05 June 2025
Jan Magee
[FYI request #31020 email]
Kia ora Jan
Your Official Information Act request, reference: GOV-040217 Thank you for your request of 19 May 2025, asking for the following information under the Official
Information Act 1982 (the Act):
Please provide number of claims made for metal on metal hip resurfacing from 1 January 2015 to the
present
On 26 May 2025, you clarified that your request is for the number of treatment injury claims caused by this
procedure (including metallosis or other metal poisoning claims caused by the coating on the protheses).
Our response
There were 264 claims lodged for ‘metal on metal’ hip procedures since 1 January 2015 of which 211 (80%)
were accepted for cover. 70 claims were lodged with an explicit reference to resurfacing or the Birmingham
or ASR resurfacing implants. 61 (87%) of these claims were accepted.
Notes about the data used for this request
The treatment injury data provided was extracted on 27 May 2025 and includes claims lodged between 1
January 2015 and 26 May 2025.
For this response, a combination of a structured data extraction (for specific treatment events) and a free
text search (listed below) was used. Free text search methods are not reliable data extraction methods and
can result in anomalies in the data. Thus, the data should be considered indicative only.
All claims lodged since 1 January 2015 relating to hip joint surgery were selected and limited to claims where
there was a text reference to ‘metal on metal’, ’metal-on-metal’, ’metal/metal’, ’metal-metal’, ‘MoM’,
‘Birmingham’ or ‘ASR’ was recorded or where the injury related to ‘metallosis’, ‘metal poisoning’, ‘metal
toxicity’, ’cobalt poisoning’, ’cobalt toxicity’, ’chromium poisoning’, ‘chromium toxicity’, ’THA
pseudotumour, ‘THA pseudo tumour’, ’THA pseudotumor’ or ‘THA pseudo tumor’. Claims referencing
‘metal on ceramic’, ’metal-on-ceramic’, ’ceramic on metal’ or ‘ceramic-metal’ were excluded.
If you have any questions about this response, please get in touch You can email me a
t [email address]. Ngā mihi
Christopher Johnston
Manager Official Information Act Services Government Engagement
