PCL, LCL and PLC Injures
Posterior Cruciate Ligament, Lateral Collateral Ligament, and Posterolateral Corner
Written and Edited By Aruna Seneviratnae, M.D.
Several ligaments stabilize the human knee. They are the Anterior Cruciate Ligament (ACL), the Posterior
Cruciate Ligament (PCL), the Medial Collateral Ligament (MCL), the Lateral Collateral Ligament (LCL), and
the Posterolateral Corner Complex (PLC). Injuries to the PCL can occur in isolation or in combination with
other injuries - usually ACL, LCL, and PLC injuries. PCL injuries can also occur in conjuction with LCL and
PLC injuries. These injuries are usually due to high-energy mechanisms and results in a knee dislocation.
They maybe limb threatening injuries and require prompt evaluation in an Emergency room setting. A vascular
injury to the blood vessel that runs behind the knee is a real threat.
Depending on the number of ligaments involved, these injuries result in knee instability.
Isolated PCL injuries - initially knee pain and a sense of instability will be felt. Typically, this
resolves with time, and most patients are able to cope with a PCL deficient knee.
PLC and LCL injuries - result in pain in the "outboard" aspect of your knee, and inability to perform
cutting maneuvers due to instability.
Combined PCL, LCL, and PLC injuries - knee pain and instability.
Biology: Why does it occur?
These injuries occur due to high-energy trauma - motor vehicle accidents or sporting injuries. They require
prompt medical attention. The LCL and PLC are outside the knee joint and have greater healing potential than
the PCL which is inside the knee joint. Therefore, early repair of the LCL and PLC have been advocated to
make use of this healing response that occurs within the first three weeks from injury. The PCL tends to
demonstrate less robust healing, and late reconstruction is advocated.
Common Diagnostic Techniques:
History: Diagnosing the problem begins with a detailed history that your surgeon will obtain from you.
Physical Exam: A thorough physical examination is conducted by your surgeon.
X-Rays: Plain radiographs (X-Rays) are the most important diagnostic study that is performed initially. For
the knee and ankle your surgeon will obtain specialized views. Usually these are weight bearing x-rays -
i.e.: you will be standing for the x-rays.
MRI: Your surgeon may obtain additional studies such as an MRI to look more closely at all ligaments.
Isolated PCL injuries are typically treated non-operatively with physical therapy and a brace.
PLC and LCL injuries require surgical repair within 2 weeks of the injury. If there are PCL and ACL injuries
they will be reconstructed after the PLC and LCL heal in 6 to 12 weeks. Repairing a ligament entails
suturing the torn edges together or tightening a stretched out ligament. Reconstructing a ligament in
contrast requires the use of other tissue such as the hamstring tendons or cadaveric tendon tissue to
rebuild the ligament. These procedures are usually arthroscope-assisted surgery requiring incisions that can
vary in length depending on injury and anatomy. If the knee is grossly unstable, an external fixator will be
utilized to stabilize the knee.
Depending on the extent of the injuries and the magnitude of the surgery, patients maybe kept in the
hospital 1 to 2 days particularly for monitoring their neurovascular status.
You will be placed into a brace, and your weight bearing maybe protected with crutches for several weeks.
Your range of motion will be restricted until healing has taken place. Physical therapy is started within 1
week of surgery for edema control, muscle activation, and other modalities to aid healing. Rehabilitation
for this type of injury can last 6 to 12 months.
What are the dangers of knee dislocation?
Knee dislocations are serious injuries that can be limb threatening in the event there is a vascular injury.
Prompt specialized medical care must be obtained in these injuries.
Can my own tissues be used to reconstruct multiple torn ligaments in my knee?
It is recommended against using your own tissue in the presence of a multi-ligament injured knee. Cadaveric
or allograft tissue is utilized for this purpose.
What are the risks of multi-ligament reconstructive surgery?
Infection, bleeding, damage to nerves and blood vessels, blood clots that form in your legs (DVT), blood
clots that can break off and travel to your lungs causing a pulmonary embolus (PE). Knee stiffness and
compartment syndrome are additional risks.