Evidence map›Paper›PMID 39118446›Full record

ArticleKnee surgery, sports traumatology, arthroscopy : official journal of the ESSKA2025

Habitual patellar dislocation exhibits less severe rotational deformities but poorer trochlear development and higher incidence of patella baja compared with recurrent patellar dislocation in skeletally mature patients.

Zhijun Zhang, Zheng Feng, Menglinqian Di, Daofeng Wang, Tong Zheng, Hui Zhang

Abstract readComparative Study
In one paragraph

Article in Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 7 papers.

0numbers the graph read from it
0cells of the map it votes in
7citing 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

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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

7 citing papers in PubMed.

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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.

Zhijun ZhangSports Medicine Service, Beijing jishuitan hospital, Capital Medical University, Beijing, China.
Zheng FengSports Medicine Service, Beijing jishuitan hospital, Capital Medical University, Beijing, China.
Menglinqian DiSports Medicine Service, Beijing jishuitan hospital, Capital Medical University, Beijing, China.
Daofeng WangSports Medicine Service, Beijing jishuitan hospital, Capital Medical University, Beijing, China.
Tong ZhengSports Medicine Service, Beijing jishuitan hospital, Capital Medical University, Beijing, China.
Hui ZhangSports Medicine Service, Beijing jishuitan hospital, Capital Medical University, Beijing, China.ORCID http://orcid.org/0000-0001-8329-1920

Funding

Beijing Jishuitan Research Funding XKXX202211Beijing Municipal Health Commission BJRITO-RDP-2024National Natural Science Foundation of China 82202777
6 · The paper itself

Abstract

purposeThis study compared the radiological characteristics between habitual and recurrent patellar dislocation in skeletally mature patients.

methodsFrom 2017 to 2019, 77 skeletally mature patients with habitual patellar dislocation were surgically treated at a single institution and reviewed retrospectively. A total of 55 knees from these patients were included in the habitual patellar dislocation group. During the same period, 55 knees with recurrent patellar dislocation were randomly selected from 242 patients and included in the recurrent patellar dislocation group. Various bony deformities were measured and compared between the two groups. Additionally, a subgroup analysis was conducted among patients with habitual patellar dislocation, comparing those with and without an 'invisible patella' observed on true lateral views with 30° of knee flexion.

resultsThe femoral anteversion angle (21.8° vs. 26.3°, p = 0.041), tibiofemoral rotation angle (9.7° vs. 12.4°, p = 0.042) and external tibial rotation angle (24.3° vs. 29.6°, p = 0.001) in the habitual patellar dislocation group were significantly lower than those in the recurrent patellar dislocation group. 54% of knees in the habitual patellar dislocation group had a patella baja, and this was in sharp contrast to the recurrent patellar dislocation group in which none of the knees had a patella baja. 49.1% of knees in the habitual patellar dislocation group showed 'invisible patella' at 30° of knee flexion, and knees with 'invisible patella' had significantly higher tibial tubercle-trochlear groove (TT-TG) distance (30.4 vs. 19.8, p < 0.001) and tibiofemoral rotation angle (13.2° vs. 6.4°, p < 0.001) than knees with a visible patella.

conclusionsA distinct difference in bony anatomical features was observed between habitual and recurrent patellar dislocation in skeletally mature patients. Habitual patellar dislocation exhibited less severe rotational deformities of the lower extremity but showed poorer trochlear and patellar development, a larger TT-TG distance and a higher incidence of patella baja compared with recurrent patellar dislocation. LEVEL OF EVIDENCE: Level III.

Indexed as

PatellaPatellar DislocationAdultFemaleFemurHumansIncidenceMaleMiddle AgedRadiographyRecurrenceRetrospective StudiesRotationTibiaYoung Adulthabitual patellar dislocationpatella bajarecurrent patellar dislocationskeletally mature patients

Identifiers

PMID39118446
PMCPMC11792102

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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.