Evidence map›Paper›PMID 42631166›Full record

ArticleJournal of experimental orthopaedics2026

Increased sagittal patellar height and reduced trochlear engagement on MRI are associated with recurrent patellar instability in skeletally immature knees: A comparative study.

Francesco Puglia, Paolo Ferrua, David H Dejour, Marco Nicoletti, Alessio Volpe, Riccardo Compagnoni, Antonio Memeo, Pietro Simone Randelli

Abstract read
In one paragraph

Article in Journal of experimental orthopaedics, 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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0cells of the map it votes in
0citing papers in PubMed
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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

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

8 authors.

Francesco PugliaU.O.C. Ortopedia e Traumatologia Pediatrica, ASST Gaetano Pini/CTO Milan Italy.ORCID https://orcid.org/0000-0002-4886-4233
Paolo FerruaU.O.C. Ortopedia Traumatologia Week Surgery, ASST Gaetano Pini/CTO Milan Italy.ORCID https://orcid.org/0000-0002-7459-6762
David H DejourLyon-Ortho-Clinic, Clinique de la Sauvegarde, Ramsay Santé Lyon France.
Marco NicolettiU.O.C. Ortopedia e Traumatologia Pediatrica, ASST Gaetano Pini/CTO Milan Italy.ORCID https://orcid.org/0009-0004-1463-2698
Alessio VolpeOrthopedics and Traumatology Residency Program University of Milan Milan Italy.ORCID https://orcid.org/0009-0003-9468-8271
Riccardo Compagnoni2° Clinica Ortopedica, ASST Centro Specialistico Ortopedico Traumatologico Gaetano Pini-CTO Milan Italy.ORCID https://orcid.org/0000-0001-8259-8488
Antonio MemeoU.O.C. Ortopedia e Traumatologia Pediatrica, ASST Gaetano Pini/CTO Milan Italy.ORCID https://orcid.org/0000-0002-9715-6989
Pietro Simone RandelliU.O.C. 1° Clinica Ortopedica, ASST Gaetano Pini/CTO Milan Italy.ORCID https://orcid.org/0000-0001-9331-820X

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Purpose: To apply the magnetic resonance imaging (MRI)-based concept of functional patella alta to skeletally immature patients and compare sagittal patellar height and trochlear engagement between paediatric knees with objective patellar instability (OPI) and controls without patellofemoral disorders. Methods: This retrospective study included 85 skeletally immature knees (42 OPI and 43 controls) from 83 patients undergoing MRI between 2021 and 2025. OPI required at least two lateral patellar dislocations. Measurements included patellar height index (PHI), sagittal patellar cartilage length (SPCL), patello-tibial distance (PTD), patellar tendon length (PTL), sagittal trochlear cartilage length (STCL) and sagittal patellofemoral engagement (SPE). Three blinded observers measured every knee; their mean was analysed. Functional patella alta was defined using control-derived interquartile-range thresholds. Interobserver reliability used two-way random-effects, absolute-agreement intraclass correlation coefficients (ICCs). Group comparisons and logistic regression were performed. Results: OPI knees had significantly higher PHI (1.178 ± 0.171 vs. 1.083 ± 0.132; Conclusion: Paediatric recurrent patellar instability is characterised by increased patellar height and reduced sagittal trochlear engagement on MRI. Functional patella alta applies to skeletally immature knees, but instability occurs at lower sagittal engagement values than in adults. These cohort-specific exploratory thresholds require external validation before clinical use. Level of Evidence: Level III, retrospective comparative study.

Indexed as

MRI measurementspatella altapatellar instabilitypatellofemoral biomechanicspediatric knee

Identifiers

PMID42631166
PMCPMC13495771

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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.