When patients hear “PCL fracture,” they often assume the ligament itself has snapped in the middle. In reality, some injuries happen at the tibial attachment of the posterior cruciate ligament (PCL), where a piece of bone is pulled off along with the ligament. This is called a PCL avulsion fracture or PCL tibial avulsion fracture. In selected cases, arthroscopic fixation is used to reduce the bony fragment and secure it back in place while preserving the patient’s native PCL attachment [1][2].
In my practice, I explain this injury carefully because it is different from a standard midsubstance PCL tear. The treatment decision is based on the exact injury pattern, the amount of displacement, whether the knee remains unstable, whether other ligaments or cartilage are injured, and whether the fragment can heal properly without surgery [2][3]. For patients in Dhaka and across Bangladesh, understanding this distinction helps prevent delay, confusion, and unrealistic expectations.
What Is a PCL Fracture?
The PCL is one of the main stabilizing ligaments inside the knee. It helps prevent the tibia from moving too far backward relative to the femur [3]. In a PCL avulsion fracture, the ligament may stay attached to a bone fragment, but the fragment is pulled off from its tibial insertion site.
This means the problem is both:
- a ligament-function problem
- a bone-fragment fixation problem
That is why arthroscopic fixation may be considered in selected patients. The goal is not only to heal a fracture but also to restore the normal function of the PCL and the stability of the knee [1][2].
How This Injury Usually Happens
High-force trauma is common
PCL injuries usually require a relatively strong force. A classic mechanism is a bent knee striking a hard surface, such as a dashboard during a road traffic accident [3]. In Bangladesh, I also think about this injury after:
- motorcycle accidents
- falls on a bent knee
- sports contact injuries
- twisting trauma with impact
- major knee trauma involving more than one structure
Why the injury can be missed
Some patients can still walk after the injury, especially once the initial pain reduces. That can create false reassurance. However, the knee may still be unstable, swollen, painful, or mechanically abnormal. In my practice, if there is significant trauma and the knee feels unreliable or swollen, I want a proper evaluation rather than guesswork.
Symptoms of a PCL Avulsion Fracture
Symptoms can vary depending on the amount of displacement and associated injuries, but patients often notice:
- pain in the knee after trauma
- swelling
- difficulty bearing weight
- limited knee motion
- a sense of instability
- pain during stairs or bending
- difficulty trusting the knee during walking or changing direction
Some patients feel more discomfort in the back of the knee. Others mainly feel the knee is weak or not normal after injury. If other structures are injured at the same time, symptoms may be more severe.
Why This Injury Deserves Careful Evaluation
One important point I want Bangladeshi patients to understand is that a PCL avulsion fracture is not just “a bruise in the knee.” If the fragment heals in a poor position, the ligament may not function normally. That can contribute to persistent posterior laxity, altered knee mechanics, pain, and long-term joint problems [2][4].
This is especially important in active patients, younger patients, and those with combined ligament injury.
How I Evaluate a Suspected PCL Fracture
History
When I evaluate a patient, I want to understand:
- how the injury happened
- whether there was a dashboard-type impact or direct blow
- whether the knee swelled immediately
- whether the patient can bear weight
- whether the knee feels unstable
- whether there may be associated ligament or meniscus injuries
In Bangladesh, practical context matters. A student, athlete, office worker, homemaker, driver, or manual laborer does not place the same demands on the knee. Treatment recommendations have to fit the patient’s real life and not just the scan result.
Physical examination
On examination, I look at:
- swelling
- range of motion
- posterior sag
- posterior drawer findings
- ligament stability in other directions
- signs of meniscus or cartilage injury
- neurovascular status after trauma
Because PCL injuries can occur with other serious knee injuries, the examination must not be too narrow. If the knee has more than one damaged structure, the management plan changes.
Imaging
X-rays are important and may reveal the avulsion fragment. However, the full extent of the injury may not always be obvious on plain films. CT scan can better define the bony fragment and displacement. MRI is useful when I need to assess the PCL fibers, meniscus, cartilage, or associated ligament injuries [2][4].
I usually explain to my patients that imaging is not just about naming the fracture. It helps answer more important questions:
- Is the fragment displaced?
- Is the knee unstable because of the fracture?
- Are there associated injuries?
- Is surgery likely to improve the final function of the knee?
When Arthroscopic Fixation Is Considered
Not every PCL injury needs surgery, and not every PCL avulsion fracture is treated the same way.
Non-surgical treatment may be considered when
- the fragment is minimally displaced
- the knee remains acceptably stable
- there is no major associated injury
- close follow-up is possible
- the treating surgeon believes healing can occur in a good position
Some isolated PCL injuries can heal reasonably well without surgery [3]. But PCL avulsion fractures are different from simple ligament sprains. If the bone fragment is displaced or the attachment cannot function properly, non-operative care may not be enough [2].
Arthroscopic fixation is more often considered when
- the avulsed fragment is displaced
- the knee has significant posterior instability
- symptoms are functionally important
- there is concern for poor healing position
- associated intra-articular assessment is needed
This is where arthroscopy can be especially useful. It allows direct visualization of the joint and minimally invasive reduction and fixation of the fragment in selected cases [1][5].
