Evidence map›Paper›PMID 42249474›Full record

ArticleBMC musculoskeletal disorders2026

Three-dimensional artificial intelligence-based computed tomography analysis of lower limb muscle volume and fatty degeneration in varus and valgus knee osteoarthritis: a single-center retrospective study.

Yoshinobu Hyakuda, Takuma Miyamoto, Munehiro Ogawa, Akihito Kawai, Hiroto Nishimura, Ryota Hara, Yusuke Inagaki, Keisuke Uemura, Masaki Takao, Kohei Kono and 3 more

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Article in BMC musculoskeletal disorders, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

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2 · The registry

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

13 authors.

Yoshinobu HyakudaDepartment of Orthopaedic Surgery, Nara Medical University, 840 Shijo-cho, Kashihara, Nara, 634-8521, Japan. yoshinobu4224@naramed-u.ac.jp.
Takuma MiyamotoDepartment of Orthopaedic Surgery, Nara Medical University, 840 Shijo-cho, Kashihara, Nara, 634-8521, Japan.
Munehiro OgawaDepartment of Sports Medicine, Nara Medical University, Kashihara, Japan.
Akihito KawaiDepartment of Orthopaedic Surgery, Nara Medical University, 840 Shijo-cho, Kashihara, Nara, 634-8521, Japan.
Hiroto NishimuraDepartment of Orthopaedic Surgery, Nara Medical University, 840 Shijo-cho, Kashihara, Nara, 634-8521, Japan.
Ryota HaraThe Center for Rheumatic Diseases, Nara Medical University, Kashihara, Japan.
Yusuke InagakiDepartment of Rehabilitation Medicine, Nara Medical University, Kashihara, Japan.
Keisuke UemuraDepartment of Orthopaedic Medical Engineering, Osaka University Graduate School of Medicine, Suita, Japan.
Masaki TakaoDepartment of Orthopaedic Surgery, Ehime University Graduate School of Medicine, Toon, Japan.
Kohei KonoDepartment of Orthopaedic Surgery, Ehime University Graduate School of Medicine, Toon, Japan.
Mazen SoufiProgram of Information and Communication Engineering, Faculty of Engineering, University of Miyazaki, Miyazaki, Japan.
Yoshito OtakeDivision of Information Science, Nara Institute of Science and Technology, Ikoma, Japan.
Kenji KawamuraDepartment of Orthopaedic Surgery, Nara Medical University, 840 Shijo-cho, Kashihara, Nara, 634-8521, Japan.

Funding

Japan Society for the Promotion of Science (JSPS) KAKENHI 25K23798
6 · The paper itself

Abstract

backgroundDespite the high prevalence of knee osteoarthritis, the anatomical factors that characterize distinct deformity patterns remain unclear. This study aimed to compare the three-dimensional (3D) lower-limb musculature between varus and valgus knee osteoarthritis (OA) using an artificial intelligence (AI)-based computed tomography (CT) segmentation, evaluating whole-muscle volume, fatty degeneration, and morphological differences to inform targeted prevention, treatment, and rehabilitation strategies.

methodsThis retrospective study included 75 patients who underwent CT imaging before total knee arthroplasty for end-stage knee OA. Patients were categorized into valgus (femorotibial angle [FTA] ≤ 176°) and varus (FTA > 176°) groups. A validated Bayesian U-Net-based AI segmentation model was used to reconstruct 3D musculature and quantify muscle volume and Hounsfield unit (HU) values. Twenty-three muscle compartments were analyzed. For the vastus medialis and tensor fasciae latae (TFL), intramuscular fat volume was additionally quantified using Mimics to calculate fat percentage. Between-group comparisons were performed using the Mann-Whitney U test, and false discovery rate correction was applied for multiple comparisons.

resultsThe valgus group (n = 16) demonstrated significantly smaller muscle volumes in the biceps femoris, TFL, and superficial posterior compartment than the varus group (n = 59) after false discovery rate correction. The HU value of the TFL was significantly lower in the valgus group. The vastus medialis showed a lower HU value before correction; however, this difference did not remain significant after false discovery rate correction. Mimics-based fat quantification revealed no significant difference in the fat percentage of the vastus medialis, whereas the TFL showed significantly higher fat infiltration in valgus knees. Correlation analyses using FTA as a continuous variable showed that greater valgus alignment was associated with lower TFL muscle volume, lower TFL HU values, and greater TFL fat infiltration.

conclusionsAI-assisted CT-based 3D analysis revealed distinct muscle morphologies and fatty degeneration patterns in varus and valgus knees of patients with OA. Valgus knees exhibited characteristic reductions in the posterior and lateral muscle groups and increased fatty infiltration of the TFL. These deformity-specific muscular alterations may inform personalized rehabilitation strategies and help elucidate the factors contributing to the progression of OA.

trial registrationNot applicable.

Indexed as

Adipose TissueArtificial IntelligenceImaging, Three-DimensionalMuscle, SkeletalOsteoarthritis, KneeTomography, X-Ray ComputedAgedFemaleHumansMaleMiddle AgedRetrospective StudiesAI-based segmentationFatty degenerationKnee osteoarthritisMuscle volumeThree-dimensional CTValgus deformityVarus deformity

Identifiers

PMID42249474
PMCPMC13459205

What Socratic holds

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LicenceCC BY
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Registered trials

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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 Socratic graph.