ArticleKnee surgery, sports traumatology, arthroscopy : official journal of the ESSKA2023
Long leg radiographs underestimate the degree of constitutional varus limb alignment and joint line obliquity in comparison with computed tomography: a radiographic study.
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 23 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
23 citing papers in PubMed, 1 synthesis or guideline pooled it.
- Discrepancies in CPAK classification between CT and long-leg radiography: a systematic review and meta-analysis.Skeletal radiology · 2026Pooled 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
- Coronal Plane Alignment of the Knee (CPAK) in children and adolescents : an analysis of 655 knees according to the CPAK classification.Bone & joint open · 2026Article
- Article
- Posterior tibial slope varies across functional tibial phenotypes but not CPAK categories: A radiographic analysis from the FP-UCBM Knee Study Group.Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA · 2026Article
- Distribution of coronal plane alignment knee phenotypes in Japanese patients with knee osteoarthritis: a comparison of two-dimensional and three-dimensional measurements.Journal of orthopaedics · 2026Article
- Interobserver reliability of Coronal Plane Alignment of the Knee (CPAK) phenotype classification : external validation using data from the Osteoarthritis Initiative.Bone & joint open · 2025Article
- Flexion gap discrepancy drives femoral rotational adjustment in robot-assisted TKA: a CPAK-Based phenotypic analysis.BMC musculoskeletal disorders · 2025Article
- Coronal plane alignment of the knee classification system does not reliably predict tibiofemoral joint gaps in arthritic knees undergoing total knee arthroplasty.Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA · 2025Article
- Femoral components are positioned in greater external rotation using functional alignment in robot-assisted total knee arthroplasty compared to mechanical alignment.Journal of experimental orthopaedics · 2025Article
- A systematic review of geographic differences in knee phenotypes based on the coronal plane alignment of the knee (CPAK) classification.Arthroplasty (London, England) · 2025Review
- Increased prevalence of lateral trochlear groove wear among valgus alignment subtypes by coronal knee alignment classification: A retrospective single-center study.Journal of orthopaedics · 2025Article
- Full-length weight-bearing radiographs and computed tomography show discrepancies in coronal alignment for robotic arm-assisted total knee arthroplasty.Scientific reports · 2025Article
- The CPAK classification in three-dimensional measurements is consistent with those in two-dimensional measurements.Archives of orthopaedic and trauma surgery · 2025Article
- The Orientation of the Prosthetic Trochlear Angle Is Predictable in Kinematically Aligned Total Knee Arthroplasty.Journal of personalized medicine · 2025Article
- CT-Based Software-Generated Measurements Permit More Objective Assessments of Arithmetic Hip-Knee-Ankle Axis and Joint Line Obliquity.Life (Basel, Switzerland) · 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
- Radiological Approach to Assessment of Lower-Limb Alignment-Coronal and Transverse Plane Analysis.Journal of clinical medicine · 2024Review
- The Distribution of Coronal Plane Alignment of the Knee Classification in a Sample of Spanish Southeast Osteoarthritic Population: A Retrospective Cross-Sectional Observational Study.Medicina (Kaunas, Lithuania) · 2024Observational
- Variability of three-dimensional knee morphology cannot be effectively assessed using a coronal plane knee alignment classification in total knee arthroplasty patients.Journal of experimental orthopaedics · 2024Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
purposeThe purpose of this study was to understand if differences exist between computed tomography (CT) and long leg radiographs (LLR) when defining coronal plane alignment of the lower limb in total knee arthroplasty (TKA). It aimed to identify any such differences between the two imaging modalities by quantifying constitutional limb alignment (arithmetic hip-knee-ankle angle (aHKA), joint line obliquity (JLO) and Coronal Plane Alignment of the Knee (CPAK) type within the same population.
methodsA retrospective radiographic study compared pre-operative LLR and CT measurements in patients undergoing robotic-assisted TKA. The aHKA, JLO and CPAK types were calculated after measuring the medial proximal tibial angle (MPTA) and lateral distal femoral angle (LDFA). The primary outcomes were the mean differences in aHKA (MPTA-LDFA), JLO (MPTA + LDFA) and proportions of CPAK types between LLR and CT groups. The secondary outcomes were the differences in CT-derived MPTA values based on four different tibial sagittal landmarks.
resultsAfter exclusions, 465 imaging sets were analysed in 394 patients. There was a statistically significant mean difference between LLR and CT, respectively, for both MPTA (87.5° vs. 86.2°; p < 0.01) and LDFA (88.7° vs. 87.3°; p < 0.01). There were also statistically significant differences for aHKA (- 0.2° vs. - 1.1°) and JLO (175.1° vs. 173.4°) for LLR and CT, respectively (both p < 0.01). CT increased the proportion of patients with CPAK Type I (constitutional varus aHKA, apex distal JLO) and CPAK Type II (neutral aHKA, apex distal JLO), and decreased numbers of CPAK Types III-VI. There were significant mean differences in the MPTA using varying sagittal landmarks.
conclusionAlignment determined by LLRs underestimates the magnitude of both constitutional varus alignment and joint line obliquity compared to CT, differences that notably increase the proportions of patients included in CPAK Types I and II. These distinctions are primarily due to underestimation of proximal tibial varus when measured on LLRs compared to CT, which more specifically defines articular weight-bearing points. LEVEL OF EVIDENCE: III.
Indexed as
Identifiers
37490128What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.