Evidence map›Paper›PMID 38805146›Full record

ArticleSpine deformity2024

Evaluation of crankshaft phenomenon after posterior fusion for early onset scoliosis using an inverse trigonometric function: a multicenter retrospective cohort study.

Shun Okuwaki, Toshiaki Kotani, Yuki Taniguchi, Teppei Suzuki, Toru Yamaguchi, Satoru Demura, Kanichiro Wada, Ryo Sugawara, Katsushi Takeshita, Kei Watanabe and 2 more

Abstract readMulticenter Study
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In one paragraph

Article in Spine deformity, 2024. 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
–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.

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.

  1. Article
  2. Article
  3. The progress of research on crankshaft phenomenon.Journal of orthopaedic surgery and research · 2025
    Review
  4. Article
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

12 authors.

Shun OkuwakiDepartment of Orthopaedic Surgery, Institute of Medicine, University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki, Japan. shunokuwaki@tsukuba-seikei.jp.ORCID 0000-0002-9614-5399
Toshiaki KotaniDepartment of Orthopaedic Surgery, Seirei Sakura Citizen Hospital, Chiba, Japan.
Yuki TaniguchiDepartment of Orthopaedic Surgery, The University of Tokyo Hospital, Tokyo, Japan.
Teppei SuzukiDepartment of Orthopaedic Surgery, National Hospital Organization, Kobe Medical Center, Hyogo, Japan.
Toru YamaguchiDepartment of Orthopaedic and Spine Surgery, Fukuoka Children's Hospital, Fukuoka, Japan.
Satoru DemuraDepartment of Orthopaedic Surgery, Graduate School of Medical Sciences, Kanazawa University, Ishikawa, Japan.
Kanichiro WadaDepartment of Orthopaedic Surgery, Hirosaki University Graduate School of Medicine, Aomori, Japan.
Ryo SugawaraDepartment of Orthopaedic Surgery, School of Medicine, Jichi Medical University, Tochigi, Japan.
Katsushi TakeshitaDepartment of Orthopaedic Surgery, School of Medicine, Jichi Medical University, Tochigi, Japan.
Kei WatanabeDepartment of Orthopaedic Surgery, School of Medicine, Niigata University, Niigata, Japan.
Tsutomu AkazawaDepartment of Orthopaedic Surgery, St. Marianna University School of Medicine, Kanagawa, Japan.
Noriaki KawakamiDepartment of Orthopaedic Surgery, Ichinomiyanishi Hospital, Aichi, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeThe crankshaft phenomenon (CSP) is a corrective loss after posterior surgery for early onset scoliosis (EOS). However, an accurate method for CSP evaluation has yet to be developed. In this study, we evaluated pedicle screw (PS) length and rotation angle using an inverse trigonometric function and investigated the prevalence of the CSP.

methodsFifty patients from nine institutions (mean age 10.6 years, male/female ratio 4:46) who underwent early definitive fusion surgery at ≤ 11 years of age were included. The rotation angle was calculated as arctan (lateral/frontal PS length) using radiography. Measurements were taken at the apex and lower instrumented vertebra (LIV) immediate, 2-, and 5-year postoperatively. CSP was defined as a rotation angle progression ≥ 5°. We divided patients into CSP and non-CSP groups and measured the demographic parameters, Risser grade, state of the triradiate cartilage, major coronal Cobb angle, T1-T12 length, T1-S1 length, and presence of distal adding-on (DAO). We compared these variables between groups and investigated the correlation between the measured variables and vertebral rotation. Logistic regression analysis investigated factors associated with CSP.

resultsThe rotation angle progressed by 2.4 and 1.3° over 5 years for the apex and LIV, respectively. CSP occurred in 15 cases (30%), DAO in 11 cases (22%), and CSP and DAO overlapped in 4 cases (8%). In the CSP group, the T1-T12 length was low immediate postoperatively. The rotation angle was negatively correlated with preoperative height (r = - 0.33), T1-T12 length (r = - 0.35), and T1-S1 length (r = - 0.30). A lower preoperative T1-T12 length was associated with CSP (odds ratio: 0.996, p = 0.048).

conclusionsCSP occurred in 30% of patients with EOS who underwent definitive fusion. The presence of CSP was associated with a lower preoperative T1-T12 length. LEVEL OF EVIDENCE: Diagnosis, level IV.

Indexed as

Pedicle ScrewsScoliosisSpinal FusionChildChild, PreschoolFemaleHumansMalePostoperative ComplicationsRadiographyRetrospective StudiesRotationThoracic VertebraeCrankshaft phenomenonDefinitive posterior fusionDistal adding-onEarly final fusionEarly onset scoliosisInverse trigonometric functionRotational deformity

Identifiers

PMID38805146

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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.