Evidence map›Paper›PMID 42143278›Full record

ArticleBMC musculoskeletal disorders2026

The coronal plane alignment of the knee classification cannot ignore the joint line convergence angle.

Guanghui Zhao, Chengyuan Ma, Jianbing Ma, Jianpeng Wang

Abstract read
In one paragraph

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.

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.

Guanghui ZhaoDepartment of Joint Surgery, Honghui hospital, Xi'An Jiaotong University, No.555 East Youyi Road, Xi'an, Shaanxi, China.
Chengyuan MaDepartment of Joint Surgery, Honghui hospital, Xi'An Jiaotong University, No.555 East Youyi Road, Xi'an, Shaanxi, China.
Jianbing MaDepartment of Joint Surgery, Honghui hospital, Xi'An Jiaotong University, No.555 East Youyi Road, Xi'an, Shaanxi, China.
Jianpeng WangDepartment of Joint Surgery, Honghui hospital, Xi'An Jiaotong University, No.555 East Youyi Road, Xi'an, Shaanxi, China. 280771976@qq.com.ORCID http://orcid.org/0000-0002-7721-0896

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundRecently, several classification systems have been proposed, among which the coronal plane alignment of the knee (CPAK) classification has gained widespread adoption. Nevertheless, existing calculation methods for CPAK do not account for the joint line convergence angle (JLCA), potentially compromising classification accuracy.

methodsA modified CPAK classification incorporating JLCA was developed using the mechanical hip-knee-ankle angle (mHKA) and actual joint line obliquity (aJLO). A retrospective review was conducted on 120 patients (240 knees) with no or mild knee osteoarthritis (OA). Radiographic parameters-including mHKA, medial proximal tibial angle (MPTA), lateral distal femoral angle (LDFA), JLCA, and mechanical joint line angle (MJLA)-were measured, and arithmetic HKA (aHKA) and CPAK JLO were calculated accordingly. Knee alignment, joint line apex positions, and phenotypic classifications were compared between the conventional and the modified CPAK.

resultsThe mean JLCA was 1.0° ± 1.1°, with only 46.7% of cases falling within the range of 0° ± 1°. The mean mHKA was 178.4° ± 3.3°, while the aHKA was - 0.5° ± 3.3°. The mean aJLO was 3.2° ± 1.7°, and the CPAK JLO was 173.1° ± 3.4°. Concordance between conventional CPAK and modified CPAK in terms of knee alignment was 75.4%, joint line apex position was 64.6%, and phenotypes was 51.7%. The most prevalent CPAK types were Type II (n = 109; 45.4%), followed by Type I (n = 57; 23.8%) and Type III (n = 51; 21.3%). In contrast, the most common modified CPAK types were Type II (n = 73; 30.4%), Type IV (n = 50; 20.8%), and Type V (n = 50; 20.8%).

conclusionThe CPAK classification remains clinically relevant in knee arthroplasty, incorporating JLCA into CPAK evaluation is essential to improve classification precision and ensure more accurate representation of native knee.

Indexed as

Knee JointOsteoarthritis, KneeAgedFemaleHumansMaleMiddle AgedRadiographyRetrospective StudiesArithmetic hip-knee-ankle angleCoronal plane alignment of the kneeJoint line convergence angleJoint line obliquityMikulicz joint line angle

Identifiers

PMID42143278
PMCPMC13349082

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC-ND
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.