Gender-specific factors influencing the glenoid version and reference values for it

Fischer et al. Journal of Orthopaedics and Traumatology (2024) 25:39 https://doi.org/10.1186/s10195-024-00778-y Journal of Orthopaedics and Traumatology Open Access ORIGINAL ARTICLE Gender‑specific factors influencing the glenoid version and reference values for it Cornelius Sebastian Fischer1, Matthias Floß2, Till Ittermann3, Christoph Emanuel Gonser1,6* , Ryan Giordmaina4, Robin Bülow5, Carsten‑Oliver Schmidt3 and Jörn Lange2 Abstract Background Glenoid version is an important factor in the evaluation of shoulder stability and shoulder pathologies. However, there are neither established reference values nor known factors that influence the glenoid version, even though valid reference values are needed for diagnostic and orthopaedic surgery like corrective osteotomy and total or reverse shoulder arthroplasty (TSA/RSA). The aim of our population-based study was to identify factors influencing the glenoid version and to establish reference values from a large-scale population cohort. Results Our study explored the glenoid versions in a large sample representing the general adult population. We investigated 3004 participants in the population-based Study of Health in Pomerania (SHIP). Glenoid version was measured for both shoulders via magnetic resonance imaging (MRI). Associations with the glenoid version were calculated for sex, age, body height, body weight and BMI. The reference values for glenoid version in the central European population range between −9° and 7.5°, while multiple factors are associated with the glenoid version. Conclusion To achieve a reliable interpretation prior to orthopaedic surgery, sex- and age-adjusted reference values are proposed. Keywords Glenoid version, Shoulder MRI, Population-based, Reference values, Associated factors, Sex, Age Introduction The glenoid version is a frequently used measure to quantify the orientation of the glenoid surface in relation to the scapular body. It is relevant for the diagnostics and *Correspondence: Christoph Emanuel Gonser 1 Department of Traumatology and Reconstructive Surgery, BG Unfallklinik Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany 2 Clinic of Trauma, Reconstructive Surgery and Rehabilitation Medicine, University Medicine Greifswald, Greifswald, Germany 3 Institute for Community Medicine, Ernst-Moritz-Arndt University of Greifswald, Greifswald, Germany 4 Department of Trauma and Orthopaedics, Mater Dei Hospital, University of Malta, Msida, Malta 5 Institute of Diagnostic Radiology and Neuroradiology, University Medicine Greifswald, Greifswald, Germany 6 BG Unfallklinik Tübingen, Eberhard Karls University Tübingen, Schnarrenbergstraße 95, 72076 Tübingen, Germany treatment of multiple pathologies of the shoulder. Particularly in anterior [1, 2] and posterior [3, 4] shoulder instability and dislocations, the glenoid version is considered an important factor [1]. Eichinger et al. detected a direct effect between glenoid version and the force required for a dislocation [5]. This knowledge is of relevance for total and reverse shoulder arthroplasty (TSA/ RSA). In TSA/RSA, accurate positioning of the glenoid component is critical to achieve a good outcome and to prevent poor function, ongoing pain and implant failure [6]. Especially in anatomical arthroplasty, incorrect positioning leads to a high failure rate [7]. Exact knowledge of the physiological glenoid version is crucial, particularly for successful preoperative planning in the treatment of many shoulder pathologies. However, published reference values are mostly based on cadaver studies of scapular bones [8] or small cohorts [9, 10], or they originate from small control groups of hospital-based patients [11]. © The Author(s) 2024. 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Journal of Orthopaedics and Traumatology (2024) 25:39 Page 2 of 8 In 1992, Friedmann et al. described the first measurement of the glenoid version using axial computed tomography (CT) images. Their data suggested that the normal glenoid version is slightly anteverted [11]. In contrast to this, some authors found that a nearly neutral [8, 12] or retroverted glenoid version [9, 13, 14] was normal. Considering the previous publications, the angulation of the glenoid seems to vary in healthy populations. Imhoff et al. were among the first to propose bony corrections of the glenoid version in posterior shoulder instability with a retroversion of > 15° [4]. However, accepted thresholds for resultant therapy have not been defined yet. Therefore, population-based studies are needed to establish reliable reference values. Additionally, associated factors of the glenoid version are rarely investigated. Possible sex-based differences in glenoid version have been assessed with varying results. Some authors have documented more retroverted glenoids for men [9, 10, 15], while other authors did not find any difference between the sexes [8, 11, 13, 14]. Regarding ethnic differences, Churchill et al. [8] described a significant difference in glenoid version between black and white patients. The influence of the patient’s age is even less well documented. Bouchaib et al. [15] determined that the glenoid version in the upper half of the glenoid decreased with age, while no influence of age was found in the lower half. Concerning side differences, varying results are described. Friedman et al. [11] and Piponov et al. [10] did not find significant differences between the left and right scapulae, whereas several authors found significantly more retroverted glenoids on the dominant side [1, 9, 16]. Associations between body height and body weight and the glenoid version have not been identified to this day [10]. Given the lack of population-based reference values and the limited knowledge of influencing factors for the glenoid version, the aim of this study was to determine reference values based on a representative sample, to determine associations between the glenoid version and sex, age, body weight and body height as well as body mass index (BMI), and to calculate adjusted reference values. Methods Design and sample This study investigated data from 3004 (...truncated)