Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT03362229 |
| Other study ID # |
2017/0262 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
October 24, 2017 |
| Est. completion date |
August 1, 2021 |
Study information
| Verified date |
August 2021 |
| Source |
Royal Infirmary of Edinburgh |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
Medial malleolus: Operative Or Non-operative (MOON study) Ankle fractures are a common
Orthopaedic trauma presentation, accounting for approximately 10% of the workload. There has
been debate regarding the significance of the contribution of the medial malleolus to ankle
stability. Some deem the lateral malleolus as the key stabiliser. With this anatomically
aligned the ankle joint should be stable. Operating on the medial malleolus fracture often
requires a second generous skin incision, soft tissue stripping and insertion of metalwork.
This carries with it the risk of wound complications, infection and increased operation time.
High risk patients including the elderly, diabetics and those with significant swelling
following injury are particularly vulnerable. The study will include adult patients (≥16
years) with capacity to consent and complete post-operative questionnaires, presenting to a
single Orthopaedic trauma unit. Participants will be randomised to fixation or non-fixation
of associated medial malleolus fractures at the same time as fixation of the lateral
malleolar fracture to assess if this impacts on validated patient outcomes, failure,
operative time and complications over a one-year follow-up. Only one trial has been
published, showing no significant difference between failure rates or outcomes, but reduced
operative time.
Participants will be enrolled into the trial following informed consent. The final decision
on whether a participant is eligible can only be made during surgery when the medial
malleolus fracture has reduced with no more than 2mm displacement. If this is confirmed the
participant will be randomised to receive either fixation or non-fixation of the medial
malleolus. Randomisation therefore occurs at the time of surgery. Participants will be
reviewed at set post-operative checkpoints, with X-rays and patient reported outcome scores.
Trial data will hopefully enable surgeons to make better informed decisions when managing
patients with ankle fracture dislocations.
Description:
This trial will include adult patients (16 years) presenting to the single centre; Edinburgh
Orthopaedic Trauma Unit, Royal Infirmary of Edinburgh, with an isolated unstable fracture of
the ankle joint requiring operative intervention. Both NHS research ethics committee (REC)
approval and NHS R&D Management approval have been granted.
All patients will be treated in the Emergency Department (ED) with closed reduction and
casting under procedural sedation and then referred to Orthopaedics via the on-call service.
Patients will be considered for the trial if the following criteria are met:
1. Aged 16 years or older.
2. An unstable fracture dislocation of the ankle joint, defined as a bimalleolar or
trimalleolar fracture pattern with or without any of the following:
- Radiographic evidence of talar shift
- Posterior malleolar fracture of >25% articular involvement or >2mm step-off
- Syndesmosis injury
Patients who consent to participate in the trial will be enrolled into the trial
pre-operatively, but the result of their randomisation will not be revealed until after
fibular fixation and assessment of medial malleolus reduction intra-operatively. Patients
will only be eligible to continue in the trial if the medial malleolus reduces to acceptable
limits without open reduction (≤2mm of displacement as seen on a radiographic
antero-posterior view). If the medial malleolus fracture does not reduce within this 2mm
limit, the patient will require formal open reduction and internal fixation and consequently
not suitable to continue in the trial. The inclusion and exclusion criteria for this trial
are displayed below.
Vulnerable populations, including patients unable to give consent and complete post-operative
questionnaires, will not be recruited. A participant information sheet will be provided for
them to read before agreeing to take part. The study protocol will then be reviewed in detail
and a member of the research team member will complete the informed consent process. With the
permission of the patient, a letter will be sent to their General Practitioner informing them
of their involvement in the trial and patients will be given a copy of their consent form.
Patients may take as long as they like to consider participation, provided that they still
meet all the eligibility criteria documented above. Patients who require additional time to
make a decision will be contacted the following day by a further face-to-face inpatient
discussion. They will also be given the contact details of an Orthopaedic specialist,
independent of the trial to allow them access to further information if they require. Upon
agreeing to take part, participants will be randomised into one of two treatment groups
intra-operatively by closed opaque envelope: operative or non-operative management of the
medial malleolus fracture. Randomisation will be stratified according to age to allow an even
distribution of both young (<65 years) and older (65+ years) patients between the operative
groups. The result of their randomisation will only be revealed if the fracture reduces
spontaneously following lateral malleolus fixation with ≤2mm of residual displacement. On
enrolment, a data collection form will be started with demographic and injury-related
information collected. Regardless of the treatment allocation, the patients will be followed
up at the following post-operative stages: 2 weeks, 6 weeks, 3 months, 6 months and one year.
This will be either in person in the outpatient clinic or via postal questionnaire. At each
visit physical examination, treatment, complications and re-operation (e.g. hardware removal)
for each patient will be recorded. Participants will be asked to complete their outcome
scores independently, as they would with the postal questionnaires. The presence or absence
of a medial sided incision and obvious differences with respect to metalwork on radiographs
means neither the patient nor the investigator can be blinded to the treatment group. The
investigators will also follow up patients' records to assess whether they underwent any
subsequent surgery on the affected ankle during the study period. This would include
debridement/irrigation for infection and/or removal of metalwork for a variety of reasons.
Interventions - Patients randomised to operative management of the associated medial
malleolus fracture will be treated routinely with standard medial malleolus fixation
techniques. The most common being the use of 2x 3.5mm partially threaded cancellous screws
(35mm - 45mm length) inserted at 90 degrees to the fracture line, following satisfactory open
reduction. Other techniques, used far less frequently include the use of a tension band wire
construct and Kirschner wires. The technique employed will be at the discretion of the
treating surgeon and aims to reproduce the decisions that are made in day-to-day trauma care.
Those participants who are not suitable for randomisation intra-operatively as the medial
malleolus does not reduce within acceptable limits will be excluded from the trial. The
result of their randomisation will not be revealed and their envelope will be return to the
study office and allocated in order to the next eligible patient. This will limit disruption
to the randomisation sequence. The subsequent care of that patient will then be at the
discretion of their treating consultant.
Post-operative immobilisation and weight bearing restrictions will be at the discretion of
the treating surgeon, which again reflects everyday practice when managing this common
orthopaedic injury. However, the default immobilisation will be in a removable supportive
orthosis (walking boot) and patients will be allowed to fully weight bear unless there is a
clinical indication, as highlighted above. Post-operative physiotherapy will be arranged at
the discretion of the treating surgeon, as occurs in routine clinical practice.
Power analysis - Prior to the study a power analysis determined the number of patients
required in each arm of the trial. The primary outcome measure will be the OMAS at one year.
To show a clinically meaningful difference in means OMAS at one year between the groups of 10
points, assuming a common standard deviation of 20 points, 80% power and 5% level of
significance the study would require 64 participants per groups (i.e. a total of 128).
However, to account for potential dropouts through the duration of the study this number will
increase by 20% to 77 per group (i.e. a total of 154).
Statistical analysis for the trial will be performed by an independent statistician employed
through the local University statistics department/Edinburgh Clinical Research Facility.
Primary and secondary outcome measures are displayed in the relevant section below.
