Evidence map›Paper›PMID 42342953›Full record

ArticleJournal of orthopaedics and traumatology : official journal of the Italian Society of Orthopaedics and Traumatology2026

Thicker polyethylene inserts for varus deformity versus thinner inserts for flexion contracture in total knee arthroplasty: a retrospective comparative study.

Seung-Hun Lee, Hyuck Min Kwon, Woo-Suk Lee, Kwan Kyu Park

Abstract readComparative Study
In one paragraph

Article in Journal of orthopaedics and traumatology : official journal of the Italian Society of Orthopaedics and Traumatology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing 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

0 citing papers in PubMed.

No citing paper in PubMed yet.

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

4 authors.

Seung-Hun LeeDepartment of Orthopaedic Surgery, Yonsei University College of Medicine, Severance Hospital, 50-1, Yonsei-Ro, Seodaemoon-Gu, Seoul, 03722, Republic of Korea.
Hyuck Min KwonDepartment of Orthopaedic Surgery, Yonsei University College of Medicine, Severance Hospital, 50-1, Yonsei-Ro, Seodaemoon-Gu, Seoul, 03722, Republic of Korea.
Woo-Suk LeeDepartment of Orthopaedic Surgery, Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul, Republic of Korea.
Kwan Kyu ParkDepartment of Orthopaedic Surgery, Yonsei University College of Medicine, Severance Hospital, 50-1, Yonsei-Ro, Seodaemoon-Gu, Seoul, 03722, Republic of Korea. kkpark@yuhs.ac.ORCID http://orcid.org/0000-0002-3429-5594

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundThe success of total knee arthroplasty (TKA) depends on achieving precise mechanical alignment and stable soft tissue balance, with the thickness of the final polyethylene (PE) insert serving as a critical component. However, the impact of preoperative factors on PE thickness remains unclear. In this study, we investigated the effects of preoperative knee alignment and clinical deformities on PE thickness. MATERIALS AND

methodsThe medical records of patients who underwent primary TKA between August 2024 and July 2025 were retrospectively evaluated. Preoperative radiographic parameters, including the hip-knee-ankle (HKA) angle, medial proximal tibial angle, lateral distal femoral angle (LDFA), joint-line convergence angle, weight-bearing line ratio (WBLR), and posterior tibial slope, were measured, along with the flexion contracture (FC) as a clinical factor. Intra-observer reliability was assessed using intraclass correlation coefficients (ICC). Linear regression analyses were performed to evaluate the effects of these preoperative factors on PE thickness.

resultsThis study included 233 knees (158 patients). The intra-observer reliability of the radiographic parameters was excellent (ICC > 0.9). Multivariable linear regression revealed that preoperative HKA angle (β = 0.033, p < 0.001), WBLR (β = -0.008, p < 0.001), and LDFA (β = 0.065, p = 0.003) were significantly associated with final PE thickness. Preoperative FC demonstrated a significant negative correlation (β = -0.027, p = 0.011). In a subgroup analysis of knees with minimal FC, the mean PE thickness increased from 10.37 mm in mild varus to 12.75 mm in extreme varus.

conclusionsPreoperative HKA angle and FC were identified as significant predictors of PE insert thickness in TKA. Specifically, greater varus deformity resulted in a thicker PE insert, whereas more severe FC led to a thinner insert. Clinically, surgeons must anticipate gap expansion after medial release in varus knees, while accommodating the tight extension space in the FC. Level of evidence Level III, retrospective comparative study.

Indexed as

Arthroplasty, Replacement, KneeContractureKnee ProsthesisPolyethyleneProsthesis DesignAgedFemaleHumansKnee JointMaleMiddle AgedRange of Motion, ArticularRetrospective StudiesPolyethyleneFlexion contractureHip–knee–ankle angleKnee alignmentPolyethylene insertTotal knee arthroplasty

Identifiers

PMID42342953
PMCPMC13554027

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

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.