OF-Pelvis classification of osteoporotic sacral and pelvic ring fractures

Bernhard W Ullrich; Klaus J Schnake; Ulrich J A Spiegl; Philipp Schenk; Thomas Mendel; Lars Behr; Philipp Bula; Laura B Flücht; Alexander Franck; Erol Gercek; Sebastian Grüninger; Philipp Hartung; Cornelius Jacobs; Sebastian Katscher; Friederike Klauke; Katja Liepold; Christian W Müller; Michael Müller; Georg Osterhoff; Axel Partenheimer; Stefan Piltz; Marion Riehle; Daniel Sauer; Max Joseph Scheyerer; Philipp Schleicher; Gregor Schmeiser; René Schmidt; Matti Scholz; Holger Siekmann; Kai Sprengel; Dietrich Stoevesandt; Akhil Verheyden; Volker Zimmermann; Spine Section of the German Society for Orthopaedics and Trauma

doi:10.1186/s12891-021-04882-6

OF-Pelvis classification of osteoporotic sacral and pelvic ring fractures

BMC Musculoskelet Disord. 2021 Nov 29;22(1):992. doi: 10.1186/s12891-021-04882-6.

Authors

Bernhard W Ullrich^{1

2}, Klaus J Schnake^{3

4}, Ulrich J A Spiegl⁵, Philipp Schenk⁶, Thomas Mendel^{7

8}, Lars Behr⁹, Philipp Bula¹⁰, Laura B Flücht⁷, Alexander Franck¹¹, Erol Gercek¹², Sebastian Grüninger⁴, Philipp Hartung¹³, Cornelius Jacobs¹⁴, Sebastian Katscher⁹, Friederike Klauke^{7

8}, Katja Liepold¹⁵, Christian W Müller¹⁶, Michael Müller¹⁷, Georg Osterhoff⁵, Axel Partenheimer¹⁸, Stefan Piltz¹¹, Marion Riehle¹⁹, Daniel Sauer²⁰, Max Joseph Scheyerer²¹, Philipp Schleicher²², Gregor Schmeiser²³, René Schmidt²⁴, Matti Scholz²², Holger Siekmann²⁵, Kai Sprengel²⁶, Dietrich Stoevesandt²⁷, Akhil Verheyden²⁸, Volker Zimmermann²⁹; Spine Section of the German Society for Orthopaedics and Trauma

Affiliations

¹ Department of Trauma, Hand and Reconstructive Surgery, Jena University Hospital, Friedrich Schiller University Jena, 07747, Jena, Germany. b.w.ullrich@me.com.
² Department of Trauma and Reconstructive Surgery, BG Klinikum Bergmannstrost Halle, Halle, Germany. b.w.ullrich@me.com.
³ Center for Spinal and Scoliosis Surgery, Waldkrankenhaus Erlangen, Erlangen, Germany.
⁴ Department of Orthopedics and Traumatology, Paracelsus Private Medical University Nuremberg, Nuremberg, Germany.
⁵ Department of Orthopaedics, Trauma Surgery, and Plastic Surgery, University of Leipzig, Leipzig, Germany.
⁶ Department of Science, Research and Education, BG Klinikum Bergmannstrost Halle, Halle, Germany.
⁷ Department of Trauma, Hand and Reconstructive Surgery, Jena University Hospital, Friedrich Schiller University Jena, 07747, Jena, Germany.
⁸ Department of Trauma and Reconstructive Surgery, BG Klinikum Bergmannstrost Halle, Halle, Germany.
⁹ Sana Klinikum Borna, Department of Spine Surgery and Neurotraumatology, Borna, Germany.
¹⁰ Departement for Trauma- and Reconstructive Surgery, Orthopedics, Hand- and Plastic Surgery, General Hospital Gütersloh, Reckenberger Straße 19, 33332, Gütersloh, Germany.
¹¹ Department of Trauma Surgery and Orthopedics, Regiomed Clinical Center Coburg, Ketschendorfer Str. 33, 96450, Coburg, Germany.
¹² Center for Trauma Surgery and Orthopedics, Helios University Hospital Wuppertal, University Witten/Herdecke, 42285, Wuppertal, Germany.
¹³ Spine Center, St. Josefs-Hospital Wiesbaden GmbH, Wiesbaden, Germany.
¹⁴ Center for Spine Surgery, St. Remigius Hospital Leverkusen, Leverkusen, Germany.
¹⁵ Department of Spine Surgery, Thuringia Clinic "Georgius Agricola" Saalfeld, Teaching Hospital of the University of Jena, Saalfeld, Germany.
¹⁶ Department of Orthopaedics and Trauma, Asklepios Klinik Wandsbek, Hamburg and Hannover Medical School (MHH), Hannover, Germany.
¹⁷ Department of Orthopedic and Trauma Surgery, University Medical Center Schleswig-Holstein, Campus Kiel, Germany.
¹⁸ Spine & Sport - Trauma / Ortopaedics / Sports Medicine, Herrenhäuser Kirchweg 38, 30167, Hannover, Germany.
¹⁹ Department of Trauma, Reconstructive Surgery and Orthopedics, RKH Krankenhaus Bietigheim, Bietigheim, Germany.
²⁰ Department of Spine Surgery, Schoen-Clinic München Harlaching, Harlachingerstrasse, 51, Munich, Germany.
²¹ Department of Orthopaedic and Traumatology, University of Cologne, Faculty of Medicine and University Hospital Cologne, Joseph-Stelzmann-Straße 24, 50931, Cologne, Germany.
²² Center for Spinal Surgery and Neurotraumatology, Berufsgenossenschaftliche Unfallklinik Frankfurt am Main gGmbH, DE-60389, Frankfurt am Main, Germany.
²³ Department of Spine Surgery, Schoen-Clinic Hamburg Eilbek, Dehnhaide 120, 22081, Hamburg, Germany.
²⁴ Department of Orthopedics and Traumatology Alb Fils Hospital Eichertstr, 3 73035, Göppingen, Germany.
²⁵ Clinic of Trauma-, Hand- and Reconstruction Surgery, AMEOS-Clinic Halberstadt, Gleimstr. 5, 38820, Halberstadt, Germany.
²⁶ Department of Trauma und Interdisciplinary Spine Center, University Hospital Zurich (USZ), University of Zurich (UZH), Raemistrasse 100, 8091, Zurich, Switzerland.
²⁷ University Clinic and Poliklinik of Radiology, Martin-Luther-University, Ernst-Grube-Str. 40, 06120, Halle (Saale), Germany.
²⁸ Clinic for Trauma, Orthopedic and Spine Surgery, Ortenauklinikum Lahr-Ettenheim, 77933, Lahr, Germany.
²⁹ Department of Trauma and Orthopedic Surgery, Klinikum Traunstein, Germany.

Abstract

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 (κ_F) was calculated for each survey. The intraRR for both surveys was calculated for each rater using Kendall's tau (τ_K). The presence of a modifier was calculated with κ_F for interRR and Cohen's kappa (κ_C) 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: κ_F = 0.764 (Survey 1) and κ_F = 0.790 (Survey 2). The interRR of the DR and UR was nearly on par (κ_F 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 (κ_F 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 (κ_F Survey 1/Survey 2: 0.646/0.629). The intraRR for subgroups showed almost perfect agreement (τ_K = 0.894, DR: τ_K = 0.901, UR: τ_K = 0.889). The modifier had an intraRR of κ_C = 0.684 (DR: κ_C = 0.723, UR: κ_C = 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.

Keywords: Classification; Consensus development; Fracture; Osteoporosis; Pelvic ring; Reliability; Sacral.

MeSH terms

Humans
Observer Variation
Pelvic Bones* / diagnostic imaging
Pelvis
Reproducibility of Results
Sacrum / diagnostic imaging