Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT00471913 |
| Other study ID # |
H06-03242 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
May 8, 2007 |
| Last updated |
April 13, 2011 |
| Start date |
April 2007 |
| Est. completion date |
April 2011 |
Study information
| Verified date |
April 2011 |
| Source |
University of British Columbia |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
Canada: Health Canada |
| Study type |
Interventional
|
Clinical Trial Summary
Study focus is femoral shaft (thigh bone) fractures (break) that require surgical treatment
under anaesthetic to stabilize the femur fracture. This is usually done by placing a metal
nail and screws inside the femur (thigh) bone.
This study has been designed to allow us to learn more about the effect of using a different
starting point to insert the nail into the body in order to access the fracture and fix it.
This question is important because to date, all entry points currently used do result in
some muscle damage. In order to minimize this damage a lateral (side) entry nail has been
developed and is currently in use at many centres. This nail is new but, the lateral entry
technique for these types of fractures has been used extensively in the past, and this nail
has been developed in order to better accommodate the technique.
It is believed that entering laterally instead of going deeper into the tissue to access the
bone to fix it is going to result in less muscle damage which in turn will improve
functional outcome.
Description:
Background:
This study has been designed to prospectively evaluate functional outcome and MR imaging of
abductor damage following antegrade femoral nailing with different entry points
Recent developments in IM nailing of the femur have favoured the use of the greater
trochanter as an entry site as opposed to using the "classical" piriformis fossa. With
either technique, a persistent problem appears however to be the damage caused to muscle
tissue during preparation of the femur and insertion of the nail. The recent development of
femoral nails with an entry point lateral to both these sites offers the potential advantage
of avoiding abductor muscle damage.
In several cadaver studies, authors state that a trochanteric entry point causes more damage
than a piriformis entry, and that an even more lateral entry point causes even less damage
to the abductor muscles compared to the classical piriformis fossa entry site. There is
however, no prospective clinical study has specifically evaluated the condition of the
abductor tendon and the amount of muscle damage after antegrade nailing in the treatment of
femoral shaft fractures. The few clinical studies that have attempted to examine the
functional outcome in patients undergoing IM nailing of femoral fractures have used general
measurement tools (general functional clinical assessment, gross evaluation of gait) which
do not reflect the state of the art at this time and which do not specifically assess
gluteal muscle condition. To date, no published study has evaluated the integrity of the
gluteus tendon, the damage to the surrounding tissues, and the functional outcome using
validated scores. Moreover, no study has compared the "traditional" entry points to a
lateral entry nail with this level of precision.
The standard of care for the treatment of femoral shaft fractures is the insertion of an
intramedullary nail through the piriformis fossa. Following insertion of femoral IM nails, a
number of studies have demonstrated excellent clinical and radiographic results with
relatively few complications such as nonunion, malunion, or infection. Intraoperative
difficulties with respect to rapid identification of the appropriate starting point have
prompted the development of nails that use the greater trochanter as an entry site as
opposed to using the "classical" piriformis fossa.
As stated earlier, with either technique, a persistent problem appears however to be the
damage caused to muscle tissue during preparation of the femur and insertion of the nail.
The recent development of femoral nails with an entry point lateral to both these sites
offers the theoretical advantage of avoiding abductor muscle damage. There is so far a lack
of prospective randomized trials which demonstrate radiological and clinical parameters of
the different entry points.
Objective To determine the abductor tendon and muscle damage with MR-imaging according to
the entry point of the femoral nail. Additionally, objective hip muscle function, general
health status and functional outcome will be assessed using validated instruments.
We aim to correlate muscle damage due to the different entry points and correlate with the
functional outcome. Further, to quantify the differences (advantages) of different IM
nailing techniques of the femur, with respect to effect on the abductor musculature, muscle
testing and gait, and patient-based functional outcome, to guide surgeons' decisions and
future research.
Recent Related Work In a recently published report by Ricci et al. the use of the
trochanteric entry point was associated with a low complication rate and good clinical
results including the assessment of a gait video. In this admittedly small prospective study
the superiority of either the trochanteric or the piriformis fossa entry point nail could
not be established. Although gait was evaluated video (in 30% of the study population), this
was limited to a subjective assessment of the presence of a Trendelenberg gait (absent,
slight or present). There was no statement about the muscle status, and functional outcome
assessment was limited to a Harris Hip Score.
Abductor tendon condition and muscle damage has previously been assessed with MR-imaging by
the group of Pfirrmann et al. in patients with total hip arthroplasty through a transgluteal
approach. This study showed a high correlation between damage and clinical outcome.
The co-applicant's research group has previously carried out many clinical studies including
its part in a multi-centre randomized trial in femur fractures. It also specifically has
carried out a functional assessment of patients following femur fractures which included:
objective muscle testing of isokinetic force using a KinCom® dynamometer, formal gait lab
analysis using an eight camera real-time motion capture system in conjunction with a
force-plate walking platform, and as part of the same study, the administration of validated
self-assessment outcome questionnaires.
So far no prospective randomized trial has investigated, as we have planned to do, the
radiological (MR), functional, and clinical outcome after insertion of a femoral nail
through two different entry points.
Method Patients will be assigned randomly (via computer generated randomization) to one of
two groups. The two groups will undergo standard treatment of IM nailing for the femoral
shaft fracture differing only in entry point of the nail: piriformis fossa entry point
versus lateral entry point.
Design Patients between 19 and 60 years of age presenting with an isolated femoral shaft
fracture that requires IM nailing will be asked to participate in this study. Informed
consent for participation in the study will be obtained by either a member of the health
care team or by a research nurse.
Consenting patients who meet the inclusion criteria will be randomized to either piriformis
fossa or lateral entry femoral nailing. Preoperative, Intraoperative, and follow-up data
will be obtained. Data will detail clinical assessment, MRI results, objective muscle
testing, and gait analysis.
Power analysis In a published report from Pfirrmann et al. distinct conclusions could be
made in a collective of 54 patients. We plan to recruit 60 patients (30 per group) with a
projected drop-out rate of 10%. As this is a pilot study, without previous reference, a
similarity in expected findings and required sample size must be inferred. Cases will be
randomized using a web-based allocation tool.
Outcome Variables:
Variables for collection and analysis are:
1. Preoperative:
i) Demographics ii) ISS (Injury Severity Score) iii) AO Fracture Classification
2. Intraoperative:
i) Elapsed time from injury to operative treatment ii) Fluoroscopy time iii) Incision
length iv) Blood loss
3. Postoperative:
i) VAS pain scores ii) Morphine requirements q 24hrs iii) Change in hemoglobin q 24hrs
iv) Hospital Length of Stay v) Clinical and Radiological follow-up at 3, 6, 9, and 12
months vi) MRI at 12 months vii) Self-administered validated outcome tools at 6 and 12
months (SF-36, SMFA, Harris Hip Score, Merle d'Aubigne score) although last two are not
validated they would allow for comparison with widely published scores in established
literature
Study Specific Measures:
Postoperative follow-up:
All patients will be reviewed clinically in the fracture clinic at two, six, twelve
weeks, and six and twelve months postoperatively. Study data will be acquired at the
six and 12 month appointments.
Clinical assessment:
Bilateral measurements will be recorded so that the results from the unaffected limb
are used as a control for the injured limb. Both the raw data and the side to side
differences will be used in the analysis. Physical examination to document any limb
length discrepancy, Trendelenberg sign, rotational malalignment, and the ranges of
motion of the hip and knee.
Questionnaires:
A study specific questionnaire will be administered to determine the extent and
location of any persistent pain in the affected limb, ability to return to their usual
occupation and recreational activities.
Functional outcome scores (SF-36, SMFA, Harris Hip Score, Merle d'Aubigne score) will
be collected at 6 and 12 months. All of these outcomes tools are widely referenced in
the literature and can be used for comparison purposes.
MR Imaging:
An MRI will be administered at 12 months and will include evaluation of abductor tendon
defects, diameter, signal intensity, ossification, and bursal fluid collections. The
abductor muscles will be evaluated by MRI for fatty atrophy.
Muscle strength testing and gait analysis:
Muscle strength testing will take place at 12 months and will utilize the KinCom
Dynamometer (a widely used, standard research protocol and specifically-designed
instrument for use in muscle strength testing) to evaluate muscle strength: Peak
isokinetic force measurement: maximum strength (nm/kg), and work (J/min) of hip
abductors, hip extensors, and knee extensors.
Gait analysis will take place at 12 months and will employ a standard eight camera
real-time motion capture system in conjunction with a force-plate walking platform to
collect and evaluate pelvic obliquity, hip abductor movement, single leg support time,
and step length.
Data Analysis:
The side-to-side differences will be summarized and compared across treatment groups.
Additionally, aggregated raw data by treatment group will be summarized and compared,
using t-test for the comparison of continuous variables' means, and Chi-square for
categorical data.
