Evidence map›Paper›PMID 42115992›Full record

ArticleBMC musculoskeletal disorders2026

Modified extramedullary femoral referencing is associated with improved femorotibial component alignment consistency and more stable mobile-bearing positional behavior in Oxford medial unicompartmental knee arthroplasty: a retrospective cohort study.

Tong Li, Fengrui Liu, Jiaxiang Gao, Ran Ding, Weiguo Wang, Philippe Hernigou, Qidong Zhang, Wanshou Guo

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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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5 · Who and what money

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8 authors.

Tong Li *Department of Orthopedics and Joint Surgery, China-Japan Friendship Hospital, Beijing, China.
Fengrui Liu *Department of Orthopedics and Joint Surgery, China-Japan Friendship School of Clinical Medicine, Peking University, Beijing, China.
Jiaxiang GaoDepartment of Orthopedics and Joint Surgery, China-Japan Friendship Hospital, Beijing, China.
Ran DingDepartment of Orthopedics and Joint Surgery, China-Japan Friendship Hospital, Beijing, China.
Weiguo WangDepartment of Orthopedics and Joint Surgery, China-Japan Friendship Hospital, Beijing, China.
Philippe HernigouDepartment of Orthopaedic Surgery, Hôpitaux Universitaires Henri-Mondor, Créteil, France.
Qidong ZhangDepartment of Orthopedics and Joint Surgery, China-Japan Friendship Hospital, Beijing, China. zhangqidong1982@sina.com.
Wanshou GuoDepartment of Orthopedics and Joint Surgery, China-Japan Friendship Hospital, Beijing, China. wanshou_guo@163.com.

Funding

Excellence & Innovation Initiative of China-Japan Friendship Hospital ZRZC2025-XYB01Natural Science Foundation of Beijing Municipality L244060
6 · The paper itself

Abstract

backgroundMobile-bearing stability in Oxford medial unicompartmental knee arthroplasty (UKA) depends on maintaining a consistent femorotibial component relationship throughout knee motion. This study evaluated whether a modified extramedullary femoral referencing technique, designed to account for extension-phase alignment, was associated with reduced motion-related variation in femorotibial component position and more stable mobile-bearing positional behavior than the previously described extramedullary technique.

methodsThis single-center retrospective cohort study included 60 patients who underwent primary medial mobile-bearing Oxford UKA between January 2023 and January 2024. Thirty consecutive patients treated with the modified technique (modified group, MG) were compared with 30 individually matched controls treated with the previous extramedullary technique (control group, CG). Standardized standing and 90° flexion anteroposterior radiographs were used to assess the normalized horizontal distance between the femoral component and the tibial lateral wall, bearing horizontal translation, and bearing rotation. Clinical outcomes included range of motion (ROM), Hospital for Special Surgery (HSS) knee score, and postoperative complications.

resultsBaseline demographic and preoperative clinical characteristics did not differ significantly between groups. Follow-up duration was similar (27.4 ± 3.3 vs. 26.5 ± 2.9 months, p = 0.267). Postoperative ROM and HSS were also comparable, with postoperative HSS scores of 90.6 ± 5.8 in the MG and 89.2 ± 5.2 in the CG (p = 0.319). The MG showed significantly lower motion-related variation in femorotibial component position than the CG (ΔDistance: -0.006 ± 0.040 vs. 0.024 ± 0.054, p = 0.018). Within-group analysis showed no significant extension-versus-flexion change in normalized femorotibial distance in the MG, whereas a significant change was observed in the CG (p = 0.021). Compared with the CG, the MG had lower extension bearing rotation (-0.001 ± 0.054 vs. 0.037 ± 0.077, p = 0.033) and smaller bearing horizontal translation (0.039 ± 0.047 vs. 0.071 ± 0.052, p = 0.018). One bearing dislocation occurred in the CG and none occurred in the MG.

conclusionsThe modified extramedullary femoral referencing technique was associated with less motion-related variation in femorotibial component position and more stable radiographically derived mobile-bearing positional behavior. These differences were not accompanied by superior short-term ROM or HSS. CLINICAL TRIAL NUMBER: Not applicable.

Indexed as

Arthroplasty, Replacement, KneeFemurKnee ProsthesisOsteoarthritis, KneeAgedFemaleHumansKnee JointMaleMiddle AgedRange of Motion, ArticularRetrospective StudiesTibiaTibiofemoral JointTreatment OutcomeFemoral component implantationFemorotibial component alignmentMobile-bearing positional behaviorOxford unicompartmental knee arthroplastyRetrospective cohort

Identifiers

PMID42115992
PMCPMC13330316

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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 OpenQuestion graph.