Research Articles

Hip Rotation Arc

Abstract

Background: Rotational deformities of the lower extremity, such as altered femoral neck anteversion (FNA) and tibial torsion (TT), are common pediatric orthopedic conditions associated with intoeing gait. Accurate diagnosis is essential for effective treatment, yet the correlation between clinical examination and three-dimensional (3D) computed tomography (CT) measurements remains unclear. This study evaluates the agreement between clinical assessments and 3D CT in children with rotational deformities.

Methods: In a cross-sectional study at Imam Khomeini Hospital, Tehran City, Iran, 21 children (42 limbs) aged ≥10 years (girls) or ≥11 years (boys) with intoeing gait were assessed. Clinical measurements included hip internal rotation (HIR), hip external rotation (HER), and thigh-foot angle (TFA). Low-dose 3D CT (0.8-1.3 mSv) measured FNA and TT. Pearson correlation coefficients evaluated relationships between clinical and CT findings, with sliding threshold analysis to assess the impact of total hip rotation arc (HIR + HER) on correlations.

Results: Mean clinical measurements were: HIR = 63.54° ± 9.30°, HER = 42.11° ± 6.80°, and TFA = 9.60° ± 8.50°. CT measurements showed FNA 27.71° ± 6.60° and TT 16.11° ± 9.90°. Correlations were moderate (HIR vs. FNA: r = 0.41; HER vs. FNA: r = 0.57; TFA vs. TT: r = 0.483). At a total arc threshold of 98.5°, HIR-FNA correlation increased to r = 0.74 for arcs > 98.5°.
Conclusion: Clinical and 3D CT measurements show moderate correlation, suggesting complementary roles. Greater hip rotation arc enhances clinical reliability, supporting refined examination protocols to reduce imaging reliance in pediatric rotational deformity assessment

1. Delgado ED, Schoenecker PL, Rich MM, Capelli AM. Treatment of severe torsional malalignment syndrome. J Pediatr Orthop. 1996;16(4):484-8. doi: 10.1097/00004694-199607000-00012. [PubMed: 8784702].
2. Montgomery BK, Jarrett DY, Donna A, Watkins C, Shore BJ. Use of 3D Imaging in Planning Varus Derotation Osteotomy in Neuromuscular Hip Subluxation. J Pediatr Orthop Soc North Am. 2022;4(4):562. doi: 10.55275/JPOSNA-2022-562.
3. Fabeck L, Tolley M, Rooze M, Burny F. Theoretical study of the decrease in the femoral neck anteversion during growth. Cells Tissues Organs. 2002;171(4):269-75. doi: 10.1159/000063127. [PubMed: 12169824].
4. Jacquemier M, Glard Y, Pomero V, Viehweger E, Jouve JL, Bollini G. Rotational profile of the lower limb in 1319 healthy children. Gait Posture. 2008;28(2):187-93. doi: 10.1016/j.gaitpost.2007.11.011. [PubMed: 18201887].
5. Boyer E, Novacheck TF, Rozumalski A, Schwartz MH. Long-term changes in femoral anteversion and hip rotation following femoral derotational osteotomy in children with cerebral palsy. Gait Posture. 2016;50:223-8. doi: 10.1016/j.gaitpost.2016.09.004. [PubMed: 27653149].
6. Loh B, Coates A, Woollett E. Paediatric rotational abnormalities: A primer. Aust J Gen Pract. 2021;50(3):132-5. doi: 10.31128/ajgp-08-20-5561. [PubMed: 33634284].
7. Kahf H, Kesbeh Y, van Baarsel E, Patel V, Alonzo N. Approach to pediatric rotational limb deformities. Orthop Rev (Pavia). 2019;11(3):8118. doi: 10.4081/or.2019.8118. [PubMed: 31579218]. [PubMed Central: PMC6769356].
8. Cai Z, Piao C, Zhang T, Li L, Xiang L. Accuracy of CT for measuring femoral neck anteversion in children with developmental dislocation of the hip verified using 3D printing technology. J Orthop Surg Res. 2021;16(1):256. doi: 10.1186/s13018-021-02400-x. [PubMed: 33853657]. [PubMed Central: PMC8045201].
9. Jin S, Xu C, Cai H, Chen C, Lu Y, Wang Z, et al. Comparative Analysis of Physical Examination, CT Scan, and Three- Dimensional Gait Analysis in Evaluating Lower Extremity Torsion Deformities in Children with Cerebral Palsy. Med Sci Monit. 2023;29:e940948. doi: 10.12659/msm.940948. [PubMed: 37721931]. [PubMed Central: PMC10512746].
10. Song KS, Yon CJ, Heo YR, Lee JH, Lee SB, Ko YK, et al. Using the Axial Oblique View of Computed Tomography (CT) in Evaluating Femoral Anteversion: A Comparative Cadaveric Study. Diagnostics (Basel). 2022;12(8). doi: 10.3390/diagnostics12081820. [PubMed: 36010171]. [PubMed Central: PMC9406648].
11. Chung CY, Lee KM, Park MS, Lee SH, Choi IH, Cho TJ. Validity and reliability of measuring femoral anteversion and neck- shaft angle in patients with cerebral palsy. J Bone Joint Surg Am. 2010;92(5):1195-205. doi: 10.2106/jbjs.I.00688. [PubMed: 20439666].
12. Waelti S, Fischer T, Griessinger J, Cip J, Dietrich TJ, Ditchfield M, et al. Ultra-low-dose computed tomography for torsion measurements of the lower extremities in children and adolescents. Insights Imaging. 2022;13(1):118. doi: 10.1186/s13244-022-01257-w. [PubMed: 35838922]. [PubMed Central: PMC9287501].
13. Keller G, Götz S, Kraus MS, Grünwald L, Springer F, Afat S. Radiation Dose Reduction in CT Torsion Measurement of the Lower Limb: Introduction of a New Ultra-Low Dose Protocol. Diagnostics (Basel). 2021;11(7):1209. doi: 10.3390/diagnostics11071209. [PubMed: 34359292]. [PubMed Central: PMC8304839].
14. Han Q, Zhang A, Wang C, Yang K, Wang J. Application of three- dimensional reconstruction to improve the preoperative measurement accuracy and applicability of femoral neck torsion angle. Medicine (Baltimore). 2019;98(45):e17727. doi: 10.1097/md.0000000000017727. [PubMed: 31702623]. [PubMed Central: PMC6855581].
15. Brody AS, Frush DP, Huda W, Brent RL. Radiation risk to children from computed tomography. Pediatrics. 2007;120(3):677-82. doi: 10.1542/peds.2007-1910. [PubMed: 17766543].
16. Mooney JF, 3rd. Lower extremity rotational and angular issues in children. Pediatr Clin North Am. 2014;61(6):1175-83. doi: 10.1016/j.pcl.2014.08.006. [PubMed: 25439018].
17. Edmonds EW, Parvaresh KC, Price MJ, Farnsworth CL, Bomar JD, Hughes JL, et al. The Reliability of Measurements for Tibial Torsion: A Comparison of CT, MRI, Biplanar Radiography, and 3D Reconstructions With and Without Standardized Measurement Training. J Pediatr Soc North Am. 2023;5(3):661. doi: 10.55275/jposna-2023-661. [PubMed: 40433330]. [PubMed Central: PMC12088203].
18. Byun HY, Shin H, Lee ES, Kong MS, Lee SH, Lee CH. The Availability of Radiological Measurement of Femoral Anteversion Angle: Three-Dimensional Computed Tomography Reconstruction. Ann Rehabil Med. 2016;40(2):237- 43. doi: 10.5535/arm.2016.40.2.237. [PubMed: 27152273]. [PubMed Central: PMC4855117].
19. Schmaranzer F, Lerch TD, Siebenrock KA, Tannast M, Steppacher SD. Differences in Femoral Torsion Among Various Measurement Methods Increase in Hips With Excessive Femoral Torsion. Clin Orthop Relat Res. 2019;477(5):1073-83. doi: 10.1097/corr.0000000000000610. [PubMed: 30624313]. [PubMed Central: PMC6494336].
20. Scorcelletti M, Reeves ND, Rittweger J, Ireland A. Femoral anteversion: significance and measurement. J Anat. 2020;237(5):811-26. doi: 10.1111/joa.13249. [PubMed: 32579722]. [PubMed Central: PMC7542196].
21. Parikh S, Noyes FR. Patellofemoral disorders: role of computed tomography and magnetic resonance imaging in defining abnormal rotational lower limb alignment. Sports Health. 2011;3(2):158-69. doi: 10.1177/1941738111399372. [PubMed: 23016003]. [PubMed Central: PMC3445137].
22. Prather H, Harris-Hayes M, Hunt DM, Steger-May K, Mathew V, Clohisy JC. Reliability and agreement of hip range of motion and provocative physical examination tests in asymptomatic volunteers. Pm r. 2010;2(10):888-95. doi: 10.1016/j.pmrj.2010.05.005. [PubMed: 20970757]. [PubMed Central: PMC3438506].
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IssueVol 12 No 1 (2026) QRcode
SectionResearch Articles
Keywords
Tibial Torsion Three-Dimensional Image Computed Tomography Bone Anteversion

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How to Cite
1.
Heidari S, Nabian MH, Ebrahim Nasab MM. Hip Rotation Arc. J Orthop Spine Trauma. 2026;12(1):9-14.