Keywords
acromioclavicular joint - fracture fixation - joint dislocations
Introduction
Acromioclavicular dislocation (ACD) occurs in 6% of dislocations. The second most
common ACD is that of the shoulder girdle.[1] Acromioclavicular dislocation may present with clavicular fractures in its medial,
middle, or lateral third. Acromioclavicular dislocation with clavicular lateral end
fracture is an unusual injury, even more so when accompanied by a displacement of
the lateral fragment of the clavicle to the acromion.
The main mechanism of traumatic ACD is falling onto the shoulder with the arm in adduction.
This injury is 5 to 10 times more frequent in males.[2]
Treatment varies according to the degree of dislocation and association with ipsilateral
clavicle fractures. Surgical treatment options include fixation with a coracoclavicular
screw, anchor ligature, Endobutton, and hook plate.
Rockwood[3] described six types of ACD. There are several classification methods for fractures
of the lateral clavicular end, and the most cited is from Robinson.[3] Fracture of the lateral clavicular end associated with ACD is a rare condition,
and it is not included in the proposed classification systems. It was only described
by one author in English[4] and by another team in German.[5]
Given the above, the present study aims to describe a rare case of fracture of the
lateral clavicular end with dislocation of the fractured fragment to the trapezius
musculature.
Case Report
The patient, a 40-year-old man, sustained direct shoulder trauma after falling from
a bicycle to the ground.
The initial clinical examination revealed intense local pain and a depressed shoulder.
Radiographs showed a fracture of the lateral end of the clavicle, fragment dislocation
and distancing to the acromion, and increased coracoclavicular space ([Fig. 1]).
Fig. 1 Radiograph showing the fracture of the lateral end of the clavicle with dislocation
of this fragment away from the acromion and increased coracoclavicular space.
The patient underwent surgery after 2 days due to severe pain and local deformity.
Through an incision over the acromioclavicular joint (ACJ) towards the clavicle diaphysis,
we removed the bone fragment from the lateral end of the clavicle in the trapezius
muscle. Next, we released the ligaments from the trapezius. We performed an osteosynthesis
using Steinmann wires followed by ligation of these steel wires to a 5-mm anchor inserted
in the coracoid with Fiber Wire[1] tied to the clavicle to reduce the coracoclavicular space. We did not perform ACJ
fixation because of the fragmentation risk.
Three weeks after surgery, the patient returned with shoulder pain and deformity,
stating that it occurred after a physical effort. A radiograph showed an increased
coracoclavicular space due to the rupture of the anchor wires and consequent new acromioclavicular
dislocation ([Fig. 2]).
Fig. 2 Radiograph revealing an increased coracoclavicular space due to rupture of the anchor
wires and consequent new acromioclavicular dislocation.
The patient underwent a second surgery to repeat the osteosynthesis. This time, we
used a locked plate and performed a new coracoclavicular ligature with another anchor
of the same type over the locked plate. To increase procedural safety, we fixated
the scapular spine with one Steinmann wire, which we removed after 6 weeks ([Fig. 3]).
Fig. 3 Osteosynthesis with a locked plate and new coracoclavicular ligature with another
anchor tied over the locked plate. Fixation of the clavicle to the scapular spine
with one Steinmann wire.
At the last follow-up, 12 months after surgery, the patient had no complaints of pain
or functional loss. A new radiograph showed fracture consolidation and no signs of
fragment osteonecrosis ([Fig. 4]). Clinical examination revealed a preserved, pain-free range of motion ([Fig. 5]).
Fig. 4 Radiograph 12 months after surgery showing fracture consolidation and no signs of
osteonecrosis.
Fig. 5 The clinical examination revealed a preserved, pain-free range of motion.
Discussion
We found only one article with the same case as that of our patient.
Borus et al.[4] describe a case identical to ours. However, we did not have access to their paper
despite several attempts to obtain it, including requesting it via e-mail to the authors.
Siebenbürger et al.[5] published a case report in which the patient had a fracture of the lateral end of
the clavicle and associated ACD. In their case, the fractured fragment did not completely
deviate from the clavicle metaphysis, as in our patient. Thus, the treatment consisted
of a closed fracture reduction and arthroscopic fixation with an Endobutton, resulting
in a satisfactory outcome.
The literature describes ACDs with fractures of the diaphysis[6]
[7]
[8] and of the medial end of the clavicle[9]
[10] and several proposed treatments, but none is similar to our case.
The critical point is that, unfortunately, the patient required two surgeries due
to the rupture of the anchor wires. We believe the loosening occurred due to the lack
of accessory fixation. Therefore, during the second surgery, we changed the osteosynthesis
method by using a locked plate and adding a ligation with an anchor. As such, we fixated
the clavicle to the scapular spine, improving stability.
We believe fractures with displacement of the lateral end of the clavicle and associated
injury to the acromioclavicular ligaments must undergo accessory fixation of the clavicle
to the acromion or the scapular spine and not just ligatures to the coracoid process.
