Closed
reduction is always preferable to open reduction provided that a comparable
reduction can be obtained and held. Closed reduction relies on the attachments
of the bone to soft tissues (periosteum and/or ligaments) to obtain and to hold
reduction. Intra-articular fractures, where fragments may not have any
soft-tissue attachments, cannot usually be reduced closed. These fractures also
need accurate reduction if traumatic secondary arthritis is to be avoided and so
are best performed open to make sure that reduction is anatomical. In children
the bones may not be clearly visible on X-ray because they have not yet fully
ossified, especially around the elbow. Open reduction may be needed to be
certain that reduction has been achieved (Table 21.4).
Pain
relief
Patients
need to be free of pain when reducing fractures, so a general anaesthetic will
be required if a regional block is not possible. If there is no neurovascular
compromise this is not an urgent operation, so time should he allowed for the
patient’s stomach to empty before a general anaesthetic is administered. It
may be best to send the patient home with a splint and analgesia so that the
procedure can be performed as a semi-planned procedure on a fully staffed list
the following morning. If there is any chance that the reduction will not be
successful, and that the fracture will need to be opened, then this should be
planned in advance (another good reason to leave the case over until the
following morning). You will also need to plan how you are going to check that
the fracture has indeed reduced satisfactorily, so you will need to book either
an image intensifier or plain X-rays, and the patient will need to be positioned
so that imaging in two planes is possible. You will also need to plan how to
hold the fracture and what facilities (such as plaster or traction pins and
frames) you will need.
Value
of the periosteum
When
a bone fractures the periosteum remains largely intact, especially on the
concave side of the fracture. This strong membrane is not visible on the X-ray
and so its value in guiding the fracture to a stable reduction may not always be
fully appreciated. Impacted fractures which are also partially displaced will
need disimpacting before the displacement
can be corrected. Disimpaction is carried out by applying steady distraction
to the fracture until you feel the bone ends separate. The force applied should
be no more than 4 or 5 kg as otherwise
there is a danger (especially in the elderly) of degloving
the limb (pulling off the skin and soft tissues). If the fracture does not
initially disimpact, then the fracture should be bent further than it is already
angulated, ‘exaggerating the deformity’. This manoeuvre should disengage the
jammed ends. The limb will lengthen slightly, and the fracture will become
floppy. Traction should be continued for another couple of minutes to drive
oedema out of the tissues around the fracture. This will allow the soft tissues
to extend to their normal length and make the reduction easier.
Engaging
the bone ends
The
intact periosteum on the concave side of the fracture can now block reduction
unless the tension is taken off it. This is done by angulating the fracture even
further than before, and sliding the fractured end of the distal fragment up the
cortex of the proximal fragment until it slips over the broken edge of the
proximal fragment. As soon as this occurs the fracture can be rolled into place
with the jagged ends of the fracture interdigitating like gear wheels. When the
fracture comes to anatomical alignment, the intact periosteum on what was the
concave side will become tight and prevent overcorrection of the fracture. Providing that any lateral pressure
exerted on the fracture is in the direction of overcorrection the fracture will
remain stable, splinted by the periosteum.
Open
reduction of fractures
Exposure
of a fracture should allow adequate access to see as much of the fracture as
necessary while minimising damage to soft tissues. It should also minimise
damage to the periosteum, which will be providing the bulk of the blood supply
to the broken bone fragments. If that blood supply is lost then the fracture
cannot unite. The incision will have to take into account any wounds already
present and should be extensile (able
to be extended if necessary). If a plate is to be put on the bone the incision
should be planned to enable the plate to be put on the side of the bone which
will be in tension. If there is skin and soft-tissue loss then incisions should
be planned with a plastic surgeon to ensure that skin and soft-tissue cover of the bone and fixation can be obtained
at the end of the operation. Fractures which are contaminated and those which
are open (which must be treated as contaminated) are an emergency, but not a
life-threatening one. Every hour that goes by increases the risk of the fracture
becoming infected, so surgery needs to be performed as soon as the anaesthetist
feels that it is safe.