Evidence map›Paper›PMID 41324483›Full record

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

Knee hyperextension is a sign of through-range laxity and may be effectively managed without routine joint line distalisation in a robotic functional alignment workflow.

Anton Lambers, Serene Lee, Kate Langton, Dermot Collopy, Gavin Clark

Abstract read
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. Not yet cited in PubMed.

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0citing papers in PubMed
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1 · What the graph read from it

What it found

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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

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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

5 authors.

Anton LambersMedical School, The University of Western Australia, Perth, Western Australia, Australia.ORCID https://orcid.org/0000-0001-7796-6047
Serene LeePerth Hip and Knee Clinic, Perth, Australia.ORCID https://orcid.org/0009-0000-4425-4529
Kate LangtonPerth Hip and Knee Clinic, Perth, Australia.
Dermot CollopyPerth Hip and Knee Clinic, Perth, Australia.ORCID https://orcid.org/0000-0003-0554-4106
Gavin ClarkPerth Hip and Knee Clinic, Perth, Australia.ORCID https://orcid.org/0000-0003-3967-1613

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeTraditional management of hyperextension deformity in total knee arthroplasty (TKA) involves routine under-resection of distal femoral bone to lower the joint line and close the extension gap. This study aimed to assess how a robotic functional alignment (FA) workflow with pre-resection gap assessment managed hyperextending knees to achieve balance compared to controls.

methodsA retrospective analysis of a prospective registry was performed using a single implant/robotic platform, two surgeons, between 2016 and 2023. 100 hyperextending TKA patients with hyperextension of 5° or more were compared to a control group of 1881 patients with 0°-10° of fixed flexion contracture.

resultsThe hyperextension group had a greater maximum flexion ROM (137° vs. 132°) compared to controls. All four mean start-of-case gaps (medial and lateral in flexion and extension) were larger for the hyperextension patients by 0.7-1.2 mm. The femoral joint line was not routinely distalised by a clinically significant amount in the hyperextension patients (0.3 mm difference in means; 0.6 mm vs. 0.3 mm. The hyperextension cohort had relative tibial under-resection (4.8 mm vs. 5.4 mm; p < 0.001) and additional insert thickness (11.2 vs. 10.3 mm; p < 0.001) resulting in an overall mean tibial joint line elevation of 1.5 mm greater than controls. At the 1-year mark, there was no difference between groups when assessing range of motion (p > 0.05) and forgotten joint score (FJS, p > 0.05). Two patients had hyperextension recurrence at 1-year review, measured at -2° and -5°.

conclusionsHyperextending arthritic knees may not require routine distalisation of the femoral joint line to achieve balance and close the extension gap. These knees have a global laxity that can often be effectively managed with predominantly tibial sided changes. LEVEL OF EVIDENCE: Level III, therapeutic retrospective comparative study.

Indexed as

Arthroplasty, Replacement, KneeJoint InstabilityKnee JointRobotic Surgical ProceduresAgedFemaleHumansMaleMiddle AgedOsteoarthritis, KneeRange of Motion, ArticularRetrospective StudiesWorkflowfunctional alignmentgap assessmenthyperextension deformityrobotic‐assisted total knee arthroplastytotal knee arthroplasty

Identifiers

PMID41324483
PMCPMC13418321

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Registered trials

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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.