Evidence map›Paper›PMID 40688447›Full record

ArticleJournal of orthopaedics2025

The influence of CPAK classification on the pivot motion between kinematic and mechanical alignment total knee arthroplasty.

Eiichi Shiigi, Tsuneari Takahashi, Koji Yoshida, Masahiro Numa, Keiko Kamata, Katsushi Takeshita, Takashi Sakai

Abstract read
In one paragraph

Article in Journal of orthopaedics, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

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

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. Trial
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.

Eiichi ShiigiDepartment of Orthopedic Surgery, Yamaguchi Prefectural Grand Medical Center, Hofu, Japan.
Tsuneari TakahashiDepartment of Orthopedics, Jichi Medical University, Shimotsuke, Japan.
Koji YoshidaDepartment of Orthopedic Surgery, Yamaguchi Prefectural Grand Medical Center, Hofu, Japan.
Masahiro NumaDepartment of Orthopedic Surgery, Yamaguchi University, Ube, Japan.
Keiko KamataDepartment of Orthopedic Surgery, Yamaguchi Saiseikai Shimonoseki General Hospital, Shimonoseki, Japan.
Katsushi TakeshitaDepartment of Orthopedics, Jichi Medical University, Shimotsuke, Japan.
Takashi SakaiDepartment of Orthopedic Surgery, Yamaguchi University, Ube, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Purpose: This study investigated whether the preoperative coronal plane alignment of the knee (CPAK), categorized as type I or II, has an effect on postoperative tibial internal rotation (TIR) relative to the femur in patients who received a medial pivot-cruciate retaining (MP-CR) total knee arthroplasty (TKA). Methods: We retrospectively analyzed 62 patients who underwent MP-CR TKA with the GMK Sphere implant (Medacta International, Switzerland) from January 2024 to May 2025. Based on their CPAK classification, patients were divided into two groups (type I or II). Intraoperative kinematic assessments were performed using augmented reality (AR) CT-guided navigation (NextAR, Medacta), evaluating the dynamic elongation of medial and lateral collateral ligaments during either kinematic (KA) or mechanical alignment (MA) procedures. The primary measure was TIR at 30°, 60°, 90°, and 120° of knee flexion.Univariate analyses identified significant differences, which were further assessed using multi-way ANOVA to determine interactions with CPAK classification. Results: Notable differences in TIR were found between CPAK types I and II at 60° (2.1° ± 4.8° vs. -2.0° ± 4.2°, p = 0.009), 90° (7.0° ± 4.3° vs. 2.1° ± 5.6°, p = 0.002), and 120° (13.1° ± 5.2° vs. 7.5° ± 4.9°, p = 0.002). Additionally, at 90°, sex and alignment method (KA vs. MA) showed significant interaction with CPAK classification (F = 6.4; p = 0.015), while the alignment method alone had no significant effect on TIR. Conclusion: The CPAK classification prior to surgery affected TIR outcomes regardless of the alignment method used, as measured via AR-CT navigation.

Indexed as

Augmented reality navigationKinematic alignmentKinematic analysisKnee osteoarthritisMechanical alignmentTotal knee arthroplasty

Identifiers

PMID40688447
PMCPMC12271803

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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.