Flexion-Extension Radiograph Imaging Protocol Reliability Study

Orthopedic surgeons often face the dilemma of whether to add fusion to a decompression procedure of the spine. Their decision mainly relies on personal experience to determine if a level is unstable preoperatively or if a specific decompression procedure might destabilize the spine. Lumbar spine flexion-extension radiographs aim to provide clinicians with images to assess the dynamism of a vertebral level, which crucial for evaluating spinal instability. However, the lack of a standardized imaging protocol for taking such flexion-extension radiographs leads to wide variability in their quality. This impacts the efficacy of radiographic measurements of angular and translational motion used for diagnosis. To effectively and reliably diagnose instability, it is crucial to control and standardize the flexion-extension radiograph protocols to promote the repeatability of intervertebral motion that characterizes a patient's full range of motion. The objective of this study is to evaluate the test-retest reliability of a standardized flexion - extension radiograph imaging protocol for the lumbar spine. This is an exploratory reliability study. A non-probability purposive sample of 45 patients with back pain from two tertiary care hospitals in The Netherlands is used. There is bo intervention. The main study parameter/endpoint is the agreement between the participants' first ("test") and second ("retest") kinematic results from their lumbar flexion-extension radiographs.

Inclusion Criteria: * referral to the orthopaedic surgeon because of pain in the back or leg and requiring lumbar spine radiographs so the orthopaedic surgeon is able to diagnose the probable cause of the pain. * over the age of 18 years * ability to flex and extend the spine sufficiently to facilitate acceptable flexion and extension radiographs. Exclusion Criteria: * any form of spine-related traumatic injury * prior lumbar spinal surgery * lateral spondylolisthesis or coronal plane curvature in the lumbar spine of \>10° * the presence of involuntary back muscle spasms * the presence of significant changes in pain during the day * inability to understand and sign the study Informed Consent form * inability to follow oral instructions