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The International Hip Dysplasia Institute (IHDI) classification is more informative than the Tönnis classification

Sand, Adam LU orcid ; Tiderius, Carl Johan LU ; Düppe, Henrik LU and Wenger, Daniel LU orcid (2023) In Acta Radiologica 64(3). p.1103-1108
Abstract

Background: A new, supposedly more reproducible radiographic classification, set to replace the Tönnis classification of hip dislocations, was proposed in 2015: the International Hip Dysplasia Institute (IHDI) classification. Purpose: To compare the IHDI classification with the Tönnis classification when evaluating the severity of hip dislocations as well as their respective inter- and intra-observer reliability. Material and Methods: Since January 2000, Swedish-born children with a hip dislocation were prospectively registered. From this registry, radiographs of 97 hips in 79 patients (91% girls; median age = 7 months), born in 2000–2009, were analyzed. Two observers, one consultant and one resident, classified each hip both by IHDI... (More)

Background: A new, supposedly more reproducible radiographic classification, set to replace the Tönnis classification of hip dislocations, was proposed in 2015: the International Hip Dysplasia Institute (IHDI) classification. Purpose: To compare the IHDI classification with the Tönnis classification when evaluating the severity of hip dislocations as well as their respective inter- and intra-observer reliability. Material and Methods: Since January 2000, Swedish-born children with a hip dislocation were prospectively registered. From this registry, radiographs of 97 hips in 79 patients (91% girls; median age = 7 months), born in 2000–2009, were analyzed. Two observers, one consultant and one resident, classified each hip both by IHDI and Tönnis twice. Results: The IHDI classification had a more even distribution of grades with the majority in grade 2–3. The Tönnis classification graded the majority (77%) of the patients as grade 2 and equally among the other grades. There was moderate inter-observer agreement using both methods calculated with Kappa, 0.61 (95% confidence interval [CI] = 0.44–0.79) for Tönnis and 0.62 (95% CI = 0.49–0.74) for IHDI. The resident calculated Tönnis with weak intra-observer reliability of 0.57 (95% CI = 0.40–0.74) compared to high intra-observer reliability of 0.86 (95% CI = 0.74–0.98) for the consultant. Both observers graded IHDI with high intra-observer reliability. Conclusion: IHDI is more discriminative than the Tönnis classification when evaluating the severity of a hip dislocation in infants.

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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
classification, developmental dysplasia of the hip, hip dislocation, DDH, IHDI, International Hip Dysplasia Institute, neonatal instability of the hip, Tönnis
in
Acta Radiologica
volume
64
issue
3
pages
1103 - 1108
publisher
SAGE Publications
external identifiers
  • pmid:35758228
  • scopus:85133321242
ISSN
0284-1851
DOI
10.1177/02841851221110447
language
English
LU publication?
yes
id
4809c19b-c4d4-4892-9098-ad750fe7db62
date added to LUP
2022-09-06 14:19:08
date last changed
2025-11-01 18:33:13
@article{4809c19b-c4d4-4892-9098-ad750fe7db62,
  abstract     = {{<p>Background: A new, supposedly more reproducible radiographic classification, set to replace the Tönnis classification of hip dislocations, was proposed in 2015: the International Hip Dysplasia Institute (IHDI) classification. Purpose: To compare the IHDI classification with the Tönnis classification when evaluating the severity of hip dislocations as well as their respective inter- and intra-observer reliability. Material and Methods: Since January 2000, Swedish-born children with a hip dislocation were prospectively registered. From this registry, radiographs of 97 hips in 79 patients (91% girls; median age = 7 months), born in 2000–2009, were analyzed. Two observers, one consultant and one resident, classified each hip both by IHDI and Tönnis twice. Results: The IHDI classification had a more even distribution of grades with the majority in grade 2–3. The Tönnis classification graded the majority (77%) of the patients as grade 2 and equally among the other grades. There was moderate inter-observer agreement using both methods calculated with Kappa, 0.61 (95% confidence interval [CI] = 0.44–0.79) for Tönnis and 0.62 (95% CI = 0.49–0.74) for IHDI. The resident calculated Tönnis with weak intra-observer reliability of 0.57 (95% CI = 0.40–0.74) compared to high intra-observer reliability of 0.86 (95% CI = 0.74–0.98) for the consultant. Both observers graded IHDI with high intra-observer reliability. Conclusion: IHDI is more discriminative than the Tönnis classification when evaluating the severity of a hip dislocation in infants.</p>}},
  author       = {{Sand, Adam and Tiderius, Carl Johan and Düppe, Henrik and Wenger, Daniel}},
  issn         = {{0284-1851}},
  keywords     = {{classification; developmental dysplasia of the hip; hip dislocation, DDH, IHDI; International Hip Dysplasia Institute; neonatal instability of the hip; Tönnis}},
  language     = {{eng}},
  number       = {{3}},
  pages        = {{1103--1108}},
  publisher    = {{SAGE Publications}},
  series       = {{Acta Radiologica}},
  title        = {{The International Hip Dysplasia Institute (IHDI) classification is more informative than the Tönnis classification}},
  url          = {{http://dx.doi.org/10.1177/02841851221110447}},
  doi          = {{10.1177/02841851221110447}},
  volume       = {{64}},
  year         = {{2023}},
}