Impact of surgeons’ experience on accuracy of radiographic segmental kyphosis assessment in thoracolumbar fractures: a prospective observational study

BACKGROUND The thoracolumbar region is where most fractures of the spine are located. Segmental kyphosis is an important factor for treatment decisions. There are various methods for measuring segmental kyphosis in thoracolumbar fractures. Our objective was to evaluate if the experience of the surgeon has any influence on kyphosis measurement by analyzing three different categories of orthopedic surgeons and evaluate possible clinical impacts. MATERIAL AND METHODS Six physicians separated into three categories according to the level of experience evaluated 30 lateral view radiographs of the thoracic spine of patients with single-level fracture taken during their outpatient follow-up visits. Images had segmental kyphosis measured by five distinct methods. The x-rays were evaluated twice and in a random order after an eight-week interval. The reproducibility of the measurements was analyzed by the intraclass correlation coefficient (ICC) and its respective 95% confidence interval. RESULTS The intraclass correlation coefficient (ICC) was calculated to evaluate the inter- and intra-examiner reliability for each method. The methods that disregard the fractured vertebra (1 and 4) achieved the highest intra and inter-observers reliability among the participants. The measurements from methods 3 and 5 were poorly reproducible between examiners. The difference between the averages of the measurements of the five methods studied was greater than 5 degrees in methods 1 and 2, suggesting risk for patient safety. CONCLUSION Methods that exclude the fractured vertebra were more reproducible for the evaluation of segmental kyphosis in thoracolumbar fractures. The evaluation of the spine fracture must be coupled with other radiographic criteria, more complex image exams and the patient's clinical state to assist the surgeon in deciding between conservative or surgical treatment. The authors suggest that the measurements should be performed by methods that exclude the fractured vertebra and conducted by experienced doctors.