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Published in: Knee Surgery, Sports Traumatology, Arthroscopy 4/2023

30-11-2022 | Knee Osteoarthritis | Knee

Variability of functional knee phenotype for coronal alignment in advanced varus knee osteoarthritis in the Japanese population

Authors: Wang Huan, Tomoharu Mochizuki, Osamu Tanifuji, Hiroyuki Kawashima

Published in: Knee Surgery, Sports Traumatology, Arthroscopy | Issue 4/2023

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Abstract

Purpose

New concept of functional knee phenotypes in Caucasians demonstrated the variability of coronal alignment in knee osteoarthritis (OA), but it remains unclear in Japanese. This study aims to analyze the knee phenotype in advanced varus knee OA for Japanese. In addition, the ethnical difference is discussed.

Methods

This study analyzed 879 knees involving 186 males (74 years) and 693 females (74 years). The knee phenotypes were assessed by the definition in Hirschmann’s group. The hip–knee–ankle angle (HKA), femoral mechanical angle (FMA) and tibial mechanical angle (TMA) were assessed in CT data according to the coordinate system. The neutral angle was 180° in HKA, 93° in FMA and 87° in TMA. The smaller angle means larger varus angles.

Results

The average angle (males, females) of the HKA (170.9 ± 4.3°, 169.4 ± 5.0°), FMA (91.5 ± 2.7°, 90.6 ± 3.0°), and TMA (82.4 ± 3.6°, 82.7 ± 3.7°) demonstrated varus angles with the sex difference (HKA, p < 0.001; FMA, p = 0.001). The phenotypes were 73 types in males and 150 types in females with a mild correlation between the HKA and the FMA or TMA. In 61.3% of males and 52.2% of females, the TMA was greater than the FMA, while the FMA was greater in 16.7% of males and 23.1% of females.

Conclusion

There were many functional knee phenotypes with sex differences for advanced varus knee OA in Japanese, showing ethnical differences of larger varus angles compared to those for Caucasians in the previous report.

Level of evidence

IV.
Literature
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go back to reference Hess S, Moser LB, Robertson EL, Behrend H, Amsler F, Iordache E, Leclercq V, Hirschmann MT (2022) Osteoarthritic and non-osteoarthritic patients show comparable coronal knee joint line orientations in a cross-sectional study based on 3D reconstructed CT images. Knee Surg Sports Traumatol Arthrosc 30:407–418. https://doi.org/10.1007/s00167-021-06740-3CrossRefPubMed Hess S, Moser LB, Robertson EL, Behrend H, Amsler F, Iordache E, Leclercq V, Hirschmann MT (2022) Osteoarthritic and non-osteoarthritic patients show comparable coronal knee joint line orientations in a cross-sectional study based on 3D reconstructed CT images. Knee Surg Sports Traumatol Arthrosc 30:407–418. https://​doi.​org/​10.​1007/​s00167-021-06740-3CrossRefPubMed
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go back to reference Mochizuki T, Koga Y, Mori T, Nishino K, Kobayashi K, Tanifuji O, Sato T, Katsumi R, Koga H, Omori G, Tanabe Y (2020) Articular surface of the medial proximal tibia is aligned parallel to the ground in three-dimensional space under weight-bearing conditions in healthy and varus osteoarthritic knees. Knee Surg Sports Traumatol Arthrosc 28:3232–3239. https://doi.org/10.1007/s00167-019-05829-0CrossRefPubMed Mochizuki T, Koga Y, Mori T, Nishino K, Kobayashi K, Tanifuji O, Sato T, Katsumi R, Koga H, Omori G, Tanabe Y (2020) Articular surface of the medial proximal tibia is aligned parallel to the ground in three-dimensional space under weight-bearing conditions in healthy and varus osteoarthritic knees. Knee Surg Sports Traumatol Arthrosc 28:3232–3239. https://​doi.​org/​10.​1007/​s00167-019-05829-0CrossRefPubMed
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Metadata
Title
Variability of functional knee phenotype for coronal alignment in advanced varus knee osteoarthritis in the Japanese population
Authors
Wang Huan
Tomoharu Mochizuki
Osamu Tanifuji
Hiroyuki Kawashima
Publication date
30-11-2022
Publisher
Springer Berlin Heidelberg
Published in
Knee Surgery, Sports Traumatology, Arthroscopy / Issue 4/2023
Print ISSN: 0942-2056
Electronic ISSN: 1433-7347
DOI
https://doi.org/10.1007/s00167-022-07248-0

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