DENS RCT: Duration of External Neck Stabilisation following odontoid fracture in older or frail adults: a randomised controlled trial of collar versus no collar

Research Question Are hard collars necessary for odontoid fractures in older and frail patients? Background

Odontoid (dens)fractures following low impact falls in frail or older people are increasing in incidence. Standard care in a hard collar aims to promote bony healing by immobilisation, prevent neck instability pain, and avoid neurological deficits. However, hard collars can cause skin pressure ulcers and necessitate increased care for activities of daily living (ADL).

Neurological deficits are very rare and bony fusion rates highly variable - up to 80% do not achieve bony fusion. Fractures without bony fusion often have stable fibrous non-bony union. QoL and pain scores do not appear dependent on whether bony union occurs.

The hard collar may therefore not be necessary. Not using a collar could avoid the harm and impact on ADL that hard collars can have.

EQ-5D-5L was chosen as primary outcome measure after literature review, discussion with patients and PPI groups. It was preferred as easy to complete, covers domains relevant to trial population, is responsive to change and is validated for proxy completion if necessary. Aims

To determine whether management without a collar improves outcome in older or frail patients with a new odontoid fracture compared to standard care hard collar for 12 weeks. Objectives

To determine difference in QoL assessed with EQ-5D-5L at 12 weeks between the no collar and collar arms. Secondary objectives include Neck Disability Index, mortality, adverse events, a qualitative process evaluation study to assess perceptions and acceptability of the intervention amongst patients and clinicians, objective measure of collar compliance using thermal sensors, and health economic analysis.

Methods

Randomised controlled trial of adults aged =65 or with a Rockwood clinical frailty score of =5. Odontoid fracture diagnosis will be confirmed by consultant radiologist and study eligibility confirmed by consultant spinal surgeon. Recruitment up to 3 weeks from injury, allowing time to recover capacity if acutely compromised. Patients in both study arms will have assessments at 2,6, and 12 weeks, and 6 and 12-months following injury, alongside standard care clinical review.

Recruit 887 participants over 2-years, to detect a minimum clinically important difference of 0.05 on EQ-5D-5L using repeated measures over 12 weeks at 90% power with a 5% significance level. An internal pilot study to assess recruitment feasibility will be undertaken - 132 (15%) patients, 18 centres, within 9 months. Stop/go criteria have been defined.

A second internal pilot will re-estimate sample size using a simulation approach after the first 300 patients, because of some uncertainty in assumptions used to determine sample size. Timelines for delivery

Commence Feb 2021. REC submission April 2021. Aug 2021 Internal pilot phase and process evaluation begins. Pilot Ends April 2022. Main study recruitment ends Aug 2023. Follow-up complete Aug 2024. Report Feb 2025 Anticipated impact and Dissemination

This study will provide definitive evidence that hard collars are not needed for older and frail patients with odontoid fractures. This will rapidly impact on clinical pathways and guidelines (e.g. NICE), as simple to implement. Dissemination through conference presentations, peer review journals and plain language summary. Medium-term potential for substantial hospital and social care cost savings.