Evidence map›Paper›PMID 26438246›Full record

ArticleKnee surgery, sports traumatology, arthroscopy : official journal of the ESSKA2016

Changes in the orientation of knee functional flexion axis during passive flexion and extension movements in navigated total knee arthroplasty.

Francesca Colle, Danilo Bruni, Francesco Iacono, Andrea Visani, Stefano Zaffagnini, Maurilio Marcacci, Nicola Lopomo

Abstract read
PubMed Publisher
In one paragraph

Article in Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing 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

3 citing papers in PubMed.

  1. A new parameter in the era of robotic total knee arthroplasty: Coronal alignment at 90° of flexion impacts clinical outcomes.Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA · 2025
    Article
  2. Article
  3. Dynamic knee behaviour: does the knee deformity change as it is flexed-an assessment and classification with computer navigation.Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA · 2016
    Article
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.

Francesca ColleLaboratorio di Biomeccanica e Innovazione Tecnologica, Istituto Ortopedico Rizzoli, Via Di Barbiano 1/10, 40136, Bologna, Italy.
Danilo BruniLaboratorio di Biomeccanica e Innovazione Tecnologica, Istituto Ortopedico Rizzoli, Via Di Barbiano 1/10, 40136, Bologna, Italy.
Francesco IaconoLaboratorio di Biomeccanica e Innovazione Tecnologica, Istituto Ortopedico Rizzoli, Via Di Barbiano 1/10, 40136, Bologna, Italy.
Andrea VisaniLaboratorio di Biomeccanica e Innovazione Tecnologica, Istituto Ortopedico Rizzoli, Via Di Barbiano 1/10, 40136, Bologna, Italy.
Stefano ZaffagniniLaboratorio di Biomeccanica e Innovazione Tecnologica, Istituto Ortopedico Rizzoli, Via Di Barbiano 1/10, 40136, Bologna, Italy.
Maurilio MarcacciLaboratorio di Biomeccanica e Innovazione Tecnologica, Istituto Ortopedico Rizzoli, Via Di Barbiano 1/10, 40136, Bologna, Italy.
Nicola LopomoLaboratorio di Biomeccanica e Innovazione Tecnologica, Istituto Ortopedico Rizzoli, Via Di Barbiano 1/10, 40136, Bologna, Italy. n.lopomo@biomec.ior.it.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeRecently, the functional flexion axis has been considered to provide a proper rotational alignment of the femoral component in total knee arthroplasty. Several factors could influence the identification of the functional flexion axis. The purpose of this study was to analyse the estimation of the functional flexion axis by separately focusing on passive flexion and extension movements and specifically assessing its orientation compared to the transepicondylar axis, in both the axial plane and the frontal plane.

methodsAnatomical and kinematic acquisitions were performed using a commercial navigation system on 79 patients undergoing total knee arthroplasty with cruciate substituting prosthesis design. The functional flexion axis was estimated from passive movements, between 0° and 120° of flexion and back. Intra-observer agreement and reliability, internal-external rotation and the angle with the surgical transepicondylar axis, in axial and frontal planes, were separately analysed for flexion and extension, in pre- and post-implant conditions.

resultsThe analysis of reliability and agreement showed good results. The identification of the functional flexion axis showed statistically significant differences both in relation to flexion and extension and to pre- and post-implant conditions, both in frontal plane and in axial plane. The analysis of internal-external rotation confirmed these differences in kinematics (p < 0.05, between 25° and 35° of flexion).

conclusionsThe identification of the functional flexion axis changed in relation to passive flexion and extension movements, above all in frontal plane, while it resulted more stable and reliable in axial plane. These findings supported the possible clinical application of the functional flexion axis in the surgical practice by implementing navigated procedures. However, further analyses are required to better understand the factors affecting the identification of the functional flexion axis. LEVEL OF EVIDENCE: IV.

Indexed as

AgedAged, 80 and overArthroplasty, Replacement, KneeBiomechanical PhenomenaFemaleFemurHumansKnee JointMaleMiddle AgedMovementProsthesis DesignRange of Motion, ArticularReproducibility of ResultsRotationComputer-aided surgeryFlexion–extension passive range of motionKnee functional flexion axisKnee kinematicsTotal knee arthroplasty

Identifiers

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.