Download Week 7 File - ACI Moodle

EMERGENCY MEDICINE
Liverpool Hospital
The Weekly Probe
18th March 2014
Volume 17 Issue 7
Measles – a recurring message but keep an eye out for measles.
THIS WEEK
Last weeks case – The “Problem” Drain
Posterolateral Corner Injuries
Next Week’s case- leg pain
Joke / Quote of the Week
The Week Ahead
LAST WEEK’S CASE – The problem Drain
A community nurse sends a patient in for removal of a drain inserted for a bile leak. They have tried
albeit unsuccessfully. It is not stitched in. Other than pulling extremely hard , how do you remove his
drain?
The tube was inserted in Radiology percutaneously so advice was sought from them. Apparently they
are inserted as a straight tube (unlike the pig tails we insert in the ED which recoil back to a pigtail
shape when the introducer or needle is withdrawn). After the tube is placed, to create the pigtail
shape, there is a string which runs inside the tubing, and is fixed at the tip. When the string is pulled ,
the tube bends into a pigtail shape. However to keep the string under tension and the pigtail in a tight
curve, the string needs to be locked taut, and this is achieved with the locking mechanism.
So to remove the drain, the tension on the string needs to be removed before the curve on the pig tail
is reduced. Two ways to do this 1) Use a 5 cent coin to unlock the mechanism 2) The easier second
option is to cut the tube well away from the skin (eg near the white-blue margin in the picture
above).
The tube is then removed with minimal traction. The photo below shows string attached to the distal
aspect of the drain
POSTEROLATERAL CORNER INJURIES
When a patient presents with post-traumatic knee pain we often look for bony injury, then assess for
evidence of significant ligamentous injuries with a focus on the cruciates (which most importantly
help stabilise the knee in a AP direction) and the collaterals which stabilise the knee with valgus /
varus forces (as a reminder vaLgus forces push the distal part of the limb (eg ankle) Laterally.
However one injury that may be overlooked is an injury to the posterolateral corner (PLC) of the
knee.
What does the posterolateral corner structures do? Resist excessive varus or excessive external
rotation forces and thus are important for proper functioning of the knee.
What makes up these structures? The major structures of the posterolateral corner (PLC) are the
iliotibial band, the lateral collateral ligament, the popliteus muscle and tendon, the lateral capsular
ligaments, the arcuate ligament, the post horn of the lateral meniscus, the lateral coronary ligaments
and posterolateral joint capsule.
Editor: Peter Wyllie
How does this injury occur? MVAs and falls most commonly. Note that it does not usually occur in
isolation but is often associated with injuries to the cruciates. Looking at function of this complex as
noted above, varus or external rotation forces, in addition to hyperextension of the knee can cause
injury to the posterolateral corner. Isolated PLC injuries may also occur when a posterolateral force is
directed against the upper tibial with the knee at or near full extension eg a football tackle.
Why should we care? If undetected / untreated, complete tear is the posterolateral corner of the
knee generally leads to poor long term functional results. They may also result in failure of a
reconstructed cruciate ligament.
How do they present? In addition to pain and swelling associated with the other injuries
(anterior cruciate ligamanet (ACL) /posterior cruciate ligament( PCL), the patient may complain of
pain in the posterolateral aspect of the knee. Due to it’s proximity there may be symptoms consistent
with peroneal nerve injury. This may result in weakness of dorsiflexion of the foot at the ankle jointwith footdrop. There will also be a loss of sensation over the dorsum of the foot, and lateral side of
the leg. Innervation is preserved on the medial side of the leg (supplied by the saphenous nerve, a
branch of the femoral), and the heel and sole (supplied by the tibial nerve, a branch of the sciatic).
Examination? When a patient presents with a knee injury with cruciate injuries, the swelling and pain
is often significant and precludes us from making a full assessment of the knee including assessment
of ligamentous stability.In this case further assessment may be completed later when pain and
swelling settles down. However if the pain is minimal then in addition to palpating for local
tenderness, certain manoeuvres may be tried including:
-
-
Posterior draw test – at both 30 degrees and 90 degrees of flexion- if normal at 90 degrees
yet abN at 30 degrees a PLC injury should be suspected
Tibial rotation – easier with prone pt – compare both sides – external rotation of tibia in
relation to femur- check at 30 and 90 degrees of flexion- if increased external rotation at both
positions then PCL and PLC injury is likley, while if abnormal at 30 degrees then only PLC
injury only
Others – posterolateral external rotation test, reverse pivot-shift test- for details I have a copy
of the article.
Imaging? The gold standard is MRI ,yet in our initial step is to perform x-rays. These may be normal
or show abnormal widening of the lateral joint space, and
Editor: Peter Wyllie
a Segond fracture (2-10mm below tib plat- ellipitical fragment ~10 x3 mm- usually considered
indicative of a tear of the ACL) or arcuate fracture of the fibular head,.
Segond #
Arcuate #
Treatment? As with all injuries there is a spectrum of severity from grade 1 minimal tears to grade 3
complete tears. It has been noted that non-operative treatment of complete tears involving the
posterolateral corner of the knee is generally leads to poor functional results.Operative management
is suggested for these injuries
While non-operative treatment of grade 1 or 2 injuries can have a good outcome yet require rehab /
close followup.
Take Home Point - look at the mechanism and consider this as a possible injury. If suspected
then organised the patient to be reassessed by an orthopod or an MRI in order to grade the injury and
document associated injuries. If documented then complete tears should be repaired
Refs –Covey D, Injuries of the posterolateral Corner of the Knee J Bone joint Surg Am 2001;83: 106
NEXT WEEK’S CASE
9 yo girl presents with right thigh and knee pain. What does the pelvic Xray show?
Editor: Peter Wyllie
JOKE / QUOTE OF THE WEEK
It’s hard to explain puns to kleptomaniacs because they always take things literally.
Please forward any funny and litigious quotes you may hear on the floor (happy to publish names if
you want)
THE WEEK AHEAD
Tuesdays - 12:00 – 13:45 Intern teaching -Thomas & Rachel Moore
Wednesday
0800-0900 Critical Care Journal Club. ICU Conf Room / 12.00-1.15 Resident MO in
Thomas & Rachel Moore
Thursday 0730-0800 Trauma Audit. Education Centre / 0800-0830 MET Review Education centre /
1300-1400 Medical Grand Rounds. Auditorium.
Editor: Peter Wyllie