In early March of this year, I was playing in a friendly netball tournament, one that would end up with a very interesting trip to A&E. While I was playing I jumped and hyperextended my leg at the knee and landed in it (ouch!). I had an x-ray taken of my knee which didn't show anything out of the ordinary, there was just a lot of fluid build up around my knee on the left side, however I struggled to put any weight on it without being in a lot of pain. I had a follow up appointment a week later, in which a very concerned doctor booked me in for an MRI. The results of which showed a fracture which was quite big and clear, but was missed by the x-ray I had taken.
The diagnosis I was given was a cancellous tibial plateau fracture, and luckily without any ligament tears. But what actually is a tibial plateau fracture?
After a lot of searching and reading here's a quick guide to tibial plateau fractures, the diagnosis and case study to further explain the importance of the process of diagnosis.
A tibial plateau fracture is an articular injury, which means there is damage to the cartilage that cushions the ends of the bones where they meet at a joint. In this example it is the knee. It is considered to have a broad spectrum of clinical presentations and can be associated with long term complications. Understanding what kind of tibial plateau fracture is being presented is key to implementing the correct treatment for a patient [1].
How an injury presents itself is dependent on how the injury was sustained in the first place. Tibial plateau fractures account for about 1% of all fractures and approximately 8% of all fractures among those aged 55 years and over, typically occurring either as consequence of fragility/low-energy trauma (typically older women as a fragility fracture) or high-energy trauma (typically younger men) [2].
What actually is the tibial plateau?
It is the bony articular surface of the proximal tibia that forms the distal half of the knee joint, meaning the half of that is further away from the centre of the body. It has a coronal and sagittal slope to allow movement in six degrees of freedom, this means it has quite a good range of movement and is therefore vital to the knee joint. This is why particularly during surgery reconstruction, it is incredibly important that this level of movement is restored [2].
Fracture classification
In 1974, Schatzker published his classification of fractures of the tibial plateau and is split into six principle types. The Schatzker classification was based on a two-dimensional representation of the fracture, organised in accordance with age of the patient, bone quality, the architecture of the fracture and the energy impact of the trauma [1].
Figure 1. The six principle tibial plateau fracture types decribed by Schatzker [1]
The types I to III are fractures of the lateral (side) of the tibial plateau as seen above in figure 1.
Type I - more common in young people who have a denser cancellous bone, and is a cleavage fracture.
Type II - a split wedge fracture of the side column associated with a depression in the bone, and so is more common in older patients due to less dense metaphyseal bone.
Type III - pure joint depression where most of the time, the joint is stable
Type IV - isolated fracture of the medial column, since this part is denser than the lateral part a higher force is required to fracture it, so is usually a high energy trauma
Type V & VI - bicondylar tibial plateau fractures, are also high energy injuries [1,2]
The case study
The classification of these fractures are very important in determining treatment plans and predicting the outcome of the injury long term. Treatment is predicted through imaging with radiographs, which do help to classify fractures but can lead to an underestimation of severity. In most cases, MRI is not performed in a routine evaluation of suspected tibial plateau fractures, which was the case for me. However, when there is a suspicion of soft tissue injury an MRI becomes a necessity [3].
I found this particular article on a patient very interesting as they had very similar symptoms to me but had a very different injury despite also being a tibial plateau fracture. "The pivot fracture: an unusual tibial plateau fracture found in association with acute ACL injury" Chang et al, describes an unusual version of the injury with a displaced and flipped posterolateral tibial plateau fracture - called the "flipped fragment sign" - which isn't described by any existing classification system and not previously reported with an anterior cruciate ligament injury (ACL) [3].
The initial radiographs of the knee showed it wasn't a simple fracture but after a CT was performed it showed that the fragment of fractured bone was flipped. The MRI then showed the ACL and menisci damage obtained which led to the ability of the injury to be fully assessed and treated properly.
This study concluded that having extra checks and screening after a tibial plateau fracture is incredibly important to help properly diagnosis the type of fracture, and I can agree with that!
Thankfully, eleven months post injury and tibial plateau open reduction, internal fixation and 6 months out from ACL reconstruction the patient has no residual instability on exam, physical therapy was still ongoing but they were able to return to running.
I have also recovered and have gone back to playing netball and handball.
References -
[1] Revisiting the Schatzker classification of tibial plateau fractures - Kfuri & Schatzker
[2] Tibial plateau fracture: anatomy, diagnosis and management - Rudran et al
[3] The pivot fracture: an unusual tibial plateau found in association with acute ACL injurry - Chang et al Assessed and Endorsed by the MedReport Medical Review Board