Fracture of the distal third of the clavicle is a problem
fracture. Its management and its outcome can be complicated. There are some
ligaments called the coracoclavicular ligament that goes between the coracoid
and the clavicle. These ligaments are called the conoid and trapezoid
ligaments. The conoid is medial (inserts about 4.5cm from end of clavicle). The
trapezoid is lateral (inserts about 3 cm from the lateral end of clavicle). The
integrity of the conoid and trapezoid ligaments (coracoclavicular ligaments) is
important. The coracoclavicular ligaments provide the primary resistance to
superior displacement of the lateral clavicle. The ligaments are holding the
clavicle down. If fracture of the lateral third of the clavicle occurs and the
medial part is not attached to the ligaments, then the medial part of the
clavicle will become displaced superiorly by the pull of the
sternocleidomastoid muscle. When you assess the fracture of the lateral or
distal third of the clavicle, you assess the stability of this fracture. The
stability of this fracture is based on the location of the fracture in
relationship to the coracoclavicular ligaments, the AC joint, and the fracture
pattern. Is the fracture pattern simple or comminuted which could be unstable. There
are several types, and they can be summed up as two types: stable fractures and
displaced fractures with coracoclavicular ligament not attached to the proximal
fragment. In displaced fractures, the proximal fragment will displace
superiorly. This type will have delayed union up to 50% and nonunion
approximately 20%. Because the proximal fragment is not attached to any
ligaments, it is just displaced superiorly. The distal segment continues to be
attached to the coracoid by the coracoclavicular ligament. Some physicians
believe that the displacement of the fracture, and the fracture stability is
usually decided in surgery, but you do not want to do that, you want to decide
the stability and the displacement of the fracture before surgery so that you
can make the proper decision for treatment and also to select the proper
implant for dealing with this problem. The Zanca view x-ray may be needed. 15
degrees cephalic tilt to show the superior inferior displacement. A fracture
that is lateral to the ligament makes the fracture stable, you will treat the
patient conservatively with a sling. A fracture that is medial to the ligament
and makes the fracture unstable is treated by open reduction internal fixation.
You can use the guideline of the ligament insertion, which is 4.5cm from the AC
joint, can use the Zanca view to help you in visualizing the displacement
superiorly or inferiorly, and when the fracture is medial to the ligament that
is unstable, this means that you need to do ORIF because if you treat it
conservatively, there will be a high incidence of nonunion. You can use
multiple techniques for reduction and fixation of the distal clavicle fracture.
One of these techniques is plates and screws called a “cluster plate” that has
multiple holes which allows you to put small screws and lock the screws to the
plate. Another technique is the hook plate which is used when there is
insufficient bone in the distal segment for fixation with plates and screws.
Not every hospital has the hook plate. You may not be able to fix the distal
clavicle fracture with plate and screws in surgery. Make sure you have the hook
plate in house in case it is needed (hook plate is a backup plan). Most hook
plates will require removal after healing of the fracture (secondary surgery).
If the fracture is a nonunion and the patient has symptoms, you need to fix
this fracture with a plate and bone graft if the fracture is atrophic. This
problem is very difficult to treat, and it does not matter what type of
fixation that you use, there will be a high incidence of failure in the
treatment of nonunion of the distal clavicle. The patient may require two types
of stabilization for this nonunion. The patient may require two types of
stabilization for this nonunion. The first type is a plate and bone graft
fixation. The second type is additional help to the plat and bone graft by
stabilizing the coracoclavicular area. You can use a tendon allograft, or you
can use anchors in the coracoid or a tight rope fixation. Fracture distal to
the line drawn vertically to the coracoid process is probably a stable
fracture. You will give the patient a sling for comfort and give a structured
PT program when the pain is less, starting with pendulum exercises and progress
to active assisted when the pain is manageable. In a child, a distal clavicle
fracture could be a periosteal sleeve fracture which will remain attached to
the intact coracoclavicular ligament.
