Evidence map›Paper›PMID 41353725›Full record

ArticleKnee surgery, sports traumatology, arthroscopy : official journal of the ESSKA2026

Smaller medial component gaps at deep flexion are associated with better patient-reported outcomes after robotic-assisted cruciate-retaining total knee arthroplasty using an anatomically designed implant.

Yutaka Nakamura, Hiroyasu Ogawa, Yusuke Ota, Kaito Takagi, Masaya Sengoku, Kazuichiro Onishi, Haruhiko Akiyama

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed, 1 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

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2 · The registry

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.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed, 1 synthesis or guideline pooled it.

  1. Pooled it
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Yutaka NakamuraDepartment of Orthopedic Surgery, Gifu University Graduate School of Medicine, Gifu, Gifu, Japan.ORCID https://orcid.org/0000-0001-8933-9382
Hiroyasu OgawaDepartment of Orthopedic Surgery, Gifu University Graduate School of Medicine, Gifu, Gifu, Japan.ORCID https://orcid.org/0000-0002-4737-6481
Yusuke OtaDepartment of Orthopedic Surgery, Gifu University Graduate School of Medicine, Gifu, Gifu, Japan.
Kaito TakagiDepartment of Orthopedic Surgery, Ogaki Tokushukai Hospital, Ogaki, Gifu, Japan.
Masaya SengokuDepartment of Orthopedic Surgery, Ogaki Tokushukai Hospital, Ogaki, Gifu, Japan.
Kazuichiro OnishiDepartment of Orthopedic Surgery, Ogaki Tokushukai Hospital, Ogaki, Gifu, Japan.
Haruhiko AkiyamaDepartment of Orthopedic Surgery, Gifu University Graduate School of Medicine, Gifu, Gifu, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeSoft tissue balance is essential for optimal function and satisfaction after total knee arthroplasty (TKA). However, the clinical significance of medial gap patterns across the entire range of motion (ROM) remains unclear. This study aimed to examine the association between intraoperative medial gap patterns and post-operative patient-reported outcome measures (PROMs) in robotic-assisted cruciate-retaining (CR) TKA. It was hypothesized that medial gap patterns with smaller deep-flexion gaps relative to mid-flexion or 90° flexion would be associated with superior PROMs.

methodsThis retrospective study included 102 patients (120 knees) who underwent primary robotic-assisted CR TKA. Bone and cartilage resection thickness and simulated gaps were assessed at the planning stage, and the final component gaps were recorded at the trial stage. Medial gap patterns were classified as: 1 (constant), 2 (gradually increasing), 3 (increasing/decreasing) and 4 (gradually decreasing). Objective outcomes were assessed using the Knee Society Score (KSS), and subjective outcomes were evaluated using the Western Ontario and McMaster Universities Arthritis Index (WOMAC), Forgotten Joint Score-12 and the satisfaction score of the 2011 KSS.

resultsTen, 47, 51 and 12 knees were classified into Patterns 1-4, respectively. The resection gaps at flexion and the flexion-extension gap difference were relatively larger in Pattern 2. Objective outcomes were comparable among patterns; however, the PROMs differed significantly. Pattern 3 demonstrated better WOMAC stiffness and KSS satisfaction scores than Patterns 1 and 2.

conclusionMedial gap patterns in which deep-flexion gaps did not exceed those at mid-flexion or 90° flexion were associated with better PROMs in robotic-assisted CR TKA. These findings support the hypothesis that avoiding underestimation of native joint gaps at deep flexion is important for optimizing patient-reported outcomes. LEVEL OF EVIDENCE: Level III.

Indexed as

Arthroplasty, Replacement, KneeKnee ProsthesisOsteoarthritis, KneePatient Reported Outcome MeasuresRobotic Surgical ProceduresAgedAged, 80 and overFemaleHumansKnee JointMaleMiddle AgedProsthesis DesignRange of Motion, ArticularRetrospective StudiesTreatment Outcomecomponent gapkinematic alignmentpatient‐reported outcome measuresrobotic‐assistedtotal knee arthroplasty

Identifiers

PMID41353725
PMCPMC13502426

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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.