Condition category
Injury, Occupational Diseases, Poisoning
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
After having surgery for leg fractures, patients are often advised not to bear weight on this leg for around 6 weeks. This delayed weight bearing allows the fracture time to heal; however, the delay has been associated with other complications, such as osteoporosis and problems with movement. Advances in surgical techniques for fractures, such as one called the N-force fixation system, have been shown to allow patients to bear weight on their limbs sooner, which may avoid these complications. This study aims to look at the differences between the effects of the N-force fixation system on early (after 2 weeks) and late (after 6 weeks) weight bearing after leg fracture surgery.

Who can participate?
Patients aged 18-80 with a proximal fracture of the leg

What does the study involve?
Participants will be randomly assigned to 1 of 2 groups. Both groups will receive fixation surgery for their leg fractures; however, one group will be asked to begin weight-bearing on this leg after 2 weeks (early) and the other will be asked to do so after 6 weeks (delayed). Participants will be asked to complete questionnaires, X-rays and CT scans throughout the study.

What are the possible benefits and risks of participating?
The possible benefit to participants taking part is that early weight-bearing may help to avoid potential complications associated with late weight-bearing. There are no known risks to participants taking part in this study.

Where is the study run from?
Leeds General Infirmary (UK)

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

Who is funding the study?
Zimmer Biomet (USA)

Who is the main contact?
Professor Peter V Giannoudis
Professor and Chairman within Academic Department of Trauma and Orthopaedic Surgery/ Honorary Orthopaedic and Trauma Consultant

Trial website

Contact information



Primary contact

Mr Hany Saleeb


Contact details

18 St James's Court
Beckett Street
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Tibia plateau pure and split depression fractures (AO 41-B2 and B3) stabilised with N-Force/iN3 bone cement +/- plate augmentation: A prospective single centre feasibility randomised controlled trial comparing early (2 weeks) versus delayed (6 weeks) weight bearing


TIB-N-Force Study

Study hypothesis

Is there a difference between early (2 weeks) and delayed (6 weeks) weight bearing for tibial plateau fractures (Schazker II and III)?

Ethics approval

Provisional favourable approval from Yorkshire & The Humber - Leeds East Research Ethics Committee, 15/08/2018, 18/YH/0293

Study design

Interventional randomised controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type

Quality of life

Patient information sheet

Not available in web format, please use contact details to request a participant information sheet


Tibial plateau fracture


Participants will be randomly allocated using unstratified block randomisation with varying block sizes into 2 arms, with 15-20 patients in each arm. Participants in both groups will receive the same treatment with the N-force system. This is an augmented fixation system, integrating fenestrated screws and a Bone Substitute Material (BSM) called N-Force Blue into a single construct to provide improved metaphyseal void fill and increase structural support of the implant. N-Force Blue is injected directly into the fenestrated screw with the use of a sheath assembly, to help minimise BSM leakage into the soft tissues. This fixation system will be used as a means of surgical fixation for participants' tibial plateau fractures.
After 2 weeks, one group will be asked to begin bearing weight on this leg (2 weeks), whereas the other group will be asked to do so after 6 weeks (delayed).
There will be a 52 week follow-up period, where participants will be assessed at 2, 6, 12, 24 and 52 weeks after surgery.

Intervention type



Drug names

Primary outcome measure

1. Quality of life, assessed at the baseline and at week 6, 12, 24 and 52, using:
1.1 12-item Short Form Health Survey (SF-12)
1.2. EuroQol-5D (EQ-5D)
2. Pain whilst weight-bearing, assessed using the Numeric Pain Rating Scale (NPRS) at the baseline and at week 2, 6, 12, 24 and 52
3. Patient mobilisation, assessed using a timed "up-and-go" test (TUG) at weeks 6 and 12

Secondary outcome measures

1. Time to bone healing, assessed using:
1.1. Clinical measures:
1.1.1. Painless full weight bearing
1.1.2. Functional IndeX in Trauma (FIX-IT) score
1.2. Radiological measures - Radiographic Union Scale in Tibial fractures (RUST) scale with a CT scan
2. Proportion of participants healed at 3 and 6 months after surgery
3. Rate of surgical re-intervention at 6 months after surgery
4. Incidence of loss of reduction, secondary collapse or further surgical intervention at the 6 month follow up

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Aged 18 years or older
2. Skeletally mature
3. Acute unilateral closed tibia plateau fractures as primary injury
4. Willing and able to provide informed consent and participate in all study activities and visit schedule
5. Ambulatory prior to injury

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Open/compound tibial plateau fracture
2. Fracture type 41 C according to Muller AO classification
3. Multi-segmental fracture (more than one fracture site within tibia)
4. Polytrauma (Injury Severity Score of 17 or more)
5. Prior or concomitant illnesses that may affect healing or outcome
6. Exposure to drugs that can affect the bone metabolic state within the past 3 months
7. Receiving chemotherapy, radiation treatment or immunosuppressant drugs
8. Currently enrolled in any other study that may impact on the results of the present study
9. Resident outside of Leeds
10. Pregnant or breastfeeding
11. If female: not currently using and not willing to use an effective form of contraception for 12 months post-surgery
12. Metal allergy

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Leeds Teaching Hospital NHS Trust
Great George St,
United Kingdom

Sponsor information


university of Leeds

Sponsor details

University of Leeds
United Kingdom

Sponsor type




Funder type

Not defined

Funder name

Zimmer Biomet

Alternative name(s)

Zimmer Biomet Spine, Zimmer Biomet Biologics

Funding Body Type

private sector organisation

Funding Body Subtype

For-profit companies (industry)


United States of America

Results and Publications

Publication and dissemination plan

Planned publication in a high-impact peer-reviewed journal

IPD sharing statement:
The datasets generated during and/or analysed during the current study are not expected to be made available due to patient confidentiality.

Intention to publish date


Participant level data

Not expected to be available

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes