Zebra lines

Kristian Kolnes; Bjørn Magne Jåtun

doi:10.4045/tidsskr.21.0275

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Zebra lines

Norwegian

Kristian Kolnes, Bjørn Magne Jåtun

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Kristian Vigdel Kolnes

Orcid

E-mail: kristian.kolnes@gmail.com

Department of Radiology

Volda Hospital

Kristian Vigdel Kolnes, senior consultant and specialist in radiology.

The author has completed the ICMJE form and declares no conflicts of interest.

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Bjørn Magne Jåtun

Department of Paediatric and Adolescent Medicine

Ålesund Hospital

Bjørn Magne Jåtun, specialist in paediatrics and senior consultant in charge of endocrinology and local follow-up of children with osteogenesis imperfecta.

The author has completed the ICMJE form and declares no conflicts of interest.

Article

This X-ray shows the knee of a teenage boy with multiple, transverse, sclerotic (white) bands in the tibial and femoral metaphyses. The patient has similar bands in several other joints. He has been diagnosed with osteogenesis imperfecta type 1 and has been receiving treatment with intravenous zoledronic acid (bisphosphonate) for five years. Each of the transverse bands corresponds to a treatment cycle/injection of bisphosphonate. More frequent injections result in shorter band intervals. The bands are most common in the metaphyses, but can also occur in the epiphyses and apophyses. The sclerotic bands are the result of increased bone mineralisation (1) and are an indirect response to inhibition of osteoclast activity as a result of treatment. In 2007, it was proposed that the bands should be called 'zebra lines' (2).

Osteogenesis imperfecta (OI) is a congenital disease of collagen fibres that affects the skeleton in particular, but also the connective tissues. There are five subtypes of osteogenesis imperfecta, with different genetic causes and severities. Type 1 is the mildest and most common form. All types are characterised by abnormal collagen fibre synthesis, with changes either to the structure of collagen or to the number of fibres produced. This results in weakening of the skeleton, reducing its ability to withstand mechanical stress and thereby increasing the risk of bone pain/fractures and skeletal deformity (3). There is no curative treatment available for the disorder. However, multidisciplinary treatment aims to reduce the risk of fractures and complications of fractures, and to help patients function as well as possible.

The need for drug treatment with intravenous bisphosphonate is assessed on the basis of fracture history and severity. Bisphosphonate increases the mineralisation of bone tissue, but does not affect the collagen abnormalities per se. Zoledronic acid is administered every six months from the age of two and usually until the child is fully grown, but treatment duration is decided on an individual basis. Zoledronic acid is not approved for use below the age of two years, and younger children are usually treated with monthly pamidronate infusions.

The patient and his parents have consented to the publication of this article.

Literature

1.
Devogelaer JP, Malghem J, Maldague B et al. Radiological manifestations of bisphosphonate treatment with APD in a child suffering from osteogenesis imperfecta. Skeletal Radiol 1987; 16: 360–3. [PubMed][CrossRef]
2.
Al Muderis M, Azzopardi T, Cundy P. Zebra lines of pamidronate therapy in children. J Bone Joint Surg Am 2007; 89: 1511–6. [PubMed][CrossRef]
3.
Biggin A, Munns CF. Osteogenesis imperfecta: diagnosis and treatment. Curr Osteoporos Rep 2014; 12: 279–88. [PubMed][CrossRef]

Comments ( 2 )

Dette kommentarfeltet modereres, men kommentarer blir ikke redaksjonelt behandlet ut over å sikre at de følger retningslinjer for vårt kommentarfelt.

23.08.2021:

I Tidsskriftet nr. 141/11 har kollegene Kolnes og Jåtun en kort, men interessant artikkel om såkalte «Sebralinjer» (1). Man får imidlertid inntrykk av at dette er et særskilt fenomen ved osteogenesis imperfecta, og at «kvar av de tverrgåande linjene svarer til ein behandlingsrunde/injeksjon med bifosfanat». Jeg går imidlertid ut fra at hver linje representerer knokkelens epifyseskive på et visst alderstrinn, noe som vel forklarer hvorfor «hyppigare injeksjonar gjev kortare avstand mellom linjene», og undres noe over at linjene «også finnast i epi- og apofysane».

Sklerotiske «avtrykk» av knokkelens vekstsoner kan etter min erfaring skyldes flere årsaker, både fysiske og psykiske (2), noe som hadde vært interessant å få belyst i artikkelen. Linjene har ellers vært kjent under betegnelsen «Harris' linjer» (etter den engelske anatomen Henry Albert Harris (1886-1968)).

Litteratur:

1 Kolnes KV., Jåtun BM. Sebralinjer. Tidsskr Nor Legeforen 2021;141, 11: 1093
2 Holck P. Harris' linjer. Røntgenfunn på et prehistorisk skjelett. Tidsskr Nor Lægeforen 1984; 104, 15: 1028-31

28.10.2021:

Vi takkar Per Holck for innspelet, og gleder oss over at ein slik framifrå kollega fann interesse i vår artikkel. Dessverre har vi ikkje blitt merksame på Holck sin kommentar før nå. Fleire artiklar gjer greie for skilnaden mellom sebralinjer og Harrislinjer, og nemner det faktum at ein tidvis ser slike sebralinjer også i epifyse og apofyse. Vi har også eksempel frå sistnemnde i eigen praksis. Vi viser til vår referanse 2 i vår artikkel (1), som går djupare inn i denne materien. I artikkelutkastet hadde vi med ein kort passus om Harrislinjer, men blei bedne av fagfelle å anten ta vekk dette, eller gå djupare inn i samanhengen mellom sebralinjer og Harrislinjer. Om vi valde det siste alternativet hadde artikkelen vorte for lang til å få plass i det aktuelle formatet (Medisinen i bilder). Vår agenda med publiseringa var primært å gjere kollegar merksame på dette iaugefallande funnet som kanskje ikkje alle radiologar og barnelegar er familiære med. Funnet er ein normal respons på bisfosfonatbehandling ved osteogenesis imperfecta, og treng soleis ikkje leie til vidare utgreiing.

Litteratur
1. Al Muderis M, Azzopardi T, Cundy P. Zebra lines of pamidronate therapy in children. J Bone Joint Surg Am 2007; 89: 1511–6

This article was published more than 12 months ago and we have therefore closed it for new comments.

Published: 26 July 2021

Tidsskr Nor Legeforen 26 July 2021 Vol. 141.

doi:

10.4045/tidsskr.21.0275

Received 4.4.2021, first revision submitted 30.5.2021, accepted 7.6.2021.

Published: 26 July 2021

Tidsskr Nor Legeforen 2021 Vol. 141.

doi: 10.4045/tidsskr.21.0275

Received 4.4.2021, first revision submitted 30.5.2021, accepted 7.6.2021.

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Zebra lines

Interessante «sebralinjer»

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