used to compare different imaging modalities to identify the best modality to diagnose spondylolisthesis accurately and correctly. There are multiple studies to that compared lateral x-rays to MRI which showed flexion-extension X-rays to be superior to MRI to diagnose spondylolisthesis, especially with small slippage distances. Standing and flexion-extension x-rays in the lateral position are the standard patient positions used to diagnose spondylolisthesis using x-rays. At MTRH dynamic radiographs is the initial diagnostic modality used to confirm a diagnosis of spondylolisthesis. This study aims to compare static and dynamic radiographs to identify the which patient position increases the specificity of diagnosing spondylolisthesis. The conclusions drawn from the study will build the foundation for future studies to identify an imaging modality will be used to diagnose spondylolisthesis. In addition, it will minimize the need of over-exposing patients to unnecessary radiation during preliminary work up for spondylolisthesis.

Objective: To compare static upright lumbar x-ray to dynamic flexion-extension x-rays as modalities for diagnosing lumbar spondylolisthesis.

Methods: A comparative study design will be employed to compare dynamic and static radiographs on patients with confirmed diagnosis of spondylolisthesis presenting at the MTRH spine clinic. The sample size was calculated based on sample size by Lee J.N et al (2021). A sample size will be seventeen patients which will be determined by consecutive sampling. Patients’ demographical data will be obtained after patients have been enrolled in the study and consent forms duly signed. Patients will then sent to the radiology department to obtain lumbar radiographs, which will include two dynamic radiographs, one with weights and another without weights, and two static radiographs, one with weights and one without weights. X-rays will be viewed on Paxera software and slippage distance for each radiograph will be determined by a consultant radiologist. Descriptive statistics will be employed to present the biodata. Comparison of the data by means of proportions, median, mean, and standard deviation will be done.

Expected findings: Radiographs are widely utilized in the diagnosis of lumbar spine disorders. The study will determine which radiograph position will make the diagnosis of spondylolisthesis easier. Dynamic radiographs with weights are expected to provide more slippage distance in spondylolisthesis followed by dynamic radiographs without weights. Knowledge acquired from the study will help define protocols to be used at the MTRH spine clinic.