OF spine classification of osteoporotic thoracolumbar vertebral body fractures by MRI and conventional radiographs only leads to high inter-observer agreement rates-an additional CT adds limited information for the of classification and the OF score.

OBJECTIVES: The purpose of this study was to investigate whether the addition of computed tomography (CT) to magnetic resonance imaging (MRI) improves the accuracy of classifying osteoporotic vertebral body fractures (OVBF). METHODS: A retrospective analysis of a prospective single-center database has been performed. All consecutive patients who had suffered an acute thoracolumbar OVBF in one level II spine center between 2017 and 2019 were analyzed. Thereby, fractures of type OF 1 and OF 5 were excluded. All fractures were initially classified by 5 board-certified orthopaedic surgeons based on MRI and conventional radiographs. Afterwards a reclassification including CT scans were performed. Differences in OF classification and OF score values between both measurements were analyzed. RESULTS: A total of 61 patients were analyzed with a mean age 75.8 years (SD: 8.8 years). In 82.9% of the cases, there was no difference in OF classification comparing classification based only on MRI versus MRI + CT. A difference of more than two OF types was observed in less than 1% of all ratings. The inter-rater reliabilities of the OF classification based on CT + MRI and MRI alone were 0.63 and 0.49, respectively. In 97.5% of the cases there was no therapy-relevant difference of the treatment recommendation with respect of a surgical or nonoperative treatment recommendation based on the OF score. CONCLUSION: In terms of the OF classification and the OF score, the addition of CT add limited value compared to conventional radiographs and MRI only. Additionally, there is only a minor rate of disagreement in treatment recommendations when adding a CT.

OF-Pelvis classification of osteoporotic sacral and pelvic ring fractures.

OBJECTIVES: Osteoporotic fractures of the pelvis (OFP) are an increasing issue in orthopedics. Current classification systems (CS) are mostly CT-based and complex and offer only moderate to substantial inter-rater reliability (interRR) and intra-rater reliability (intraRR). MRI is thus gaining importance as a complement. This study aimed to develop a simple and reliable CT- and MRI-based CS for OFP. METHODS: A structured iterative procedure was conducted to reach a consensus among German-speaking spinal and pelvic trauma experts over 5 years. As a result, the proposed OF-Pelvis CS was developed. To assess its reliability, 28 experienced trauma and orthopedic surgeons categorized 25 anonymized cases using X-ray, CT, and MRI scans twice via online surveys. A period of 4 weeks separated the completion of the first from the second survey, and the cases were presented in an altered order. While 13 of the raters were also involved in developing the CS (developing raters (DR)), 15 user raters (UR) were not deeply involved in the development process. To assess the interRR of the OF-Pelvis categories, Fleiss' kappa (κF) was calculated for each survey. The intraRR for both surveys was calculated for each rater using Kendall's tau (τK). The presence of a modifier was calculated with κF for interRR and Cohen's kappa (κC) for intraRR. RESULTS: The OF-Pelvis consists of five subgroups and three modifiers. Instability increases from subgroups 1 (OF1) to 5 (OF5) and by a given modifier. The three modifiers can be assigned alone or in combination. In both surveys, the interRR for subgroups was substantial: κF = 0.764 (Survey 1) and κF = 0.790 (Survey 2). The interRR of the DR and UR was nearly on par (κF Survey 1/Survey 2: DR 0.776/0.813; UR 0.748/0.766). The agreement for each of the five subgroups was also strong (κF min.-max. Survey 1/Survey 2: 0.708-0.827/0.747-0.852). The existence of at least one modifier was rated with substantial agreement (κF Survey 1/Survey 2: 0.646/0.629). The intraRR for subgroups showed almost perfect agreement (τK = 0.894, DR: τK = 0.901, UR: τK = 0.889). The modifier had an intraRR of κC = 0.684 (DR: κC = 0.723, UR: κC = 0.651), which is also considered substantial. CONCLUSION: The OF-Pelvis is a reliable tool to categorize OFP with substantial interRR and almost perfect intraRR. The similar reliabilities between experienced DRs and URs demonstrate that the training status of the user is not important. However, it may be a reliable basis for an indication of the treatment score.