Condition category
Musculoskeletal Diseases
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Hallux vulgaris, more commonly known as a bunion, is a bony deformity of the joint at the base of the big toe at the side of the foot. Although some people never experience any symptoms, many people suffer for years with bunions, as pressure from shoes against it can cause pain and discomfort. An operation to correct the deformity may be offered, if non-surgical treatments do not cause any relief. Bunion correction surgery has traditionally been performed by making an approximately 15cm long cut on the inside of the foot, known as an ‘open procedure’ with good results. Over recent years, there has been a move to achieve the same results of surgery though small keyhole incisions, known as a ‘minimally invasive procedures’. The aim of this study is to discover whether patients have a preference for the type of bunion surgery they have, and to discover whether one surgical technique produces better results for patients than the other.

Who can participate?
Adults with bunions suitable to be corrected by either an open procedure or by a minimally invasive procedure.

What does the study involve?
Participants are randomly allocated to one of two groups. Those in the first group have an open surgical procedure, and those in the second group have a minimally invasive surgical procedure. Before surgery, participants in both groups are asked to fill out a questionnaire and the range of movement in the joint is measured. The advice and regime following surgery are exactly the same whichever surgical procedure has been performed. The foot has a dressing applied and is placed in a heel weight bearing shoe. Participants then attend an appointments two weeks later so that the dressing can be removed and to check the wound and be placed in a light splint inside the heel weight bearing shoe, at this stage participants are encouraged to get the toe moving. Six weeks and then six months after surgery, participants have the range of movement in the joint measured again. One year after surgery, participants are contacted by a research nurse by telephone to complete a questionnaire.

What are the possible benefits and risks of participating?
There are no direct benefits from taking part in the study. However, it is hoped that the information obtained from the study will help further research in bunion surgical procedures. Both procedures are currently performed in routine practice within the NHS. The main complications or risks of surgery are common to both procedures. These include wound infection, fracture, pain, failure of fixation, removal of metalwork in the future and recurrence of the deformity. One of the aims of the study is to help find out which procedure is best tolerated and of lower risk to patients.

Where is the study run from?
1. North Tyneside General Hospital (UK)
2. Hexham Hospital (UK)

When is the study starting and how long is it expected to run for?
January 2017 to September 2020

Who is funding the study?
Northumbria Healthcare NHS Foundation Trust (UK)

Who is the main contact?
1. Mrs Deborah Bunn (public)
2. Mr Nicholas Hutt (scientific)

Trial website

Contact information



Primary contact

Mrs Deborah Bunn


Contact details

Northumbria Healthcare NHS Foundation Trust
North Tyneside General Hospital
Rake Lane
North Shields
Newcastle Upon Tyne
NE29 8NH
United Kingdom



Additional contact

Mr Nicholas Hutt


Contact details

Northumbria Healthcare NHS Foundation Trust
North Tyneside General Hospital
Rake Lane
North Shields
NE29 8NH
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

COSMIC study - Comparing Open Scarf osteotomy and Minimally Invasive Chevron for Hallux Valgus Correction. A Feasibility Study



Study hypothesis

The aim of this study is to assess the feasibility of conducting a study to compare the patient recorded and clinical outcomes for the surgical management of Hallux Valgus correction.

Ethics approval

North East - Tyne and Wear South Research Ethics Committee, 08/04/2016, ref: 16/NE/0049

Study design

Prospective randomised parallel trial

Primary study design


Secondary study design

Randomised parallel trial

Trial setting


Trial type


Patient information sheet

See additional files


Hallux Valgus


Participants will be identified in outpatient clinics and offered to participate in the study. Pre-operative patient questionnaires will be recorded. The patients will then be randomized into one of the treatment arms for their surgical intervention.

Group 1: Participants undergo Open Scarf/Akin osteotomy. A Scarf osteotomy is performed through an open incision. A Z shaped osteotomy of the metatarsal which allows lateral translation and therefore correction of the hallux valgus deformity. This is fixed with 2 screws. This is combined with a lateral soft tissue release and is also often accompanied by an Akin osteotomy, a medial closed wedge osteotomy of the proximal phalanx of the great toe that corrects hallux valgus interphalangeus and improves the cosmetic result.
Group 2: Participants undergo Minimally Invasive Chevron/Akin osteotomy. Through a minimally invasive approach, a lateral release is performed. Then an extracapsular chevron osteotomy is performed allowing lateral translation and therefore correction of the deformity. This is held in place by 2 screws. This is often performed with a minimally invasive Akin osteotomy held with screw fixation.

Post-operative care and rehabilitation will follow the same program in both arms as follows:

0-2 weeks:
Placement in weight bearing heel rocker post op shoe
2 weeks:
Wound check in dressings clinic and placement of Darco Splint, Instructions on mobilization of 1st Metatarsal Phalangeal Joint
6 weeks:
Out patient clinic review Begin mobilizing in normal footwear with Darco Splint, continue mobilization of 1st MPTJ.
Range of movement of 1st MTP recorded
6 months:
Final Outpatient Clinic review (including range of movement of 1st MTP and Patient Reported Outcome Questionnaire)
12 months:
Questionnaire by telephone or post

Intervention type



Drug names

Primary outcome measure

The primary outcome measure is feasibility of the study. This will be assessed via the number of patients able to be recruited into the study. Retention of those patients throughout the study and from analyzing the initial data, discussed in secondary outcome measures, to assess if any concerns are raised during the study period.

Secondary outcome measures

1. Patient reported outcomes - This outcome measure will be the patient reported outcomes obtained by patient questionnaire. MOXFQ-index will be obtained from patients’ questionnaires pre operatively for baseline and subsequently at 6 and 12 months for both groups
2. Range of movement of the 1st MTPJ will be measured with a goniometer preoperatively and at Outpatient follow up and 6 weeks and 6 months. The differences between the two groups will be statistically analyzed
3. Adverse Events are recorded through clinical observations throughout the post-operative period

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Patients over 18 years of age
2. Patients with Hallux valgus deformity suitable for treatment by both Open Scarf/Akin and MICA procedures
3. Patients with no significant co-morbidities that would increase their risk of procedure
4. Patients able to understand and complete questionnaires
5. Patients with the capacity to provide informed consent
6. Patients who have in addition to Hallux Valgus deformity, have lesser toe deformities requiring correction distal to the metatarsal phalangeal joint at time of procedure
7. Patients without significant other mid foot or hind foot pathology

Participant type


Age group




Target number of participants

100 patients approached

Participant exclusion criteria

1. Patients under 18 years of age
2. Patients with severity of Hallux valgus deformity necessitating Open procedure
3. Patients with significant co-morbidities that would increase the risk of surgery
4. Patients unable to understand or complete questionnaires
5. Patients without the capacity to provide informed consent
6. Patients with additional deformity requiring additional procedures proximal to the metatarsal phalangeal joint

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

North Tyneside General Hospital
Rake Lane
North Shields
NE29 8NH
United Kingdom

Trial participating centre

Hexham Hospital
Corbridge Road
NE46 1QJ
United Kingdom

Sponsor information


Northumbria Healthcare NHS Foundation Trust,  

Sponsor details

North Tyneside General Hospital
Rake Lane
North Shields
NE29 8NH
United Kingdom

Sponsor type

Hospital/treatment centre



Funder type

Hospital/treatment centre

Funder name

Northumbria Healthcare NHS Foundation Trust

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Presentation at international Foot and Ankle conference and planned publication in a high-impact peer reviewed journal within one year of trial end date.

IPD Sharing plan:
The current data sharing plans for the current study are unknown and will be made available at a later date.

Intention to publish date


Participant level data

To be made available at a later date

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

22/03/2019: The following changes were made: 1. The recruitment end date was changed from 13/09/2018 to 13/09/2019. 2. The overall trial end date was changed from 13/09/2019 to 13/09/2020. 3. The intention to publish date was changed from 30/09/2020 to 30/09/2021. 14/02/2018: The following changes were made: 1. Recruitment end date was changed from 02/01/2018 to 13/09/2018 2. Overall trial end date was changed from 02/01/2019 to 13/09/2019. 3. Intention to publish date was changed from 03/01/2019 to 30/09/2020. 24/10/2017: The recruitment start date was changed from 02/01/2017 to 13/09/2017.