Evidence map›Paper›PMID 29958159›Full record

ArticleGait & posture2018

How does patellar tendon advancement alter the knee extensor mechanism in children treated for crouch gait?

Moria F Bittmann, Rachel L Lenhart, Michael H Schwartz, Tom F Novacheck, Scott Hetzel, Darryl G Thelen

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Gait & posture, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.

0numbers the graph read from it
0cells of the map it votes in
4citing papers in PubMed
1.2field-weighted citation impact, top 22% of its field
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

4 citing papers in PubMed, 18 citations in OpenAlex.

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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

6 authors at 3 institutions in 1 country.

Moria F BittmannDepartment of Mechanical Engineering, University of Wisconsin-Madison, USA.
Rachel L LenhartDepartment of Mechanical Engineering, University of Wisconsin-Madison, USA.
Michael H SchwartzGillette Children's Specialty Healthcare, USA; Department of Orthopaedic Surgery, University of Minnesota -Twin Cities, USA.
Tom F NovacheckGillette Children's Specialty Healthcare, USA; Department of Orthopaedic Surgery, University of Minnesota -Twin Cities, USA.
Scott HetzelDepartment of Orthopedics and Rehabilitation, University of Wisconsin-Madison, USA.
Darryl G ThelenDepartment of Mechanical Engineering, University of Wisconsin-Madison, USA; Department of Orthopedics and Rehabilitation, University of Wisconsin-Madison, USA; Department of Biomedical Engineering, University of Wisconsin-Madison, USA. Electronic address: dgthelen@wisc.edu.
University of Wisconsin–Madison · USTwin Cities Orthopedics · USUniversity of Minnesota · US

Funding

INTEGRATED TRAINING FOR PHYSICIAN-SCIENTISTST32GM008692 · NIGMS · UNIVERSITY OF WISCONSIN-MADISON · PI BURKARD, MARK E · 1998 to 2020
$10.3M
Impact of Crouch Gait and Surgical Treatment on Knee Mechanics and FunctionR21HD084213 · NICHD · UNIVERSITY OF WISCONSIN-MADISON · PI THELEN, DARRYL G · 2015 to 2016
$386k
Influence of Surgery on Musculoskeletal Mechanics in Children with Crouch GaitF30AR065838 · NIAMS · UNIVERSITY OF WISCONSIN-MADISON · PI LENHART, RACHEL L · 2014 to 2016
$125k
NIAMS NIH HHS F30 AR065838NICHD NIH HHS R21 HD084213NIGMS NIH HHS T32 GM008692
6 · The paper itself

Abstract

backgroundThe patellar tendon advancement (PTA) procedure, often coupled with a distal femoral extension osteotomy (DFEO), is increasingly used to treat persistent crouch gait. In this study, we investigated relationships between patella position, knee flexion, and the patellar tendon moment arm in children treated with the DFEO and PTA procedures.

methodsWe retrospectively analyzed pre- and post-operative radiographs and gait metrics from 63 knees that underwent DFEO and PTA procedures at Gillette Children's Specialty Healthcare. A computational musculoskeletal model of the knee was used to simulate the PTA procedure and predict the effects on the patellar tendon moment arm.

resultsApproximately 80% of the knees exhibited patella alta prior to surgery. Post-operatively, 86% of the knees exhibited patella baja. The surgically altered patella position produced a 13% increase in the patellar tendon moment arm in extended knee postures, which agreed well with model predictions. However, the computational model also suggests that baja may compromise patellar tendon moment arms in flexed knee postures. Crouch gait was significantly reduced postoperatively, with a 27 ± 18° reduction in average knee flexion in stance. There was considerable inter-subject variability in outcomes with nine knees not exhibiting a meaningful enhancement of knee extension (<15° change). The subjects who improved were significantly younger and exhibited greater enhancement of the patellar tendon moment arm after surgery.

conclusionsThis study shows that the PTA procedure enhances the lever arm of the knee extensor mechanism, and this factor may be important in resolving crouch gait.

Indexed as

Cerebral PalsyChildDatabases, FactualFemaleGaitGait Disorders, NeurologicHumansKnee JointMaleOsteotomyPatellaPatellar LigamentPostoperative PeriodRange of Motion, ArticularRetrospective StudiesTendon TransferCerebral palsyKnee extensor lagMoment armPatella altaQuadriceps insufficiencyTibiofemoral joint

Identifiers

PMID29958159
PMCPMC6181142
OpenAlexW2805334271

What OpenQuestion holds

Textmetadata
LicenceTDM
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.