CT-based micromotion analysis for tracking fracture displacement and fragment movement in trochanteric hip fractures: an agreement study
DOI:
https://doi.org/10.2340/17453674.2026.45785Keywords:
Fractures, Hip, Implants, Radiological imagingAbstract
Background and purpose: 2-dimensional radiographs may underestimate 3-dimensional fracture displacement. CT-based micromotion analysis (CTMA) enables precise quantification of interfragmentary movement in 3 dimensions. We aimed to evaluate CTMA for quantifying fracture displacement, surgical reduction, and postoperative fragment movement in trochanteric hip fractures, and assessed measurement agreement from repeated follow-up scans.
Methods: We conducted a prospective cohort study including 15 patients with trochanteric fractures treated with a cephalomedullary nail at Uppsala University Hospital between 2020 and 2023. Each patient underwent CT imaging preoperatively, postoperatively, and at follow-up. Measurement agreement was assessed using 2 follow-up CT scans acquired after patient repositioning, when the fractures were healed. The femoral shaft (or nail) served as the fixed reference, and the femoral head (or spiral blade) was analyzed relative to the mirrored contralateral hip to quantify fracture displacement. Fracture movement during healing was assessed by comparing postoperative and follow-up scans.
Results: 12 patients had complete imaging. Measurement agreement between repeated CTMA scans showed sub-millimetric repeatability for translation and < 1° for rotation. Mean initial fracture displacement relative to the mirrored contralateral hip was 55.6° in total rotation and 48.4 mm in total translation, improving postoperatively to 17.5° and 15.9 mm, and remaining essentially stable at follow-up. Between the postoperative and follow-up scans, total movement of the femoral head averaged 5.4° (95% confidence interval [CI] 2.8–8.1) and 6.4 mm (CI 3.9–8.9). Spiral blade total translation averaged 5.4 mm (CI 3.0–7.9). Observed movement followed expected directions, with predominant femoral shortening (z-translation −4.4 mm), medialization (x-translation −3.3 mm), and slight external rotation (z-rotation +2.4°) of the femoral shaft.
Conclusion: CTMA demonstrated good measurement agreement and repeatability for quantifying fracture displacement, surgical reduction, and postoperative fragment movement in trochanteric fractures.
Downloads
References
Michaëlsson K, Baron J A, Byberg L, Larsson S C, Melhus H, Gedeborg R. Declining hip fracture burden in Sweden 1998–2019 and consequences for projections through 2050. Sci Rep 2024; 14(1): 706. doi: 10.1038/s41598-024-51363-6. DOI: https://doi.org/10.1038/s41598-024-51363-6
Knauf T, Buecking B, Hack J, Barthel J, Bliemel C, Aigner R, et al. Development of the Barthel Index 5 years after hip fracture: results of a prospective study. Geriatr Gerontol Int 2019; 19(8): 809–14. doi: 10.1111/ggi.13723. DOI: https://doi.org/10.1111/ggi.13723
Tosounidis T H, Castillo R, Kanakaris N K, Giannoudis P V. Common complications in hip fracture surgery: tips/tricks and solutions to avoid them. Injury 2015; 46:S3–S11. doi: 10.1016/j.injury.2015.08.006. DOI: https://doi.org/10.1016/j.injury.2015.08.006
Embden D van, Stollenwerck G A N L, Koster L A, Kaptein B L, Nelissen R G H H, Schipper I B. The stability of fixation of proximal femoral fractures: a radiostereometric analysis. Bone Jt J 2015; 97-B(3): 391–7. doi: 10.1302/0301-620x.97b3.35077. DOI: https://doi.org/10.1302/0301-620X.97B3.35077
Chang S M, Wang Z H, Tian K W, Sun G X, Wang X, Rui Y F. A sophisticated fracture classification system of the proximal femur trochanteric region (AO/OTA-31A) based on 3D-CT images. Front Surg 2022; 9: 919225. doi: 10.3389/fsurg.2022.919225. DOI: https://doi.org/10.3389/fsurg.2022.919225
Olivecrona H, Maguire G Q, Noz M E, Zeleznik M P, Kesteris U, Weidenhielm L. A CT method for following patients with both prosthetic replacement and implanted tantalum beads: preliminary analysis with a pelvic model and in seven patients. J Orthop Surg Res 2016; 11(1): 27. doi: 10.1186/s13018-016-0360-7. DOI: https://doi.org/10.1186/s13018-016-0360-7
Brodén C, Sandberg O, Olivecrona H, Emery R, Sköldenberg O. Precision of CT-based micromotion analysis is comparable to radiostereometry for early migration measurements in cemented acetabular cups. Acta Orthop 2021; 92(4): 1–5. doi: 10.1080/17453674.2021.1906082. DOI: https://doi.org/10.1080/17453674.2021.1906082
Vusse S F V D, Laat N N D, Koster L A, Kaptein B L. The accuracy and precision of CT-RSA in arthroplasty: a systematic review and meta-analysis. Acta Orthop 2025; 96: 295–303. doi: 10.2340/17453674.2025.43334. DOI: https://doi.org/10.2340/17453674.2025.43334
Angelomenos V, Shareghi B, Itayem R, Mohaddes M. Comparison of the CT-based micromotion analysis method versus marker-based RSA in measuring femoral head translation and evaluation of its intra- and interobserver reliability: a prospective agreement diagnostic study on 27 patients up to 1 year. Acta Orthop 2025; 96: 38–44. doi: 10.2340/17453674.2024.42705. DOI: https://doi.org/10.2340/17453674.2024.42705
Lundin N, Olivecrona H, Bakhshayesh P, Murkes L G, Enocson A. Computed tomography micromotion analysis in the follow-up of patients with surgically treated pelvic fractures: a prospective clinical study. Eur J Orthop Surg Traumatol 2023; 33(7): 3143–51. doi: 10.1007/s00590-023-03542-w. DOI: https://doi.org/10.1007/s00590-023-03542-w
Lundqvist E, Olivecrona H, Wretenberg P, Sagerfors M. CT-based micromotion analysis after locking plate fixation of AO Type C distal radius fractures. Indian J Orthop 2023; 57(12): 2031–9. doi: 10.1007/s43465-023-01020-3. DOI: https://doi.org/10.1007/s43465-023-01020-3
Kaptein B L, Pijls B, Koster L, Kärrholm J, Hull M, Niesen A, et al. Guideline for RSA and CT-RSA implant migration measurements: an update of standardizations and recommendations. Acta Orthop 2024; 95: 256–67. doi: 10.2340/17453674.2024.40709. DOI: https://doi.org/10.2340/17453674.2024.40709
Kottner J, Gajewski B J, Streiner D L. Guidelines for Reporting Reliability and Agreement Studies (GRRAS). Int J Nurs Stud 2011; 48(6): 659–60. doi: 10.1016/j.ijnurstu.2011.01.017. DOI: https://doi.org/10.1016/j.ijnurstu.2011.01.017
Christensen R, Ranstam J, Overgaard S, Wagner P. Guidelines for a structured manuscript: statistical methods and reporting in biomedical research journals. Acta Orthop 2023; 94: 243–9. doi: 10.2340/17453674.2023.11656. DOI: https://doi.org/10.2340/17453674.2023.11656
Alm C E, Karlsten A, Madsen J E, Nordsletten L, Brattgjerd J E, Pripp A H, et al. No benefit of the trochanteric stabilizing plate on loss of fracture reduction in AO/OTA 31-A2 trochanteric fractures. Bone Jt Open 2024; 5(1): 37–45. doi: 10.1302/2633-1462.51.bjo-2023-0082.r1. DOI: https://doi.org/10.1302/2633-1462.51.BJO-2023-0082.R1
Bojan A J, Jönsson A, Granhed H, Ekholm C, Kärrholm J. Trochanteric fracture-implant motion during healing: a radiostereometry (RSA) study. Injury 2018; 49(3): 673–9. doi: 10.1016/j.injury.2018.01.005. DOI: https://doi.org/10.1016/j.injury.2018.01.005
Wittauer M, Henry J, Sánchez-Rosenberg G, Lambers A P, Jones C W, Yates P J. Evaluation of reduction quality and implant positioning in intertrochanteric fracture fixation: a review of key radiographic parameters. World J Orthop 2025; 16(8): 106982. doi: 10.5312/wjo.v16.i8.106982. DOI: https://doi.org/10.5312/wjo.v16.i8.106982
Wee M A T, Dobbe J G G, Kievit A J, Schafroth M U, Maas M, Blankevoort L, et al. Inducible displacement CT for implant loosening detection: a scoping review on methods, validation, and challenges. Acta Orthop 2026; 97: 136–47. doi: 10.2340/17453674.2026.45512. DOI: https://doi.org/10.2340/17453674.2026.45512
Grunz J P, Huflage H. Photon-counting detector CT applications in musculoskeletal radiology. Investig Radiol 2025; 60(3): 198–204. doi: 10.1097/rli.0000000000001108. DOI: https://doi.org/10.1097/RLI.0000000000001108
Additional Files
Published
How to Cite
License
Copyright (c) 2026 Henrik Åberg, Mari Hänni, Olof Sandberg, Kenneth B Jonsson
This work is licensed under a Creative Commons Attribution 4.0 International License.
PlumX (by Elsevier) is an altmetrics platform that tracks and visualizes the online attention, usage, captures, citations, and social media engagement.
