BASBone and Arthrosurgery Science3083-48562981-8222Bio-Byword Scientific Publishing Pty. Ltd.10.26689/BAS.v4i4.15981ArticleEvaluating the Link Between Femoral 3D Spatial Torsion and Anteversion Angle via a Stationary Coordinate Systemhttps://artdesignp.com/journal/BAS/4/4/10.26689/BAS.v4i4.15981JiangGuangliang,HuangJinbai2026442026-08-31Background: Femoral neck anteversion is an important anatomical parameter that plays a major role in the clinical prognosis of interventions in developmental dysplasia of the hip (DDH), internal fixation of femoral neck fractures, and total hip arthroplasty. Conversely, the conventional two-dimensional computed tomography (CT) method, although commonly used clinically, is fundamentally inadequate to accurately resolve the complicated three-dimensional torsional anatomy of the femoral neck, thereby affecting the accuracy and reproducibility of measurements. Objective: This study compared 3D and Reikeras 2D techniques of femoral neck anteversion based on a fixed 3D coordinate system, evaluating reliability, method-specific variations, and the effect of torsion on deviation magnitude. Methods: We retrospectively reviewed CT data from 63 patients. Through axial cross-sectional image superimposition, we mapped the safe screw trajectory precisely. A fixed spatial coordinate system was then built to quantify femoral neck torsion and anteversion, with parallel 2D measurements completed using the Reikeras method. To assess reliability, we determined the intraclass correlation coefficient (ICC), used paired t-tests to compare 3D and 2D measurement results, and applied Pearson correlation analysis to investigate how torsion angles correlate with anteversion measurement errors. Results: The angle of femoral neck anteversion obtained using the fixed-coordinate 3D method was statistically significantly different compared to the results of the traditional 2D method (P < 0.05). The 3D method had better intra- and inter-rater reliability (ICCs of 0.96–0.98) as compared to the 2D method (ICCs of 0.72–0.82). Moreover, the difference in the angle of anteversion between the two techniques showed a significant positive relationship with femoral neck torsion (r = 0.72, P < 0.001), whereas torsion only showed a weak correlation with absolute measurements of anteversion angles (all r < 0.2). Conclusion: The 3D measurement technique is based on a fixed spatial coordinate system, which overcomes the drawbacks of conventional 2D methods and provides reliable measurements of femoral neck anteversion. This technique is extremely useful for pre-operative planning in complex hip reconstruction procedures.Femoral neck torsion, Assessment of anteversion, Three-dimensional measurement, Fixed reference frame

[1] Li H, Han M, Wang Z, et al., 2026, Morphology Re-Observation of Tension Bone Trabeculae at the Upper End of the Femur and Its Clinical Significance. Chinese Journal of Clinical Anatomy, 44(01): 16–22. [2] Kinami Y, Horita M, Fujiwara K, 2024, Measurement Method of Femoral Anteversion During Surgery for Trochanteric Fractures. Cureus, 16(10): e72532. [3] Dawson Z, Stanton SS, Roy S, et al., 2024, Opioid Consumption After Discharge From Total Knee and Hip Arthroplasty: A Systematic Review and Meta-Analysis. Arthroplasty, 39(8): 2130–2136.e7. [4] Xi W, Xing X, Wang F, et al., 2023, Comparison of Three Measurement Methods of Femoral Anteversion Angle. Chinese Journal of Anatomy and Clinics, 28(11): 703–708. [5] Kunze KN, Alter TD, Newhouse AC, et al., 2021, Association Between Orientation and Magnitude of Femoral Torsion and Propensity for Clinically Meaningful Improvement After Hip Arthroscopy for Femoroacetabular Impingement Syndrome: A Computed Tomography Analysis. Am J Sports Med, 49(9): 2466–2474. [6] Li B, Li L, et al., 2025, Feasibility Study on Measuring Anteversion Angle of Acetabular Prosthesis After Total Hip Arthroplasty Using Arbitrary Point Method. Zhongguo Xiufu Chongjian Waike Zazhi, 39(4): 420–424. [7] Boymans TAEJ, Veldman HD, Noble PC, et al., 2017, The Femoral Head Center Shifts in a Mediocaudal Direction During Aging. Journal of Arthroplasty, 32(2): 581–586. [8] Zhang YL, Zhang W, Zhang CQ, 2017, A New Angle and Its Relationship with Early Fixation Failure of Femoral Neck Fractures Treated with Three Cannulated Compression Screws. Orthopaedics & Traumatology: Surgery & Research, 103(2): 229–234. [9] Sankar WN, Neubuerger CO, Moseley CF, 2009, Femoral Anteversion in Developmental Dysplasia of the Hip. Journal of Pediatric Orthopaedics, 29(8): 885–888. [10] Chung CY, Lee KM, Park MS, et al., 2010, Validity and Reliability of Measuring Femoral Anteversion and Neck-Shaft Angle in Patients with Cerebral Palsy. Journal of Bone and Joint Surgery (American Volume), 92(5): 1195–1205. [11] Liu Z, Song K, 2023, Analysis of Factors Associated with the Influence of Femoral Stem Anteversion After Total Hip Arthroplasty. Zhongguo Xiufu Chongjian Waike Zazhi, 37(9): 1075–1080. [12] Suzuki M, Kinoshita K, Sakamoto T, et al., 2024, Side-to-Side Variability in the Femoral Neck Anteversion Angle: A Study of the Japanese Population with Osteonecrosis of the Femoral Head. J Orthop Sci, 29(2): 589–595. [13] Cai Z, Piao C, Zhang T, et al., 2021, Accuracy of CT for Measuring Femoral Neck Anteversion in Children with Developmental Dislocation of the Hip Verified Using 3D Printing Technology. Journal of Orthopaedic Surgery and Research, 16(1): 256. [14] Park Y, Byun H, Kim MJ, et al., 2023, Change of Femoral Anteversion Angle in Children with Intoeing Gait Measured by Three-Dimensional Computed Tomography Reconstruction: 3-Year Follow-Up Study. Annals of Rehabilitation Medicine, 47(3): 182–191. [15] Byun HY, Shin H, Lee ES, et al., 2016, The Availability of Radiological Measurement of Femoral Anteversion Angle: Three-Dimensional Computed Tomography Reconstruction. Annals of Rehabilitation Medicine, 40(2): 237–243. [16] Kong M, Jo H, Lee CH, et al., 2018, Change of Femoral Anteversion Angle in Children with Intoeing Gait Measured by Three-Dimensional Computed Tomography Reconstruction: One-Year Follow-Up Study. Annals of Rehabilitation Medicine, 42(1): 137–144. [17] Ahn JK, Kwon DR, Park GY, et al., 2017, Therapeutic Effect of Microcurrent Therapy in Children with In-Toeing Gait Caused by Increased Femoral Anteversion: A Pilot Study. Annals of Rehabilitation Medicine, 41(1): 104–112. [18] Yang R, et al., 2025, Measurement of the Femoral Neck Anteversion Angle Using a Three-Dimensional Reconstruction in the Fixed Coordinate System Based on the Basal Anterior Cortex of the Femoral Neck: An Observational Study. BMC Surgery, 25(1): 190. [19] Esposito CI, Miller TT, Lipman JD, et al., 2020, Biplanar Low-Dose Radiography Is Accurate for Measuring Combined Anteversion After Total Hip Arthroplasty. HSS Journal, 16(1): 23–29. [20] Deng YS, et al., 2023, Orientated-Quantitative Computed Tomography Study on Individualized Axial Safety Target Area of Femoral Neck Screw Channel and Establishment of a Stable Spatial Coordinate System Based on Anterior Cortex of Femoral Neck Basilar. International Journal of Surgery, 109(5): 1158–1168.