ArticleKnee surgery, sports traumatology, arthroscopy : official journal of the ESSKA2023
Significant changes in lower limb alignment due to flexion and rotation-a systematic 3D simulation of radiographic measurements.
Article in Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 26 papers, 2 of them syntheses that pooled it.
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Who cites it
26 citing papers in PubMed, 2 syntheses or guidelines pooled it.
- Discrepancies in CPAK classification between CT and long-leg radiography: a systematic review and meta-analysis.Skeletal radiology · 2026Pooled it
- High variability exists in 3D leg alignment analysis, but underlying principles that might lead to agreement on a universal framework could be identified: A systematic review.Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA · 2025Pooled it
- Differences in the coronal plane alignment of the knee (CPAK) measurements using long-leg radiographs and computed tomography.Archives of orthopaedic and trauma surgery · 2026Trial
- Intentional valgus alignment correction using metaphyseal comminution as a "natural osteotomy" during dual-plate fixation for AO/OTA 33-C3 distal femoral fractures with medial knee osteoarthritis: a preliminary feasibility series.International orthopaedics · 2026Article
- A SHAP-based machine learning approach to decoding the relationship between running posture features and tibial load in novice runners with MTSS: towards accurate and intelligent rehabilitation strategies.BMC musculoskeletal disorders · 2026Article
- Does the preoperative CPAK classification influence clinical outcomes after medial and lateral unicompartmental knee arthroplasty? Short-term outcomes and phenotype distribution in a retrospective series of consecutive cases.Archives of orthopaedic and trauma surgery · 2026Article
- Combining deep learning with statistical shape modelling enables automated lower limb measurements with observer-level reliability using weight-bearing computed tomography.Journal of experimental orthopaedics · 2026Article
- Impact of quantified knee positioning on the measurement of minimal joint space width using statistical shape models: A cross-sectional and longitudinal analysis in the IMI-APPROACH.Osteoarthritis imaging · 2025Article
- Interobserver reliability of Coronal Plane Alignment of the Knee (CPAK) phenotype classification : external validation using data from the Osteoarthritis Initiative.Bone & joint open · 2025Article
- Biplanar radiographic analysis of knee alignment: a stepwise approach for phenotype classification and knee arthroplasty planning.EFORT open reviews · 2025Review
- Posterior tibial slope is independent of coronal plane knee alignment and needs to be assessed to determine knee phenotype.Journal of orthopaedics · 2025Article
- A structured framework for standardized 3D leg alignment analysis: An international Delphi consensus study.Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA · 2025Article
- High accuracy in lower limb alignment analysis using convolutional neural networks, with improvements needed for joint-level metrics.Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA · 2025Article
- Navigated versus conventionally instrumented total knee arthroplasty techniques: No difference in functional alignment or balance.Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA · 2025Article
- Malrotation Strongly Influences Posterior Tibial Slope Measurement on Lateral Radiographs of the Knee.Orthopaedic journal of sports medicine · 2025Article
- A controlled study of personalized versus standard osteotomy in medial unicompartmental knee osteoarthritis.Journal of orthopaedic surgery and research · 2025Article
- Influence of limb position on femoral neck anteversion angle measurement during computed tomography imaging.Asia-Pacific journal of sports medicine, arthroscopy, rehabilitation and technology · 2025Article
- Effect of radiographic malpositioning on patellar height measurements: implications for diagnosis and surgical planning. A retrospective observational study.European journal of orthopaedic surgery & traumatology : orthopedie traumatologie · 2025Observational
- Comparative impact of high tibial osteotomy and supramalleolar osteotomy on limb alignment and ankle function: a retrospective study.Journal of orthopaedic surgery and research · 2025Article
- Comparing supine CT scanogram and standing long-leg radiograph for postoperative alignment in total knee arthroplasty: a prospective study.Archives of orthopaedic and trauma surgery · 2024Article
Corrections and comments
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Authors and funding
6 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundMany radiographic lower limb alignment measurements are dependent on patients' position, which makes a standardised image acquisition of long-leg radiographs (LLRs) essential for valid measurements. The purpose of this study was to investigate the influence of rotation and flexion of the lower limb on common radiological alignment parameters using three-dimensional (3D) simulation.
methodsJoint angles and alignment parameters of 3D lower limb bone models (n = 60), generated from computed tomography (CT) scans, were assessed and projected into the coronal plane to mimic radiographic imaging. Bone models were subsequently rotated around the longitudinal mechanical axis up to 15° inward/outward and additionally flexed along the femoral intercondylar axis up to 30°. This resulted in 28 combinations of rotation and flexion for each leg. The results were statistically analysed on a descriptive level and using a linear mixed effects model.
resultsA total of 1680 simulations were performed. Mechanical axis deviation (MAD) revealed a medial deviation with increasing internal rotation and a lateral deviation with increasing external rotation. This effect increased significantly (p < 0.05) with combined flexion up to 30° flexion (- 25.4 mm to 25.2 mm). With the knee extended, the mean deviation of hip-knee-ankle angle (HKA) was small over all rotational steps but increased toward more varus/valgus when combined with flexion (8.4° to - 8.5°). Rotation alone changed the medial proximal tibial angle (MPTA) and the mechanical lateral distal femoral angle (mLDFA) in opposite directions, and the effects increased significantly (p < 0.05) when flexion was present.
conclusionsAxial rotation and flexion of the 3D lower limb has a huge impact on the projected two-dimensional alignment measurements in the coronal plane. The observed effects were small for isolated rotation or flexion, but became pronounced and clinically relevant when there was a combination of both. This must be considered when evaluating X-ray images. Extension deficits of the knee make LLR prone to error and this calls into question direct postoperative alignment controls. LEVEL OF EVIDENCE: III (retrospective cohort study).
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