Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT04154020 |
| Other study ID # |
TODD II |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
November 30, 2019 |
| Est. completion date |
October 28, 2021 |
Study information
| Verified date |
October 2021 |
| Source |
Steno Diabetes Center Copenhagen |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
1. Aim Patients with diabetes, hammer, mallet and claw toes and ulcers associated with the
named deformities will be randomized to tenotomy (cutting) of flexor tendons to the
afflicted toes, done by needle and standard offloading or offloading alone. The effects
of the surgery on time to healing of ulcers associated with the named deformities,
recurrence of the ulcers, and rate of complications associated with the surgery. In
addition to this all patients gait and balance will be examined before start of the
study, and after 3 months, to se if there is an effect of the surgery on patients gait
and balance.
2. Method A prospective randomized clinical study, which means a study were patients will
be allocated randomly to surgery and standard care or standard care alone.
Patients will attend a total of up to 14 visits over a 12-month period.
3.
Description:
1. STUDY RATIONAL Diabetes is one of the largest medical challenges facing the world today.
12% of the world's health budget is spent on diabetes, which is USD 673 billion (Euros
585 billion). It is estimated that a lower limb is amputated due to diabetes every 30
sec. on a global scale, and its known that 85% of all amputations are performed due to a
diabetic ulcer1. In Denmark 320.000 citizens has a diabetes diagnosis, an additional
200.000 are estimated to have diabetes unknowingly, and 750.000 to have the pre-stages
of diabetes2. These numbers have doubled in the past ten years and are estimated to cost
DKK 86 million a day (or Euros 11.6 million a day)1. One of the complications to
diabetes is the "diabetic foot syndrome", which is a result of neurological
abnormalities, vascular complications or a combination of the two. Knowledge about the
causes of the disease has been gathered since the late nineteenth century3. In recent
years, preventive therapy has been the focus of treatment, resulting in several national
and international guidelines4,5,6. Focus has been on education in self-care and
awareness of risk factors, combined with "Foot-at-Risk" evaluation7, at least once a
year and off-loading therapy crafted and applied by specialized personnel3,4.
Steno Diabetes Center Copenhagen, University of Copenhagen, Denmark is a
highly-specialized treatment facility focusing on the patient with diabetes. In spite of
optimized treatment for patients with diabetes, and the fact that incidence of
first-time ulcers in patients with type 1 and 2 diabetes is declining, the incidence of
first time ulcers is still 2.6 and 8.7 per. 1000 patient years for type 1 and 2,
respectively8. Diabetic foot ulcers have a known association with increased mortality,
morbidity and economic burden9,10,11, at the same time most amputations in patients with
diabetes are preceded by an ulcer12.
Hammer, mallet and claw-toe deformities are some of the most common deformities
associated with the diabetic foot syndrome. Prevalence has been reported between 32% and
46%13,14. These deformities are predictors of diabetic foot ulcers15,16. There are
several theories on the etiology of hammer, mallet and claw toe deformities - the three
classic deformities of the toes. In the diabetic patient setting, the classical theory
is based on neuropathy (nerve damage associated with diabetes and other diseases),
resulting in intrinsic muscle (muscles of the foot) dysfunction, changes that lead to
imbalance between the flexor and extensor tendons, which in turn leads to hyperextension
of the metatarsophalangeal (MTP) joint and/or flexion in the interphalangeal joints
(IP), leading to the three classic deformities of the toes. The neuropathic theory is
not sufficient to explain the full 4 scope of the problem, and other theories have been
proposed17. In the non-diabetic patient, the neuropathic explanation is not viable, but
the explanations still center on an imbalance between in- and extrinsic musculature,
resulting from deformities in the foot either as flexor-substitution or stabilization
deformities18. The deformities change the pressure on the plantar aspect of the foot19.
These changes in pressure make specific contact point's predilection sites for ulcers.
The sites have been described as tip of the toe ulcers, cock-up ulcers, kissing ulcers
and plantar metatarsal ulcers20, these sites will be referred to as ulcers associated
with hammer, mallet and claw toe deformities, and are defined as cock-up ulcers that are
placed at the dorsal side of proximal phalangeal joint of toes 2-5 and inter phalangeal
joint of the hallux. A tip of the toe ulcer is placed at the pulpa of the affected toe.
Metatarsal ulcers are placed at the plantar aspect of the distal head of the metatarsal
bone of the involved toe. Kissing ulcers, which are placed between toes, and is due to
pressure from the deformed toe/toes.
The treatment of hammer, mallet and claw toe deformities in diabetes has classically
consisted of offloading in the form of shoes, insoles and/or orthosis (i.e. silicone
spacers, felt pads etc.) or flexor tendon tenotomy (cutting tendons) done by scalpel.
Several studies on flexor tenotomies performed with scalpel have been performed21,22;
all have reported acceptable or positive results on ulcer healing and low complication
rates, including one study from our own institute23. At Diabetic Foot Study Group 2018
we presented unpublished results from a study showing that tenotomy done by needle has
comparable results to the classical scalpel. However, no study has, to our knowledge,
been published comparing conservative treatment with surgical approach to these
deformities, let alone randomized controlled trials (RCT). At the same time no studies
have, to our knowledge, looked at the effect on plantar pressure (pressure profile of
the foot) and balance post flexor tenotomy in the above-mentioned setting.
2. WHAT DOES THIS TRIAL ADD TO CURRENT KNOWLEDGE? This is to our knowledge the first RCT
looking at flexor tenotomies compared to conservative treatment. At the same time this
is the first study looking at needle flexor tenotomies, as opposed to the classic
tenotomies done by scalpel. The effect of flexor tenotomy on the balance of patients
with diabetes has not been described earlier.
3. HYPOTHESIS We hypothesize that treating ulcers associated with hammer, mallet and claw
toe deformities in patients with type 1 and 2 diabetes with needle tenotomy is a safe
and effective treatment, and superior to offloading (conservative) treatment done by
silicon spacer, insoles, felt, and/or therapeutic sandals.
I addition we hypothesize that needle tenotomy performed as a treatment for ulcers
associated with hammer, mallet and claw toe deformities in patients with type 1 and 2
diabetes will not affect the patients balance or gait significantly.
4. AIM This study is a randomized controlled trial (RCT) . The aim of the RCT is to
evaluate the effect of needle tenotomy when treating hammer, mallet and claw toe
deformities and an associated ulcer in patients with diabetes.
5. Study 5.1 Design A prospective RCT involving patients with diabetes as well as one of
the three deformities and an active ulcer associated with the mentioned deformities.
5.2 Patients Note Patients who don't meet the additional inclusion and exclusion
criteria for gait and balance will be excluded from gait and balance but not the rest of
the study. Conversely patients who don't meet inclusion and exclusion criteria other
than those additional for gait and balance will not be eligible for enrollment in any
part of the study.
Discontinuation of patients
- Patient discontinues assigned treatment for any reason, while not fulfilling one of
the studies accepted endpoints
- Patient incurs a serious adverse event (SAE), defined as death or sepsis related to
the study procedure
- Investigator decides to discontinue patient due to health or compliance reasons
- Patient misses 3 consecutive visits
- Patient misses 5 or more visits during the full treatment period Patients who
discontinue the study early will be invited to have a clinical visit before being
discontinued.
Patients that are discontinued will revert to their normal treatment plan, and continue
in their respective clinics.
5.3 Statistical Analysis Plan
Sample-size The calculation is based on a Type 1 error rate of 5%, and a power of 80%.
The primary endpoint is time-to-heal of ulcer associated with hammer, mallet or claw toe
deformity. The mean of the intervention group is set at 4 weeks, which is the average
time to healing we observed in a pilot study done on needle tenotomies at our
institute24, while the mean of the control group is set at 10 weeks, which has been
reported by Zimny when evaluating diabetic foot ulcers treated with standard care25,26.
However, time-to-heal, when looking at the diabetic foot ulcer, is dependent on multiple
factors like size, etiology and patient co-morbidities, therefore the standard deviation
is set at 10. The clinical minimal relevant difference (miredif) for time-to-heal is set
at 6 weeks. 6 weeks shorter time-to-heal, is seen as clinically relevant difference, on
based on clinical experience, and a goal of time to heal at 4 weeks compared to the
above reported 10 week average healing time attained with standard care31,32.
The calculator used is a 2 means, 2 sample, 2-sided equality calculator. With the above
described parameters, the sample size is 44 patients, which due to an expected dropout
of 10% will be extended to 50 patients.
6. PERSPECTIVE
The results of these studies will allow us to evaluate if there is a clinical advantage
in performing tenotomies. Several studies have shown that tenotomies done by scalpel are
safe and that most ulcers heal27,28, but none have compared tenotomies with standard
care. Our hypothesis is that patients with ulcers associated with hammer, mallet and
claw toe deformities will heal faster when treated by tenotomy. At the same time,
unpublished data from our institute show that tenotomy done by needle has comparable
results to tenotomy done by scalpel. If this minimal invasive procedure, that can easily
be performed in an everyday clinical setting, can lead to significant reductions in
healing times, there is a potential for significant reductions in socioeconomic costs.
7. QUALITY CONTROL AND MONITORING
The studies will be performed in accordance with the Helsinki Declaration, International
Council for Harmonization of technical requirements for pharmaceuticals for human use
(ICH) Guidelines for good Clinical Practice (GCP)29 and after approval by the The
National Committee on Health Research Ethics and the Data Monitoring Board in Denmark.
The study will be registered on http://www.clinicaltrials.gov/.
Permission for a third person to have access to patient data will be obtained at
screening visit. Investigators will provide access to source data and relevant documents
in connection with monitoring, inspections, and audits to all relevant authorities.
8. ETHICAL CONSIDERATIONS AND DATA SAFETY
8.1 Ethics The study will be conducted in accordance with the ethical principles that
have their origin in the Declaration of Helsinki 1996 and the principles of GCP30 8.1
Ethical committee approval The appropriate approval from a local Danish ethical
committee will be obtained before start of trial, and their guidelines will be followed
throughout the process. Patients will receive oral and written information on the study,
before being required to sign an informed consent paper.
8.2 Personal data usage and protection The appropriate approval from the Danish data
protection agency will be obtained before the study commences, and their guidelines will
be followed throughout the process. All patient data will be stored and treated in
accordance with regulation 2016/679 from the European parliament on the protection of
natural persons with regard to the processing of personal data and on the free movement
of such data, dated 27 April 201631, and the Danish amendment to regulation 2016/67932.
8.3 Patient Perspective and Conclusion Patients enrolled in this study will receive a
treatment that is already implemented in our and several other clinics, and the
unpublished data from our retrospective study and the formerly published data on
tenotomies, points towards tenotomies being a safe and effective treatment of hammer,
mallet and claw toes, with a low risk of complications for patients with diabetes. The
enrolled patients will in addition receive a gait and balance analysis that can be used
as a diagnostic tool to help in treatment generally. Patients who don't receive
intervention in the form of tenotomies in the study, will receive standard offloading
and ulcer treatment, and be offered to undergo tenotomy after completing 10 weeks
observation in the study if relevant in addition they will be offered a gait and balance
examination with mentioned benefits. In conclusion the patients enrolled in the study
will receive a treatment with potential benefits for them, and a low risk of
complications making the study ethically sound.
9. DISSEMINATION OF RESULTS The study is initiated by Peter Rossing. Data is owned by the
investigators. Positive, inconclusive as well as negative study results will be
published in both national and international oral and written presentations as well as
peer-reviewed international scientific journals. If data against expectations are not
published in international journals, positive as well as negative study results will be
published on a public website, for example www.clinicaltrials.gov.
10. PATIENT INFORMATION
10.1 Written Information All patients will receive information detailing the project, written
information on their rights as Participants in research projects from the Danish ethics
committee33, and written information on the procedure, potential unintended side effects, and
what to expect after the operation.
10.2 Verbal Information All patients will be informed in layman's terms on the details of the
operations, potential unintended side effects, and what to expect after the operation.
