Material and methods
trauma, fracture, fractures, Trauma, Fractures
SECONDARY, PATHOLOGICAL FRACTURES
50 plain X-rays of patients from the emergency department (ER) of a Level I Trauma Center with tibial shaft fractures (AO:42A/B/C and 43A) were prospectively evaluated by different physicians. 25 of the 50 patients had an additional fracture of the posterior malleolus. To avoid a selection bias, the last 25 patients admitted to the ER at a Level I Trauma Center meeting the inclusion criteria were used as the study sample for each group (25 tibial shaft fractures with additional PM fractur and 25 tibial shaft fractures without additional fractures; date of data collection: April 1, 2021). Mean age was 47.1 ± 20.0 years old (min. 18, max. 92).All X-rays were initially screened by a specialist in trauma surgery and a specialist in radiology, who independently assessed the images based on the inclusion and exclusion criteria. Tibial shaft fractures were included if there was no direct joint involvement and both plain X-ray and CT imaging of the ankle were available. Fractures without direct joint involvement were defined as all fractures where the main/obvious fracture does not affect a joint. CT imaging was used to confirm the presence of a PM fracture. If both specialists agreed, the diagnosis (PM fracture or no PM fracture) was regarded as certain and used as a basis for the subsequent evaluation of the plain X-ray images. Pathological fractures, open fractures, multiple trauma, imaging of insufficient quality and children under 18 years of age were excluded. The patient data (name, date of birth) were irreversibly anonymized and replaced by numerical codes on all research materials.The selected plain X-rays (at least one AP and one lateral view of sufficient quality) were evaluated by two groups of physicians. Each group consisted of a radiological resident and a senior physician, as well as a trauma surgery resident and a senior physician. All residents had at least three years of professional experience. The assessing physicians did not have access to the CT imaging. All examinations were carried out at the physicians' daily workplaces.The first group (group 1) was unaware of the previous study describing the incidence of concomitant posterior malleolus fractures in type A fractures as the analysis was carried out before the study results were published (January 2022). All physicians were asked to provide a full diagnosis for all patients and to request further imaging if necessary. Only the trauma surgeons were specifically tasked with recommending appropriate treatment options in addition.The second group (group 2) was explicitly informed of the results of the preliminary studies and asked explicitly about a fracture of the posterior malleolus. Again, this group could request additional imaging if necessary and the surgeons could suggest treatment options. In this group, the examination of the same radiographs was repeated in a different order after 4–6 weeks.To avoid bias, all physicians were only asked for additional CT-imaging necessary to make the diagnosis, not for surgical planning.The primary outcome was the correct diagnosis of accompanying PM fractures in plain X-rays and the secondary outcome was the preoperative detection of accompanying PM fractures. A PM fracture was considered as detected if it was diagnosed in plain X-ray or a CT showing the ankle was requested or both (CT requests for surgical planning were not counted).All statistical testing was carried out with Jamovi 2.2.5 (jamovi.org) and for Fleiss’ kappa with SPSS 28 (IBM Germany). Descriptive statistics were presented as mean ± standard deviation. The Fleiss’ kappa and Cohen’s kappa are both statistical measures used to assess the level of agreement between multiple raters. [The study was performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments. The use of patient data was allowed by the local Ethics Committee.