Evidence map›Paper›PMID 42089934›Full record

ArticleSports medicine - open2026

Initial Tendon Retraction is Associated with Muscle Degeneration After Nonoperatively Treated Proximal Hamstring Avulsions.

Sofia Laszlo, Anne-Mari Rosenlund, Elsa Pihl, Målfrid Holen Kristoffersen, Olof Sköldenberg, Jörg Schilcher, Martin Eklund, Frede Frihagen, Mikael Skorpil, Kenneth B Jonsson

Registry-linked trialAbstract read
In one paragraph

Article in Sports medicine - open, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT03311997 (The Proximal Hamstring Avulsion Clinical Trial - Nonoperative Treatment Compared With Suture Anchor Reinsertion of Proximal Hamstrings Avulsions), which is not on this 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.

NCT03311997 nacompletednot on this map

The Proximal Hamstring Avulsion Clinical Trial - Nonoperative Treatment Compared With Suture Anchor Reinsertion of Proximal Hamstrings Avulsions

TypeinterventionalSponsorUppsala UniversityRan2017 to 2022Enrolled216ConditionsHamstring Tendon InjuryArmsSurgical reattachment of hamstring tendons
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

10 authors.

Sofia LaszloDepartment of Surgical Sciences, Unit of Orthopedic Surgery, Uppsala University, Uppsala University Hospital, 75185, Uppsala, Sweden.
Anne-Mari RosenlundDivision of Orthopaedic Surgery, Oslo University Hospital, Oslo, Norway.
Elsa PihlDepartment of Clinical Sciences at Danderyds Hospital, Karolinska Institutet, Stockholm, Sweden.
Målfrid Holen KristoffersenDepartment of Orthopedic Surgery, Haukeland University Hospital, Bergen, Norway.
Olof SköldenbergDepartment of Clinical Sciences at Danderyds Hospital, Karolinska Institutet, Stockholm, Sweden.
Jörg SchilcherDepartment of Orthopedic Surgery, Faculty of Health Sciences, Linköping University, Linköping, Sweden.
Martin EklundDepartment of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
Frede FrihagenInstitute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
Mikael SkorpilDepartment of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
Kenneth B JonssonDepartment of Surgical Sciences, Unit of Orthopedic Surgery, Uppsala University, Uppsala University Hospital, 75185, Uppsala, Sweden. Kenneth.Jonsson@uu.se.ORCID http://orcid.org/0000-0002-2268-8008

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

background and purposeMagnetic resonance imaging (MRI) is essential in assessing proximal hamstring avulsions (PHA), where tendon retraction is a key pathological consequence. Beyond its diagnostic role, MRI may also provide prognostic information on subsequent muscle degeneration. This study aimed to determine whether pre-treatment MRI findings, particularly tendon retraction, predict later muscle degeneration and clinical outcomes in nonoperatively treated PHA patients.

methodsThis study is a post hoc analysis of nonoperatively treated patients (n = 95) with complete proximal hamstring avulsions from the Proximal Hamstring Avulsion Clinical Trial (PHACT). Diagnostic MRIs were reassessed for tendon retraction, Wood classification, number of tendons avulsed, and hematoma size. The primary outcome was muscle degeneration, defined by the loss of lean muscle volume (LMV) and an increase in muscle fat fraction (MFF) quantified by DIXON MRI at 24 months. The secondary outcome was maximum hamstring muscle isometric force at 24 months. Outcome data was expressed as the limb symmetry index (LSI), which was the measurement of the injured hamstring expressed as a percentage of measurement of the uninjured hamstring. Linear regression was used to analyze the association between diagnostic MRI measurements, patient factors, and LSIs for LMV, MFF, and maximum isometric force.

resultsThe median (IQR) LSIs of the LMV, MFF and maximum strength were 78% (67.2, 87.1), 139% (124.5, 166.8), and 84% (75.4, 94.0), respectively, at 24-month follow-up. A multivariate linear regression model including tendon retraction, age, sex, hematoma size and whether the dominant limb was injured explained 48%, 48% and 23% of the variance in the LSIs of LMV, MFF and maximum force, respectively. Tendon retraction was the strongest explanatory factor for the variance of muscle degeneration observed in patients with nonoperatively treated PHA.

interpretationGreater initial tendon retraction is associated with increased muscle atrophy and fat infiltration in the hamstring muscles in patients with nonoperatively treated PHA.

trial registrationNCT03311997.

Identifiers

PMID42089934
PMCPMC13149700

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

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.