Evidence map›Paper›PMID 25274088›Full record

ArticleKnee surgery, sports traumatology, arthroscopy : official journal of the ESSKA2014

Femoral and tibial insert downsizing increases the laxity envelope in TKA.

John Kyle P Mueller, Fred A Wentorf, Richard E Moore

Abstract read
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In one paragraph

Article in Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 14 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
14citing papers in PubMed, 1 pooled it
–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

14 citing papers in PubMed, 1 synthesis or guideline pooled it.

  1. Pooled it
  2. Article
  3. Article
  4. Review
  5. Article
  6. Article
  7. Tibial shaft anatomy differs between Caucasians and East Asian individuals.Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA · 2018
    Article
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  14. Level of constraint in revision knee arthroplasty.Current reviews in musculoskeletal medicine · 2015
    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

3 authors.

John Kyle P MuellerZimmer, Inc., P.O. Box 708, 1800 W Center Street, Warsaw, IN, 46581-0708, USA, johnkyle.mueller@zimmer.com.
Fred A Wentorf
Richard E Moore

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeThis study examines the effect of component downsizing in a modern total knee arthroplasty (TKA) system on the laxity envelope of the knee throughout flexion.

methodsA robotic testing system was utilized to measure laxity envelopes in the implanted knee by in the anterior-posterior (AP), medial-lateral (ML), internal-external (IE) and varus-valgus (VV) directions. Five fresh-frozen cadavers were tested with a modern cruciate retaining TKA implantation, a 1-mm thinner polyethylene insert and a femoral component 2 mm smaller in the AP dimension.

resultsThe downsized tibial insert was more lax throughout the flexion arc with up to 2.0 mm more laxity in the AP direction at full extension, a 43.8% increase over the original implantation. A thinner insert consistently increased laxity throughout the arc of flexion in all degrees of freedom. Downsizing the femoral component resulted in 8.5 mm increase in AP laxity at 90°, a 73.9% increase. In mid-flexion, downsizing the femur produced similar laxity values to the downsized insert in AP, ML, IE and VV directions.

conclusionDownsizing the TKA components had significant effects on laxity throughout flexion. Downsizing a femoral component 2 mm had an equivalent increase in laxity in mid-flexion as downsizing the tibial insert 1 mm. This study quantifies the importance of choosing the appropriate implant component size, having the appropriate size available and the effect of downsizing. The laxity of the implanted knee contributes to how the implant feels to the patient and ultimately the patient's satisfaction with their new knee.

Indexed as

Knee ProsthesisAdultArthroplasty, Replacement, KneeBiomechanical PhenomenaCadaverFemurHumansJoint InstabilityKnee JointRange of Motion, ArticularRoboticsTibia

Identifiers

PMID25274088
PMCPMC4237933

What OpenQuestion holds

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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.