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Research groups


With the involvement of children with cerebral palsy, their parents and health professionals, researchers developed an international agreed set of most important lower limb orthopaedic surgical outcomes and measurement instruments (core outcome domains and measurements set) which all researchers can used in future studies.

Tim Theologis


Associate Professor

  • Honorary Senior Clinical Lecturer
  • Former Consultant Orthopaedic Surgeon

Mr Tim Theologis has been a Consultant Orthopaedic Surgeon in Oxford since 1996 and a Honorary Senior Clinical Lecturer at the University of Oxford since 1999. His clinical and research work focuses on children with cerebral palsy and neuromuscular disorders. He maintains a strong clinical and research link with the Oxford Gait Laboratory at the Nuffield Orthopaedic Centre. He is Treasurer of the British Society for Children's Orthopaedic Surgery, Emeritus Editor of Gait and Posture and Clinical Lead for Paediatric Orthopaedics and the Gait Laboratory at Oxford.

Previous research has led to the development of the Oxford Foot Model, a biomechanical model for the study of foot motion during walking. This has been adopted internationally by researchers, clinicians and the motion analysis industry as the standard tool for analysis of foot motion in children and adults. The development of the Oxford Foot and Ankle Children's Questionnaire, a validated measure of foot-related disability, was also an important milestone in the understanding of paediatric foot conditions and their impact on lifestyle.

The 'keyhole' or 'minimally-invasive' technique in performing both bony and soft tissue procedures as part of multi-level surgery in children with cerebral palsy has been developed through research at the Oxford Gait Laboratory. It involves surgical techniques which are used in other conditions in children but have not previously been used in the context of surgery in cerebral palsy. It causes less trauma and scarring to the muscles and is quicker to perform compared to open, conventional techniques. Children are able to mobilise immediately following surgery and improvements in walking ability have been shown to be at least as good as with conventional multi-level surgery.

In 2016 he led the development of a Research Committee under the auspices of BSCOS, the British Society of Children's Orthopaedic Surgery. He has chaired the Committee since and has completed a Delphi process among BSCOS members on research priorities, a network with the clinical trial units, the Royal Colleges, the NIHR and the BOA. International networking with the North American equivalent (IMPACCT) and the Paediatric Orthopaedic Society of North America ensued. He has subsequently secured funding from BSCOS, the BOA and from NDORMS to undertake a James Lind Alliance priorities setting project on lower limb surgery in children with orthopaedic conditions.

Having completed these tasks with the BSCOS Research Committee, he was granted BRC funding, which started in April 2017, in order to undertake paediatric orthopaedic research. The aim is to lead and drive excellent quality academic research in children's orthopaedics at Oxford and nationally. The BRC funding marked a step change in his career as it gave him the time and opportunity to build collaborations, write grant applications, appoint graduate students to undertake research and a develop a national group of collaborators willing to recruit patients into trials.

His current research plans are divided into 3 themes: general paediatric orthopaedics, cerebral palsy and foot conditions.

Key publications

Recent publications

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