Same level fibular plating versus not plating in distal metaphyseal tibia fractures treated with intramedullary nails: a randomized trial.

Intramedullary nailing has become the standard of care for the majority of
displaced midshaft tibial fractures. The use of an intramedullary nail obviates
the need for extensive surgical dissection, spares the extraosseous blood
supply, and allows the device to function in a load-sharing manner. It results
in a stable construct with high union rates, and additional fibular fixation is
unnecessary when a combined fracture of the mid tibia and fibula occurs.
Intramedullary nails have also been advocated for the treatment of distal
metaphyseal tibia fractures. However, because of the lack of interference fit,
it can be difficult to reduce and control distal tibia fractures with an
intramedullary device, and malalignment rates of 20 to 50% have been reported.
Malalignment can impair functional outcome, and may lead to significantly more
bodily pain. It is also known that distal tibial malalignment substantially
decreases the tibiotalar joint contact area. This leads to inappropriate
pressure increase on tibia-talar cartilage and may cause joint degeneration in
the long-term.

Some studies of nailing for distal tibia fractures reported that concurrent
fibula fixation results in less malalignment of the tibia. Human cadaveric
studies suggested that fibular plating increased rotational stability of the
tibial fracture treated with a nail, which may reduce the risk of valgus
malunion. In addition a retrospective chart and radiographic review showed that
adjunctive fibular plating compared to not plating significantly lowered the
risk for loss of reduction in the treatment of 72 combined distal third tibia
and fibula fractures.
However, it is widely accepted that relative stability with moderate axial
movement provides an effective stimulus for periosteal callus formation. An
increased potential for delayed healing of the tibia may be seen when the
distal fibula is additionally stabilized. Vallier et al. reported that
non-union was more common in patients with distal tibia fractures who had
concurrent fixation of their fibula fracture. Whorton and Henley found no
significant differences in healing rates, incidence of non-union and
malalignment, or in the number of required subsequent procedures with patients
who did and did not undergo fibular stabilization.

The optimal treatment for combined same level displaced distal tibia and fibula
fractures, therefore, remains under debate, and to our knowledge no randomized
trials have been reported on additional fibular plating. We designed a
randomized controlled trial to answer the following questions: (1) Does
additional fibular plating lower the incidence of malalignment after surgical
treatment of distal metaphyseal tibia and fibula fractures treated with locked
intramedullary nailing? (2) Does fixation of the fibula lead to higher rates of
non-union of the distal tibia? We hypothesize that additional fibular plating
would be beneficial to obtain and maintain optimal distal tibia fracture
reduction, which may lead to a better functional outcome after 2-years
follow-up.

Primary question:
I. Does additional fibular plating lower the incidence of malalignment after
surgical treatment of distal same level metaphyseal tibia and fibula fractures
treated with locked intramedullary nailing?

Secondary questions:
I. Does additional fibular plating give better functional results?
II. Does fixation of the fibula lead to higher rates of non-union of the distal
tibia?

A prospective multicenter open-label parallel randomized controlled clinical
trial comparing two strategies of patients treatment with distal same level
metaphyseal tibia and fibula fractures, in participating academic medical
centers in Canada and Europe.

Randomization
We will use a computer-generated randomization. We will stratify patients
according to center and according to the American Society of
Anaesthesiologists* (ASA) Physical Status classification. We have chosen to
stratify according to center rather than surgeon because: 1. The surgeon to
whom a patient is admitted may not be the surgeon who performs the operation,
and 2. Since this is a pragmatic study, we are interested in the effectiveness
of the intervention under usual circumstances of average surgical skills. We
have chosen to stratify according to the ASA class because: 1. It is used
worldwide by anaesthesiologists as a preoperative categorization system by
patient co morbidities, thus it is readily available preoperatively, and 2.
Although it is not a risk stratification system, it will ensure equal
representation of patient co-morbidities between the two treatment groups.

We will randomize in random blocks of 4 or 6 in 1:1 allocation ratio.
Participating centers will be unaware of block size. After obtaining consent
from the patient and checking the eligibility criteria and as close to the
operation as possible, the surgeon or the resident will call the randomization
service. After entering the center number, patient hospital identification
number and ASA class, the computer will provide the caller a treatment
allocation (additional fibular plating or not). The central randomization
service will ensure concealment of allocation.

Operation:
At the start of surgery, the surgeon will follow the treatment allocation. The
surgeon will either apply a plate to the distal fibula using a separate
incision and then proceed with tibia nailing (index group) or start with tibia
nailing (control group):

* In the index group a lateral skin incision and subcutaneous tissue dissection
will be used to stabilize the distal fibula fracture with a one/third tubular
plate fixated with small fragment screws. Depending on the length and
comminution of the fracture site, an appropriate size plate will be chosen by
the surgeon. If length of the fibula determination is problematic then the best
length and alignment should be chosen for fibular fixation. Time for fibular
plating will be recorded.
* In both groups a standard skin incision in line with the central axis of the
intramedullary canal will be used for nailing of the tibia. Depending on the
anatomy of the patient this incision can be transpatellar, medial, or lateral
parapatellar. The incision starts proximally at the distal pole of the patella
along the patellar ligament down to the tibial tuberosity. The infrapatellar
corpus adiposum can be mobilized laterally and dorsally without opening the
synovia. Free access of the nail to the insertion point must be guaranteed.
* A closed reduction or open reduction if the fracture is open (after
debridement) will be performed manually by axial traction under image
intensification. The length of time to pass the reaming guide wire will be
documented. The use of a large distractor may be appropriate in certain
circumstances, and will be documented. The reduction can be temporarily fixed
with reduction clamps, and will be documented.
* The tibial canal will then be enlarged. A medullary reamer will be used to
the desired diameter (ream-to-fit). The appropriate sized intramedullary nail
will be inserted over a guide rod, and statically locked with one bolt
proximally and two bolts distally.
* A C-arm image intensifier will be used to obtain intra-operative AP and
lateral X-rays of the tibia to assess the quality of reduction and position of
the locking bolts, and to assess the distal third articular surface for
articular extenson of fracture lines.

There are no differences in complications for placement of the tibial nail in
the treatment groups. As an extra incision will be used for placement of the
fibular plate, the risk for infection and lesion of the sensory branch of the
superficial peroneal nerve is increased.

Following the randomized treatment, normal and routine care compared to all
other patients will be provided. Visits in the fracture clinic at 2 weeks, 6
weeks, 3 months, 6 months, 12 months, and 24 months postoperatively have to be
attended. The visits up to 12 months are part of routine care, however, the
last visit at 24 months is an addition for the research study. Furthermore,
patients will be asked to ccomplete questionnaires at 3 months, 6 months, 12
months and 24 months for trial purposes. These wil take up to 15 minutes each
visit.