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CPinBOSS - Cerebral Palsy in the British Orthopaedic Surgery Surveillance Study


Cerebral palsy (CP) is the most common physical disability in childhood.

Children affected with CP frequently have surgery to improve functional outcome. Diplegia is the form of CP that predominantly affects the legs and restricts the ability to walk. Typically for diplegia, surgery follows an approach which involves several operations performed in a single sitting. This is called single event multi level surgery (SEMLS) and can often take all day to complete. There are major differences between Centres that perform SEMLS in terms of patient selection, and choice of the specific surgical interventions.

The study aims to establish a surveillance cohort of SEMLS surgery patients in the United Kingdom (UK) to determine its efficacy. All patients aged 5-16 years with diplegic CP treated within a UK hospital will be eligible to participate.

Patients must have a clinical assessment (Gross Motor Function Classification (GMFCS) Level I-III and a gait analysis report) and will be recommended for SEMLS surgery by the gait analysis team or their treating clinician. Patients who do not pursue surgery will be included in the data collection as part of routine 2 year follow up, their reason for not having surgery will be recorded. This data will be anonymised and uploaded by the clinical team at each participating site onto an online secure database. This is part of a service evaluation. Baseline and follow up data will be collected including: minimal demographic data, GMFCS level, Functional Mobility Scale (FMS), Gait Profile score (GPS) and the latest gait analyses report.

Within the anonymised surveillance cohort, patients will also be invited to participate in a consented cohort. 

Routine clinical data will be collected plus these consented patients will complete patient reported outcome measures at baseline and at 1 and 2 year follow-up.


  • To measure the number of patients with cerebral palsy eligible for SEML surgery in the United Kingdom.
  • To review regional variation in number of operations. 
  • To describe clinical indications and surgeon factors in the surgical management of these patients.
  • To assess and compare gait and function measures and PROMS at 12 and 24 month from baseline.

on sheets


Data from NHS Digital will be used during this study to identify how many patients are having SEML surgery at each of the Trusts in the UK. NHS Digital will securely transfer the data to the University of Oxford as pseudonymised data (i.e. all identifiers will be removed and replaced with a unique patient ID). The pseudonymised data cannot be linked back to the patient by the University of Oxford and processing in such a way that researchers will not be able to identify patients.

For more information about how NHS Digital use patient information, including how it is collected and how patients can opt out, follow the links below:

NHS Digital - Data collection

NHS Digital - opt out

The lawful basis for processing: The lawful basis for processing under GDPR are Article 6(1)(e) (‘task in the public interest’) and 9(2)(j) (‘research purposes’).

Department of Health disclaimer: The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health.

Privacy Notice

University of Oxford are not seeking personal identifiable data, but aggregated data only which cannot be used to identify a specific patient. The data that is being sort will be utilised to identify NHS Trusts that have performed SEMLS over the specific recruitment period. All HES data will be held for 2 years post the end of the study (March 2025) so that research publications can be completed.

There is no automated decision making within this study. There are no automated computer algorithms that will identify patients without human intervention. Therefore, University of Oxford will not be using automated decision making, including profiling, within this project.

The University of Oxford's lead Data Protection Officer (DPO) contact details are as follows:

• James Bristow
• 01865 270285

The lead DPO is the officer for the Controller and the Processor. 

Funded by

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Definition of SEMLS

“The most frequently asked question by centres participating in the CPinBOSS study relates to the definition of SEMLS.

For the purpose of the CPinBOSS study we have defined SEMLS as the intervention that involves a minimum of two surgical procedures (bony or soft tissue) undertaken at a minimum of two different levels (e.g. hip and knee or thigh and calf). The original definition of SEMLS by the Melbourne group does not contain the word “bilateral surgery”. In the context of the CPinBOSS study we would like to ensure that all recruited patients have bilateral involvement but not necessarily bilateral surgery.

You can therefore recruit patients who require one lower limb treated surgically if the other lower limb is also affected by the condition.

Tim Theologis (CI)

SEE OUR Completed trials 

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