JIRA Link: https://projects.jira.snomed.org/browse/IHTSDO-539

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Release used for analysis: March 2023

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Content Issue Summary 

a. Summary of issue 

Avascular necrosis of bone and aseptic necrosis of bone are considered synonymous with osteonecrosis. In current release of SNOMED CT, 240196003|Bone necrosis (disorder) has a synonym of osteonecrosis and different sub-hierarchies and associated morphologies, such as:

• 398199007|Aseptic necrosis of bone (disorder)

• 397758007|Avascular necrosis of bone (disorder)

As these are synonymous these two hierarchies need to be merged. 

b. Related content projects and requests 

A CRS request has been received from a member country highlighting the issue of synonymy and requesting a resolution.  In addition there had been over 100 CMT requests for new osteonecrosis concepts but these had already been rejected due to low usage.  However should further new concept requests be re

The morphology 6574001 |Necrosis (morphologic abnormality)| and related clinical finding content has already been subject to quality improvement but this issue was out of scope for that project.

https://projects.jira.snomed.org/browse/QI-527

Analysis of Issue

References overwhelmingly consider aseptic bone necrosis, avascular bone necrosis and osteonecrosis as synonymous:

1. Osteonecrosis is a degenerative bone condition characterized by death of cellular components of bone owing to interruption of the subchondral blood supply; resorptive component of the repair process results in loss of structural integrity.  Also called avascular necrosis. https://www.clinicalkey.com/#!/content/clinical_overview/67-s2.0-fd4709c8-0af4-470f-8dd3-0821645d9872

2. Osteonecrosis, also known as avascular necrosis (AVN), aseptic necrosis or ischemic bone necrosis, is a disease resulting in the death of bone cells.  https://rarediseases.org/rare-diseases/osteonecrosis/

3. Osteonecrosis is also called avascular necrosis (AVN) or aseptic necrosis.  https://orthoinfo.aaos.org/en/diseases--conditions/osteonecrosis-of-the-hip

At the time of analysis there were 155 concepts identified as in scope for this work based on the ECL below:

<< 404684003 |Clinical finding (finding)| : << 116676008 |Associated morphology (attribute)| = << 6574001 |Necrosis (morphologic abnormality)|, << 363698007 |Finding site (attribute)| = << 272673000 |Bone structure (body structure)|

• 25 concepts with 'aseptic necrosis' as the FSN and modelled with 72756009 |Aseptic necrosis (morphologic abnormality)| e.g. 43453000 |Aseptic necrosis of talus (disorder)|

• 21 concepts with 'avascular necrosis' as the FSN and modelled with 86217007 |Avascular necrosis (morphologic abnormality)| e.g. 203478002 |Avascular necrosis of the talus (disorder)|

• 40 concepts with 'osteonecrosis' as the FSN, mainly of the type, due to trauma or caused by drug and modelled with 6574001 |Necrosis (morphologic abnormality)|  e.g. 315791000119107 |Osteonecrosis of carpus caused by drug (disorder)|

Additional issues identified

• 72756009 |Aseptic necrosis (morphologic abnormality)| should also be reviewed for continued use.  Other than bone structures this morphology is only used in one concept 38079004 |Aseptic necrosis of pancreas (disorder)|

Solution

The content needs to be reviewed for duplication e.g. 43453000 |Aseptic necrosis of talus (disorder)| and 203478002 |Avascular necrosis of the talus (disorder)|.  Suggest inactivating those of the type 'aseptic necrosis' as duplicates of 'avascular necrosis'

Following this descriptions should be updated as described below and all content modelled with 86217007 |Avascular necrosis (morphologic abnormality)| as all bone necrosis is due to disruption in the blood supply.

Based on the evidence the FSN should be Avascular necrosis of X bone (disorder) with the PT Osteonecrosis of X .  Avascular necrosis of X bone should be a synonym.  Aseptic necrosis of X bone is generally outdated but should also be added as a synonym given the presence in authoritative references as a synonym and may still be used in some countries.

Construction 

1. Inactivate 240196003 |Bone necrosis (disorder)| and 398199007 |Aseptic necrosis of bone (disorder)| as duplicates of 397758007 |Avascular necrosis of bone (disorder)||

2. Inactivate any duplicates found under 398199007 |Aseptic necrosis of bone (disorder)| 

3. Add consistent FSNs in the format of Avascular necrosis of X bone - model with 86217007 |Avascular necrosis (morphologic abnormality)|

4. Add consistent Preferred Terms of Osteonecrosis of X

5. Add synonyms of Avascular necrosis of x bone and Aseptic necrosis of X bone.

Transition phase 

Glossary of Terms