Evidence map›Paper›PMID 39902143›Full record

ArticleJournal of orthopaedics2025

Patellofemoral positioning CT protocol has diagnostic ability to differentiate patellar maltracking phenotype.

Justin E Kung, Chase Gauthier, Miraj Desai, John O'Keefe, Heidi Ventresca, Ross Duffett, J Benjamin Jackson, Christopher Mazoue, Jeffrey A Guy

Abstract read
In one paragraph

Article in Journal of orthopaedics, 2025. 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

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

9 authors.

Justin E KungOrthopedic Surgery, Prisma Health Midlands/University of South Carolina School of Medicine, Columbia, SC, USA.
Chase GauthierOrthopedic Surgery, Prisma Health Midlands/University of South Carolina School of Medicine, Columbia, SC, USA.
Miraj DesaiOrthopedic Surgery, Prisma Health Midlands/University of South Carolina School of Medicine, Columbia, SC, USA.
John O'KeefeOrthopedic Surgery, Prisma Health Midlands/University of South Carolina School of Medicine, Columbia, SC, USA.
Heidi VentrescaOrthopedic Surgery, Prisma Health Midlands/University of South Carolina School of Medicine, Columbia, SC, USA.
Ross DuffettOrthopedic Surgery, Prisma Health Midlands/University of South Carolina School of Medicine, Columbia, SC, USA.
J Benjamin JacksonOrthopedic Surgery, Prisma Health Midlands/University of South Carolina School of Medicine, Columbia, SC, USA.
Christopher MazoueOrthopedic Surgery, Prisma Health Midlands/University of South Carolina School of Medicine, Columbia, SC, USA.
Jeffrey A GuyOrthopedic Surgery, Prisma Health Midlands/University of South Carolina School of Medicine, Columbia, SC, USA.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Introduction: Traditional radiographs often fail to capture the dynamic nature of patellar maltracking in patellofemoral pain syndrome (PFPS) and patellar instability, necessitating improved diagnostic protocols. This study aimed to: (1) introduce a CT protocol with scans at three knee positions (45° flexion, extension, and extension with quadriceps contraction), (2) assess how positioning influences patellofemoral indices measured from radiographs and CT, and (3) to evaluate the protocol's ability to classify maltracking phenotypes: dislocator, subluxator, or symptomatic without dislocation/subluxation (Neither). Methods: Patients who underwent surgery for PFPS from April to December 2022 were retrospectively reviewed. Patellofemoral indices from the three scans within the CT protocol were compared among themselves and with standard radiographs. Patients were grouped by maltracking phenotype, and their patellofemoral indices on radiographs and CT were compared to determine which imaging modality best distinguished the phenotypes. Statistical analyses included bivariate and multivariate logistic regression. Results: The study included 65 patients (51 females, 14 males) with mean age of 27. Patellofemoral indices measured on CT-45° versus CT-Extended differed significantly (p < 0.05), indicated the influence of knee position. Quadriceps contraction further worsened most indices, highlighting the importance of load-bearing conditions. Radiographs and CT-45° had limited capability to differentiate Dislocator, Subluxator, and Neither, but CT-Extended and CT-Quad showed significant differences among these groups. Multivariate analysis identified four independent predictors of patellar maltracking severity (p < 0.05): (1) Lateral Offset and (2) Insall-Salvati Ratio measured on CT-Extended, as changes in (3) Lateral Offset and (4) Lateral patellofemoral angle (LPFA) between extension and quadriceps contraction. Conclusions: Radiographs alone cannot reliably distinguish Dislocator, Subluxator, and Neither. A dedicated CT protocol featuring scans in neutral extension and with quadriceps contraction better delineates patellofemoral maltracking phenotypes and offers improved diagnostic accuracy in PFPS. This approach may guide tailored interventions to address distinct underlying mechanics of each phenotype. Level of evidence: III.

Indexed as

Dynamic CTPatellar instabilityPatellar maltrackingPatellofemoral pain syndromeQuadriceps contraction

Identifiers

PMID39902143
PMCPMC11787662

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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.